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Sample records for autogenous cortical bone

  1. Autogenous tooth bone graft: Ingenious bone regeneration material

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    Chadalavada Sarala

    2018-01-01

    Full Text Available Tooth-derived bone graft material, which is proved to be rich in bone growth factors and bone morphogenic proteins (BMPs, have been becoming a practical substitute to bone grafting. It can also be used as a carrier for growth factors and stem cells as reported in many recent studies. Autogenous-tooth bone grafting technique is significant as this biomaterial has excellent bone regeneration capacity and also relatively non-existent chances of antigenicity, genetic diseases and disease transmission. In this article, a broad overview of the published findings with regard to the properties and uses of tooth-derived regenerative bone grafting is discussed.

  2. USE OF CORTICAL BONE FENESTRATION, AUTOGENOUS FREE SKIN GRAFT, AND THERMOGRAPHY FOR WOUND TREATMENT AND MONITORING IN A RED WOLF (CANIS RUFUS GREGORYI).

    Science.gov (United States)

    Hurley-Sanders, Jennifer L; Sladky, Kurt K; Nolan, Elizabeth C; Loomis, Michael R

    2015-09-01

    A 2-yr-old female red wolf (Canis rufus gregoryi) sustained a degloving injury to the left thoracic limb while in a display habitat. Initial attempts to resolve the extensive wound by using conservative measures were unsuccessful. Subsequent treatment using a free skin graft consisted first of establishment of an adequate granulation bed via cortical bone fenestration. After establishment of a healthy granulation bed was achieved, free skin graft was harvested and transposed over the bed. To monitor viability and incorporation of the graft, serial thermographic imaging was performed. Thermography noninvasively detects radiant heat patterns and can be used to assess vascularization of tissue, potentially allowing early detection of graft failure. In this case, thermography documented successful graft attachment.

  3. Hydroxyapatite as a bone graft substitute: Use in cortical and cancellous bone

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    Agarwala Sanjay

    2005-01-01

    Full Text Available Background : Autogenous bone is regarded as the best bone graft material. Various grafting materials have been advocated to fill bony defects. Our purpose was to study the utility of amorphous hydroxyapatite as an autogenous bone graft substitute in cancellous and cortical bone. Methods : A prospective study was undertaken over a period of five years. Patients included were those which would otherwise require bone grafting in cancellous and cortical bone fractures (15 in each group. Hydroxyapatite (HA ceramic blocks of standard size (5mm x10m were either used alone or mixed with autogenous cancellous graft in metaphyseal locations, along with bone marrow (derived from reaming or drilling in intertrochanteric regions and mixed with cancellous graft in cortical areas. The results were assessed on standard radiographs. Biopsy of hydroxyapatite regenerated bone was taken at implant removal. Results: In cancellous areas as graft incorporation ensues over months the intrinsic structure of the hydroxyapatite blocks blurred with blunting of the sharp edges (on radiographs. Biopsy confirmed bone in-growth. In cortical areas the blocks did not show evidence of bone in-growth. Conclusion: Hydroxyapatite alone or when mixed with cancellous bone marrow is an effective adjuvant for autogenous bone grafts, especially in cancellous areas of bone. Mixing it with host marrow provides osteoinductive stimulus. It is biocompatible, osteoconductive but not osteogenic.

  4. Autogenous bone graft associated with enamel matrix proteins in bone repair.

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    Prata, Celina A; Lacerda, Suzie A; Brentegani, Luiz Guilherme

    2007-12-01

    Autogenous bone has been used with success as implants in intrabony defects, because of its biological advantages and osteogenic potential. The objective of this study was to evaluate histological and histometrically the bony repair in intrabony defects after dental extractions in rats with graft of a combination of the enamel matrix protein (EMP) (Emdogain, Strauman USA, LLC, Andover, MA. Headquarters in Basel, Switzerland) and autogenous bone. Male rats (Rattus norvegicus, Wistar variety) weighing from 250 to 300 g were anesthetized and submitted to the extraction of the superior incisive and divided in (a) group with autogenous bone (fragment of bone of the alveolar ridge was grafted inside the alveolus) and (b) group with autogenous bone associated with EMP. The animals were killed on the 7th, 21st, and 42nd day after the extraction. The maxillae were processed to obtain fine sections (5 microm) stained with hematoxylin-eosin. The percentual volume of bone tissue in contiguous areas of the graft was calculated through a counting point system of image. The results showed that the bone fragments grafted in the cervical third of the alveolus developed a progressive osseointegration without foreign-body reaction. The quantification of the bony repair in the areas adjacent to the graft showed that the autogenous bone associated with EMP produced a greater amount of bone (10%-15% by analysis of variance, P = 0.05) in all the studied periods. It was concluded that the autogenous bone associated with EMP grafted in bony defects, immediately after the dental extraction in rats, demonstrated biocompatibility and accelerated the repair of bone defect.

  5. Periodontally accelerated osteogenic orthodontics combined with autogenous bone grafting.

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    Nowzari, Hessam; Yorita, Frank Kazuo; Chang, Hsuan-Chen

    2008-05-01

    This case report documents the first use of particulate autogenous bone graft with the corticotomy-assisted rapid orthodontic procedure known as periodontally accelerated osteogenic orthodontics (PAOO). A 41-year-old man, with class II, division 2 crowded occlusion, was treated with the PAOO procedure. Buccal mucoperiosteal flaps were reflected, and selected vertical and horizontal corticotomy was performed around the roots in both the maxillary and mandibular arches. Particulate bone graft was harvested from the rami and exostosis for alveolar ridge augmentation. Orthodontic movement was initiated immediately after the surgical intervention and adjusted every 2 weeks. Eight months after corticotomy surgery, total active orthodontic treatment was completed. No detrimental periodontal effects or root resorption were observed. The alveolar ridges of both the maxilla and mandible maintained the original thickness and configuration despite facial tipping of the incisors. It was concluded that PAOO is an effective treatment approach in adults to decrease treatment time and reduce the risk of root resorption. Selected corticotomy limited to the buccal and labial aspects also significantly reduces treatment time. More clinical studies with additional patients and long-term follow-up are needed to determine the optimal amount of autogenous bone graft.

  6. Histological evaluation of the influence of magnetic field application in autogenous bone grafts in rats

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    Ponzoni Deise

    2009-01-01

    Full Text Available Abstract Background Bone grafts are widely used in oral and maxillofacial reconstruction. The influence of electromagnetic fields and magnets on the endogenous stimulation of target tissues has been investigated. This work aimed to assess the quality of bone healing in surgical cavities filled with autogenous bone grafts, under the influence of a permanent magnetic field produced by in vivo buried devices. Methods Metal devices consisting of commercially pure martensitic stainless steel washers and titanium screws were employed. Thirty male Wistar rats were divided into 3 experimental and 3 control groups. A surgical bone cavity was produced on the right femur, and a bone graft was collected and placed in each hole. Two metallic washers, magnetized in the experimental group but not in the control group, were attached on the borders of the cavity. Results The animals were sacrificed on postoperative days 15, 45 and 60. The histological analysis of control and experimental samples showed adequate integration of the bone grafts, with intense bone neoformation. On days 45 and 60, a continued influence of the magnetic field on the surgical cavity and on the bone graft was observed in samples from the experimental group. Conclusion The results showed intense bone neoformation in the experimental group as compared to control animals. The intense extra-cortical bone neoformation observed suggests that the osteoconductor condition of the graft may be more susceptible to stimulation, when submitted to a magnetic field.

  7. Bone healing around nanocrystalline hydroxyapatite, deproteinized bovine bone mineral, biphasic calcium phosphate, and autogenous bone in mandibular bone defects

    DEFF Research Database (Denmark)

    Broggini, Nina; Bosshardt, Dieter D; Jensen, Simon S

    2015-01-01

    with nanocrystalline hydroxyapatite (HA-SiO), deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate (BCP) with a 60/40% HA/β-TCP (BCP 60/40) ratio, or particulate autogenous bone (A) for histological and histomorphometric analysis. At 2 weeks, percent filler amongst the test groups (DBBM (35.65%), HA...

  8. Volume changes of grafted autogenous bone in sinus augmentation procedure.

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    Sbordone, Carolina; Sbordone, Ludovico; Toti, Paolo; Martuscelli, Ranieri; Califano, Luigi; Guidetti, Franco

    2011-06-01

    To evaluate associations between the osseous remodeling and the 3-dimensional features of both the grafted bone and the recipient site, as well as the density of the grafted bone, and to assess the relation between the degree of bone resorption and the type of autogenous bone-grafting procedure or the source (block or particulate bone from iliac crest or block bone from chin). A retrospective chart review of patients receiving sinus lifting and grafting procedures for implant positioning was conducted: radiographic analysis of the volume and area of both sinuses and autogenous bone grafts was performed, as per Smolka et al and Krennmair et al. The volumetric remodeling--measured at 1 year after implant positioning as the percentage of residual bone (%R)--was correlated, with Spearman analysis, to 3-dimensional features of both graft and recipient sites. All quantities correlated with %R at a statistically significant level were used for 2-dimensional and multidimensional visualizations with scattergrams. Twenty-five iliac crest or chin grafts were inlay positioned in the maxillary sinuses of patients. Computed tomography scans, taken before implant positioning and after 1 year, showed a 1-year negligible volume remodeling for block graft from chin (97.9%) but slightly greater resorption values (%R) for particulate and block grafts from iliac crest (93.8% and 83.3%, respectively). Three- and four-dimensional scattergrams of significant data resulting from Spearman correlation tests (particulate and block grafts both from iliac crest) showed a variation of the remodeling pattern dependent on 3-dimensional features, namely inlay graft thickness, surface area of the graft in contact with basal bone, volume of the recipient site, and surface area of the graft projecting into the sinus cavity. Retrospective data analysis shows that iliac crest grafts positioned on a small basal bone volume (≤ 2.5 mL) may point to a very favorable remodeling of the volume when the

  9. Evaluation of peri-implant bone resorption around Straumann Bone Level implants placed in areas reconstructed with autogenous vertical onlay bone grafts.

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    Chiapasco, Matteo; Casentini, Paolo; Zaniboni, Marco; Corsi, Elena

    2012-09-01

    To evaluate the survival and success rate of Straumann Bone Level implants placed in vertically atrophied edentulous jaws previously reconstructed with autogenous onlay bone grafts taken from the calvarium or the mandibular ramus. From 2007 to 2009, 18 patients presenting with vertical deficits of the edentulous ridges were treated with autogenous cortical bone grafts harvested from the mandibular ramus or the calvarium. Four to seven months afterward, 60 Straumann Bone Level implants were placed in the reconstructed areas. After a further waiting period of 2-3 months, patients were rehabilitated with implant-supported fixed prostheses. Follow-up ranged from 12 to 36 months (mean: 19 months) after the start of prosthetic loading. Graft resorption before implant placement, as well as survival and success rates of implants, were recorded. The mean bone resorption prior to implant placement was 0.18 mm for calvarial grafts and 0.42 mm for ramus grafts. Survival rate was 100% either for implants placed in calvarial grafts or implants placed in ramus grafts, while success rate was 90.3% for implants placed in calvarial grafts, and 93.1% for implants placed in ramus grafts. Results from this study seem to demonstrate that implants with a platform-switching design may predictably integrate in edentulous areas reconstructed with autogenous bone grafts, with survival rates consistent with those reported in recent literature reviews on the same topic, and also with implants placed in native bone. Conversely, this study was not able to demonstrate that implants with platform-switching design may reduce bone resorption around implants placed in reconstructed areas. © 2011 John Wiley & Sons A/S.

  10. Bone-to-implant contact after maxillary sinus floor augmentation with Bio-Oss and autogenous bone in different ratios in mini pigs

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, Søren; Gundersen, Hans Jørgen G

    2012-01-01

    OBJECTIVES: The objective was to test the hypotheses: (i) no differences in bone-to-implant contact formation, and (ii) no differences between the use of autogenous mandibular or iliac bone grafts, when autogenous bone, Bio-Oss mixed with autogenous bone, or Bio-Oss is used as graft for the maxil......OBJECTIVES: The objective was to test the hypotheses: (i) no differences in bone-to-implant contact formation, and (ii) no differences between the use of autogenous mandibular or iliac bone grafts, when autogenous bone, Bio-Oss mixed with autogenous bone, or Bio-Oss is used as graft...... for the maxillary sinus floor augmentation. MATERIAL AND METHODS: Bilateral sinus floor augmentation was performed in 40 mini pigs with: (A) 100% autogenous bone, (B) 75% autogenous bone and 25% Bio-Oss, (C) 50% autogenous bone and 50% Bio-Oss, (D) 25% autogenous bone and 75% Bio-Oss, or (E) 100% Bio......-Oss. Autogenous bone was harvested from the iliac crest or the mandible and the graft composition was selected at random and placed concomitant with the implant placement. The animals were euthanized 12 weeks after surgery. Bone-to-implant contact was estimated by stereological methods and summarized as median...

  11. Histomorphometric evaluation of bone regeneration using autogenous bone and beta-tricalcium phosphate in diabetic rabbits

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    Živadinović Milka

    2016-01-01

    Full Text Available Background/Aim. The mechanism of impaired bone healing in diabetes mellitus includes different tissue and cellular level activities due to micro- and macrovascular changes. As a chronic metabolic disease with vascular complications, diabetes affects a process of bone regeneration as well. The therapeutic approach in bone regeneration is based on the use of osteoinductive autogenous grafts as well as osteoconductive synthetic material, like a β-tricalcium phosphate. The aim of the study was to determine the quality and quantity of new bone formation after the use of autogenous bone and β-tricalcium phosphate in the model of calvarial critical-sized defect in rabbits with induced diabetes mellitus type I. Methods. The study included eight 4-month-old Chincilla rabbits with alloxan-induced diabetes mellitus type I. In all animals, there were surgically created two calvarial bilateral defects (diameter 12 mm, which were grafted with autogenous bone and β-tricalcium phosphate (n = 4 or served as unfilled controls (n = 4. After 4 weeks of healing, animals were sacrificed and calvarial bone blocks were taken for histologic and histomorphometric analysis. Beside descriptive histologic evaluation, the percentage of new bone formation, connective tissue and residual graft were calculated. All parameters were statistically evaluated by Friedman Test and post hock Wilcoxon Singed Ranks Test with a significance of p < 0.05. Results. Histology revealed active new bone formation peripherally with centrally located connective tissue, newly formed woven bone and well incorporated residual grafts in all treated defects. Control samples showed no bone bridging of defects. There was a significantly more new bone in autogeonous graft (53% compared with β-tricalcium phosphate (30%, (p < 0.030 and control (7%, (p < 0.000 groups. A significant difference was also recorded between β-tricalcium phosphate and control groups (p < 0.008. Conclusion. In the present

  12. Comparative study between cortical bone graft versus bone dust for reconstruction of cranial burr holes.

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    Worm, Paulo V; Ferreira, Nelson P; Faria, Mario B; Ferreira, Marcelo P; Kraemer, Jorge L; Collares, Marcus V M

    2010-12-22

    As a consequence of the progressive evolution of neurosurgical techniques, there has been increasing concern with the esthetic aspects of burr holes. Therefore, the objective of this study was to compare the use of cortical bone graft and bone dust for correcting cranial deformities caused by neurosurgical trephines. Twenty-three patients were enrolled for cranial burr hole reconstruction with a 1-year follow-up. A total of 108 burr holes were treated; 36 burr holes were reconstructed with autogenous cortical bone discs (33.3%), and the remaining 72 with autogenous wet bone powder (66.6%). A trephine was specifically designed to produce this coin-shaped bone plug of 14 mm in diameter, which fit perfectly over the burr holes. The reconstructions were studied 12 months after the surgical procedure, using three-dimensional quantitative computed tomography. Additionally, general and plastic surgeons blinded for the study evaluated the cosmetic results of those areas, attributing scores from 0 to 10. The mean bone densities were 987.95 ± 186.83 Hounsfield units (HU) for bone fragment and 473.55 ± 220.34 HU for bone dust (P holes because of their lower degree of bone resorption and, consequently, better cosmetic results. The lack of donor site morbidity associated with procedural low cost qualifies the cortical autograft as the first choice for correcting cranial defects created by neurosurgical trephines.

  13. Repair process of surgical defects filled with autogenous bone grafts in tibiae of diabetic rats

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    Jônatas Caldeira Esteves

    2008-10-01

    Full Text Available From a biological standpoint, the best material for reconstruction of bone defects is the autogenous bone graft. However, as tissue healing is affected under diabetic conditions, major changes might take place in the revascularization, incorporation, replacement and remodeling phases of the grafted area. The purpose of this study was to assess the bone healing process in surgical wounds prepared in tibiae of diabetic rats and filled with autogenous bone. Forty male rats (Rattus norvegicus albinus, Wistar were randomly assigned to receive an endovenous injection (penile vein of either citrate buffer solution (Group 1 - control; n=20 or streptozotocin dissolved in citrate buffer solution (35 mg/kg to induce diabetes (Group 2 - diabetic; n=20. After determination of glycemia, the animals were anesthetized and the anterolateral regions of the tibiae of both limbs were shaved, antisepsis was performed and longitudinal incisions were made in each limb. The tibiae were exposed and two 2mm-diameter surgical cavities were prepared: one in the right limb, filled with particulate autogenous bone and the other in the left limb, filled with blood clot. The animals were euthanized at 10 and 30 postoperative days. The anatomic pieces were obtained, submitted to laboratory processing and sections were stained by hematoxylin and eosin and Masson's Trichrome for histomorphologic and histometric analyses. In both groups, the wounds filled with autogenous bone graft showed better results than those filled with blood clot. The control group showed higher new bone formation in wounds filled with autogenous bone graft at 30 days than the diabetic group, but without statistical significance. It may be concluded that, in general, the new bone formation occurred with autogenous graft was quantitatively similar between control and diabetic groups and qualitatively better in the control group.

  14. Reconstruction of mandibular defects with autogenous bone grafts: a review of 30 cases

    International Nuclear Information System (INIS)

    Sajid, M.A.; Warraich, R.A.; Abid, H.; Haq, M.E.; Shah, K.L.; Khan, Z.

    2012-01-01

    Multitudes of options are available for reconstruction of functional and cosmetic defects of the mandible, caused by various ailments. At the present time, autogenous bone grafting is the gold standard by which all other techniques of reconstruction of the mandible can be judged. The purpose of this study was to evaluate the outcome of different osseous reconstruction options using autogenous bone grafts for mandibular reconstruction. Methods: This Interventional study was conducted at Department of Oral and Maxillofacial Surgery, King Edward Medical University/Mayo Hospital Lahore, from January 2008 to July 2009 including one year follow-up. The study was carried out on thirty patients having bony mandibular defects. They were reconstructed with the autogenous bone grafts from different graft donor sites. On post-operative visits they were evaluated for outcome variables. Results: Success rate of autogenous bone grafts in this study was 90%. Only 10% of the cases showed poor results regarding infection, resorption and graft failure. Conclusion: Autogenous bone grafts, non-vascularized or vascularized, are a reliable treatment modality for the reconstruction of the bony mandibular defects with predictable functional and aesthetic outcome. (author)

  15. Augmentation of localized defects of the anterior maxillary ridge with autogenous bone before insertion of implants

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    Raghoebar, GM; Batenburg, RHK; Vissink, A; Reintsema, H

    1996-01-01

    Purpose: This study evaluated the applicability of intraorally harvested autogenous bone grafts for the augmentation of the narrow maxillary alveolar ridge to enable insertion of implants for single tooth replacement. Materials and Methods: Local defects of the anterior maxilla were reconstructed in

  16. A case of monostotic fibrous dysplasia of proximal femur managed with curettage and cortical bone grafting

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    A D Sud

    2013-01-01

    Full Text Available We present a case report of a young military personnel with monostotic fibrous dysplasia of proximal femur with painful, dysplasticlesion of the femoral neck and fatigue fracture who underwent cortical bone grafting using autogenous fibular strut graft and iliac crest bone graft. The fibular cortical grafts was used to bridge the lesion in the femoral neck and were securely anchored to the normal bone of the lateral femoral cortex and a head of the femur. No supplemental internal fixation was required.

  17. Autogenous Partial Bone Chip Grafting on the Exposed Inferior Alveolar Nerve After Cystic Enucleation.

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    Seo, Mi Hyun; Eo, Mi Young; Cho, Yun Ju; Kim, Soung Min; Lee, Suk Keun

    2018-03-01

    This prospective study evaluated the clinical effectiveness of the new approach of partial autogenous bone chip grafts for the treatment of mandibular cystic lesions related to the inferior alveolar nerve (IAN). A total of 38 patients treated for mandibular cysts or benign tumors were included in this prospective study and subsequently divided into 3 groups depending on the bone grafting method used: cystic enucleation without a bone graft (group 1), partial bone chip graft covering the exposed IAN (group 2), and autogenous bone graft covering the entire defect (group 3). We evaluated the symptoms, clinical signs, and radiographic changes using dental panorama preoperatively, immediate postoperatively, and at 1, 3, 6, and 12 months postoperatively. Radiographic densities were compared using Adobe Photoshop CS5 (Adobe Systems Inc., San Jose, CA). Repeated measures analysis of variance was used for statistical evaluation with SPSS 22.0 (SPSS Inc, Chicago, IL), and P < 0.05 was considered statistically significant.Radiopacities were the most increased at 1 year postoperative in group 3; groups 2 and 3 did not show statistically significant differences, whereas groups 1 and 3 were statistically significant. In terms of radiographic bone healing with clinical regeneration of the exposed IAN, healing occurred in all patients, although the best healing was achieved in group 2.This autogenous partial bone chip grafting procedure to cover the exposed IAN is suggested as a new surgical protocol for the treatment of cystic lesions associated with the IAN.

  18. Maxillary sinus floor elevation surgery with BioOss (R) mixed with a bone marrow concentrate or autogenous bone : test of principle on implant survival and clinical performance

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    Rickert, D.; Vissink, A.; Slot, Jan; Sauerbier, S.; Meijer, H. J. A.; Raghoebar, G. M.

    The purpose of this study was to assess implant survival and 1-year clinical performance of implants placed in the posterior maxilla that had been subjected to maxillary sinus floor elevation surgery with bovine bone mineral (BioOss (R)) mixed with autogenous bone marrow concentrate or autogenous

  19. Autogenous bone block in the treatment of teeth with hopeless prognosis

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    Nymphea Pandit

    2012-01-01

    Full Text Available Background: Autogenous bone graft, although considered as a gold standard, has been relegated to background because of limited quantity and donor site morbidity. Revival of interest in its use has been reflected by its tremendous capacity for regeneration in less than ideal situation. Bone blocks have been used for implant site augmentation, with varied success. Aim: Aim of the study was to evaluate the efficacy of autogenous bone block in the regeneration of bone, for saving teeth with a hopeless prognosis. Settings and Design: A total of six patients and 12 sites with grade II and III mobile teeth were treated with autogenous bone blocks and fiber splinting. Subjects and Methods: Attachment loss, probing depths, and radiographic bone loss were recorded at baseline and at 12 months interval. Statistical Analysis Used: The Student paired t test was used for evaluation of the changes from baseline to 12 months. Results: At 12 months post-operatively, there was a highly significant amount of bone gain as compared to the baseline. The mean amount of bone loss reduced from 9.41 ± 1.16 to 5.41 ± 1.01. The clinical attachment loss reduced from 7.37 ± 1.24 mm to 3.79 ± 0.89 mm and probing depth reduced from 7 ± 1.67 mm to 5.5 ± 0.63 mm. The grafted bone was observed to have been incorporated with the host bone in most of the sites as evidenced by radiographs. Conclusions: For teeth with hopeless prognosis, this method can be considered to be a very viable alternative to extraction and replacement by costly implants.

  20. Teriparatide treatment of femoral fracture nonunion that autogenous bone grafting failed to heal: a case report.

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    Yu, Wei; Guo, Xiaodong

    2017-12-01

    Management of fracture nonunion is challenging as another surgical intervention for the patient is often a necessity, which has a huge impact on both quality of life and economic burden of the patient. Thus, a less aggressive and better accepted treatment for nonunion is required. We gave teriparatide to a 45-year-old man with femoral fracture nonunion 1 year after he underwent surgery with autogenous bone grafting that failed to heal his initial nonunion. Successful union was obtained after once-daily administration of teriparatide for 9 months. Our case showed teriparatide could successfully treat a femoral fracture nonunion that autogenous bone grafting failed to heal. Teriparatide may provide an alternative treatment for fracture nonunion.

  1. Simultaneous maxillary sinus lifting and implant placement with autogenous parietal bone graft: outcome of 17 cases.

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    Sakka, Salah; Krenkel, Christian

    2011-04-01

    The aim of this study was to retrospectively evaluate the surgical technique of sinus floor elevation with autogenous parietal bone grafting in conjunction with immediate dental implants for the reconstruction of the maxilla in deficient maxillary alveolar ridges. Seventeen patients who underwent sinus floor elevation with bone graft from the parietal bone between 2005 and 2007 were included in the study. Cases of extremely deficient bone level in the alveolar ridgeAnkylos®) with different length and diameter were placed immediately after the graft was placed. Strict oral hygiene was required for the patients. Presurgical and postsurgical panoramic radiographs were taken. A high-quality reconstruction with an increase in lifted sinus bone height was achieved with parietal bone particulates. Seventy-three implants were clinically osseointegrated and four implants were lost giving a success rate 94.8%. No correlation was found between failure and the surgery. The encouraging results of this study suggest that the technique of reconstruction of the sinus floor and the resorbed alveolar ridge using an autogenous parietal bone graft is reliable, giving the surgeon the opportunity to successfully perform immediate implant placement in more difficult and deficient maxillary alveolar bone height. Copyright © 2010. Published by Elsevier Ltd.

  2. Autogenous bone graft and ePTFE membrane in the treatment of peri-implantitis. II. Stereologic and histologic observations in cynomolgus monkeys

    DEFF Research Database (Denmark)

    Schou, Søren; Holmstrup, Palle; Skovgaard, Lene Theil

    2003-01-01

    autogenous bone graft; guided bone regeneration; histology; membrane; non-human primates; oral implants; osseointegration; pathalogy; peri-implantitis; stereology; treatment......autogenous bone graft; guided bone regeneration; histology; membrane; non-human primates; oral implants; osseointegration; pathalogy; peri-implantitis; stereology; treatment...

  3. Treatment of ankylosed maxillary central incisors by segmental osteotomy with autogenous bone graft.

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    You, Kug-Ho; Min, Yon-Sook; Baik, Hyoung-Seon

    2012-04-01

    This case report describes the treatment of a 16-year-old girl with ankylosed maxillary central incisors that were noticeably infraoccluded and labially displaced. We performed a segmental osteotomy with an autogenous bone graft in a single-stage surgery to align and level the ankylosed teeth. The dento-osseous segment was successfully repositioned with satisfactory periodontal results. Copyright © 2012 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.

  4. Autogenous Corticocancellous Iliac Bone Graft in Reconstruction of ...

    African Journals Online (AJOL)

    Mandible resection and subsequent defect created lead to aesthetic and functional abnormalities. The surgical reconstruction of the defect is a major challenge in maxillofacial surgery. Lack of appropriate facilities and the high cost of newer modalities made the use of non-vascularized iliac bone graft in reconstruction of ...

  5. Changes of mineralization of free autogenous bone grafts used for sinus floor elevation.

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    Schlegel, Karl Andreas; Schultze-Mosgau, Stefan; Wiltfang, Jörg; Neukam, Friedrich Wilhelm; Rupprecht, Stephan; Thorwarth, Michael

    2006-12-01

    For augmentations before implant placement in areas of minor bone quantity, autogenous bone is considered the reference to all bone substitutes used alternatively. Autogenous bone transplants originate from various donor areas and can be prepared in different ways before augmentation. They may either be used as block grafts or may be milled to granules that can be used solitarily or in combination with a bone substitute. In a prospective study, 61 patients of the Maxillofacial Surgery Department of our University receiving two-stage sinus floor elevation because of insufficient bone supply were randomly selected. At first-stage surgery, the local augmentation procedure, monocortical probes were obtained on the site of bone harvesting. At second-stage surgery, the implant insertion 6 months after the elevation procedure, bone cores were harvested in the areas of implant placement. Donor regions were the following three areas: the posterior (N=28) and anterior pelvic region (N=15) and the chin region (N=18). The implanted bone in all three groups was particulated to granules of 2-3 mm(2) using a bone mill. All biopsies were analyzed by means of microradiography. The anterior pelvic bone grafts showed a mineralized tissue grade of 35.1+/-7.6% before milling and augmentation. The posterior pelvic bone grafts exhibited a mineralization of 30.7+/-9.5% and the chin bone grafts 74.6+/-8.6%. At second-stage surgery after 6 months, the mineralization was 36.1+/-7.59% in the areas where bone grafts from the anterior pelvic crest were used. Probes harvested from sites with posterior pelvic bone augmentations showed a mineralization rate of 34.5+/-6.5%, and sites were chin bone grafts were applied expressed a mineralization of 54+/-8.6% (P=0.003 compared with the pre-operative value). The comparison of the microradiographical results demonstrated significant differences in the mineralization grades depending on the origin of the graft. The origin of the grafts and their

  6. Is More Cortical Bone Decortication Effective on Guided Bone Augmentation?

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    Acar, Ahmet Hüseyin; Alan, Hilal; Özgür, Cem; Vardi, Nigar; Asutay, Fatih; Güler, Çiğdem

    2016-10-01

    This study aims to evaluate the possible effect of more cortical bone decortication (CBD) on guided bone augmentation. A total of 16 New Zealand rabbits and 32 titanium domes were used. No cortical bone decortication was applied to the control group and in the study groups, the cortical bones were decorticated with a round burr (Group A: 1 hole with bleeding, Group B: 5 holes with bleeding, Group C: a thin layer of compact bone was completely removed with no bleeding). Then 2 titanium domes were placed on the calvarium of each rabbit with hydroxyapatite/beta-tricalcium phosphate. After 3 months, the animals were sacrificed and specimens were sent for histological and histomorphometric analysis. Histological and histomorphometric analysis showed that bone decortication with burr significantly increased new bone regeneration in all the experimental groups compared with the control group (P guided bone augmentation. However, a greater amount of CBD does not have a greater effect.

  7. Paradiaphyseal calcific tendinitis with cortical bone erosion.

    Science.gov (United States)

    Fritz, P; Bardin, T; Laredo, J D; Ziza, J M; D'Anglejan, G; Lansaman, J; Bucki, B; Forest, M; Kuntz, D

    1994-05-01

    To determine the clinical, radiologic, and histologic features of calcific tendinitis with cortical bone erosion. The records of 6 patients with paradiaphyseal calcific tendinitis and adjacent bone cortex erosion were reviewed. Calcific tendinitis involved the linea aspera in 4 patients, the bicipital groove in 1 patient, and the deltoid insertion in another. Calcium deposits were associated with cortical bone erosions, revealed on plain radiographs in 4 patients and computed tomography scans in 2. Bone scans were performed in 2 patients and showed local hyperfixation of the isotope. In 4 patients, suspicion of a neoplasm led to a biopsy. Calcium deposits appeared to be surrounded by a foreign body reaction with numerous giant cells. Apatite crystals were identified by transmission electron microscopy and elemental analysis in 1 surgical sample. Paradiaphyseal calcific tendinitis with cortical bone erosion is an uncommon presentation of apatite deposition disease.

  8. Canine investigation of rhBMP-2, autogenous bone graft, and rhBMP-2 with autogenous bone graft for the healing of a large segmental tibial defect.

    Science.gov (United States)

    Boyce, Andrew S; Reveal, Greg; Scheid, D Kevin; Kaehr, David M; Maar, Dean; Watts, Melanie; Stone, Marcus B

    2009-01-01

    The purpose of this study was to compare the effects of bone morphogenetic protein, bone morphogenetic protein with autogenous bone graft (ABG), and ABG alone on the healing of a large bone defect in the canine tibia. Fifteen 45- to 55-lb canines were randomly assigned to 1 of 5 treatment groups, 3 per group. The groups included (1) recombinant human bone morphogenetic protein (rhBMP-2, 0.43 mg/mL)/absorbable collagen sponge (ACS) + collagen/ceramic matrix (CCM), (2) rhBMP-2 (0.22 mg/mL) ACS + CCM, (3) rhBMP-2 (0.43 mg/mL) ACS + ABG, (4) rhBMP-2 (0.22 mg/mL) ACS + ABG, and (5) ABG alone. A 5-mL defect was created in the right tibia and fixed with a 4.5 mm locking plate and 1 of the grafts described above implanted. X-rays were taken biweekly for 12 weeks and evaluated for radiographic union. Representative histology was also examined. All defects treated with rhBMP-2 (any combination) healed at 6.0 +/- 0.9 weeks. None of the ABG alone-treated defects were healed at 12 weeks. Dogs receiving rhBMP-2/ACS + CCM healed at 5.7 +/- 0.8 weeks, whereas rhBMP-2/ACS + ABG defects healed at 6.3 +/- 0.8 weeks. Histology showed healing consistent with 12-week radiologic results. Large segmental defects in canine tibiae can be effectively healed with stable fixation and rhBMP-2/ACS + ABG or CCM. These conclusions may offer insight into the clinical treatment of segmental defect nonunions in the human.

  9. Unprotected autogenous bone block grafts in anterior maxilla: Resorption rates and clinical outcomes

    Directory of Open Access Journals (Sweden)

    Kosanić Ivan

    2017-01-01

    Full Text Available Background/Aim. The use of autogenous bone grafts for augmentation of the resorbed alveolar ridge is still considered the gold standard in implant dentistry. The aim of this study was to analyze the resorption rate of autogenous bone block grafts from the retromolar region placed in the frontal segment of the upper jaw unprotected by barrier membranes, to assess the stability of implants placed into the grafted bone, as well as to monitor its changes during the healing period. Methods. The study included 18 patients with a total of 20 grafted sites. The residual alveolar ridge was measured before and after the augmentation and prior to implant placement. All implants were restored with provisional crowns within 48 hours after the placement. Implant stability was assessed using resonance frequency analysis. Results. The average period from ridge augmentation to reentry was 5.4 months (range 4–6 months. At reentry the healed alveolar ridge had a mean width of 6.1 ± 1.27 mm. The mean calculated width gain was 3.04 ± 1.22 mm. The overall surface resorption of block grafts was 0.68 ± 0.69 mm (18.85%. At the time of implant placement the mean value of implant stability quotient (ISQ was 71.25 ± 5.77. The lowest ISQ values were noted after three weeks of healing, followed by a gradual increase until week 12. After 12 weeks implants showed significantly higher ISQ values compared to primary stability (p < 0.05 Wilcoxon signed ranks test. During the 3-years followup period no cases of implant loss were recorded. Conclusion. Despite a significant resorption of bone grafts, it was possible to place implants in all the cases and to use the immediate loading protocol without affecting implant survival rate. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no.175021

  10. Osteocyte lacunar properties in rat cortical bone

    DEFF Research Database (Denmark)

    Bach-Gansmo, Fiona Linnea; Weaver, James C.; Jensen, Mads Hartmann

    2015-01-01

    Recently, the roles of osteocytes in bone maintenance have gained increasing attention. Osteocytes reside in lacunae that are interconnected by canaliculi resulting in a vast cellular network within the mineralized bone matrix. As the structure of the lacuno-canalicular network is highly connected......-species but also inter-site variation in lacunar properties. Here, osteocyte lacunae in rat cortical bone have been studied using synchrotron radiation micro computed tomography (SR μCT) and backscattered electron (BE) microscopy. Quantitative lacunar geometric characteristics are reported based on the synchrotron...... radiation data, differentiating between circumferential lamellar bone and a central, more disordered bone type. From these studies, no significant differences were found in lacunar volumes between lamellar and central bone, whereas significant differences in lacunar orientation, shape and density values...

  11. Maxillary sinus lift with solely autogenous bone compared to a combination of autogenous bone and growth factors or (solely) bone substitutes. A systematic review : a systematic review

    NARCIS (Netherlands)

    Rickert, D.; Slater, J. J. R. Huddleston; Meijer, H. J. A.; Vissink, A.; Raghoebar, G. M.

    Literature regarding the outcome of maxillary sinus floor elevation to create sufficient bone fraction to enable implant placement was systematically reviewed. Bone fraction and implant survival rate were assessed to determine whether grafting material or applied growth factor affected bone

  12. Filling of extraction sockets with autogenous bone in cats Preenchimento de alvéolos dentais de gatos com osso autógeno

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    Adelina Maria da Silva

    2012-01-01

    Full Text Available PURPOSE: To evaluate bone healing in the extraction socket of the feline mandibular canine tooth after grafting. METHODS: Eighteen adult cats were submitted to unilateral extraction of mandibular canine tooth and divided into three groups. In group 1 (n=6, control, the extraction socket was left empty. In group 2 (n=6, the extraction socket was filled with autogenous cancelous bone from the iliac crest and in group 3 (n=6, with cortical bone chips from the iliac crest. Cats were euthanized at 6 weeks postoperative. RESULTS: Immediate postoperative radiographs in dorsoventral view showed a radiolucent area at the extraction wound. A decreased radiolucency was observed on the radiographs taken at 6 weeks postoperative. Histological examination showed formation of woven bone within the extraction socket. The percentage of newly formed bone within the extraction socket, measured by the histometry, showed no statistically significant difference among the values of the three groups (Kruskal-Wallis'test p>0.05 (group 1: 52.54 ± 15.46, group 2: 50.51 ± 5.01, group 3: 51.85 ± 9.52. CONCLUSION: The bone regeneration observed in the extraction sockets filled with autogenous cancellous bone or autogenous cortical bone chips was similar to that observed in the control sites, given an observation period of 6 weeks after extraction of the mandibular canine tooth.OBJETIVO: Avaliar a regeneração óssea de alvéolos dentais de gatos após enxertia. MÉTODOS: Dezoito gatos adultos, distribuídos em três grupos de 6 animais cada, foram submetidos a extração do canino mandibular direito ou esquerdo. No grupo 1, controle, o alvéolo foi deixado vazio. No grupo 2, o alvéolo foi preenchido com osso esponjoso autógeno do osso ilíaco e no grupo 3, com raspa de osso cortical do osso ilíaco. Os animais foram submetidos à eutanásia 6 semanas após a cirurgia. RESULTADOS: Nas radiografias realizadas no pós-operatório imediato na projeção ventrodorsal

  13. Restoration of mandibular continuity defects using combinations of hydroxylapatite and autogenous bone: microscopic observations.

    Science.gov (United States)

    Cobb, C M; Eick, J D; Barker, B F; Mosby, E L; Hiatt, W R

    1990-03-01

    The purpose of this investigation was to assess by light, transmission, and scanning electron microscopy the healing of mandibular continuity defects reconstructed with varying ratios of an alloplastic hydroxylapatite implant material (HA) mixed with autogenous bone (AB). This study reports the microscopic observations of implant and control sites at 6 and 18 months postsurgery. The results confirm the biocompatibility of dense HA granules. Specimens exhibited differing degrees of osseous regeneration that appeared related to the percent composition of HA. At 18 months, 86% and 91% of the HA granules were completely surrounded by bone in those specimens reconstructed with implants consisting of 25% and 50% HA, respectively. In contrast, specimens receiving implants consisting of 75% and 100% HA features osseous encapsulation of 75% and 66% of the granules, respectively. The results of this limited study indicate that dense HA granules mixed with AB in ratios ranging from 3:1 to 1:1 (AB:HA) may be successfully used as a bone extender during reconstructive surgery.

  14. Histological evaluation of healing after transalveolar maxillary sinus augmentation with bioglass and autogenous bone

    DEFF Research Database (Denmark)

    Stavropoulos, Andreas; Sima, Catalin; Sima, Andrea

    2012-01-01

    . RESULTS: Bone and connective tissue fraction in the newly formed tissues inside the sinus cavity averaged 23.4 ± 13.2% and 54.1 ± 23.5%, respectively. Residual biomaterial, empty spaces, and debris averaged 1.9 ± 3.5%, 10.5 ± 6.3%, and 8.4 ± 14.5%, respectively. In the transalveolar osteotomy, bone...... and connective tissue fraction averaged 41.6 ± 14.3% and 46.1 ± 13%, respectively, while the amount of residual biomaterial, empty spaces, and debris was 2.8 ± 5%, 4.7 ± 1.9%, and 3.2 ± 2.6%, respectively. Statistically significant differences between the sinus cavity and the transalveolar osteotomy were found......OBJECTIVES: The aim was to evaluate histologically the outcome of a bioglass and autogenous bone (at 1 : 1 ratio) composite implantation for transalveolar sinus augmentation. METHODS: In 31 patients, during implant installation ca. 4 months after sinus augmentation, biopsies were harvested through...

  15. Lateral Ridge Augmentation Using Autogenous Block Grafts and Guided Bone Regeneration: A 10-Year Prospective Case Series Study.

    Science.gov (United States)

    Chappuis, Vivianne; Cavusoglu, Yeliz; Buser, Daniel; von Arx, Thomas

    2017-02-01

    The use of autogenous block grafts harvested from intraoral donor sites has proven to be effective for the reconstruction of horizontal bone defects. The objective of this study was to analyze implant success and the rate of block graft resorption 10 years after ridge augmentation to elucidate contributing factors influencing graft maintenance. A staged horizontal block graft augmentation was performed in 52 implant sites exhibiting severe horizontal bone atrophy using autogenous block grafts protected by DBBM and collagen membranes. The crest width was assessed intraoperatively at surgery and at re-entry after 6 months. At the 10 year reexamination clinical and radiographic parameters were assessed using cone beam computed tomography. The 10-year implant success rate amounted to 98.1%, with minimal peri-implant bone loss (-0.17 mm for the maxilla, -0.09 mm for the mandible). The surface resorption rate after 10 years was 7.7% (0.38 mm). Grafts originating from the chin demonstrated significantly better graft maintenance at 10 years compared to retromolar grafts. Recipient site and age had no significant impact on graft resorption, whereas females showed more bone loss at the 10-year examination. Lateral ridge augmentation using autogenous block grafts and guided bone regeneration demonstrated a favorable success rate of 98.1% with minimal block graft resorption of 7.7% after 10 years. Modulating factors were origin of the graft and gender. © 2016 Wiley Periodicals, Inc.

  16. Blocks of autogenous bone versus xenografts for the rehabilitation of atrophic jaws with dental implants: preliminary data from a pilot randomised controlled trial.

    Science.gov (United States)

    Pistilli, Roberto; Felice, Pietro; Piatelli, Maurizio; Nisii, Alessandro; Barausse, Carlo; Esposito, Marco

    2014-01-01

    To compare the effectiveness of onlay bone blocks of equine origin (test or XB group) with autogenous bone blocks (control or AB group) harvested from the ramus or the iliac crest for the rehabilitation of partially or fully edentulous atrophic jaws with implant supported prostheses. Forty patients with partially or fully edentulous atrophic jaws having less than 5 mm of residual crestal bone height and/or less than 3 mm of bone thickness, as measured on computerised tomography (CT) scans, were randomised into two groups according to a parallel group design, either to be augmented with autogenous onlay bone blocks (20 patients; AB group) from the mandibular ramus or the iliac crest, or with onlays blocks of spongious bone of equine origin (20 patients; XB group). Two centres treated 20 patients each. Six XB blocks were modelled on lithographic models of the jaws before grafting. The blocks were fixed with screws and osteosynthesis plates and were covered with resorbable barriers made of equine cortical bone and fixed with tacks. The autogenous bone grafts were left to heal for 4 months and the xenografts for 7 months before placing implants, which were submerged. After 4 months, either bar-retained overdentures or provisional reinforced acrylic prostheses were delivered. Provisional prostheses were replaced, after 4 months, by definitive fixed prostheses. Outcome measures were: prosthesis and implant failures; complications; patient satisfaction; pain recorded 3 and 10 days post-augmentation; number of days of hospitalisation, total and partial infirmity days. All patients were followed for 4 months after loading. All patients could be rehabilitated with implant-supported prostheses and none dropped out. Twenty-eight patients were augmented in the maxilla (15 with AB and 13 with XB) and 12 in the mandible (5 with AB and 7 with XB). No AB graft failed totally versus 10 XB grafts (difference = 0.5; 95% CI 0.23 to 0.68; P = 0.0004). In particular, all 7 XB mandibular

  17. Comparison of lyophilization, and freezing in honey as techniques to preserve cortical bone allografts used to repair experimental femoral defects in domestic adult cats

    Directory of Open Access Journals (Sweden)

    M.P. Ferreira

    2012-04-01

    Full Text Available Cats with orthopedic conditions are a prominent part of the clinical work of veterinary. Conditions such as comminuted fractures, bone tumors and non-unions are often difficult to repair and may require the use of bone grafts for treatment. This study evaluated cortical bone allografts preserved in honey, frozen or lyophilized for correcting long bone defects created in the diaphysis of the right femur of domestic cats (n=24. In the control group (n=6, the defect was repaired using autogenous cortical bone graft. In the remaining animals (n=6/group, the defect was repaired with cortical bone allografts preserved in honey, frozen or lyophilized. Success of graft incorporation and length of time for consolidation were assessed through clinical, radiographic and histological evaluations performed up to 180 days. In the control, frozen, honey and lyophylized groups, respectively, success of graft incorporation was 91.6%, 83.3%, 75%, and 25%, with corresponding mean length of time for consolidation of 83.1, 78, 105 and 120 days. Incorporation percentage in the lyophilized group was significantly lower than in the frozen and control groups. In conclusion, bone grafts preserved in honey or frozen were effective for repairing cortical defects in the femurs of cats as compared to autogenous cortical bone grafts.

  18. Estimation of in vivo cortical bone thickness using ultrasonic waves.

    Science.gov (United States)

    Mano, Isao; Horii, Kaoru; Hagino, Hiroshi; Miki, Takami; Matsukawa, Mami; Otani, Takahiko

    2015-07-01

    To verify the measurement of cortical bone thickness at the distal radius in vivo using an ultrasonic method. The method for estimating cortical bone thickness was derived from experiments with in vitro bovine specimens. Propagation time of echo waves and propagation time of slow waves were used for the estimation. The outside diameter of cortical bone and the cortical bone thickness at the distal 5.5 % site of radius were measured with the new ultrasonic bone measurement system, and the results were compared with X-ray pQCT clinical measurements. There was a high positive correlation (r: 0.76) between the cortical bone thickness measured by the new ultrasonic system and the X-ray pQCT results. We will be able to measure not only cancellous bone density but also cortical bone thickness in vivo using ultrasonic waves (without X-ray) safely and repeatedly.

  19. Remodeling of Autogenous Bone Grafts after Osteotome Sinus Floor Elevation Assessed by Limited Cone Beam Computed Tomography

    Directory of Open Access Journals (Sweden)

    Tetsuya Nishida

    2013-01-01

    Full Text Available This study assessed the radiographic appearance of bone graft domes longitudinally after osteotome sinus floor elevation using cone beam computed tomography (CBCT. This study presents the radiological findings of a 6-month follow-up CBCT study in maxillary osteotome sinus floor elevation. We examined 52 patients with a crestal bone height of less than 8 mm in the posterior maxilla who required sinus augmentation. Implants ( were subsequently placed in regenerated bone following osteotome sinus floor elevation; autogenous bone was used as the augmentation material. In all cases, the grafted augmentation material tended to be absorbed, but at least 1 mm of grafted augmentation material was recognized around the implant fixtures on CBCT at the second implant operation. The border between the grafted augmentation material and the existing bone was indistinct. The grafted area apical to the implants undergoes shrinkage and remodeling. It was suggested that sufficient grafted autogenous bone changes into bone to support an implant.

  20. Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft in animals: a systematic review

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, S; Stavropoulos, A

    2012-01-01

    The objective of the present systematic review was to test the hypothesis of no differences between the use of Bio-Oss or Bio-Oss mixed with autogenous bone as graft for maxillary sinus floor augmentation (MSFA) applying the lateral window technique, as evaluated in animals. A MEDLINE (Pub...... of the graft improved significantly with increased proportion of Bio-Oss. Bone regeneration, bone-to-implant contact (BIC), biomechanical implant test values, and biodegradation of Bio-Oss after MSFA with Bio-Oss or Bio-Oss mixed with autogenous bone have never been compared within the same study in animals...

  1. Comparative Effectiveness of Bone Grafting Using Xenograft Freeze-Dried Cortical Bovine, Allograft Freeze-Dried Cortical New Zealand White Rabbit, Xenograft Hydroxyapatite Bovine, and Xenograft Demineralized Bone Matrix Bovine in Bone Defect of Femoral Diaphysis of White Rabbit: Experimental Study In Vivo

    Directory of Open Access Journals (Sweden)

    Ferdiansyah Mahyudin

    2017-01-01

    Full Text Available Autogenous bone graft is gold standard in treating bone defects, but it might have difficulty in corporation and rejection reaction. This study is to compare the effectiveness among freeze-dried xenograft, freeze-dried allograft, hydroxyapatite xenograft, and demineralized bone matrix xenograft as bone graft to fill bone defect in femoral diaphysis of white rabbit. Thirty male New Zealand white rabbits were distributed into five groups. Bone defect was filled correspondingly with xenograft freeze-dried cortical bovine, allograft freeze-dried cortical New Zealand white rabbit, xenograft hydroxyapatite bovine, and xenograft demineralized bone matrix bovine. No graft was used in control group. VEGF, osteoblast, and woven bone were higher in allograft freeze-dried cortical New Zealand white rabbit (mean 5.6625 (p<0.05 and xenograft demineralized bone matrix bovine (mean 5.2475 (p<0.05 with calcification of woven bone was already seen in week 2 in the latter group. There was a decrease of woven bone (mean 4.685 (p<0.05 fibrous tissue (mean 41.07 (p<0.05 in xenograft demineralized bone matrix bovine. The Immunoglobulin-G was elevated in control and all study groups but not significantly (p=0.07855. Bone healing process in xenograft demineralized bone matrix bovine is more effective than in xenograft hydroxyapatite bovine, allograft freeze-dried New Zealand white rabbit, xenograft freeze-dried cortical bovine, and control.

  2. Bone scintigraphy in evaluating the viability of composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and free non-revascularized periosteal grafts

    International Nuclear Information System (INIS)

    Berggren, A.; Weiland, A.J.; Ostrup, L.T.

    1982-01-01

    Researchers studied the value of bone scintigraphy in the assessment of anastomotic patency and bone-cell viability in free bone grafts revascularized by microvascular anastomoses in twenty-seven dogs. The dogs were divided into three different groups, and scintigraphy was carried out using technetium-labeled methylene diphosphonate in composite bone grafts revascularized by microvascular anastomoses, conventional autogenous bone grafts, and periosteal grafts placed in different recipient beds. The viability of the grafts were evaluated by histological examination and fluorescence microscopy after triple labeling with oxytetracycline on the first postoperative day, alizarin complexone on the fourth postoperative day, and DCAF on the eleventh postoperative day. A positive scintiscan within the first week following surgery indicated patent microvascular anastomoses, and histological study and fluorescence microscopy confirmed that bone throughout the graft was viable. A positive scintiscan one week after surgery or later does not necessarily indicate microvascular patency or bone-cell survival, because new bone formed by creeping substitution on the surface of a dead bone graft can result in this finding

  3. Regional cortical and trabecular bone loss after spinal cord injury

    OpenAIRE

    Dudley-Javoroski, Shauna; Shields, Richard K.

    2012-01-01

    Spinal cord injury (SCI) triggers rapid loss of trabecular bone mineral density (BMD) in bone epiphyses and a loss of cortical cross-sectional area (CSA) in bone diaphyses, increasing fracture risk for people with SCI. The purpose of this study was to measure trabecular BMD and cortical CSA loss at several previously unexamined lower-limb sites (4% fibula, 12% femur, 86% tibia, cortical) in individuals with SCI. Using peripheral quantitative computed tomography, we scanned 13 participants wit...

  4. Vertical Bone Augmentation with an Autogenous Block or Particles in Combination with Guided Bone Regeneration: A Clinical and Histological Preliminary Study in Humans.

    Science.gov (United States)

    Rocchietta, Isabella; Simion, Massimo; Hoffmann, Maria; Trisciuoglio, Davide; Benigni, Marco; Dahlin, Christer

    2016-02-01

    Vertical ridge augmentation with the use of solid bone blocks or particulate bone autograft, exposed or covered by a nonresorbable expanded polytetrafluoroethylene (ePTFE) membrane, are well known in the literature and have been shown to be effective in treating bone atrophy. The aim of our study was to assess the two techniques in respect to biological properties of transplanted bone in graft revascularization and bone remodeling in conjunction with dental implants. Ten patients were treated within the study, with a total of 12 sites with posterior mandibular edentulous ridges with insufficient bone to allow implant placement. Bone regeneration was performed using autogenous intraoral block graft or autogenous particulate graft with an ePTFE barrier membrane. At 6-10 months, reentry surgery was performed; bone biopsies, including microscrews, were harvested; and implants were placed. Eleven sites out of 12 healed uneventfully. A mean height gain of 5.03 mm was achieved. Mean bone-to-implant contact and bone fill were assessed by means of histomorphometric analysis. The block specimens revealed a bone-to-implant contact of 42.34%, and the particulate grafts had a bone-to-implant contact of 26.62% (p Bone fill values reported were 68.32% and 48.28% (p bone remodeling, of the two techniques differed significantly. The block grafts outperformed the particulate grafts in terms of bone-to-implant contact and bone fill values; however, the morbidity associated with the donor site of the block must be considered. © 2015 Wiley Periodicals, Inc.

  5. The role of ubiquinone supplementation on osteogenesis of nonvascularized autogenous bone graft

    Directory of Open Access Journals (Sweden)

    Irham Taufiqurrahman

    2015-03-01

    Full Text Available Background: Ubiquinone is one of food supplement which is known have positive effect in wound healing. However the study to evaluate the possible role of ubiquinone in bone healing in autogenous bone grafting after mandibular resection has not been studied. An in vitro study is required to evaluate whether ubiquinone or coenzyme Q-10 (CoQ10 has a positive effect on osteogenesis. Viability test of CoQ10 and a model of osteogenic-induced and hypoxic-condition mesenchymal stem cell culture were established to support the study. Purpose: The study was made to evaluate the role of ubiquinone in osteogenesis by analyzing the toxicity effect and the optimal dose of CoQ10 that might interfere in bone marrow derived mesenchymal stem cell (BM-MSC that was dose in cell culture medium. The BM-MSC culture under hypoxia condition were also observed. Method: The toxicity and the optimum viability concentration of ubiquinone were observed using MTT assay. The osteogenic differentiation under hypoxic condition was done on BM-MSC in osteogenic medium that composed of ascorbic acid, glycerolphosphate and dexamethasone in hypoxia chamber for 21 days. Osteogenic differentiation and cellular hypoxia features were tested with immunocytochemical staining using anti-Runx2 and anti-HIF1α monoclonal antibody, respectively. Result: The maximum density value of  1.826 was found in the group of ubiquinone concentration of 75μM/ml, increasing of in concentration of ubiquinone resulted with the decrease ofoptical density of CoQ10. Statistic analysis using Anova showed with no significant difference among groups with various concentration. Immunocytochemical staining showed that Runx2 expression in 3% hypoxia group (p<0.05. Conclusion:Ubiquinone was found non toxic in its optimum dose of 75μM/ml, showed by optimum result in the expression ofRunx2 and HIF1α further study is necessary to evaluate the angiogenic and osteogenic effect ofubiquione.

  6. Mandibular reconstruction: a histological and histomorphometric study on the use of autogenous scaffolds, particulate cortico-cancellous bone grafts and platelet rich plasma in goats.

    NARCIS (Netherlands)

    Fennis, J.P.M.; Stoelinga, P.J.W.; Jansen, J.A.

    2004-01-01

    Twenty-eight goats underwent a continuity resection of the mandibular angle. In all goats primary reconstruction was carried out using specially designed pre-shaped osteosynthesis plates and monocortical screws. The original cortical scaffold was used to bridge the defect, filled with an autogenous

  7. Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft: a systematic review

    DEFF Research Database (Denmark)

    Jensen, Thomas; Schou, Søren; Stavropoulos, Andreas

    2012-01-01

    Aims: The objective of the present systematic review was to test the hypothesis of no differences in the implant treatment outcome when Bio-Oss or Bio-Oss mixed with autogenous bone is used as graft for the maxillary sinus floor augmentation (MSFA) applying the lateral window technique. Material ......, Holmstrup P. Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft: a systematic review. Clin. Oral Impl. Res. xx, 2011; 000-000 doi: 10.1111/j.1600-0501.2011.02168.x....

  8. Augmentation procedures using bone substitute materials or autogenous bone - a systematic review and meta-analysis.

    Science.gov (United States)

    Al-Nawas, Bilal; Schiegnitz, Eik

    2014-01-01

    Bone substitute materials (BSM) are described as a reasonable alternative to autologous bone (AB) to simplify the grafting procedure. In a systematic review and meta-analysis, the influence of BSM compared to AB on treatment success in augmentation procedures of the edentulous jaw was analysed. Literature analysis resulted in only two studies addressing reconstruction of the totally edentulous jaw using BSM. Therefore the literature analysis was extended to partially and totally edentulous jaws. The following augmentation procedures were analysed: maxillary sinus floor augmentation (MSFA) and vertical and/or lateral alveolar ridge augmentation; guided bone regeneration (minor and contained defects) were excluded. Meta-analysis was implemented using the literature from the years 2000 to early 2014 and only studies with a mean follow-up of at least 10 months were included. After screening 843 abstracts from the electronic database, 52 studies in qualitative and 14 in quantitative synthesis were included. In studies examining MSFA, the mean implant survival rate was 98.6% ± 2.6 for BSM, 88.6 ± 4.1% for BSM mixed with AB and 97.4 ± 2.2% for AB alone. For MSFA, meta-analysis showed a trend towards a higher implant survival when using BSM compared to AB, however the difference was not statistically significant ([OR], 0.59; [CI], 0.33-1.03). No statistically significant difference in implant survival for MSFA between BSM mixed with AB and AB was seen ([OR], 0.84; [CI], 0.5-1.42). Concerning ridge augmentation, the mean implant survival rate was 97.4 ± 2.5% for BSM, 100 ± 0% for BSM mixed with AB and 98.6 ± 2.9% for AB alone. Metaanalysis revealed no statistically significant difference in implant survival for ridge augmentation using BSM or AB ([OR], 1.85; [CI], 0.38 to 8.94). For BSM mixed with AB versus AB alone, a meta-analysis was not possible due to missing data. Within the limitation of the meta-analytical approach taken, implant survival seems to be

  9. Lack of beneficial effects of platelet-rich plasma on sinus augmentation using a fluorohydroxyapatite or autogenous bone: an explorative study.

    Science.gov (United States)

    Klongnoi, Boworn; Rupprecht, Stephan; Kessler, Peter; Zimmermann, Robert; Thorwarth, Michael; Pongsiri, Sumitra; Neukam, Friedrich-Wilhelm; Wiltfang, Joerg; Schlegel, Karl Andreas

    2006-07-01

    Maxillary sinus augmentation is frequently necessary before placement of dental implants in the posterior maxilla. Besides autogenous bone graft, various bone substitutes have been used, with favourable results. Although platelet-rich plasma (PRP) has been used in the field of oral and maxillofacial surgery for years, its beneficial effects on osseous regeneration still remain unclear. The aim of this study was to evaluate the short and long time effects of PRP on single-stage sinus augmentation using autogenous bone or a fluorohydroxyapatite (Algipore) in a randomized prospective animal study. After extraction of maxillary premolars of sixteen minipigs, the wounds were allowed to heal for 2 months. Then, sinus augmentations were performed bilaterally using one of the following grafting materials: autogenous bone and Algipore with or without PRP. Three dental implants (Ankylos) were installed in each sinus simultaneously. Four animals were euthanized at each period of observation (1, 2, 8 and 12 months). Implant-bearing specimens were sectioned bucco-lingually along the long axis of implants and undecalcified ground specimens were prepared. The bone-implant-contact (BIC) was measured by means of microradiographic examination. For histological evaluation, the specimens were stained with toluidin blue, and the percentage of the newly formed bone and the remaining bone substitute were evaluated. The grafting materials chosen showed increasing levels of BIC and newly formed bone throughout the period of observation in both PRP and non-PRP groups. Adding PRP resulted in lower BIC and newly formed bone compared with autogenous bone grafts or Algipore alone. However, a statistical significance was not found. The percentages of the remaining bone substitute in both the PRP and non-PRP groups were closely comparable in all observation periods. The application of PRP could not reveal significant beneficial effects on the BIC, the percentage of the newly formed bone and the

  10. The combined use of rhBMP-2/ACS, autogenous bone graft, a bovine bone mineral biomaterial, platelet-rich plasma, and guided bone regeneration at nonsubmerged implant placement for supracrestal bone augmentation. A case report.

    Science.gov (United States)

    Sclar, Anthony G; Best, Steven P

    2013-01-01

    This case report presents the clinical application and outcomes of the use of a combined approach to treat a patient with a severe alveolar defect. Recombinant human bone morphogenetic protein-2 in an absorbable collagen sponge carrier, along with autogenous bone graft, bovine bone mineral, platelet-rich plasma, and guided bone regeneration, were used simultaneous with nonsubmerged implant placement. At 1 year postsurgery, healthy peri-implant soft tissues and radiographically stable peri-implant crestal bone levels were observed along with locally increased radiographic bone density. In addition, a cone beam computed tomography (CBCT) scan demonstrated apparent supracrestal peri-implant bone augmentation with the appearance of normal alveolar ridge contours, including the facial bone wall.

  11. Extraskeletal and intraskeletal new bone formation induced by demineralized bone matrix combined with bone marrow cells

    International Nuclear Information System (INIS)

    Lindholm, T.S.; Nilsson, O.S.; Lindholm, T.C.

    1982-01-01

    Dilutions of fresh autogenous bone marrow cells in combination with allogeneic demineralized cortical bone matrix were tested extraskeletally in rats using roentgenographic, histologic, and 45 Ca techniques. Suspensions of bone marrow cells (especially diluted 1:2 with culture media) combined with demineralized cortical bone seemed to induce significantly more new bone than did demineralized bone, bone marrow, or composite grafts with whole bone marrow, respectively. In a short-term spinal fusion experiment, demineralized cortical bone combined with fresh bone marrow produced new bone and bridged the interspace between the spinous processes faster than other transplantation procedures. The induction of undifferentiated host cells by demineralized bone matrix is further complemented by addition of autogenous, especially slightly diluted, bone marrow cells

  12. Influence of platelet-rich plasma on a bioglass and autogenous bone in sinus augmentation. An explorative study.

    Science.gov (United States)

    Klongnoi, Boworn; Rupprecht, Stephan; Kessler, Peter; Thorwarth, Michael; Wiltfang, Joerg; Schlegel, Karl Andreas

    2006-06-01

    Platelet-rich plasma (PRP) has been introduced to the field of oral and maxillofacial surgery for a decade, but its beneficial effects on maxillary sinus augmentation remain unclear. The aim of this study was to evaluate the short- and long-term effects of PRP on osseointegration following single-stage sinus augmentation in a randomized prospective animal study. The maxillary premolars of 24 minipigs were extracted bilaterally and allowed to heal for 2 months. Consecutively all animals underwent bilateral sinus floor elevation using autogenous bone, Biogran as well as a combination of the materials with PRP. Three dental implants (Ankylos, Dentsply Co., Mannheim, Germany) were installed in each sinus simultaneously. Four animals were sacrificed at each period of observation (1, 2, 8 and 12 months). Microradiographic images of the specimens were made for quantitative evaluation of the bone-implant contact (BIC) and light microscopic images were made for qualitative analysis. An increment of the BIC during the observation time could be seen over the observation time in all groups. Autogenous bone exhibited a level of BIC from 25.1 +/- 9.96% at 1 month to 55.1 +/- 13.10% at 12 months; on adding PRP, the BIC ranged from 28.4 +/- 4.64% to 52.5 +/- 17.06%. Biogran with and without PRP led to BIC levels from 16.3 +/- 4.64% to 37.6 +/- 16.40% and 21.7 +/- 4.33% to 46.6 +/- 19.37%, respectively. The results of this study did not show a significantly positive effect of PRP on the BIC following sinus augmentation in both groups.

  13. Swine cortical and cancellous bone: histomorphometric and densitometric characterisation

    Directory of Open Access Journals (Sweden)

    Maria Elena Andreis

    2017-06-01

    Full Text Available Introduction: Swine bone morphology, composition and remodelling are similar to humans’, therefore they are considered good models in bone-related research. They have been used for several studies involving bone growth, bone and cartilage fractures and femoral head osteonecrosis. Nevertheless, the literature about pig normal bone features is incomplete. This work aims to fill the literature gaps on the microarchitecture and Bone Mineral Density (BMD of swine femoral diaphysis and distal epiphysis and tibial plateau and diaphysis. Materials and methods: Five hind limbs were collected from slaughtered 80-100 kg pigs. Microscopic analysis of cortical and cancellous bone from middle/distal femur and proximal/middle tibia was performed to determine basic histomorphometric parameters at different sites. Dual-energy X-Rays Absorptiometry was also employed to evaluate BMD. ANOVA and correlation between BMD, bone area (BA and cortical thickness were performed. Results and discussion: Diaphyseal cortical bone was mostly plexiform both in the tibia and the femur; primary/secondary osteons without clear organization were also found. Mean values for bone area, bone perimeter, trabecular width, number and separation and BMD at different anatomical sites were defined. No significant difference was found for these values at different anatomical sites. BMD proved to be positively correlated with cortical thickness (r=0,80; p<0,01. Despite the small sample size, these results seem homogeneous. They could therefore represent reference values for normal bone parameters in pigs. Applied anatomy and regenerative medicine, in fact, demand very precise information about bone micromorphology, composition and density to provide reliable indication in bone substitutes building. Moreover, since the interpretation of bone abnormalities is based on mastering normal bone characteristics, the definition of reference parameters is mandatory to avoid misinterpretation and

  14. Influence of cortical endplates on ultrasonic properties of trabecular bone

    International Nuclear Information System (INIS)

    Kim, Yoon Mi; Lee, Kang Il

    2015-01-01

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  15. Influence of cortical endplates on ultrasonic properties of trabecular bone

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Mi; Lee, Kang Il [Dept. of Physics, Kangwon National University, Chuncheon (Korea, Republic of)

    2015-04-15

    The present study investigated the influence of thick cortical endplates on the ultrasonic properties of trabecular bone in a femur with a high fracture risk. Twelve trabecular bone samples were prepared from bovine femurs, and acrylic plates with thicknesses of 1.25, 1.80, and 2.75 mm were manufactured to simulate the cortical endplates using acrylic with a density and a sound speed similar to cortical bone. Although the thickness of the acrylic plates attached to the two sides of the trabecular bone increased, high correlations were observed between the speed of sound and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.80-0.86. High correlations were also observed between the attenuation coefficient at 0.5 mm and the apparent bone density of the trabecular bone, with Pearson's correlation coefficients of 0.84-0.91. These results suggest that the speed of sound and attenuation coefficient at a specific frequency measured in a femur with relatively thick cortical endplates compared to the calcaneus could be used as indices for predicting the bone mineral density of the femur.

  16. Localized cortical bone sclerosis and intramedullar linear sclerosis in neurofibromatosis

    International Nuclear Information System (INIS)

    Kuur, E.; Hjarbaek, J.; Teisen, H.

    1988-01-01

    A case of localised cortical bone sclerosis of the left tibia and intramedullar linear sclerosis in the left femur, in association with neurofibromatosis in a 25-year-old female, is presented. The differential diagnostic problems in relation to bone tumours are emphasised. (orig.) [de

  17. Dynamic Mechanical Testing Techniques for Cortical and Cancellous Bone

    Science.gov (United States)

    Cloete, Trevor

    2017-06-01

    Bone fracture typically occurs as an impact loading event (sporting accidents, vehicle collisions), the simulation of which requires in-depth understanding of dynamic bone behavior. Bone is a natural composite material with a complex multi length-scale hierarchical microstructure. At a macroscopic level, it is classified into hard/compact cortical bone and soft/spongy cancellous (trabecular) bone, though both are low-impedance materials relative to steels. Cortical bone is predominant in long bones, while in complex bone geometries (joints, flat bones) a cancellous bone core supports a thin cortical shell. Bone has primarily been studied at quasi-static strain rates (ɛ˙ failure, with interrupted quasi-static tests revealing a strong microstructure dependence. However, bone specimens are typically destroyed during dynamic tests, leading to a lack of dynamic microstructural damage investigations. In this paper, a short overview of dynamic bone testing is presented to give context to the challenges of testing low impedance, strain-rate dependent, non-linear, visco-elastic-brittle materials. Recent state-of-the-art experimental developments in dynamic bone testing are reviewed, with emphasis on pulse shaping, momentum trapping and ISR testing. These techniques allow for dynamic bone testing at small strains and near-constant strain rates with intact specimen recovery. The results are compared to those obtained with varying strain rate tests. Interrupted dynamic test results with microstructural analysis of the recovered specimens are presented and discussed. The paper concludes with a discussion of the experimental and modeling challenges that lie ahead in the field of dynamic bone behavior. The financial assistance of the National Research Foundation and the University of Cape Town towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at are those of the author alone.

  18. Probiotics protect mice from ovariectomy-induced cortical bone loss.

    Directory of Open Access Journals (Sweden)

    Claes Ohlsson

    Full Text Available The gut microbiota (GM modulates the hosts metabolism and immune system. Probiotic bacteria are defined as live microorganisms which when administered in adequate amounts confer a health benefit on the host and can alter the composition of the GM. Germ-free mice have increased bone mass associated with reduced bone resorption indicating that the GM also regulates bone mass. Ovariectomy (ovx results in bone loss associated with altered immune status. The purpose of this study was to determine if probiotic treatment protects mice from ovx-induced bone loss. Mice were treated with either a single Lactobacillus (L strain, L. paracasei DSM13434 (L. para or a mixture of three strains, L. paracasei DSM13434, L. plantarum DSM 15312 and DSM 15313 (L. mix given in the drinking water during 6 weeks, starting two weeks before ovx. Both the L. para and the L. mix treatment protected mice from ovx-induced cortical bone loss and bone resorption. Cortical bone mineral content was higher in both L. para and L. mix treated ovx mice compared to vehicle (veh treated ovx mice. Serum levels of the resorption marker C-terminal telopeptides and the urinary fractional excretion of calcium were increased by ovx in the veh treated but not in the L. para or the L. mix treated mice. Probiotic treatment reduced the expression of the two inflammatory cytokines, TNFα and IL-1β, and increased the expression of OPG, a potent inhibitor of osteoclastogenesis, in cortical bone of ovx mice. In addition, ovx decreased the frequency of regulatory T cells in bone marrow of veh treated but not probiotic treated mice. In conclusion, treatment with L. para or the L. mix prevents ovx-induced cortical bone loss. Our findings indicate that these probiotic treatments alter the immune status in bone resulting in attenuated bone resorption in ovx mice.

  19. Buccal cortical bone thickness on CBCT for mini-implant

    Energy Technology Data Exchange (ETDEWEB)

    Goo, Jong Gook; Lim, Sung Hoon; Lee, Byoung Jin; Kim, Jae Duk [School of Dentistry, Chosun University, Gwangju (Korea, Republic of)

    2010-12-15

    Cortical bone thickness is one of the important factor in mini-implant stability. This study was performed to investigate the buccal cortical bone thickness at every interdental area as an aid in planning mini-implant placement. Two-dimensional slices at every interdental area were selected from the cone-beam computed tomography scans of 20 patients in third decade. Buccal cortical bone thickness was measured at 2, 4, and 6 mm levels from the alveolar crest in the interdental bones of posterior regions of both jaws using the plot profile function of Ez3D2009TM (Vatech, Yongin, Korea). The results were analyzed using by Mann-Whitney test. Buccal cortical bone was thicker in the mandible than in the maxilla. The thickness increased with further distance from the alveolar crest in the maxilla and with coming from the posterior to anterior region in the mandible (p?0.01). The maximum CT value showed an increasing tendency with further distance from the alveolar crest and with coming from posterior to anterior region in both jaws. Interdental buccal cortical bone thickness varied in both jaws, however our study showed a distinct tendency. We expect that these results could be helpful for the selection and preparation of mini-implant sites.

  20. Histomorphometric analysis of bone formation in bony defects around implants in adult dogs: a comparison of grafts of low and high heat-treated autogenous tooth ash.

    Science.gov (United States)

    Kim, Jin-Ha; Kim, Su-Gwan; Lim, Sung-Chul; Oh, Ji-Su; You, Jae-Seek; Jeong, Mi-Ae

    2013-12-01

    The purpose of this study was to compare the bone formation of autogenous tooth ash treated with different temperatures. Heat treatment was rendered by powder after extraction of teeth from dogs. The bony defects were made at iliac and resorbable blast medium surfaced implant placement and bone graft was performed; no bone graft group (control group), low heat-treated tooth ash group (group 1), high heat-treated tooth ash group (group 2). Right side had healing periods of 12 weeks, and the left side had 6 weeks. Histomorphometrical analysis was performed at 12 weeks. The control group had poor bone formation and showed large loose connective tissue. Group 1 displayed good healing and bone formation. Group 2 showed higher rate of bone formation than group 1 and the control group. The high heat-treated tooth ash group showed a statistically significant increase in the rate of bone formation in the early stage. The heat-treated autogenous tooth ash powder showed excellent new bone formation. The temperature of heat treatment is an important factor in new bone formation. The high heat treatment was the optimal treatment method for making tooth ash than the low heat treatment.

  1. The cortical representation of sensory inputs arising from bone.

    Science.gov (United States)

    Ivanusic, Jason J; Sahai, Vineet; Mahns, David A

    2009-05-07

    In the present study, we show that sensory information from bone reaches the discriminative areas of the somatosensory cortices by electrically stimulating the nerve to the cat humerus and recording evoked potentials on the surface of the primary (SI) and secondary (SII) somatosensory cortex. The SI focus was located over the rostral part of the postcruciate cortex, caudal to the lateral aspect of the cruciate sulcus. The SII focus was identified on the anterior ectosylvian gyrus, lateral to the suprasylvian sulcus. These foci were located adjacent to, or within areas that responded to stimulation of the median, ulnar and/or musculocutaneous nerves. The latency (6-11 ms) to onset of cortical responses in SI and SII were indistinguishable (unpaired t-test; P>0.05), and were consistent with activation of A delta fibers in the peripheral nerve. The amplitudes of the cortical responses were graded as a function of stimulus intensity, and may reflect a mechanism for intensity coding. We did not observe long latency cortical responses (50-300 ms) that would be consistent with C fiber activation in the peripheral nerve, and provide evidence that this may be attributable to inhibition of cortical responsiveness following the initial A delta response. Our finding of discrete, short latency evoked potentials (presumably of A delta origin) in the primary and secondary somatosensory cortices, following stimulation of a nerve innervating bone, may reflect a mechanism for the discriminative component of bone pain.

  2. Disuse exaggerates the detrimental effects of alcohol on cortical bone

    Science.gov (United States)

    Hefferan, Theresa E.; Kennedy, Angela M.; Evans, Glenda L.; Turner, Russell T.

    2003-01-01

    BACKGROUND: Alcohol abuse is associated with an increased risk for osteoporosis. However, comorbidity factors may play an important role in the pathogenesis of alcohol-related bone fractures. Suboptimal mechanical loading of the skeleton, an established risk factor for bone loss, may occur in some alcohol abusers due to reduced physical activity, muscle atrophy, or both. The effect of alcohol consumption and reduced physical activity on bone metabolism has not been well studied. The purpose of this study was to determine whether mechanical disuse alters bone metabolism in a rat model for chronic alcohol abuse. METHODS: Alcohol was administered in the diet (35% caloric intake) of 6-month-old male rats for 4 weeks. Rats were hindlimb-unloaded the final 2 weeks of the experiment to prevent dynamic weight bearing. Afterward, cortical bone histomorphometry was evaluated at the tibia-fibula synostosis. RESULTS: At the periosteal surface of the tibial diaphysis, alcohol and hindlimb unloading independently decreased the mineralizing perimeter, mineral apposition rate, and bone formation rate. In addition, alcohol, but not hindlimb unloading, increased endocortical bone resorption. The respective detrimental effects of alcohol and hindlimb unloading to inhibit bone formation were additive; there was no interaction between the two variables. CONCLUSIONS: Reduced weight bearing accentuates the detrimental effects of alcohol on cortical bone in adult male rats by further inhibiting bone formation. This finding suggests that reduced physical activity may be a comorbidity factor for osteoporosis in alcohol abusers.

  3. Regional cortical and trabecular bone loss after spinal cord injury.

    Science.gov (United States)

    Dudley-Javoroski, Shauna; Shields, Richard K

    2012-01-01

    Spinal cord injury (SCI) triggers rapid loss of trabecular bone mineral density (BMD) in bone epiphyses and a loss of cortical cross-sectional area (CSA) in bone diaphyses, increasing fracture risk for people with SCI. The purpose of this study was to measure trabecular BMD and cortical CSA loss at several previously unexamined lower-limb sites (4% fibula, 12% femur, 86% tibia, cortical) in individuals with SCI. Using peripheral quantitative computed tomography, we scanned 13 participants with SCI longitudinally and 16 on one occasion; 21 participants without SCI served as controls. In the first year post-SCI, 15% to 35% of BMD was lost at the distal femur, proximal tibia, and distal fibula. Bone loss at the distal fibula accelerated between 1 and 2 years post-SCI. BMD at these sites reached a steady state value of ~50% of the non-SCI value 4 years post-SCI. At the tibia diaphysis, cortical CSA decline was slower, eventually reaching 65% of the non-SCI value. Because of the extensive loss of bone observed at these sites, careful consideration needs to be given to the dose of musculoskeletal stress delivered during rehabilitation interventions like standing, muscle electrical stimulation, and aggressive stretching of spastic muscles.

  4. Rapid cortical bone loss in patients with chronic kidney disease.

    Science.gov (United States)

    Nickolas, Thomas L; Stein, Emily M; Dworakowski, Elzbieta; Nishiyama, Kyle K; Komandah-Kosseh, Mafo; Zhang, Chiyuan A; McMahon, Donald J; Liu, Xiaowei S; Boutroy, Stephanie; Cremers, Serge; Shane, Elizabeth

    2013-08-01

    Chronic kidney disease (CKD) patients may have high rates of bone loss and fractures, but microarchitectural and biochemical mechanisms of bone loss in CKD patients have not been fully described. In this longitudinal study of 53 patients with CKD Stages 2 to 5D, we used dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HRpQCT), and biochemical markers of bone metabolism to elucidate effects of CKD on the skeleton. Median follow-up was 1.5 years (range 0.9 to 4.3 years); bone changes were annualized and compared with baseline. By DXA, there were significant declines in areal bone mineral density (BMD) of the total hip and ultradistal radius: -1.3% (95% confidence interval [CI] -2.1 to -0.6) and -2.4% (95% CI -4.0 to -0.9), respectively. By HRpQCT at the distal radius, there were significant declines in cortical area, density, and thickness and increases in porosity: -2.9% (95% CI -3.7 to -2.2), -1.3% (95% CI -1.6 to -0.6), -2.8% (95% CI -3.6 to -1.9), and +4.2% (95% CI 2.0 to 6.4), respectively. Radius trabecular area increased significantly: +0.4% (95% CI 0.2 to 0.6), without significant changes in trabecular density or microarchitecture. Elevated time-averaged levels of parathyroid hormone (PTH) and bone turnover markers predicted cortical deterioration. Higher levels of serum 25-hydroxyvitamin D predicted decreases in trabecular network heterogeneity. These data suggest that significant cortical loss occurs with CKD, which is mediated by hyperparathyroidism and elevated turnover. Future investigations are required to determine whether these cortical losses can be attenuated by treatments that reduce PTH levels and remodeling rates. Copyright © 2013 American Society for Bone and Mineral Research.

  5. Collagen barrier membranes adsorb growth factors liberated from autogenous bone chips.

    Science.gov (United States)

    Caballé-Serrano, Jordi; Sawada, Kosaku; Miron, Richard J; Bosshardt, Dieter D; Buser, Daniel; Gruber, Reinhard

    2017-02-01

    Collagen membranes serve as barriers to separate bone grafts from soft tissues. Bone grafts harvested with a bone scraper release growth factors activating transforming growth factor-β (TGF-β) signaling in mesenchymal cells. The aim of the present pilot study was to determine whether collagen membranes adsorb molecules from bone-conditioned medium (BCM) with the capacity to provoke the expression of TGF-β target genes in vitro. Collagen membranes were soaked in aqueous extracts from fresh and demineralized bone chips placed in cell culture medium. Recombinant human TGF-β1 served as control. Gingival fibroblasts were seeded onto the washed collagen membranes and evaluated for the expression of adrenomedullin, pentraxin 3, interleukin 11, and proteoglycan 4. Cell viability and morphology with phalloidin staining were also determined. Incubation of collagen membranes with BCM for at least one minute caused fibroblasts to decrease the expression of adrenomedullin and pentraxin 3, and to increase the expression of interleukin 11 and proteoglycan 4. Four different membrane treatments - incubated with recombinant TGF-β1, pre-wetted with saline solution, exposed to UV light, and dry out and stored one week at room temperature - also provoked significant changes in gene expression. Likewise, conditioned medium from demineralized bone chips caused gene expression changes. BCM did not alter the viability or morphology of gingival fibroblasts. These findings demonstrate that collagen membranes rapidly adsorb the TGF-β activity released from bone chips, a molecular process that might contribute to guided bone regeneration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Non-Vascularized Autogenous Bone Grafts for Reconstruction of Maxillofacial Osseous Defects.

    Science.gov (United States)

    Ahmed, Waseem; Asim, Muhammad Adil; Ehsan, Afeefa; Abbas, Qalab

    2018-01-01

    To determine the outcomes of non-vascularized bone grafts for reconstruction of maxillofacial defects. Case series. Department of Oral and Maxillofacial Surgery, Armed Forces Institute of Dentistry, Rawalpindi, from January 2013 to December 2015. Descriptive analyses of 30 patients, who underwent maxillofacial reconstruction with non-vascularized bone grafts, were conducted. The demographic information, diagnosis, and type of graft harvested to reconstruct the defect were statistically analyzed. Outcomes of reconstruction with non-vascularized bone grafts were analyzed in terms of mouth opening, success of dental rehabilitation, and postoperative complications, i.e. surgical site infection and hardware loosening. A total of 30 patients ranging from 8 to 60 years (33.57 ±14.74 years) had maxillofacial defects reconstructed mostly due to gunshot injuries, followed by post-resection defects. Overall 15 cases (50%) were reconstructed with iliac crest cortico-cancellous bone graft, 11 cases (36.7%) with rib; while in four cases (13.3%), costochondral graft was used for reconstruction. In 26 cases (86.7%), graft was found to be successful. In three cases, re-operation for onlay bone graft was required to provide optimal dental rehabilitation; while in just one case, postoperative surgical site infection was observed. Non-vascularized bone grafts provide a reasonable and effective modality for reconstruction of maxillofacial defects.

  7. Clinical and 3-Dimensional Radiographic Evaluation of Autogenous Iliac Block Bone Grafting and Guided Bone Regeneration in Patients With Atrophic Maxilla.

    Science.gov (United States)

    Gultekin, B Alper; Cansiz, Erol; Borahan, M Oguz

    2017-04-01

    To evaluate the rate of graft resorption in autogenous iliac bone grafting (IBG) and guided bone regeneration (GBR) in patients with atrophic maxillae. We performed a retrospective study involving patients requiring implant placement who underwent IBG or GBR. Volumetric changes of the graft sites were evaluated by imaging studies. The primary predictor and outcome variables were augmentation technique and rate of volumetric resorption, respectively. Secondary outcome variables included bone gain, success of grafting, insertion torque of implants, and requirement for vestibuloplasty. The sample comprised 39 patients (21 with GBR and 18 with IBG). One patient in the IBG group had temporary sensory disturbance at the donor site, and one patient in the GBR group had late exposure of the nonresorbable membrane. The average values of percent volume reduction in the GBR and IBG groups were 12.26% ± 2.35% and 35.94% ± 7.94%, respectively, after healing and 15.87% ± 1.99% and 41.62% ± 6.97%, respectively, at last follow-up. The IBG group exhibited a significantly higher reduction in bone volume than the GBR group at both time points (P = .001). The mean values of horizontal and vertical bone gain after healing in the IBG group were significantly higher than those in the GBR group (P = .006 and P = .001, respectively). The mean implant torque during implant placement in the GBR group was significantly higher than that in the IBG group (P = .024). There was no significant difference in the requirement for vestibuloplasty between the two groups (P > .05). Although both hard tissue augmentation approaches provide an adequate volume of bone graft for implant insertion, IBG results in greater graft resorption at maxillary augmented sites than GBR. Clinicians should consider the differences in the extent of graft resorption between the two methods while choosing the treatment approach. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published

  8. Cortical bone fracture analysis using XFEM - case study.

    Science.gov (United States)

    Idkaidek, Ashraf; Jasiuk, Iwona

    2017-04-01

    We aim to achieve an accurate simulation of human cortical bone fracture using the extended finite element method within a commercial finite element software abaqus. A two-dimensional unit cell model of cortical bone is built based on a microscopy image of the mid-diaphysis of tibia of a 70-year-old human male donor. Each phase of this model, an interstitial bone, a cement line, and an osteon, are considered linear elastic and isotropic with material properties obtained by nanoindentation, taken from literature. The effect of using fracture analysis methods (cohesive segment approach versus linear elastic fracture mechanics approach), finite element type, and boundary conditions (traction, displacement, and mixed) on cortical bone crack initiation and propagation are studied. In this study cohesive segment damage evolution for a traction separation law based on energy and displacement is used. In addition, effects of the increment size and mesh density on analysis results are investigated. We find that both cohesive segment and linear elastic fracture mechanics approaches within the extended finite element method can effectively simulate cortical bone fracture. Mesh density and simulation increment size can influence analysis results when employing either approach, and using finer mesh and/or smaller increment size does not always provide more accurate results. Both approaches provide close but not identical results, and crack propagation speed is found to be slower when using the cohesive segment approach. Also, using reduced integration elements along with the cohesive segment approach decreases crack propagation speed compared with using full integration elements. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Allogeneic and autogenous transplantations of MSCs in treatment of the physeal bone bridge in rabbits

    Czech Academy of Sciences Publication Activity Database

    Plánka, L.; Gál, P.; Kecová, H.; Klíma, Jiří; Hlučilová, Jana; Filová, Eva; Amler, Evžen; Krupa, P.; Křen, L.; Srnec, R.; Urbanová, L.; Lorenzová, J.; Nečas, A.

    2008-01-01

    Roč. 8, - (2008), s. 70-79 ISSN 1472-6750 R&D Projects: GA MŠk 2B06130 Grant - others:GA MZd(CZ) NR8483 Institutional research plan: CEZ:AV0Z50450515; CEZ:AV0Z50390703 Keywords : bone bridge Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.383, year: 2008 http://www.biomedcentral.com/1472-6750/8/70

  10. Cortical Bone Resorption Following Muscle Paralysis is Spatially Heterogeneous

    Science.gov (United States)

    Ausk, Brandon J.; Huber, Philippe; Poliachik, Sandra L.; Bain, Steven D.; Srinivasan, Sundar; Gross, Ted S.

    2011-01-01

    Mechanical loading of the skeleton, as induced by muscle function during activity, plays a critical role in maintaining bone homeostasis. It is not understood, however, whether diminished loading (and thus diminished mechanical stimuli) directly mediates the bone resorption that is associated with disuse. Our group has recently developed a murine model in which we have observed rapid and profound bone loss in the tibia following transient paralysis of the calf muscles. As cortical bone loss is achieved via rapid endocortical expansion without alterations in periosteal morphology, we believe this model holds unique potential to explore the spatial relation between altered mechanical stimuli and subsequent bone resorption. Given the available literature, we hypothesized that endocortical resorption following transient muscle paralysis would be spatially homogeneous. To test this hypothesis, we first validated an image registration algorithm that quantified site-specific cortical bone alterations with high precision and accuracy. We then quantified endocortical expansion in the tibial diaphysis within 21 days following transient muscle paralysis and found that, within the analyzed mid-diaphyseal region (3.15 mm), site-specific bone loss was focused on the anterior surface in the proximal region but shifted to the posterior surface at the distal end of the analyzed volume. This site-specific, but highly repeatable biologic response suggests active osteoclast chemotaxis or focal activation of osteoclastic resorption underlies the spatially consistent endocortical resorption induced by transient muscle paralysis. Clarifying this relation holds potential to yield unique insight into how the removal of factors critical for bone homeostasis acutely precipitates local modulation of cellular responses within bone. PMID:21920486

  11. Knee loading stimulates cortical bone formation in murine femurs

    Directory of Open Access Journals (Sweden)

    Tanaka Shigeo M

    2006-09-01

    Full Text Available Abstract Background Bone alters its architecture and mass in response to the mechanical environment, and thus varying loading modalities have been examined for studying load-driven bone formation. The current study aimed to evaluate the anabolic effects of knee loading on diaphyseal cortical bone in the femur. Methods Using a custom-made piezoelectric loader, 0.5-N loads were laterally applied to the left knee of C57/BL/6 mice at 5, 10, 15, and 20 Hz for 3 minutes per day for 3 consecutive days. Animals were sacrificed for examination 13 days after the last loading. The contralateral femur was used as a non-loading control, and the statistical significance of loading effects was evaluated with p Results Although diaphyseal strains were measured as small as 12 μstrains, bone histomorphometry clearly demonstrated frequency-dependent enhancement of bone formation. Compared to a non-loading control, bone formation on the periosteal surface was significantly enhanced. The loading at 15 Hz was most effective in elevating the mineralizing surface (1.7 x; p p p p p p Conclusion The results support the anabolic effects of knee loading on diaphyseal cortical bone in the femur with small in situ strain, and they extend our knowledge on the interplay between bone and joints. Strengthening the femur contributes to preventing femoral fractures, and the discovery about the described knee loading might provide a novel strategy to strengthen osteoporotic bones. Further analyses are required to understand the biophysical and molecular mechanism behind knee loading.

  12. Influences of organic component on mechanical property of cortical bone with different water content by nanoindentation

    Science.gov (United States)

    Sun, Xingdong; Li, Lijia; Guo, Yue; Zhao, Hongwei; Zhang, Shizhong; Yu, Yang; Wu, Di; Liu, Hang; Yu, Miao; Shi, Dong; Liu, Zeyang; Zhou, Mingxing; Ren, Luquan; Fu, Lu

    2018-03-01

    The phenomenon that water in bone has important influences on mechanical properties of cortical bone has been known. However, the detail of the influence mechanism is not clear, especially in the component hierarchy. The main objective of this paper is to investigate the mechanical properties of deproteinization bone and cortical bone with different water content by nanoindentation experiments. The deproteinization bone is cortical bone removed organic component, and demineralization bone is cortical bone removed inorganic component. The experiments results showed that the elastic modulus and hardness all increased with the decreasing of water content in both cortical bone and deproteinization bone. However, variations of deproteinization bone were more significant than the normal one. Without organic component, the shape and size of inorganic component (hydroxyapatite particles) turned to irregular. The plastic energy of both cortical bone and deproteinization bone all decreased with the decreasing of water content and the variations range of deproteinization bone was wider than cortical bone. This research may give some deeply understanding for the studies of influence of water on mechanical properties of cortical bone.

  13. Implants in reconstructed bone: a comparative study on the outcome of Straumann® tissue level and bone level implants placed in vertically deficient alveolar ridges treated by means of autogenous onlay bone grafts.

    Science.gov (United States)

    Chiapasco, Matteo; Casentini, Paolo; Zaniboni, Marco

    2014-02-01

    To evaluate: (1) the survival rate of Straumann® Tissue Level and Bone Level implants placed in atrophic edentulous jaws previously reconstructed by means of autogenous onlay bone grafts; (2) to compare peri-implant bone resorption values over time. From 2005 to 2010, 50 patients presenting with vertical or tridimensional defects of the edentulous ridges were treated with autogenous bone grafts. Three to 7 months afterward, 192 implants were placed (Group A: 97 Tissue Level implants; Group B: 95 Bone Level implants) in the reconstructed areas. After a further waiting period of 2 to 3 months, patients were rehabilitated with implant-supported fixed prostheses. The follow-up ranged from 12 to 68 months after the start of prosthetic loading (mean: 33 months). No implants were removed (survival rate: 100%), but in Group B 13 implants (8 placed in iliac grafts, 2 placed in ramus grafts, and 3 placed in calvarial grafts) presented peri-implant bone resorption values higher than those proposed by Albrektsson and colleagues. for successful implants: the overall implant success rate was then 100% for Group A and 86.8% for Group B. No prosthetic failures were recorded, thus leading to a 100% prostheses success rate. No significant differences were found between the two types of implants as far as implant survival rate is concerned, but results from this study seem to demonstrate that Tissue Level implants may present better long-term results in terms of peri-implant bone maintenance, as compared with Bone Level implants, when placed in reconstructed areas. © 2012 Wiley Periodicals, Inc.

  14. Os acromiale open reduction and internal fixation: a review of iliac crest autogenous bone grafting and local bone grafting.

    Science.gov (United States)

    Atinga, Mordicai; Gregor, Reinhold; Selvaraj, Karthik M; Hong, Thin F

    2018-01-17

    Symptomatic os acromiale are fairly uncommon, and treatment has included fragment excision, decompression, and open reduction and internal fixation. Nonunion rates as high as 40% have been reported after fixation of os acromiale. This study assessed whether union of an os acromiale could be reliably achieved without the use of an iliac crest bone graft. This was a retrospective study of 32 consecutive shoulders that were treated with screw fixation and a local bone graft or iliac crest bone graft. The mean age was 50.3 years (range, 21-74 years), and the mean follow-up was 46.9 months (range, 12-120 months). Fusion was assessed clinically and radiologically. All 32 os acromiale were fused by 3 months on x-ray imaging. There were 18 shoulders in the iliac crest bone graft group and 14 in the local bone graft group. Rotator cuff repairs were performed concomitantly in 25 patients. Hardware was removed in 4 patients, a seroma was drained in 1 patient, and a superficial infection occurred in 1 patient. This is the largest study of os acromiale fixation using screws and a tension band to our knowledge. We report a 100% union rate using this technique, with 13% requiring hardware removal and the occurrence of 1 superficial infection. This study shows a local bone graft is as effective as iliac crest bone graft in achieving fusion. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  15. Autogenous femoral head as grafting material for mandibular augmentation

    NARCIS (Netherlands)

    Vos, M. D.; Raghoebar, G. M.; van der Wal, J. E.; Kalk, W. W. I.; Vissink, A.

    2009-01-01

    Bone grafting is commonly used for augmentation of the atrophic edentulous maxilla and mandible. Although bone substitutes and allogeneic frozen bone grafts have been applied successfully, fresh autogenous bone grafts remain the 'gold standard' in maxillofacial reconstructive surgery. A disadvantage

  16. Midline lumbar fusion using cortical bone trajectory screws. Preliminary report

    OpenAIRE

    Bielecki, Mateusz; Kunert, Przemys?aw; Prokopienko, Marek; Nowak, Arkadiusz; Czernicki, Tomasz; Marchel, Andrzej

    2016-01-01

    Introduction : Midline lumbar fusion (MIDLF) using cortical bone trajectory is an alternative method of transpedicular spinal fusion for degenerative disease. The new entry points’ location and screwdriving direction allow the approach-related morbidity to be reduced. Aim: To present our preliminary experience with the MIDLF technique on the first 5 patients with lumbar degenerative disease and with follow-up of at least 6 months. Material and methods: Retrospective analysis was...

  17. Noncontact ultrasound imaging applied to cortical bone phantoms

    OpenAIRE

    Bulman, J. B.; Ganezer, K. S.; Halcrow, P. W.; Neeson, Ian

    2012-01-01

    Purpose: The purpose of this paper was to take the first steps toward applying noncontact ultrasound (NCU) to the tasks of monitoring osteoporosis and quantitative ultrasound imaging (QUS) of cortical bone. The authors also focused on the advantages of NCU, such as its lack of reliance on a technologist to apply transducers and a layer of acoustical coupling gel, the ability of the transducers to operate autonomously as specified by preprogrammed software, and the likely reduction in statisti...

  18. Prevention of Bone Bridge Formation Using Transplantation of the Autogenous Mesenchymal Stem Cells to Physeal Defects: An Experimental Study in Rabbits

    Directory of Open Access Journals (Sweden)

    L. Plánka

    2007-01-01

    Full Text Available Physeal cartilage is known to have poor self-repair capacity after injury. Evaluation of the ability of cultured mesenchymal stem cells to repair damaged physis is the topic of current research. In 10 immature New Zealand white rabbits autogenous mesenchymal stem cells were transplanted into a iatrogenic physeal defect in a lateral portion of the distal growth plate of the right femur. The same defect without stem cells transplantation in the left femoral distal physis served as a control. In our study, we used our own technique of implantation of MSCs with a newly modified gel scaffold (New Composite Hyaluronate/Collagen Type I/Fibrin Scaffold. The rabbits were euthanized 4 months after transplantation. Bone length discrepancy and valgus deformity were measured from femoral radiographs. Healing of the defect was investigated histologically. The ability of mesenchymal stem cells to survive and promote cartilage healing in the physeal defect was assessed by immunofluorescence. Average difference in femur length measured from surgery to euthanasia (4 months was 0.61 ± 0.19 cm after preventive transplantation of MSCs in the right femur, but only 0.11 ± 0.07 cm in the left femur. Average angular (valgus deformity of the right femur with MSCs preventively transplanted to iatrogenically damaged distal femoral physis was 1.2 ± 0.72 °. Valgus deformity in the left femur was 5.4 ± 2.5 °. Prophylactic transplantation of autogenous mesenchymal stem cells to iatrogenically damaged distal growth plate of the rabbit femur prevented a bone bridge formation and resulted in healing of the physeal defect with hyaline cartilage. Immunofluorescence examination showed that the chondrocytes newly formed in growth zone are the result of implanted MSCs differentiation. Femur growth in traumatized physis was maintained even after transplantation of autogenous MSCs. As compared with the opposite femur (with physeal defect but without transplanted MSCs, the bone

  19. Reconstruction of mandibular defects using nonvascularized autogenous bone graft in Nigerians

    Directory of Open Access Journals (Sweden)

    Kizito Chioma Ndukwe

    2014-01-01

    Full Text Available Objectives: The aim of this study is to evaluate the success rate and complications of mandibular reconstruction with nonvascularized bone graft in Ile-Ife, Nigeria. Patients and Methods: A total of 25 patients who underwent reconstruction of mandibular discontinuity defects between January 2003 and February 2012, at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife constituted the study sample. Relevant information was retrieved from the patients′ records. This information include patients′ demographics (age and sex as well as the type of mandibular defect, cause of the defect, type of mandibular resection done, source of the bone graft used, and the method of graft immobilization. Morbidity associated with the graft procedures were assessed by retrieving information on graft failures, length of hospital stay following surgery, rehabilitation device used and associated graft donor and recipient site complications. Result: There were 12 males and 13 females with a male:female ratio was 1:1.1. The age of the patients ranged from 13 to 73 years with a mean age for males 32.7 ± standard deviation (SD 12.9 and for females 35.0 ± SD 17.1. Jaw defect was caused by resection for tumours and other jaw pathologies in 92% of cases. Complete symphyseal involvement defect was the most common defect recorded 11 (44%. Reconstruction with nonvascularized rib graft accounted for 68% of cases while iliac crest graft was used in 32% of the patients. Successful take of the grafts was recorded in 22 patients while three cases failed. Wound dehiscence (two patients and postoperative wound infection (eight patients were the most common complications recorded. Conclusion: The use of nonvascularized graft is still relevant in the reconstruction of large mandibular defects caused by surgical ablation of benign conditions in Nigerians. Precise surgical planning and execution, extended antibiotic therapy, and meticulous postoperative care

  20. Automatic Detection of Cortical Bones Haversian Osteonal Boundaries

    Directory of Open Access Journals (Sweden)

    Ilige Hage

    2015-10-01

    Full Text Available This work aims to automatically detect cement lines in decalcified cortical bone sections stained with H&E. Employed is a methodology developed previously by the authors and proven to successfully count and disambiguate the micro-architectural features (namely Haversian canals, canaliculi, and osteocyte lacunae present in the secondary osteons/Haversian system (osteon of cortical bone. This methodology combines methods typically considered separately, namely pulse coupled neural networks (PCNN, particle swarm optimization (PSO, and adaptive threshold (AT. In lieu of human bone, slides (at 20× magnification from bovid cortical bone are used in this study as proxy of human bone. Having been characterized, features with same orientation are used to detect the cement line viewed as the next coaxial layer adjacent to the outermost lamella of the osteon. Employed for this purpose are three attributes for each and every micro-sized feature identified in the osteon lamellar system: (1 orientation, (2 size (ellipse perimeter and (3 Euler number (a topological measure. From a training image, automated parameters for the PCNN network are obtained by forming fitness functions extracted from these attributes. It is found that a 3-way combination of these features attributes yields good representations of the overall osteon boundary (cement line. Near-unity values of classical metrics of quality (precision, sensitivity, specificity, accuracy, and dice suggest that the segments obtained automatically by the optimized artificial intelligent methodology are of high fidelity as compared with manual tracing. For bench marking, cement lines segmented by k-means did not fare as well. An analysis based on the modified Hausdorff distance (MHD of the segmented cement lines also testified to the quality of the detected cement lines vis-a-vis the k-means method.

  1. Repair of microdamage in osteonal cortical bone adjacent to bone screw.

    Directory of Open Access Journals (Sweden)

    Lei Wang

    Full Text Available Up to date, little is known about the repair mode of microdamage in osteonal cortical bone resulting from bone screw implantation. In this study, self-tapping titanium cortical bone screws were inserted into the tibial diaphyses of 24 adult male rabbits. The animals were sacrificed at 1 day, 2 weeks, 1 month and 2 months after surgery. Histomorphometric measurement and confocal microscopy were performed on basic fuchsin stained bone sections to examine the morphological characteristics of microdamage, bone resorption activity and spatial relationship between microdamage and bone resorption. Diffuse and linear cracks were coexisted in peri-screw bone. Intracortical bone resorption was significantly increased 2 weeks after screw installation and reach to the maximum at 1 month. There was no significant difference in bone resorption between 1-month and 2-months groups. Microdamage was significantly decreased within 1 month after surgery. Bone resorption was predisposed to occur in the region of <100 µm from the bone-screw interface, where had extensive diffuse damage mixed with linear cracks. Different patterns of resorption cavities appeared in peri-screw bone. These data suggest that 1 the complex microdamage composed of diffuse damage and linear cracks is a strong stimulator for initiating targeted bone remodeling; 2 bone resorption activities taking place on the surfaces of differently oriented Haversian and Volkmann canals work in a team for the repair of extensive microdamage; 3 targeted bone remodeling is a short-term reaction to microdamage and thereby it may not be able to remove all microdamage resulting from bone screw insertion.

  2. Comparative analysis of guided bone regeneration using autogenous tooth bone graft material with and without resorbable membrane

    Directory of Open Access Journals (Sweden)

    Ji-Young Lee

    2013-09-01

    Conclusion: Both groups showed clinically acceptable bone regeneration without any eventful complications. Within the limitation of this study, we can carefully conclude that the use of resorbable membrane is not a critical factor in GBR when using AutoBT.

  3. Reconstruction of orbital floor blow-out fractures with autogenous iliac crest bone: a retrospective study including maxillofacial and ophthalmology perspectives.

    Science.gov (United States)

    O'Connell, John Edward; Hartnett, Claire; Hickey-Dwyer, Marie; Kearns, Gerard J

    2015-03-01

    This is a 10-year retrospective study of patients with an isolated unilateral orbital floor fracture reconstructed with an autogenous iliac crest bone graft. The following inclusion criteria applied: isolated orbital floor fracture without involvement of the orbital rim or other craniofacial injuries, pre-/post-operative ophthalmological/orthoptic follow-up, pre-operative CT. Variables recorded were patient age and gender, aetiology of injury, time to surgery, follow-up period, surgical morbidity, diplopia pre- and post-operatively (Hess test), eyelid position, visual acuity, and the presence of en-/or exophthalmos (Hertel exophthalmometer). Twenty patients met the inclusion criteria. The mean age was 29 years. The mean follow up period was 26 months. No patient experienced significant donor site morbidity. There were no episodes of post-operative infection or graft extrusion. Three patients had diplopia in extremes of vision post-operatively, but no interference with activities of daily living. One patient had post-operative enophthalmos. Isolated orbital blow-out fractures may be safely and predictably reconstructed using autogenous iliac crest bone. The rate of complications in the group of patients studied was low. The value of pre- and post-operative ophthalmology consultation cannot be underestimated, and should be considered the standard of care in all patients with orbitozygomatic fractures, in particular those with blow-out fractures. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. Comparative study between cortical bone graft versus bone dust for reconstruction of cranial burr holes

    OpenAIRE

    Worm, Paulo Valdeci; Ferreira, Nelson Pires; Faria, Mário de Barros; Ferreira, Marcelo Paglioli; Kraemer, Jorge Luiz; Collares, Marcus Vinicius Martins

    2010-01-01

    Background: As a consequence of the progressive evolution of neurosurgical techniques, there has been increasing concern with the esthetic aspects of burr holes. Therefore, the objective of this study was to compare the use of cortical bone graft and bone dust for correcting cranial deformities caused by neurosurgical trephines. Methods: Twenty-three patients were enrolled for cranial burr hole reconstruction with a 1-year follow-up. A total of 108 burr holes were treated; 36 burr holes were ...

  5. Bone Density and Cortical Thickness in Normal, Osteopenic, and Osteoporotic Sacra

    Directory of Open Access Journals (Sweden)

    Andrew M. Richards

    2010-01-01

    Full Text Available It is unclear if a decrease in cancellous bone density or cortical bone thickness is related to sacral insufficiency fractures. We hypothesized that reduction in overall bone density leads to local reductions in bone density and cortical thickness in cadaveric sacra that match clinically observed fracture patterns in patients with sacral insufficiency fractures. We used quantitative computed tomography to measure cancellous density and cortical thickness in multiple areas of normal, osteopenic, and osteoporotic sacra. Cancellous bone density was significantly lower in osteoporotic specimens in the central and anterior regions of the sacral ala compared with other regions of these specimens. Cortical thickness decreased uniformly in all regions of osteopenic and osteoporotic specimens. These results support our hypothesis that areas of the sacrum where sacral insufficiency fractures often occur have significantly larger decreases in cancellous bone density; however, they do not support the hypothesis that these areas have local reduction of cortical bone thickness.

  6. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl C; Overgaard, Søren

    2010-01-01

    The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone – Validation of large animal model for tissue engineering and biomaterial research Ming Ding,1* Carl Christian Danielsen,2 Søren Overgaard1 1Orthopaedic Research Laboratory...... by glucocorticoid treatment and the changes in properties of cancellous bone were comparable with those observed in humans after long-term glucocorticoid treatment. However, the influence on cortical bone has not been thoroughly elucidated. This study aimed to investigate the influence of glucocorticoid on sheep...... cortical bone after long-term treatment. Specifically, we quantify the microarchitecture, mechanical properties, collagen and mineral quality of sheep cortical bone. We hypothesized that glucocorticoid treatment also had significant influences on cortical bone that might increase risk of fracture...

  7. Pharmacokinetics of Cefuroxime in Cortical and Cancellous Bone Obtained by Microdialysis - a Porcine Study

    DEFF Research Database (Denmark)

    Tøttrup, Mikkel; Forsingdal Hardlei, Tore; Bendtsen, Michael

    2014-01-01

    (MD) technique for measurement of cefuroxime in bone, and to obtain pharmacokinetic profiles for the same drug in porcine cortical and cancellous bone. Measurements were conducted in bone-wax sealed and unsealed drill holes in cortical bone, in drill holes in cancellous bone and in subcutaneous tissue......-time curves (AUC) from 0 to 5 hours were 6013±1339, 3222±1086, 2232±635 and 952±290 min μg/mL for free plasma, subcutaneous tissue, cancellous and cortical bone, respectively (ANOVA P bone was also significantly different from that of cancellous bone (P = 0.04). The heterogeneous......Traditionally, the pharmacokinetics of antimicrobials in bone have been investigated using bone biopsies, but this approach suffers from considerable methodological limitations. Consequently, new methods are needed. The objectives of this study were to assess the feasibility of the microdialysis...

  8. Noncontact ultrasound imaging applied to cortical bone phantoms.

    Science.gov (United States)

    Bulman, J B; Ganezer, K S; Halcrow, P W; Neeson, Ian

    2012-06-01

    The purpose of this paper was to take the first steps toward applying noncontact ultrasound (NCU) to the tasks of monitoring osteoporosis and quantitative ultrasound imaging (QUS) of cortical bone. The authors also focused on the advantages of NCU, such as its lack of reliance on a technologist to apply transducers and a layer of acoustical coupling gel, the ability of the transducers to operate autonomously as specified by preprogrammed software, and the likely reduction in statistical and systematic errors associated with the variability in the pressure applied by the clinician to the transmitting transducer that NCU might provide. The authors also undertook this study in order to find additional applications of NCU beyond its past limited usage in assessing the severity of third degree burns. A noncontact ultrasound imaging system using a pair of specially designed broadband, 1.5 MHz noncontact piezoelectric transducers and cortical bone phantoms, were used to determine bone mineral density (BMD), speed of sound (SOS), integrated response (IR), and ultrasonic transmittance. Air gaps of greater than 3 cm, two transmission and two reflection paths, and a digital signal processor were also used in the collection of data from phantoms of nominal mass densities that varied from 1.17 to 2.25 g/cm(3) and in bone mineral density from 0 to 1.7 g/cm(3). Good correlations between known BMD and measured SOS, IR, and transmittance were obtained for all 17 phantoms, and methods for quantifying and minimizing sources of systematic errors were outlined. The BMD of the phantom sets extended through most of the in vivo range found in cortical bone. A total of 16-20 repeated measurements of the SOS, thickness, and IR for the phantom set that were conducted over a period of several months showed a small variation in the range of measurements of ±1%-2%. These NCU data were shown to be in agreement with similar results using contact ultrasound to be within 1%-2%. Transmittance

  9. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  10. Aging and Fracture of Human Cortical Bone and Tooth Dentin

    Energy Technology Data Exchange (ETDEWEB)

    Ager, Joel; Koester, Kurt J.; Ager III, Joel W.; Ritchie, Robert O.

    2008-05-07

    Mineralized tissues, such as bone and tooth dentin, serve as structural materials in the human body and, as such, have evolved to resist fracture. In assessing their quantitative fracture resistance or toughness, it is important to distinguish between intrinsic toughening mechanisms which function ahead of the crack tip, such as plasticity in metals, and extrinsic mechanisms which function primarily behind the tip, such as crack bridging in ceramics. Bone and dentin derive their resistance to fracture principally from extrinsic toughening mechanisms which have their origins in the hierarchical microstructure of these mineralized tissues. Experimentally, quantification of these toughening mechanisms requires a crack-growth resistance approach, which can be achieved by measuring the crack-driving force, e.g., the stress intensity, as a function of crack extension ("R-curve approach"). Here this methodology is used to study of the effect of aging on the fracture properties of human cortical bone and human dentin in order to discern the microstructural origins of toughness in these materials.

  11. Clinical application of autogenous partially demineralized dentin matrix prepared immediately after extraction for alveolar bone regeneration in implant dentistry: a pilot study.

    Science.gov (United States)

    Minamizato, T; Koga, T; I, Takashi; Nakatani, Y; Umebayashi, M; Sumita, Y; Ikeda, T; Asahina, I

    2018-01-01

    The aim of this study was to examine the efficacy and safety of autogenous partially demineralized dentin matrix (APDDM) prepared onsite, for clinical application in bone regeneration procedures related to implant dentistry, including socket preservation, alveolar ridge augmentation, and maxillary sinus floor augmentation. In this study, 16 patients underwent dental implant placement using APDDM transplantation. There were no systemic or local complications (including surgical site infection) in any of the cases, and oral rehabilitation using dental implants was successful in all cases for at least 2 years after attachment of the suprastructure. This report describes the clinical application of APDDM prepared immediately after tooth extraction to bone augmentation, taking advantage of the relatively short preparation time due to partial demineralization. APDDM, as introduced in this study, is an efficient, safe, and reasonable bone substitute. Consequently, this material has the potential to become one of the options as a bone substitute in implant dentistry. Copyright © 2017 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. A prospective controlled trial comparing xenograft/autogenous bone and collagen-stabilized xenograft for maxillary sinus augmentation-Complications, patient-reported outcomes and volumetric analysis.

    Science.gov (United States)

    Alayan, Jamil; Ivanovski, Saso

    2018-02-01

    Compare maxillary sinus augmentation (MSA) using two different materials-anorganic bovine bone mineral (ABBM) + autogenous bone (AB) (control group) vs. collagen-stabilized ABBM (test group) in terms of complications, patient-reported outcome measures (PROMs) and volumetric analysis. Sixty patients underwent sinus augmentation (30 control + 30 test group). Intra- and postoperative complications were recorded. PROMs measured the impact of grafting on daily activities, pain and morbidity. CT scans were used to measure graft volume, ridge height, material selection and degree of contact of graft-to-surrounding sinus walls. Dental implant placement parameters were also recorded. All complications were minor and did not prevent completion of the augmentation or subsequent implant placement. Schneiderian membrane perforation was the most frequently encountered complication. Both treatment groups reported moderate limitation in the 1st 48 hr post-surgery but little or none by day 3 or 4. Jaw opening, chewing and bruising were significantly higher in the control group. The impact on work and social life was moderate initially but reduced to little or none by the 2nd day. Mild to moderate pain and interference to daily activities were reported for the first 3 days requiring the use of NSAIDs only. A mean graft volume of 1.46 cm 3 (±0.77) was calculated in the control group and 1.27 cm 3 (±0.65) in the test group. Extent of contact between graft and surrounding sinus walls had a significant impact on bone volume. Shorter (8 mm) implants were utilized more frequently in the test group, which was also more likely to require additional vertical augmentation, but this was not statistically significant. MSA using a lateral wall approach is safe and associated with mild to moderate pain and restrictions to daily activities for 48-72 hr. Patients' reports of morbidity were greater with autogenous bone harvesting. Collagen-stabilized ABBM provides comparable bone volume to

  13. Effect of porosity, tissue density, and mechanical properties on radial sound speed in human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Eneh, C. T. M., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Töyräs, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Jurvelin, J. S., E-mail: jukka.jurvelin@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211, Finland and Diagnostic Imaging Center, Kuopio University Hospital, P.O. Box 100, Kuopio FI-70029 (Finland); Malo, M. K. H., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Liukkonen, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211 (Finland); Karjalainen, J. P., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Bone Index Finland Ltd., P.O. Box 1188, Kuopio FI-70211 (Finland)

    2016-05-15

    Purpose: The purpose of this study was to investigate the effect of simultaneous changes in cortical porosity, tissue mineral density, and elastic properties on radial speed of sound (SOS) in cortical bone. The authors applied quantitative pulse-echo (PE) ultrasound techniques that hold much potential especially for screening of osteoporosis at primary healthcare facilities. Currently, most PE measurements of cortical thickness, a well-known indicator of fracture risk, use a predefined estimate for SOS in bone to calculate thickness. Due to variation of cortical bone porosity, the use of a constant SOS value propagates to an unknown error in cortical thickness assessment by PE ultrasound. Methods: The authors conducted 2.25 and 5.00 MHz focused PE ultrasound time of flight measurements on femoral diaphyses of 18 cadavers in vitro. Cortical porosities of the samples were determined using microcomputed tomography and related to SOS in the samples. Additionally, the effect of cortical bone porosity and mechanical properties of the calcified matrix on SOS was investigated using numerical finite difference time domain simulations. Results: Both experimental measurements and simulations demonstrated significant negative correlation between radial SOS and cortical porosity (R{sup 2} ≥ 0.493, p < 0.01 and R{sup 2} ≥ 0.989, p < 0.01, respectively). When a constant SOS was assumed for cortical bone, the error due to variation of cortical bone porosity (4.9%–16.4%) was about 6% in the cortical thickness assessment in vitro. Conclusions: Use of a predefined, constant value for radial SOS in cortical bone, i.e., neglecting the effect of measured variation in cortical porosity, propagated to an error of 6% in cortical thickness. This error can be critical as characteristic cortical thinning of 1.10% ± 1.06% per yr decreases bending strength of the distal radius and results in increased fragility in postmenopausal women. Provided that the cortical porosity can be estimated

  14. Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men.

    Science.gov (United States)

    Jepsen, Karl J; Bigelow, Erin M R; Schlecht, Stephen H

    2015-08-01

    The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear. We asked (1) do black women build bones with reduced cortical area compared with black men; (2) do white women build bones with reduced cortical area compared with white men; and (3) do female mice build bones with reduced cortical area compared with male mice? Bone strength and cross-sectional morphology of adult human and mouse bone were calculated from quantitative CT images of the femoral midshaft. The data were tested for normality and regression analyses were used to test for differences in cortical area between men and women after adjusting for body size and bone size by general linear model (GLM). Linear regression analysis showed that the femurs of black women had 11% lower cortical area compared with those of black men after adjusting for body size and bone size (women: mean=357.7 mm2; 95% confidence interval [CI], 347.9-367.5 mm2; men: mean=400.1 mm2; 95% CI, 391.5-408.7 mm2; effect size=1.2; pbone size (women: mean=350.1 mm2; 95% CI, 340.4-359.8 mm2; men: mean=394.3 mm2; 95% CI, 386.5-402.1 mm2; effect size=1.3; pbone size (female: mean=0.73 mm2; 95% CI, 0.71-0.74 mm2; male: mean=0.70 mm2; 95% CI, 0.68-0.71 mm2; effect size=0.74; p=0.04, GLM). Female femurs are not simply a more slender version of male

  15. Fatigue crack growth behavior in equine cortical bone

    Science.gov (United States)

    Shelton, Debbie Renee

    2001-07-01

    Objectives for this research were to experimentally determine crack growth rates, da/dN, as a function of alternating stress intensity factor, DeltaK, for specimens from lateral and dorsal regions of equine third metacarpal cortical bone tissue, and to determine if the results were described by the Paris law. In one set of experiments, specimens were oriented for crack propagation in the circumferential direction with the crack plane transverse to the long axis of the bone. In the second set of experiments, specimens were oriented for radial crack growth with the crack plane parallel to the long axis of the bone. Results of fatigue tests from the latter specimens were used to evaluate the hypothesis that crack growth rates differ regionally. The final experiments were designed to determine if crack resistance was dependent on region, proportion of hooped osteons (those with circumferentially oriented collagen fibers in the outer lamellae) or number of osteons penetrated by the crack, and to address the hypothesis that hooped osteons resist invasion by cracks better than other osteonal types. The transverse crack growth data for dorsal specimens were described by the Paris law with an exponent of 10.4 and suggested a threshold stress intensity factor, DeltaKth, of 2.0 MPa·m1/2 and fracture toughness of 4.38 MPa·m 1/2. Similar results were not obtained for lateral specimens because the crack always deviated from the intended path and ran parallel to the loading direction. Crack growth for the dorsal and lateral specimens in the radial orientation was described by the Paris law with exponents of 8.7 and 10.2, respectively, and there were no regional differences in the apparent DeltaK th (0.5 MPa·m1/2) or fracture toughness (1.2 MPa·m 1/2). Crack resistance was not associated with cortical region, proportion of hooped osteons or the number of osteons penetrated by the crack. The extent to which cracks penetrate osteons was influenced by whether the collagen fiber

  16. Comparative cortical bone thickness between the long bones of humans and five common non-human mammal taxa.

    Science.gov (United States)

    Croker, Sarah L; Reed, Warren; Donlon, Denise

    2016-03-01

    The task of identifying fragments of long bone shafts as human or non-human is difficult but necessary, for both forensic and archaeological cases, and a fast simple method is particularly useful. Previous literature suggests there may be differences in the thickness of the cortical bone between these two groups, but this has not been tested thoroughly. The aim of this study was not only to test this suggestion, but also to provide data that could be of practical assistance for future comparisons. The major limb bones (humerus, radius, femur and tibia) of 50 Caucasoid adult skeletons of known age and sex were radiographed, along with corresponding skeletal elements from sheep, pigs, cattle, large dogs and kangaroos. Measurements were taken from the radiographs at five points along the bone shaft, of shaft diameter, cortical bone thickness, and a cortical thickness index (sum of cortices divided by shaft diameter) in both anteroposterior and mediolateral orientations. Each variable for actual cortical bone thickness as well as cortical thickness indices were compared between the human group (split by sex) and each of the non-human groups in turn, using Student's t-tests. Results showed that while significant differences did exist between the human groups and many of the non-human groups, these were not all in the same direction. That is, some variables in the human groups were significantly greater than, and others were significantly less than, the corresponding variable in the non-human groups, depending on the particular non-human group, sex of the human group, or variable under comparison. This was the case for measurements of both actual cortical bone thickness and cortical thickness index. Therefore, for bone shaft fragments for which the skeletal element is unknown, the overlap in cortical bone thickness between different areas of different bones is too great to allow identification using this method alone. However, by providing extensive cortical bone

  17. Precision of pQCT-measured total, trabecular and cortical bone area, content, density and estimated bone strength in children.

    Science.gov (United States)

    Duff, W R D; Björkman, K M; Kawalilak, C E; Kehrig, A M; Wiebe, S; Kontulainen, S

    2017-06-01

    To define pQCT precision errors, least-significant-changes, and identify associated factors for bone outcomes at the radius and tibia in children. We obtained duplicate radius and tibia pQCT scans from 35 children (8-14yrs). We report root-mean-squared coefficient of variation (CV% RMS ) and 95% limits-of-agreement to characterize repeatability across scan quality and least-significant-changes for bone outcomes at distal (total and trabecular area, content and density; and compressive bone strength) and shaft sites (total area and content; cortical area content, density and thickness; and torsional bone strength). We used Spearman's rho to identify associations between CV% and time between measurements, child's age or anthropometrics. After excluding unanalyzable scans (6-10% of scans per bone site), CV% RMS ranged from 4% (total density) to 19% (trabecular content) at the distal radius, 4% (cortical content) to 8% (cortical thickness) at the radius shaft, 2% (total density) to 14% (trabecular content) at the distal tibia and from 2% (cortical content) to 6% (bone strength) at the tibia shaft. Precision errors were within 95% limits-of-agreement across scan quality. Age was associated (rho -0.4 to -0.5, p⟨0.05) with CV% at the tibia. Bone density outcomes and cortical bone properties appeared most precise (CV% RMS ⟨5%) in children.

  18. Usefulness of Sweep Imaging With Fourier Transform for Evaluation of Cortical Bone in Diabetic Rats.

    Science.gov (United States)

    Minami, Masataka; Ikoma, Kazuya; Horii, Motoyuki; Sukenari, Tsuyoshi; Onishi, Okihiro; Fujiwara, Hiroyoshi; Ogi, Hiroshi; Itoh, Kyoko; Kubo, Toshikazu

    2018-01-23

    Diabetes decreases bone strength, possibly because of cortical bone changes. Sweep imaging with Fourier transform (SWIFT) has been reported to be useful for cortical bone evaluation. To evaluate cortical bone changes in diabetic rats using SWIFT, assess the usefulness of this technique through comparisons with microcomputed tomography (μCT) and conventional MRI, and clarify the mechanism underlying cortical bone changes using histomorphometry STUDY TYPE: Animal cohort. 8-week-old male Wistar/ST rats (N = 36) were divided into diabetes (induced by streptozotocin injection) and control groups. 7.04T MRI, SWIFT. Six animals from each group were sacrificed at 2, 4, and 8 weeks after injection. Tibial bones were extracted and evaluated using μCT and MRI. The cortical bone mineral density (BMD) was measured using μCT. Proton density-weighted imaging (PDWI) and SWIFT were also performed. The signal-to-noise ratio (SNR) was calculated for each acquisition. The bone formation rate was evaluated using histomorphometry. Findings at each timepoint were compared using Mann-Whitney U-tests. Cortical BMD was significantly lower in the diabetes group than in the control group only at 8 weeks (P < 0.05). At all timepoints, PDWI-SNR showed no significant differences between groups (P = 0.59, 0.70, and 0.82 at 2, 4, and 8 weeks, respectively). SWIFT-SNR was significantly lower in the diabetes group than in the control group (P < 0.05 at 2 and 4 weeks and P < 0.01 at 8 weeks), and the bone formation rate was significantly lower in the diabetes group than in the control group (P < 0.01 for all). SWIFT can detect cortical bone changes even before a decline in the cortical BMD in a diabetic model. 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018. © 2018 International Society for Magnetic Resonance in Medicine.

  19. Age- and menopause-related bone loss compromise cortical and trabecular microstructure.

    Science.gov (United States)

    Seeman, Ego

    2013-10-01

    All factors influencing the material composition and structure of bone do so through the final common cellular pathways of modeling and remodeling. During growth, modeling, the formation of new bone in different locations without prior bone resorption, deposits matrix upon the periosteum, enlarging the cross-sectional area of bone. Concurrently, endocortical resorption excavates the medullary canal while remodeling, the resorption and deposition of bone in the same location, assembles cortical osteons, each with their central Haversian canal. The Haversian canals and the connecting Volkmann canals form an intracortical canal network that occupies 30% of the total cortical volume. The remaining 70% is mineralized bone matrix volume. Around midlife, in women, remodeling balance becomes negative; less bone is deposited than it is resorbed by each bone's basic multicellular units (BMUs), and remodeling rate increases; there are more BMUs removing bone upon its intracortical, endocortical, and trabecular surfaces. Canals enlarge and coalesce creating giant pores. Remodeling upon trabeculae removes them, whereas intracortical and endocortical remodeling cavitates and fragments the cortex. Bone loss becomes almost entirely cortical as trabeculae disappear. Remodeling removes more bone from a diminishing total mineralized bone matrix volume so that by old age, total mineralized bone matrix volume is halved; 70% of all bone loss is cortical because 80% of the skeleton is cortical; 30% of the bone loss arises from the 20% of the skeleton that is trabecular. Of all fractures occurring, 80% are nonvertebral and 20% are vertebral. The notion of osteoporosis as a disease of trabecular bone loss and vertebral fractures needs to be revised.

  20. Computed tomography evaluation of autogenous graft in sinus lift surgery

    International Nuclear Information System (INIS)

    Ajzen, Sergio Aron; Moscatiello, Rafael Andrade; Lima, Aida Maria Custodio de; Moscatiello, Vitoria Aparecida Muglia; Helio Kiitiro Yamashita; Mosacatiello, Rafael Muglia; Nishiguchi, Celso Itiro; Alves, Maria Teresa de Seixas

    2001-01-01

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  1. The Hounsfield value for cortical bone geometry in the proximal humerus - an in vitro study

    International Nuclear Information System (INIS)

    Lim Fat, Daren; Kennedy, Jim; Galvin, Rose; O'Brien, Fergal; Mc Grath, Frank; Mullett, Hannan

    2012-01-01

    Fractures of the proximal humerus represent a major osteoporotic burden. Recent developments in CT imaging have emphasized the importance of cortical bone thickness distribution in the prevention and management of fragility fractures. We aimed to experimentally define the CT density of cortical bone in the proximal humerus for building cortical geometry maps. With ethical approval, we used ten fresh-frozen human proximal humeri. These were stripped of all soft tissue and high-resolution CT images were then taken. The humeral heads were then subsequently resected to allow access to the metaphyseal area. Using curettes, cancellous bone was removed down to hard cortical bone. Another set of CT images of the reamed specimen was then taken. Using CT imaging software and a CAD interface, we then compared cortical contours at different CT density thresholds to the reference inner cortical contour of our reamed specimens. Working with 3D model representations of these cortical maps, we were able to accurately make distance comparison analyses based on different CT thresholds. We could compute a single closest value at 700 HU. No difference was found in the HU-based contours generated along the 500-900 HU pixels (p = 1.000). The contours were significantly different from those generated at 300, 400, 1,000, and 1,100 HU. A Hounsfield range of 500-900 HU can accurately depict cortical bone geometry in the proximal humerus. Thresholding outside this range leads to statistically significant inaccuracies. Our results concur with a similar range reported in the literature for the proximal femur. Knowledge of regional variations in cortical bone thickness has direct implications for basic science studies on osteoporosis and its treatment, but is also important for the orthopedic surgeon since our decision for treatment options is often guided by local bone quality. (orig.)

  2. The Hounsfield value for cortical bone geometry in the proximal humerus - an in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Lim Fat, Daren; Kennedy, Jim; Galvin, Rose; O' Brien, Fergal; Mc Grath, Frank; Mullett, Hannan [Royal College of Surgeons in Ireland, Investigations Carried Out at Anatomy Lab, Dublin (Ireland)

    2012-05-15

    Fractures of the proximal humerus represent a major osteoporotic burden. Recent developments in CT imaging have emphasized the importance of cortical bone thickness distribution in the prevention and management of fragility fractures. We aimed to experimentally define the CT density of cortical bone in the proximal humerus for building cortical geometry maps. With ethical approval, we used ten fresh-frozen human proximal humeri. These were stripped of all soft tissue and high-resolution CT images were then taken. The humeral heads were then subsequently resected to allow access to the metaphyseal area. Using curettes, cancellous bone was removed down to hard cortical bone. Another set of CT images of the reamed specimen was then taken. Using CT imaging software and a CAD interface, we then compared cortical contours at different CT density thresholds to the reference inner cortical contour of our reamed specimens. Working with 3D model representations of these cortical maps, we were able to accurately make distance comparison analyses based on different CT thresholds. We could compute a single closest value at 700 HU. No difference was found in the HU-based contours generated along the 500-900 HU pixels (p = 1.000). The contours were significantly different from those generated at 300, 400, 1,000, and 1,100 HU. A Hounsfield range of 500-900 HU can accurately depict cortical bone geometry in the proximal humerus. Thresholding outside this range leads to statistically significant inaccuracies. Our results concur with a similar range reported in the literature for the proximal femur. Knowledge of regional variations in cortical bone thickness has direct implications for basic science studies on osteoporosis and its treatment, but is also important for the orthopedic surgeon since our decision for treatment options is often guided by local bone quality. (orig.)

  3. Propagation of a dorsal cortical fracture of the third metacarpal bone in two horses

    International Nuclear Information System (INIS)

    Spurlock, G.H.

    1988-01-01

    Seemingly, propagation of a dorsal cortical fracture in the third metacarpal bone developed after continued race performance in 2 horses. Historically, both horses had intermittent lameness that had responded to nonsteroidal anti-inflammatory drugs and brief rest periods. However, lameness in both horses had increased in severity. Radiography revealed a dorsal cortical fracture of the third metacarpal bone, with propagation of the fracture plane proximally. Fractures were incomplete and healed with stall rest in both horses

  4. Site-specific variability in trabecular bone dosimetry: Considerations of energy loss to cortical bone

    International Nuclear Information System (INIS)

    Patton, P.W.; Rajon, D.A.; Shah, A.P.; Jokisch, D.W.; Inglis, B.A.; Bolch, W.E.

    2002-01-01

    With continual advances in radionuclide therapies, increasing emphasis is being placed on improving the patient specificity of dose estimates to marrow tissues. While much work has been focused on determining patient-specific assessments of radionuclide uptake in the skeleton, few studies have been initiated to explore the individual variability of absorbed fraction data for electron and beta-particle sources in various skeletal sites. The most recent values of radionuclide S values used in clinical medicine continue to utilize a formalism in which electrons are transported under a trabecular bone geometry of infinite extent. No provisions are thus made for the fraction of energy lost to the cortical bone cortex of the skeletal site and its surrounding tissues. In the present study, NMR microscopy was performed on trabecular bone samples taken from the femoral head and humeral proximal epiphysis of three subjects: a 51-year male, an 82-year female, and an 86-year female. Following image segmentation and coupling to EGS4, electrons were transported within macrostructural models of the various skeletal sites that explicitly include the spatial extent of the spongiosa, as well as the thickness of the surrounding cortical bone. These energy-dependent profiles of absorbed fractions to marrow tissues were then compared to transport simulations made within an infinite region of spongiosa. Ratios of mean absorbed fraction, as weighted by the beta energy spectra, under both transport methodologies were then assembled for the radionuclides 32 P and 90 Y. These ratios indicate that corrections to existing radionuclide S values for 32 P can vary by as much as 5% for the male, 6% for the 82-year female, and 8% for the 86-year female. For the higher-energy beta spectrum of 90 Y, these same corrections can reach 8%, 10%, and 11%, respectively

  5. Successful use of autogenous bone graft for the treatment of a radius-ulna nonunion in an amputee dog

    Directory of Open Access Journals (Sweden)

    B.W. Minto

    2015-08-01

    Full Text Available Fracture nonunions represent important complications in orthopedic surgeries. Nonunion repairs or bone defects are surgically challenging. Our aim was to describe a nonunion case, which was repaired with rapid bone recovery. An 8-month-old male mixed breed dog that has been previously operated was presented to the Veterinary Medical Teaching Hospital of São Paulo State University, with a right radius-ulna nonunion and an amputated contralateral forelimb. A cancellous bone graft was collected from a partially amputated limb, in order to correct the nonunion, and used in association with a locking plate. After four weeks, the bone graft had been incorporated into the original bone. Clinical union with good weight bearing was achieved after eight weeks.

  6. An Experimental Study of Radiographic Density of Alveolar Bone and Cortical Thickness of Mandible by Osteoporosis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Byeong Do [Dept. of Oral and Maxillofacial Radiology, School of Dentistry, Wonkwang University, Iksan (Korea, Republic of)

    2000-12-15

    To evaluate the effect of the systemic osteoporosis on radiographic density of alveolar bone and cortical thickness of mandible. The bone mineral density values of lumbar and femur were measured by dual-energy X-ray absorptiometry and T scores of lumbar, femur were obtained respectively. Radiographic densities of alveolar bones and panorama mandibular index (PMI, represents as cortical thickness) were analysed statistically according to age and T score variavles. The radiographic density of alveolar bone of maxillary molar showed significant difference by age and femur T group. That of mandibular molar showed significant difference between femur T group. Panorama mandibular index showed significant difference between age groups. The radiographic density of alvealar bones was more dependent on age femur T than lumbar T. Cortical thickness of mandible was correlated with increasing age.

  7. Midline lumbar fusion using cortical bone trajectory screws. Preliminary report.

    Science.gov (United States)

    Bielecki, Mateusz; Kunert, Przemysław; Prokopienko, Marek; Nowak, Arkadiusz; Czernicki, Tomasz; Marchel, Andrzej

    2016-01-01

    Midline lumbar fusion (MIDLF) using cortical bone trajectory is an alternative method of transpedicular spinal fusion for degenerative disease. The new entry points' location and screwdriving direction allow the approach-related morbidity to be reduced. To present our preliminary experience with the MIDLF technique on the first 5 patients with lumbar degenerative disease and with follow-up of at least 6 months. Retrospective analysis was performed on the first 5 patients with foraminal (4) or central (1) stenosis operated on between December 2014 and February 2015. Three patients were fused at L4-L5 and two at the L5-S1 level. No intra- or post-operative complications occurred with this approach. An improvement regarding the leading symptom in the early postoperative period (sciatica 4/4, claudication 1/1) was achieved in all patients. The mean improvements in the visual analogue scale for low back and leg pain were 2.2 and 4.8 respectively. The mean Oswestry Disability Index scores were 52% (range: 16-82%) before surgery and 33% (range: 12-56%) at 3-month follow-up (mean improvement 19%). At the most recent follow-up, 4 patients reported the maintenance of the satisfactory result. The early standing and follow-up X-rays showed satisfactory screw placement in all patients. In our initial experience, the MIDLF technique seems to be an encouraging alternative to traditional transpedicular trajectory screws when short level lumbar fusion is needed. Nevertheless, longer observations on larger groups of patients are needed to reliably evaluate the safety of the method and the sustainability of the results.

  8. Midline lumbar fusion using cortical bone trajectory screws. Preliminary report

    Directory of Open Access Journals (Sweden)

    Mateusz Bielecki

    2016-09-01

    Full Text Available Introduction : Midline lumbar fusion (MIDLF using cortical bone trajectory is an alternative method of transpedicular spinal fusion for degenerative disease. The new entry points’ location and screwdriving direction allow the approach-related morbidity to be reduced. Aim: To present our preliminary experience with the MIDLF technique on the first 5 patients with lumbar degenerative disease and with follow-up of at least 6 months. Material and methods: Retrospective analysis was performed on the first 5 patients with foraminal (4 or central (1 stenosis operated on between December 2014 and February 2015. Three patients were fused at L4–L5 and two at the L5–S1 level. Results: No intra- or post-operative complications occurred with this approach. An improvement regarding the leading symptom in the early postoperative period (sciatica 4/4, claudication 1/1 was achieved in all patients. The mean improvements in the visual analogue scale for low back and leg pain were 2.2 and 4.8 respectively. The mean Oswestry Disability Index scores were 52% (range: 16–82% before surgery and 33% (range: 12–56% at 3-month follow-up (mean improvement 19%. At the most recent follow-up, 4 patients reported the maintenance of the satisfactory result. The early standing and follow-up X-rays showed satisfactory screw placement in all patients. Conclusions : In our initial experience, the MIDLF technique seems to be an encouraging alternative to traditional transpedicular trajectory screws when short level lumbar fusion is needed. Nevertheless, longer observations on larger groups of patients are needed to reliably evaluate the safety of the method and the sustainability of the results.

  9. Effect of unreamed, limited reamed, and standard reamed intramedullary nailing on cortical bone porosity and new bone formation.

    Science.gov (United States)

    Hupel, T M; Weinberg, J A; Aksenov, S A; Schemitsch, E H

    2001-01-01

    To compare the effects of unreamed nail insertion and reamed nail insertion with limited and standard canal reaming on cortical bone porosity and new bone formation. A canine segmental tibial fracture was created in fifteen adult dogs. The tibiae were stabilized with a statically locked 6.5-millimeter intramedullary nail without prior canal reaming (n = 5), after limited reaming to 7.0 millimeters (n = 5), or after standard canal reaming to 9.0 millimeters (n = 5). Porosity, new bone formation, and the mineral apposition rate of cortical bone were directly compared between the three nailing techniques. A significant increase in cortical bone porosity and new bone formation was seen in all three groups of experimental animals compared with the control tibiae. The overall lowest porosity levels were measured in the limited reamed group, with similar porosity levels measured in the unreamed and standard reamed groups. Porosity was lower in the limited reamed group in the entire cortex of the segmental and distal cross sections, as well as the endosteal, anterior, and posterior cortices along the length of the tibia. Overall, there was no difference in the amount of new bone formation or the mineral apposition rate between the three groups of animals at eleven weeks after surgery. The results of this study suggest that limited intramedullary reaming is a biologically sound alternative for the treatment of tibial diaphyseal fractures in which the circulation is already compromised.

  10. A grape-enriched diet increases bone calcium retention and cortical bone properties in ovariectomized rats.

    Science.gov (United States)

    Hohman, Emily E; Weaver, Connie M

    2015-02-01

    Grapes and their associated phytochemicals have been investigated for beneficial effects on cardiovascular health, cancer prevention, and other chronic diseases, but the effect of grape consumption on bone health has not been fully determined. We previously found short-term benefits of grape products on reducing bone turnover in ovariectomized rats. The objective of this study was to determine the long-term benefits of a grape-enriched diet on bone in ovariectomized rats. Rats were ovariectomized at 3 mo of age and were administered a single dose of (45)Ca to prelabel bones at 4 mo of age. After a 1-mo equilibration period, baseline urinary (45)Ca excretion was determined. Rats (n = 22/group) were then randomly assigned to a modified AIN93M diet containing 25% freeze-dried grape powder or to a control diet for 8 wk. Urinary (45)Ca excretion was monitored throughout the study to determine changes in bone (45)Ca retention. Calcium balance was assessed after 1 and 8 wk of consuming the experimental diets, and a calcium kinetic study was performed at 8 wk. After 8 wk, femurs were collected for micro-computed tomographic imaging, 3-point bending, and reference point indentation. Rats fed the grape-enriched diet had 44% greater net bone calcium retention than did rats fed the control diet. There were no differences in calcium balance due to diet at either week 1 or week 8, but there was a significant increase in net calcium absorption (10.6%) and retention (5.7%) from week 1 to week 8 in the grape-enriched diet group only. Grape-enriched diet-fed rats had 3% greater cortical thickness and 11% greater breaking strength. There were no differences in femur bone mineral density, trabecular microarchitecture, or reference point indentation variables due to diet. This study of ovariectomized rats indicates that the consumption of grape products may improve calcium utilization and suppress bone turnover, resulting in improvements in bone quality. © 2015 American Society for

  11. Treatment of Atypical Ulnar Fractures Associated with Long-Term Bisphosphonate Therapy for Osteoporosis: Autogenous Bone Graft with Internal Fixation

    Directory of Open Access Journals (Sweden)

    Yohei Shimada

    2017-01-01

    Full Text Available Long-term bisphosphonate use has been suggested to result in decreased bone remodelling and an increased risk of atypical fractures. Fractures of this nature commonly occur in the femur, and relatively few reports exist to show that they occur in other bones. Among eight previous reports of atypical ulnar fractures associated with bisphosphonate use, one report described nonunion in a patient who was treated with cast immobilization and another described ulna nonunion in one of three patients, all of whom were treated surgically with a locking plate. The remaining two surgical patients achieved bone union uneventfully following resection of the osteosclerotic lesion and iliac bone grafting before rigid fixation. We hypothesized that the discontinuation of bisphosphonate therapy, the use of teriparatide treatment, and low-intensity pulsed ultrasound (LIPUS might have been associated with fracture healing.

  12. The relationship between age and the mandibular cortical bone thickness by using panoramic radiograph

    International Nuclear Information System (INIS)

    Kim, Yun Suk; Kim, Kyoung A; Koh, Kwang Joon

    2010-01-01

    This study was to determine the relationship between age and the mandibular cortical bone thickness on panoramic radiograph. Panoramic radiographs of 360 patients (180 men and 180 women) over 20 years old, who visited the Chonbuk National University Hospital from January to December in 2007, were assessed. The subjects were divided into 5 age groups. Five indices such as cortical bone thickness at the gonion (GI), antegonion (AI), and below the mental foramen (MI), the panoramic mandibular index (PMI), the mandibular cortical index (MCI) were measured on panoramic radiographs. All five indices including GI, AI, MI, PMI, and MCI showed significant differences between third decade and over 8 decade groups (p,0.05). PMI, MI and GI showed significant differences with gender statistically (p<0.05). The mandibular cortical bone thickness showed negative correlation with age, and the value of the thickness (PMI, MI, and GI) was greater in men than in women.

  13. The relationship between age and the mandibular cortical bone thickness by using panoramic radiograph

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Suk; Kim, Kyoung A; Koh, Kwang Joon [Department of Oral and Maxillofacial Radiology, School of Dentistry, and Institute of Oral Bio Science, Chonbuk National University, Jeonju (Korea, Republic of)

    2010-06-15

    This study was to determine the relationship between age and the mandibular cortical bone thickness on panoramic radiograph. Panoramic radiographs of 360 patients (180 men and 180 women) over 20 years old, who visited the Chonbuk National University Hospital from January to December in 2007, were assessed. The subjects were divided into 5 age groups. Five indices such as cortical bone thickness at the gonion (GI), antegonion (AI), and below the mental foramen (MI), the panoramic mandibular index (PMI), the mandibular cortical index (MCI) were measured on panoramic radiographs. All five indices including GI, AI, MI, PMI, and MCI showed significant differences between third decade and over 8 decade groups (p,0.05). PMI, MI and GI showed significant differences with gender statistically (p<0.05). The mandibular cortical bone thickness showed negative correlation with age, and the value of the thickness (PMI, MI, and GI) was greater in men than in women.

  14. Progressive femoral cortical and cancellous bone density loss after uncemented tapered-design stem fixation

    Science.gov (United States)

    Nowak, Tobias E; Haeberle, Lothar; Mueller, Lars P; Kress, Alexander; Voelk, Michael; Pfander, David; Forst, Raimund; Schmidt, Rainer

    2010-01-01

    Background Aseptic implant loosening and periprosthetic bone loss are major problems after total hip arthroplasty (THA). We present an in vivo method of computed tomography (CT) assisted osteodensitometry after THA that differentiates between cortical and cancellous bone density (BD) and area around the femoral component. Method Cortical and cancellous periprosthetic femoral BD (mg CaHA/mL), area (mm2) and contact area between the prothesis and cortical bone were determined prospectively in 31 patients 10 days, 1 year, and 6 years after uncemented THA (mean age at implantation: 55 years) using CT-osteodensitometry. Results 6 years postoperatively, cancellous BD had decreased by as much as 41% and cortical BD by up to 27% at the metaphyseal portion of the femur; this decrease was progressive between the 1-year and 6-year examinations. Mild cortical hypertrophy was observed along the entire length of the diaphysis. No statistically significant changes in cortical BD were observed along the diaphysis of the stem. Interpretation Periprosthetic CT-assisted osteodensitometry has the technical ability to discriminate between cortical and cancellous bone structures with respect to strain-adapted remodeling. Continuous loss of cortical and cancellous BD at the femoral metaphysis, a homeostatic cortical strain configuration, and mild cortical hypertrophy along the diaphysis suggest a diaphyseal fixation of the implanted stem. CT-assisted osteodensitometry has the potential to become an effective instrument for quality control in THA by means of in vivo determination of periprosthetic BD, which may be a causal factor in implant loosening after THA. PMID:20180716

  15. Effect of micromorphology of cortical bone tissue on crack propagation under dynamic loading

    Directory of Open Access Journals (Sweden)

    Wang Mayao

    2015-01-01

    Full Text Available Structural integrity of bone tissue plays an important role in daily activities of humans. However, traumatic incidents such as sports injuries, collisions and falls can cause bone fracture, servere pain and mobility loss. In addition, ageing and degenerative bone diseases such as osteoporosis can increase the risk of fracture [1]. As a composite-like material, a cortical bone tissue is capable of tolerating moderate fracture/cracks without complete failure. The key to this is its heterogeneously distributed microstructural constituents providing both intrinsic and extrinsic toughening mechanisms. At micro-scale level, cortical bone can be considered as a four-phase composite material consisting of osteons, Haversian canals, cement lines and interstitial matrix. These microstructural constituents can directly affect local distributions of stresses and strains, and, hence, crack initiation and propagation. Therefore, understanding the effect of micromorphology of cortical bone on crack initiation and propagation, especially under dynamic loading regimes is of great importance for fracture risk evaluation. In this study, random microstructures of a cortical bone tissue were modelled with finite elements for four groups: healthy (control, young age, osteoporosis and bisphosphonate-treated, based on osteonal morphometric parameters measured from microscopic images for these groups. The developed models were loaded under the same dynamic loading conditions, representing a direct impact incident, resulting in progressive crack propagation. An extended finite-element method (X-FEM was implemented to realize solution-dependent crack propagation within the microstructured cortical bone tissues. The obtained simulation results demonstrate significant differences due to micromorphology of cortical bone, in terms of crack propagation characteristics for different groups, with the young group showing highest fracture resistance and the senior group the

  16. Greater association of peak neuromuscular performance with cortical bone geometry, bone mass and bone strength than bone density: A study in 417 older women.

    Science.gov (United States)

    Belavý, Daniel L; Armbrecht, Gabriele; Blenk, Tilo; Bock, Oliver; Börst, Hendrikje; Kocakaya, Emine; Luhn, Franziska; Rantalainen, Timo; Rawer, Rainer; Tomasius, Frederike; Willnecker, Johannes; Felsenberg, Dieter

    2016-02-01

    We evaluated which aspects of neuromuscular performance are associated with bone mass, density, strength and geometry. 417 women aged 60-94years were examined. Countermovement jump, sit-to-stand test, grip strength, forearm and calf muscle cross-sectional area, areal bone mineral content and density (aBMC and aBMD) at the hip and lumbar spine via dual X-ray absorptiometry, and measures of volumetric vBMC and vBMD, bone geometry and section modulus at 4% and 66% of radius length and 4%, 38% and 66% of tibia length via peripheral quantitative computed tomography were performed. The first principal component of the neuromuscular variables was calculated to generate a summary neuromuscular variable. Percentage of total variance in bone parameters explained by the neuromuscular parameters was calculated. Step-wise regression was also performed. At all pQCT bone sites (radius, ulna, tibia, fibula), a greater percentage of total variance in measures of bone mass, cortical geometry and/or bone strength was explained by peak neuromuscular performance than for vBMD. Sit-to-stand performance did not relate strongly to bone parameters. No obvious differential in the explanatory power of neuromuscular performance was seen for DXA aBMC versus aBMD. In step-wise regression, bone mass, cortical morphology, and/or strength remained significant in relation to the first principal component of the neuromuscular variables. In no case was vBMD positively related to neuromuscular performance in the final step-wise regression models. Peak neuromuscular performance has a stronger relationship with leg and forearm bone mass and cortical geometry as well as proximal forearm section modulus than with vBMD. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. A Retrospective Study on Indian Population to evaluate Cortical Bone Thickness in Maxilla and Mandible using Computed Tomography Images

    Directory of Open Access Journals (Sweden)

    Jeegar Ketan Vakil

    2014-01-01

    Conclusion: Mini-implants have gained considerable popularity due to their low cost, effectiveness, clinical management and stability. Among the factors related to microimplant stability, bone density and cortical bone thickness appear to be critical for successful placement. This study will provide knowledge of cortical bone thickness in various areas which can guide the clinicians in selecting the placement site.

  18. Automated cortical bone segmentation for multirow-detector CT imaging with validation and application to human studies.

    Science.gov (United States)

    Li, Cheng; Jin, Dakai; Chen, Cheng; Letuchy, Elena M; Janz, Kathleen F; Burns, Trudy L; Torner, James C; Levy, Steven M; Saha, Punam K

    2015-08-01

    Cortical bone supports and protects human skeletal functions and plays an important role in determining bone strength and fracture risk. Cortical bone segmentation at a peripheral site using multirow-detector CT (MD-CT) imaging is useful for in vivo assessment of bone strength and fracture risk. Major challenges for the task emerge from limited spatial resolution, low signal-to-noise ratio, presence of cortical pores, and structural complexity over the transition between trabecular and cortical bones. An automated algorithm for cortical bone segmentation at the distal tibia from in vivo MD-CT imaging is presented and its performance and application are examined. The algorithm is completed in two major steps-(1) bone filling, alignment, and region-of-interest computation and (2) segmentation of cortical bone. After the first step, the following sequence of tasks is performed to accomplish cortical bone segmentation-(1) detection of marrow space and possible pores, (2) computation of cortical bone thickness, detection of recession points, and confirmation and filling of true pores, and (3) detection of endosteal boundary and delineation of cortical bone. Effective generalizations of several digital topologic and geometric techniques are introduced and a fully automated algorithm is presented for cortical bone segmentation. An accuracy of 95.1% in terms of volume of agreement with manual outlining of cortical bone was observed in human MD-CT scans, while an accuracy of 88.5% was achieved when compared with manual outlining on postregistered high resolution micro-CT imaging. An intraclass correlation coefficient of 0.98 was obtained in cadaveric repeat scans. A pilot study was conducted to describe gender differences in cortical bone properties. This study involved 51 female and 46 male participants (age: 19-20 yr) from the Iowa Bone Development Study. Results from this pilot study suggest that, on average after adjustment for height and weight differences, males have

  19. [Reconstruction of periprosthetic fractures of hip with cortical bone plates allografts].

    Science.gov (United States)

    Zhou, Zong-ke; Pei, Fu-xing; Tu, Chong-qi; Yang, Jing; Shen, Bin; Liu, Lei; Fatou, Camara-yagouba

    2004-12-22

    To observe clinical results for reconstruction of periprosthetic fractures of hip with cortical bone plates allografts by deep-freezing and ethylene oxide treatment. Seven patients with periprosthetic fractures of hip underwent cortical bone plates allografts by deep-freezing at -70 degrees C after being treatment of 48 degrees C ethylene oxide. And evaluate clinical outcome by examining T lymphocytes, Harris scores, X-rays photograph, and bone scintigraphy. There were not activity of immune rejection and infection in all patients. Harris scores of patients increased 21, 32, 40, 40 scores at 3, 6, 12, 24 months after surgery. T-lymphocytes, antibody and immunocomplex in blood was normal postoperation. X-ray film indicated that fracture was healed at 3 months and there was partially bone conjunction between allograft strut and host bone. There was incorporation of 85% allograft strut to host bone, and 15% allograft strut was partially absorbed at 12 months after surgery. The size of femur of host was added 3 mm to 5 mm, averaged 4.3 mm at 12 months postoperation. Density of 80% allograft plates was as same as host bone after remodeling and the absorbtion of 10% allograft plates stopped at 24 months after surgery. There was thick of nuclein in the area of allograft cortical bone plates by bone scintigraphy examination at 3 months postoperation, and the thick of nuclein was stronger at 6, and 12 months after surgery. Allograft cortical bone plates by deep frozen at -70 degrees C after being treatment of 48 degrees C ethylene oxide is suitable for mechanical fixation and biological bone transplantation, and it can increase bone reservation, augment strength of femur once the allograft strut incorporates to host bone, and avoid removing metal implant in second operation when being applied into reconstruction femoral fracture in joint replacement.

  20. Effect of Cortical Bone Thickness on Detection of Intraosseous Lesions by Ultrasonography

    Directory of Open Access Journals (Sweden)

    Sadaf Adibi

    2015-01-01

    Full Text Available Background. Usefulness of ultrasound (US in detection of intrabony lesions has been showed. A cortical bone perforation or a very thin and intact cortical bone is prerequisite for this purpose. Objective. The current in vitro study was aimed at measuring the cut-off thickness of the overlying cortical bone which allows ultrasonic assessment of bony defects. Materials and Methods. 20 bovine scapula blocks were obtained. Samples were numbered from 1 to 20. In each sample, 5 artificial lesions were made. The lesions were made in order to increase the overlying bone thickness, from 0.1 mm in the first sample to 2 mm in the last one (with 0.1 mm interval. After that, the samples underwent ultrasound examinations by two practicing radiologists. Results. All five lesions in samples numbered 1 to 11 were detected as hypoechoic area. Cortical bone thickness more than 1.1 mm resulted in a failure in the detection of central lesions. Conclusion. We can conclude that neither bony perforation nor very thin cortical bones are needed to consider US to be an effective imaging technique in the evaluation of bony lesion.

  1. Specifications for machining the bovine cortical bone in relation to its microstructure.

    Science.gov (United States)

    Sugita, Naohiko; Mitsuishi, Mamoru

    2009-12-11

    Until date, many devices have been developed for cutting human bones during orthopedic surgeries. However, bones are anisotropic material, and their machining characteristics depend on the tool feed direction. In this study, microcutting of the bovine cortical bone is performed and its structure observed under a microscope. Furthermore, the formation of cutting chips and measurement of the cutting force during bone machining are dynamically observed while considering the anisotropy of bone tissue. In particular, the fracture of secondary osteons and crack propagation in bones are observed and analyzed. The results indicate that when the cut depth exceeds 20mum and is greater than the interval of concentric lamellae, cracks are formed together with chips. A new method for bone machining is proposed. This method is based on the characteristics of crack propagation in bones and is expected to produce low mechanical stress and realize highly efficient and precise machining of living tissues such as bones.

  2. Mandibular cortical bone evaluation on cone beam computed tomography images of patients with bisphosphonate-related osteonecrosis of the jaw

    OpenAIRE

    Torres, Sandra R.; Chen, Curtis S. K.; Leroux, Brian G.; Lee, Peggy P.; Hollender, Lars G.; Santos, Eduardo C. A. [UNESP; Drew, Shane P.; Hung, Kuei-Ching; Schubert, Mark M.

    2012-01-01

    Objectives. The objective of this study was to develop a technique for detecting cortical bone dimensional changes in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ).Study Design. Subjects with BRONJ who had cone-beam computed tomography imaging were selected, with age- and gender-matched controls. Mandibular cortical bone measurements to detect bisphosphonate-related cortical bone changes were made inferior to mental foramen, in 3 different ways: within a fixed sized re...

  3. Maxillary Sinus Floor Augmentation Surgery with Autogenous Bone Grafts as Ceiling : A Pilot Study and Test of Principle

    NARCIS (Netherlands)

    Raghoebar, Gerry M.; Meijer, Henny J. A.; Telleman, Gerdien; Vissink, Arjan

    Background: Studies have pointed out that the mere elevation of the maxillary sinus membrane might suffice to allow for bone formation indicating the additional use of augmentation materials to be redundant. Purpose: The purpose of this study was to assess whether elevation of the sinus mucosal

  4. Randomized, controlled, prospective clinical trial of autologous greater omentum free graft versus autogenous cancellous bone graft in radial and ulnar fractures in miniature breed dogs.

    Science.gov (United States)

    Ree, Jennifer J; Baltzer, Wendy I; Nemanic, Sarah

    2018-02-19

    To determine the rate of radiographic healing, complications, vascularization, and bone density after repair of radial and ulnar fractures in dogs bone graft (BG) or free autologous omentum graft (OG). Prospective, randomized, controlled clinical trial with owners/radiologists blinded to treatment. 25 dogs with naturally occurring traumatic radial/ulnar fractures. Fractures underwent plate fixation with OG or BG. Power Doppler ultrasonographic, computed tomographic (CT), and radiographic examinations of the affected antebrachium were performed preoperatively and every 3 weeks postoperatively until healed. Pressure-sensitive walkway gait analysis and owner and veterinarian assessments were obtained preoperatively (0 weeks) and 3, 6, 9, 12, and 24 weeks postoperatively. Owner/veterinarian assessments improved postoperatively but did not differ significantly between groups. The improvement in peak vertical force/vertical impulse was greater in dogs with OG than in those with BG, beginning 3 weeks postoperatively. Radiographic healing occurred earlier in bones treated with OG (median, 9 weeks) than in those treated with BG (12 weeks). Cortical bone density derived from CT of the distal ulna was higher in bones with BG compared with bones with OG. Signal intensity and the number of vessels in the fracture callus declined over time in both groups, according to results of ultrasonography. However, bones retained more vessels and greater signal intensity when treated with OG compared with treatment with BG, according to multiple views at 6 and 9 weeks postoperatively. Omental grafting was not associated with major complications, and it accelerated bone healing and return to weight bearing in dogs. Omental grafting should be considered as an adjunct to stabilization of antebrachial fractures in toy and small breed dogs. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  5. An approach to the histomorphological and histochemical variations of the humerus cortical bone through human ontogeny

    Science.gov (United States)

    Cambra-Moo, Oscar; Nacarino Meneses, Carmen; Rodríguez Barbero, Miguel Ángel; García Gil, Orosia; Rascón Pérez, Josefina; Rello-Varona, Santiago; D'Angelo, Manuel; Campo Martín, Manuel; González Martín, Armando

    2014-01-01

    For many years, clinical and non-clinical investigations have investigated cortical bone structure in an attempt to address questions related to normal bone development, mineralisation, pathologies and even evolutionary trends in our lineage (adaptations). Research in the fields of medicine, materials science, physical anthropology, palaeontology, and even archaeobiology has contributed interesting data. However, many questions remain regarding the histomorphological and histochemical variations in human cortical bone during different stages of life. In the present work, we describe a study of long bone cortex transformations during ontogeny. We analysed cross-sections of 15 human humeri histomorphologically and histochemically from perinatal to adult age, marking and quantifying the spatial distribution of bone tissue types using GIS software and analysing the mineral composition and crystallinity of the mineralised cortex using Raman spectroscopy and X-ray diffraction. Our results allowed us to propose that human cortical bone undergoes three main ‘events’ through ontogeny that critically change the proportions and structure of the cortex. In early development, bone is not well mineralised and proportionally presents a wide cortex that narrows through the end of childhood. Before reaching complete maturity, the bone mineral area increases, allowing the bone to nearly reach the adult size. The medullary cavity is reduced, and the mineral areas have a highly ordered crystalline structure. The last event occurs in adulthood, when the ‘oldest’ individuals present a reduced mineralised area, with increasing non-mineralised cavities (including the medullary cavity) and reduced crystalline organisation. PMID:24660964

  6. Mechanistic fracture criteria for the failure of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Nalla, Ravi K.; Kinney, John H.; Ritchie, Robert O.

    2002-12-13

    A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.

  7. Growth hormone effects on cortical bone dimensions in young adults with childhood-onset growth hormone deficiency

    DEFF Research Database (Denmark)

    Hyldstrup, L; Conway, G S; Racz, K

    2012-01-01

    Growth hormone (GH) treatment in young adults with childhood-onset GH deficiency has beneficial effects on bone mass. The present study shows that cortical bone dimensions also benefit from GH treatment, with endosteal expansion and increased cortical thickness leading to improved bone strength....... INTRODUCTION: In young adults with childhood-onset growth hormone deficiency (CO GHD), GH treatment after final height is reached has been shown to have beneficial effects on spine and hip bone mineral density. The objective of the study was to evaluate the influence of GH on cortical bone dimensions. METHODS......: Patients (n = 160; mean age, 21.2 years; 63% males) with CO GHD were randomised 2:1 to GH or no treatment for 24 months. Cortical bone dimensions were evaluated by digital x-ray radiogrammetry of the metacarpal bones every 6 months. RESULTS: After 24 months, cortical thickness was increased compared...

  8. Predicting Diaphyseal Cortical Bone Status Using Measures of Muscle Force Capacity.

    Science.gov (United States)

    Higgins, Simon; Sokolowski, Chester M; Vishwanathan, Megha; Anderson, Jessica G; Schmidt, Michael D; Lewis, Richard D; Evans, Ellen M

    2018-02-16

    Muscle cross sectional area (MCSA) is often used as a surrogate for the forces applied to bones during physical activity. Though MCSA is a strong predictor of cortical bone status, its use makes assumptions about the relationship between muscle size and force that are inaccurate. Furthermore, to measure MCSA and other muscle force surrogates typically requires expensive and/or radiative laboratory equipment. Thus, this study aimed to determine whether clinical lab- and field-based methodologies for measuring muscular force capacity accounted for similar variance in diaphyseal cortical bone status as a commonly used muscular force surrogate; MCSA, at the mid-tibia in young men and women. Healthy young adults (n = 142, 19.7 ± 0.7 yo, 52.8% female) were assessed via peripheral quantitative computed tomography at the mid-tibia for cortical bone status and MCSA. Muscle force capacity was measured via Biodex dynamometer, Nottingham leg extensor power rig, and Vertec vertical jump. Regression analysis compared the independent variance predicted by each muscle force measure to that of MCSA, accounting for relevant confounders. MCSA, knee extension peak torque, and peak anaerobic power from vertical jump were independent predictors of select cortical structural outcomes (cortical thickness and area, periosteal and endosteal circumference, and estimated strength) accounting for up to 78.4% of the variance explained (all p<.05). However, cortical volumetric bone mineral density was unrelated to any measure or surrogate of muscle force capacity. MCSA is a strong independent predictor of cortical bone structure; however, both lab- and field-based measures of peak torque and/or peak anaerobic power are promising alternatives, explaining similar and sometimes greater variance than MCSA.

  9. Simulation study of axial ultrasound transmission in heterogeneous cortical bone model

    Science.gov (United States)

    Takano, Koki; Nagatani, Yoshiki; Matsukawa, Mami

    2017-07-01

    Ultrasound propagation in a heterogeneous cortical bone was studied. Using a bovine radius, the longitudinal wave velocity distribution in the axial direction was experimentally measured in the MHz range. The bilinear interpolation and piecewise cubic Hermite interpolation methods were applied to create a three-dimensional (3D) precise velocity model of the bone using experimental data. By assuming the uniaxial anisotropy of the bone, the distributions of all elastic moduli of a 3D heterogeneous model were estimated. The elastic finite-difference time-domain method was used to simulate axial ultrasonic wave propagation. The wave propagation in the initial model was compared with that in the thinner model, where the inner part of the cortical bone model was removed. The wave front of the first arriving signal (FAS) slightly depended on the heterogeneity in each model. Owing to the decrease in bone thickness, the propagation behavior also changed and the FAS velocity clearly decreased.

  10. Muscle volume is related to trabecular and cortical bone architecture in typically developing children.

    Science.gov (United States)

    Bajaj, Deepti; Allerton, Brianne M; Kirby, Joshua T; Miller, Freeman; Rowe, David A; Pohlig, Ryan T; Modlesky, Christopher M

    2015-12-01

    Muscle is strongly related to cortical bone architecture in children; however, the relationship between muscle volume and trabecular bone architecture is poorly studied. The aim of this study was to determine if muscle volume is related to trabecular bone architecture in children and if the relationship is different than the relationship between muscle volume and cortical bone architecture. Forty typically developing children (20 boys and 20 girls; 6 to 12y) were included in the study. Measures of trabecular bone architecture [i.e., apparent trabecular bone volume to total volume (appBV/TV), trabecular number (appTb.N), trabecular thickness (appTb.Th) and trabecular separation (appTb.Sp)] in the distal femur, cortical bone architecture [cortical volume, total volume, section modulus (Z) and polar moment of inertia (J)] in the midfemur, muscle volume in the midthigh and femur length were assessed using magnetic resonance imaging. Total physical activity and moderate-to-vigorous physical activity were assessed using an accelerometer-based activity monitor worn around the waist for four days. Calcium intake was assessed using diet records. Relationships among the measures were tested using multiple linear regression analysis. Muscle volume was moderately-to-strongly related to measures of trabecular bone architecture [appBV/TV (r=0.81), appTb.N (r=0.53), appTb.Th (r=0.67), appTb.Sp (r=-0.71); all parchitecture [cortical volume (r=0.96), total volume (r=0.94), Z (r=0.94) and J (r=0.92; all parchitecture. Sex, physical activity and calcium intake were not related to any measure of bone architecture (p>0.05). Because muscle volume and femur length were strongly related (r=0.91, parchitecture (partial r=0.47 to 0.54; parchitecture in the distal femur of typically developing children. The relationship is weaker than the relationship between muscle volume in the midthigh and cortical bone architecture in the midfemur, but the discrepancy is driven, in large part, by the

  11. Comparison of posterior lumbar interbody fusion (PLIF) with autogenous bone chips and PLIF with cage for treatment of double-level isthmic spondylolisthesis.

    Science.gov (United States)

    Song, Deyong; Chen, Zhong; Song, Dewei; Li, Zaixue

    2015-11-01

    Spondylolytic defects involving multiple vertebral levels are rare. It is reported that only 1.48% of patients with back pain were diagnosed with multi-level spondylolysis. The incidence of multiple-level spondylolisthesis is even rarer, so far there have been few reports of multi-level isthmic spondylolisthesis in the literature. The aim of this study is to evaluate clinical and radiological outcomes of two different fusion techniques for treatment of double-level isthmic spondylolisthesis. Fifty-four patients who were managed surgically for treatment of double-level symptomatic isthmic spondylolisthesis were included in this study. Between May 2004 and September 2012, 29 consecutive patients underwent posterior lumbar interbody fusion (PLIF) with autogenous bone chips (group I) at Foshan Hospital of Traditional Chinese Medicine, Guangdong, China. Between March 2005 and December 2013, 25 consecutive patients underwent PLIF with cage (group II) at Zhujiang Hospital of Southern Medical University, Guangdong, China. The mean follow-up periods were 27.2 and 26.8 months, respectively. The mean VAS scores of back and leg pain significantly decreased from 7.2 to 2.2 and 5.8 to 2.1 in the group I and from 7.0 to 1.9 and 6.1 to 1.8 in the group II, respectively. In the group I, mean ODI scores improved significantly from 54% to 14.2% and, in the group II, from 60% to 12.6%. In both groups, VAS and ODI scores significantly changed from pre- to postoperatively (p0.05). In both groups, changes in disc height, degree of listhesis, and whole lumbar lordosis between the pre- and postoperative periods were significant. Clinical and functional outcomes demonstrate no significant differences between groups in treating back and leg pain of adult patients with double-level isthmic spondylolisthesis. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Strain rate influence on human cortical bone toughness: A comparative study of four paired anatomical sites.

    Science.gov (United States)

    Gauthier, Rémy; Follet, Hélène; Langer, Max; Meille, Sylvain; Chevalier, Jérôme; Rongiéras, Frédéric; Peyrin, Françoise; Mitton, David

    2017-07-01

    Bone fracture is a major health issue worldwide and consequently there have been extensive investigations into the fracture behavior of human cortical bone. However, the fracture properties of human cortical bone under fall-like loading conditions remains poorly documented. Further, most published research has been performed on femoral diaphyseal bone, whereas it is known that the femoral neck and the radius are the most vulnerable sites to fracture. Hence, the aim of this study is to provide information on human cortical bone fracture behavior by comparing different anatomical sites including the radius and the femoral neck acquired from 32 elderly subjects (50 - 98 y.o.). In order to investigate the intrinsic fracture behavior of human cortical bone, toughness experiments were performed at two different strain rates: standard quasi-static conditions, and a higher strain rate representative of a fall from a standing position. The tests were performed on paired femoral neck, femoral, tibial and radius diaphyseal samples. Linear elastic fracture toughness and the non-linear J-integral method were used to take into account both the elastic and non-elastic behavior of cortical bone. Under quasi-static conditions, the radius presents a significantly higher toughness than the other sites. At the higher strain rate, all sites showed a significantly lower toughness. Also, at the high strain rate, there is no significant difference in fracture properties between the four anatomical sites. These results suggest that regardless of the anatomical site (femur, femoral neck, tibia and radius), the bone has the same fracture properties under fall loading conditions. This should be considered in biomechanical models under fall-like loading conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Acute hypothalamic suppression significantly affects trabecular bone but not cortical bone following recovery and ovariectomy surgery in a rat model

    Directory of Open Access Journals (Sweden)

    Vanessa R. Yingling

    2016-01-01

    Full Text Available Background. Osteoporosis is “a pediatric disease with geriatric consequences.” Bone morphology and tissue quality co-adapt during ontogeny for sufficient bone stiffness. Altered bone morphology from hypothalamic amenorrhea, a risk factor for low bone mass in women, may affect bone strength later in life. Our purpose was to determine if altered morphology following hypothalamic suppression during development affects cortical bone strength and trabecular bone volume (BV/TV at maturity.Methods. Female rats (25 days old were assigned to a control (C group (n = 45 that received saline injections (.2 cc or an experimental group (GnRH-a (n = 45 that received gonadotropin releasing hormone antagonist injections (.24 mg per dose for 25 days. Fifteen animals from each group were sacrificed immediately after the injection protocol at Day 50 (C, GnRH-a. The remaining animals recovered for 135 days and a subset of each group was sacrificed at Day 185 ((C-R (n = 15 and (G-R (n = 15. The remaining animals had an ovariectomy surgery (OVX at 185 days of age and were sacrificed 40 days later (C-OVX (n = 15 and (G-OVX (n = 15. After sacrifice femurs were mechanically tested and scanned using micro CT. Serum C-terminal telopeptides (CTX and insulin-like growth factor 1 (IGF-1 were measured. Two-way ANOVA (2 groups (GnRH-a and Control X 3 time points (Injection Protocol, Recovery, post-OVX was computed.Results. GnRH-a injections suppressed uterine weights (72% and increased CTX levels by 59%. Bone stiffness was greater in the GnRH-a groups compared to C. Ash content and cortical bone area were similar between groups at all time points. Polar moment of inertia, a measure of bone architecture, was 15% larger in the GnRH-a group and remained larger than C (19% following recovery. Both the polar moment of inertia and cortical area increased linearly with the increases in body weight. Following the injection protocol, trabecular BV/TV was 31% lower in the Gn

  14. Body Mass Influences Cortical Bone Mass Independent of Leptin Signaling

    OpenAIRE

    Iwaniec, U.T.; Dube, M.G.; Boghossian, S.; Song, H.; Helferich, W.G.; Turner, R.T.; Kalra, S.P.

    2008-01-01

    Obesity in humans is associated with increased bone mass. Leptin, a hormone produced by fat cells, functions as a sentinel of energy balance, and may mediate the putative positive effects of body mass on bone. We performed studies in male C57Bl/6 wild type (WT) and leptin-deficient ob/ob mice to determine whether body mass gain induced by high fat intake increases bone mass and, if so, whether this requires central leptin signaling. The relationship between body mass and bone mass and archite...

  15. Insulin Resistance Is Associated With Smaller Cortical Bone Size in Nondiabetic Men at the Age of Peak Bone Mass.

    Science.gov (United States)

    Verroken, Charlotte; Zmierczak, Hans-Georg; Goemaere, Stefan; Kaufman, Jean-Marc; Lapauw, Bruno

    2017-06-01

    In type 2 diabetes mellitus, fracture risk is increased despite preserved areal bone mineral density. Although this apparent paradox may in part be explained by insulin resistance affecting bone structure and/or material properties, few studies have investigated the association between insulin resistance and bone geometry. We aimed to explore this association in a cohort of nondiabetic men at the age of peak bone mass. Nine hundred ninety-six nondiabetic men aged 25 to 45 years were recruited in a cross-sectional, population-based sibling pair study at a university research center. Insulin resistance was evaluated using the homeostasis model assessment of insulin resistance (HOMA-IR), with insulin and glucose measured from fasting serum samples. Bone geometry was assessed using peripheral quantitative computed tomography at the distal radius and the radial and tibial shafts. In age-, height-, and weight-adjusted analyses, HOMA-IR was inversely associated with trabecular area at the distal radius and with cortical area, periosteal and endosteal circumference, and polar strength strain index at the radial and tibial shafts (β ≤ -0.13, P insulin-like growth factor 1, or sex steroid levels. In this cohort of nondiabetic men at the age of peak bone mass, insulin resistance is inversely associated with trabecular and cortical bone size. These associations persist after adjustment for body composition, muscle size or function, or sex steroid levels, suggesting an independent effect of insulin resistance on bone geometry. Copyright © 2017 Endocrine Society

  16. Neglected anterior dislocation of shoulder with large Hillsach's lesion & deficient glenoid: Treated by autogenous bone graft & modified Latarjet procedure☆

    Science.gov (United States)

    Peshin, Chetan; Jangira, Vivek; Gupta, Ravi Kumar; Jindal, Rohit

    2015-01-01

    Neglected anterior dislocation of shoulder is rare in spite of the fact that the anterior dislocation of the shoulder is seen in around 90% of the acute cases. Most of the series of neglected dislocation describe posterior dislocation to be far more common.1,2 We hereby report a case of the neglected anterior shoulder dislocation in a 15 year old boy who had a history of epilepsy. There was a large Hill Sachs lesion in humeral head which was impacted in glenoid inferiorly and glenoid was eburnated at that margin. The humeral head was reconstructed with a tricortical iliac graft. Glenoid was reconstructed by transfer of coracoids process of scapula to antero-inferior glenoid (modified Latarjet procedure). This case is unique because management of humeral head defect with bone graft is not mentioned in anterior dislocation. PMID:26566343

  17. Neglected anterior dislocation of shoulder with large Hillsach's lesion & deficient glenoid: Treated by autogenous bone graft & modified Latarjet procedure.

    Science.gov (United States)

    Peshin, Chetan; Jangira, Vivek; Gupta, Ravi Kumar; Jindal, Rohit

    2015-12-01

    Neglected anterior dislocation of shoulder is rare in spite of the fact that the anterior dislocation of the shoulder is seen in around 90% of the acute cases. Most of the series of neglected dislocation describe posterior dislocation to be far more common.(1) (,2) We hereby report a case of the neglected anterior shoulder dislocation in a 15 year old boy who had a history of epilepsy. There was a large Hill Sachs lesion in humeral head which was impacted in glenoid inferiorly and glenoid was eburnated at that margin. The humeral head was reconstructed with a tricortical iliac graft. Glenoid was reconstructed by transfer of coracoids process of scapula to antero-inferior glenoid (modified Latarjet procedure). This case is unique because management of humeral head defect with bone graft is not mentioned in anterior dislocation.

  18. Pullout strength of thoracic pedicle screws improved with cortical bone ratio: a cadaveric study.

    Science.gov (United States)

    Chou, Wen-Kai; Chien, Andy; Wang, Jaw-Lin

    2014-11-01

    The application of pedicle screw constructs for the osteoporotic vertebrae remains a serious clinical challenge for spinal surgeons and has been intensely studied recently. However, the exact role of the pedicular cortical bone composition and the screw-bone gap on the screw fixation failure has yet to be quantitatively documented. The current study aims to address this gap in our knowledge and elucidate possible relationships. Twelve fresh-frozen human cadaveric thoracic spine vertebrae (T9-T12) were harvested from six human cadavers (five males; one female; 63.5 ± 17 years). A three-dimensional reconstruction of the individual vertebrae was firstly rendered from computed tomography (CT) scan images to allow calculation of the cortical bone ratio. Specimens were then subdivided into three groups: Intact, 1-mm screw-bone gap, and 2-mm screw-bone gap. The gap groups were subjected to a standard cyclic fatigue-loading protocol. The pullout strength of the pedicle screws for all specimens were then determined. The pullout strength of the 1-mm and 2-mm groups were significantly reduced when compared with the intact group. A moderate to excellent positive correlation was identified between the cortical bone area ratio and pullout strength for all groups (r > 0.55). A cortical shell ratio of 0.73 or higher was also found to be a safe cut-off index for screw fixation failure, even with an observable 1-mm screw-bone gap. The current in vitro cadaveric spine study identified a significant correlation between cortical bone area ratio and the thoracic pedicle screw pullout strength. The presented results also demonstrate that the fatigue-loading-induced screw-bone gap of 1-mm was sufficient to cause a significant decrease in the pullout strength. However, a cortical bone area ratio of 0.73 or higher in this group was able to preserve most of the screw-bone interfacial strength, and subsequently may prevent a complete implant failure.

  19. Effects of treadmill exercise on cortical bone in the third metacarpus of young horses

    International Nuclear Information System (INIS)

    McCarthy, R.N.; Jeffcott, L.B.

    1992-01-01

    The effects of exercise and relative inactivity on cortical bone were compared in young horses. Two groups were used; one was given a 14-week programme of exercise (n = 6) and the other kept as unexercised controls (n = 6). The first nine weeks of exercise involved trotting and cantering (2 to 4 km d-1 at speeds up to 12 m s-1) on a treadmill set at an incline of 3 degrees. Over the next five weeks the horses were trained at near maximal speeds (that is, up to 14.5 m s-1) with no incline of the treadmill. At the end of the programme marked differences in cortical porosity and distribution of subperiosteal osteogenesis at the mid-shaft of the third metacarpal bone were found between the groups. Histomorphometrical examination of the dorsal cortex showed minimal bone remodelling in the exercised horses, but extensive modelling as evidenced by the large amount of subperiosteal bone formation. In contrast, the unexercised horses had significantly more bone remodelling and less formation of subperiosteal bone. The histomorphometric and microradiographic findings provided an explanation for changes in the non-invasive bone measurements that occurred during training. Bone mineral content of the mid-metacarpus was found to increase more in the exercised than the unexercised horses despite a lower overall growth in bodyweight. In those horses that completed the full training programme, ultrasound speed increased significantly by the end of the training programme. It remained unchanged in the horse that did not complete the full exercise programme and decreased slightly in the unexercised horses. The difference in ultrasound speed between the groups was considered to reflect differences in intracortical bone porosity, endosteal bone formation and alterations in skin thickness. The stiffness of cortical bone increased significantly in the exercised horses but remained unaltered in the unexercised horses

  20. The effect of high voltage, high frequency pulsed electric field on slain ovine cortical bone.

    Science.gov (United States)

    Asgarifar, Hajarossadat; Oloyede, Adekunle; Zare, Firuz

    2014-04-01

    High power, high frequency pulsed electric fields known as pulsed power (PP) has been applied recently in biology and medicine. However, little attention has been paid to investigate the application of pulse power in musculoskeletal system and its possible effect on functional behavior and biomechanical properties of bone tissue. This paper presents the first research investigating whether or not PP can be applied safely on bone tissue as a stimuli and what will be the possible effect of these signals on the characteristics of cortical bone by comparing the mechanical properties of this type of bone pre and post expose to PP and in comparison with the control samples. A positive buck-boost converter was applied to generate adjustable high voltage, high frequency pulses (up to 500 V and 10 kHz). The functional behavior of bone in response to pulse power excitation was elucidated by applying compressive loading until failure. The stiffness, failure stress (strength) and the total fracture energy (bone toughness) were determined as a measure of the main bone characteristics. Furthermore, an ultrasonic technique was applied to determine and comprise bone elasticity before and after pulse power stimulation. The elastic property of cortical bone samples appeared to remain unchanged following exposure to pulse power excitation for all three orthogonal directions obtained from ultrasonic technique and similarly from the compression test. Nevertheless, the compressive strength and toughness of bone samples were increased when they were exposed to 66 h of high power pulsed electromagnetic field compared to the control samples. As the toughness and the strength of the cortical bone tissue are directly associated with the quality and integrity of the collagen matrix whereas its stiffness is primarily related to bone mineral content these overall results may address that although, the pulse power stimulation can influence the arrangement or the quality of the collagen network

  1. Effects of deleting cannabinoid receptor-2 on mechanical and material properties of cortical and trabecular bone

    Directory of Open Access Journals (Sweden)

    Aysha B. Khalid

    2015-12-01

    Full Text Available Cnr2 is one of two cannabinoid receptors known to regulate bone metabolism. Here, we compared the whole bone properties of femora and tibiae from three-month-old Cnr2−/- mice with wild-type controls using a C57BL/6 background. Bending stiffness was measured by three-point bending. The elastic modulus, density and mineral content were measured using ultrasound, Archimedes’ principle and ashing. Micro-CT was used to measure the second moment of area, inner and outer perimeters of the cortical shaft and trabecular parameters. Deleting Cnr2 increased the bending stiffness by increasing the second moment of area. Bone from affected male mice had a greater modulus than controls, although no difference was observed in females. The fractional volume of trabecular bone was greater in Cnr2−/- females than controls, while no difference was seen in males. These data indicate that inactivating Cnr2 increases the amount of cortical bone in both males and females at 3 months of age, but the effect on trabecular bone is different in the two sexes. These findings extend previous studies looking only at trabecular bone and provide further support for the possible use of Cnr2 antagonists for improving bone properties that may be of value in the treatment of bone disorders.

  2. Modalities for visualization of cortical bone remodeling: the past, present and near future

    Directory of Open Access Journals (Sweden)

    Kimberly Dawn Harrison

    2015-08-01

    Full Text Available Bone’s ability to respond to load-related phenomena and repair microdamage is achieved through the remodeling process which renews bone by activating groups of cells known as Basic Multicellular Units (BMUs. The products of BMUs, secondary osteons, have been extensively studied via classic two-dimensional (2D techniques which have provided a wealth of information on how histomorphology relates to skeletal structure and function. Remodeling is critical in maintaining healthy bone tissue; however, in osteoporotic bone imbalanced resorption results in increased bone fragility and fracture. With increasing life expectancy, such degenerative bone diseases are a growing concern. The three-dimensional (3D morphology of BMUs and their correlation to function, however, are not well characterized and little is known about the specific mechanisms that initiate and regulate their activity within cortical bone. We believe a key limitation has been the lack 3D information about BMU morphology and activity. Thus, this paper reviews methodologies for 3D investigation of cortical bone remodeling and, specifically, structures associated with BMU activity (resorption spaces and the structures they create (secondary osteons, spanning from histology to modern ex vivo imaging modalities, culminating with the growing potential of in vivo imaging. This collection of papers focuses on the theme of putting the why back into bone archytecture. Remodeling is one of two mechanisms how bone structure is dynamically modified and thus an improved 3D understanding of this fundamental process is crucial to ultimately understanding the why.

  3. Implant design and its effects on osseointegration over time within cortical and trabecular bone.

    Science.gov (United States)

    Beutel, Bryan G; Danna, Natalie R; Granato, Rodrigo; Bonfante, Estevam A; Marin, Charles; Tovar, Nick; Suzuki, Marcelo; Coelho, Paulo G

    2016-08-01

    Healing chambers present at the interface between implant and bone have become a target for improving osseointegration. The objective of the present study was to compare osseointegration of several implant healing chamber configurations at early time points and regions of interest within bone using an in vivo animal femur model. Six implants, each with a different healing chamber configuration, were surgically implanted into each femur of six skeletally mature beagle dogs (n = 12 implants per dog, total n = 72). The implants were harvested at 3 and 5 weeks post-implantation, non-decalcified processed to slides, and underwent histomorphometry with measurement of bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within healing chambers at both cortical and trabecular bone sites. Microscopy demonstrated predominantly woven bone at 3 weeks and initial replacement of woven bone by lamellar bone by 5 weeks. BIC and BAFO were both significantly increased by 5 weeks (p < 0.001), and significantly higher in cortical than trabecular bone (p < 0.001). The trapezoidal healing chamber design demonstrated a higher BIC than other configurations. Overall, a strong temporal and region-specific dependence of implant osseointegration in femurs was noted. Moreover, the findings suggest that a trapezoidal healing chamber configuration may facilitate the best osseointegration. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1091-1097, 2016. © 2015 Wiley Periodicals, Inc.

  4. Neutron activation analysis of medullar and cortical bone tissues from animals

    International Nuclear Information System (INIS)

    Takata, Marcelo Kazuo; Saiki, Mitiko

    2000-01-01

    In this work, neutron activation analysis was applied in the determination of the elements Ba, Br, Ca, Cl, Cr, Fe, K, Mg, Mn, Na, P, Rb, Sb, Sc, Sr and Zn present in animal bone tissues. The obtained results indicated a significant difference between the elemental concentrations present in medullar and cortical tissues. The results obtained for bone tissues from distinct animal species were also different. (author)

  5. Influence of hydrochloric acid concentration on the demineralization of cortical bone

    OpenAIRE

    Figueiredo, M; Cunha, S; Martins, G; Freitas, J; Judas, F; Figueiredo, G

    2011-01-01

    Although demineralized bone matrix has been considered a successful grafting material, combining both osteoconductive and osteoinductive properties, conflicting results have been published in the literature regarding its bone-inducing abilities. This may be a consequence of following different demineralization procedures that naturally result in products with different properties. The present work examines the evaluation of the demineralization process of similar samples of human cortical...

  6. How Tough is Human Cortical Bone? In-Situ Measurements on Realistically Short Cracks

    Energy Technology Data Exchange (ETDEWEB)

    Ritchie, Robert O; Koester, K. J.; Ager III, J. W.; Ritchie, R.O.

    2008-05-10

    Bone is more difficult to break than to split. Although this is well known, and many studies exist on the behavior of long cracks in bone, there is a need for data on the orientation-dependent crack-growth resistance behavior of human cortical bone which accurately assesses its toughness at appropriate size-scales. Here we use in-situ mechanical testing in the scanning electron microscope and x-ray computed tomography to examine how physiologically-pertinent short (<600 mu m) cracks propagate in both the transverse and longitudinal orientations in cortical bone, using both crack-deflection/twist mechanics and nonlinear-elastic fracture mechanics to determine crack-resistance curves. We find that after only 500 mu m of cracking, the driving force for crack propagation was more than five times higher in the transverse (breaking) direction than in the longitudinal (splitting) direction due to major crack deflections/twists principally at cement sheathes. Indeed, our results show that the true transverse toughness of cortical bone is far higher than previously reported. However, the toughness in the longitudinal orientation, where cracks tend to follow the cement lines, is quite low at these small crack sizes; it is only when cracks become several millimeters in length that bridging mechanisms can develop leading to the (larger-crack) toughnesses generally quoted for bone.

  7. Genetic algorithms-based inversion of multimode guided waves for cortical bone characterization

    Science.gov (United States)

    Bochud, N.; Vallet, Q.; Bala, Y.; Follet, H.; Minonzio, J.-G.; Laugier, P.

    2016-10-01

    Recent progress in quantitative ultrasound has exploited the multimode waveguide response of long bones. Measurements of the guided modes, along with suitable waveguide modeling, have the potential to infer strength-related factors such as stiffness (mainly determined by cortical porosity) and cortical thickness. However, the development of such model-based approaches is challenging, in particular because of the multiparametric nature of the inverse problem. Current estimation methods in the bone field rely on a number of assumptions for pairing the incomplete experimental data with the theoretical guided modes (e.g. semi-automatic selection and classification of the data). The availability of an alternative inversion scheme that is user-independent is highly desirable. Thus, this paper introduces an efficient inversion method based on genetic algorithms using multimode guided waves, in which the mode-order is kept blind. Prior to its evaluation on bone, our proposal is validated using laboratory-controlled measurements on isotropic plates and bone-mimicking phantoms. The results show that the model parameters (i.e. cortical thickness and porosity) estimated from measurements on a few ex vivo human radii are in good agreement with the reference values derived from x-ray micro-computed tomography. Further, the cortical thickness estimated from in vivo measurements at the third from the distal end of the radius is in good agreement with the values delivered by site-matched high-resolution x-ray peripheral computed tomography.

  8. Identification of fatigue damage in cortical bone by diffraction enhanced imaging

    International Nuclear Information System (INIS)

    Connor, D.M.; Sayers, D.; Sumner, D.R.; Zhong, Z.

    2005-01-01

    In an effort to explore Diffraction Enhanced Imaging of bone tissue, experiments were performed to determine if it was possible to use Diffraction Enhanced Imaging to detect microdamage in bovine cortical bone. Measurements were made at the National Synchrotron Light Source where pre- and post-fatigue rocking curve widths of the bone were studied. The rocking curve widths were then compared. Since no consistent pattern of narrowing or broadening of the rocking curve emerged, it is likely that the ultra-small-angle X-ray scattering present in the bone overshadowed any additional changes to rocking curve caused by microdamage of the bone. Larger bone structures were able to be visualized which suggests that microdamage may be visualized with a higher resolution detector

  9. Experimental Investigations on Microcracks in Vibrational and Conventional Drilling of Cortical Bone

    Directory of Open Access Journals (Sweden)

    Yu Wang

    2013-01-01

    Full Text Available Bone drilling is widely used in orthopedic surgery. Microcracks will be generated in bone drilling, which may cause fatigue damages and stress fractures. Fresh bovine cortical bones were drilled via vibrational and conventional ways. Drilling operations were performed by a dynamic material testing machine, which can provide the vibration while maintaining uniform feed motion. The drill site and bone debris were observed through scanning electron microscope (SEM. The experimental results showed that fewer and shorter micro-cracks were formed in vibrational drilling than those formed in conventional way. And the surface morphology of bone debris from two different drilling ways was also quite different. It is expected that vibrational drilling in orthopedic surgery operation could decrease the microdamage to the bone, which could lower the incidence of stress fracture and contribute to the postoperative recovery.

  10. Hopkinson bar techniques for the intermediate strain rate testing of bovine cortical bone.

    Science.gov (United States)

    Cloete, T J; Paul, G; Ismail, E B

    2014-05-13

    Detailed knowledge of the dynamic viscoelastic properties of bone is required to understand the mechanisms of macroscopic bone fracture in humans, and other terrestrial mammals, during impact loading events (e.g. falls, vehicle accidents, etc.). While the dynamic response of bone has been studied for several decades, high-quality data remain limited, and it is only within the last decade that techniques for conducting dynamic compression tests on bone at near-constant strain rates have been developed. Furthermore, there appears to be a lack of published bone data in the intermediate strain rate (ISR) range (i.e. 1-100 s(-1)), which represents a regime in which many dynamic bone fractures occur. In this paper, preliminary results for the dynamic compression of bovine cortical bone in the ISR regime are presented. The results are obtained using two Hopkinson-bar-related techniques, namely the conventional split Hopkinson bar arrangement incorporating a novel cone-in-tube striker design, and the recently developed wedge bar apparatus. The experimental results show a rapid transition in the strain rate sensitive behaviour of bovine cortical bone in the ISR range. Finally, a new viscoelastic model is proposed that captures the observed transition behaviour.

  11. Using smooth particle hydrodynamics to investigate femoral cortical bone remodelling at the Haversian level.

    Science.gov (United States)

    Fernandez, J W; Das, R; Cleary, P W; Hunter, P J; Thomas, C D L; Clement, J G

    2013-01-01

    In the neck of the femur, about 70% of the strength is contributed by the cortical bone, which is the most highly stressed part of the structure and is the site where failure is almost certainly initiated. A better understanding of cortical bone remodelling mechanisms can help discern changes at this anatomical site, which are essential if an understanding of the mechanisms by which hips weaken and become vulnerable to fracture is to be gained. The aims of this study were to (i) examine a hypothesis that low strain fields arise because of subject-specific Haversian canal distributions causing bone resorption and reduced bone integrity and (ii) introduce the use of a meshless particle-based computational modelling approach SPH to capture bone remodelling features at the level of the Haversian canals. We show that bone remodelling initiated by strain at the Haversian level is highly influenced by the subject-specific pore distribution, bone density, loading and osteocyte density. SPH is shown to be effective at capturing the intricate bone pore shapes that evolved over time. Copyright © 2012 John Wiley & Sons, Ltd.

  12. Multiscale characterization of cortical bone composition, microstructure, and nanomechanical properties in experimentally induced osteoporosis.

    Science.gov (United States)

    Shah, Furqan A; Stoica, Adrian; Cardemil, Carina; Palmquist, Anders

    2018-04-01

    Cortical bone plays a vital role in determining overall bone strength. We investigate the structural, compositional, and nanomechanical properties of cortical bone following ovariectomy (OVX) of 12-week-old Sprague Dawley rats, since this animal model is frequently employed to evaluate the performance of implantable biomaterials in compromised bone healing conditions. Morphological parameters and material properties of bone in the geometrical center of the femoral cortex were investigated four and eight weeks post-OVX and in unoperated controls (Ctrl), using X-ray micro-computed tomography, backscattered electron scanning electron microscopy, Raman spectroscopy, and nanoindentation. The OVX animals showed increase in body weight, diminished bone mineral density, increased intracortical porosity, but increased bone mass through periosteal apposition (e.g., increases in periosteal perimeter, cortical cross-sectional thickness, and cross-sectional area). However, osteocyte densities, osteocyte lacunar dimensions, and the nanomechanical behavior on the single mineralized collagen fibril level remained unaffected. Our correlative multiscale investigation provides structural, chemical, and nanomechanical evidence substantiating earlier reports suggesting that rats ovariectomized at 12 weeks undergo simultaneous bone loss and growth, resulting in the effects of OVX being less obvious. Periosteal apposition contradicts the conventional view of bone loss in osteoporosis but appears advantageous for the greater functional demand imposed on the skeleton by increased body weight and fragility induced by increased intracortical porosity. Through a variety of morphological changes, it is likely that 12-week-old rats are able to adapt to OVX-related microstructural and compositional alterations. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 997-1007, 2018. © 2017 Wiley Periodicals, Inc.

  13. Adaptations in tibial cortical thickness and total volumetric bone density in postmenopausal South Asian women with small bone size.

    Science.gov (United States)

    Darling, Andrea L; Hakim, Ohood A; Horton, Khim; Gibbs, Michelle A; Cui, Liang; Berry, Jacqueline L; Lanham-New, Susan A; Hart, Kathryn H

    2013-07-01

    There is some evidence that South Asian women may have an increased risk of osteoporosis compared with Caucasian women, although whether South Asians are at increased risk of fracture is not clear. It is unknown whether older South Asian women differ from Caucasian women in bone geometry. This is the first study, to the authors' knowledge, to use peripheral Quantitative Computed Tomography (pQCT) to measure radial and tibial bone geometry in postmenopausal South Asian women. In comparison to Caucasian women, Asian women had smaller bone size at the 4% (-18% pAsians had increased cortical thickness (-17% p=0.04) at the 38% tibia, (in proportion to bone size (-30% p=0.003)). Furthermore, at the 4% and 14% tibia there were increased total densities (+12% to +29% pAsians. These differences at the 14% and 38% (but not 4%) remained statistically significant after adjustment for Body Mass Index (BMI). These adaptations are similar to those seen previously in Chinese women. Asian women had reduced strength at the radius and tibia, evidenced by the 20-40% reduction in both polar Strength Strain Index (SSIp) and fracture load (under bending). Overall, the smaller bone size in South Asians is likely to be detrimental to bone strength, despite some adaptations in tibial cortical thickness and tibial and radial density which may partially compensate for this. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Synergistic effect of parathyroid hormone and growth hormone on trabecular and cortical bone formation in hypophysectomized rats.

    Science.gov (United States)

    Guevarra, Maria Sarah N; Yeh, James K; Castro Magana, Mariano; Aloia, John F

    2010-01-01

    Growth hormone (GH) deficiency in pediatric patients results in short stature and osteopenia. We postulated that the GH and parathyroid hormone (PTH) combination would result in improvement in bone growth and bone formation. Forty hypophysectomized female rats at age 8 weeks were divided into hypophysectomy (HX), HX + PTH (62.5 microg/kg, s.c. daily), HX + GH (3.33 mg/kg, s.c. daily), and HX + PTH + GH for a 4-week study. GH increased body weight, bone growth, bone mineral content (BMC) and bone mineral density (BMD), whereas PTH increased BMC and BMD without a significant effect on bone size. GH increased both periosteal and endocortical bone formation and cortical size, while PTH increased only endocortical bone formation. GH mitigated the trabecular bone loss by increasing bone formation, while PTH increased bone mass by increasing bone formation and suppressing osteoclast number per bone area. The result of combined intervention shows an increase in trabecular, periosteal and endocortical bone formation and suppression of bone resorption resulting in a synergistic effect on increasing trabecular and cortical bone volume and BMD. The combination treatment of PTH and GH increases bone growth, bone formation, decreases bone resorption and has a synergistic effect on increasing bone density and bone mass. Copyright (c) 2010 S. Karger AG, Basel.

  15. Effect of trabecular bone loss on cortical strain rate during impact in an in vitro model of avian femur

    Directory of Open Access Journals (Sweden)

    Gefen Amit

    2006-07-01

    Full Text Available Abstract Background Osteoporotic hip fractures occur due to loss of cortical and trabecular bone mass and consequent degradation in whole bone strength. The direct cause of most fractures is a fall, and hence, characterizing the mechanical behavior of a whole osteopenic bone under impact is important. However, very little is known about the mechanical interactions between cortical and trabecular bone during impact, and it is specifically unclear to what extent epiphyseal trabecular bone contributes to impact resistance of whole bones. We hypothesized that trabecular bone serves as a structural support to the cortex during impact, and hence, loss of a critical mass of trabecular bone reduces internal constraining of the cortex, and, thereby, decreases the impact tolerance of the whole bone. Methods To test this hypothesis, we conducted cortical strain rate measurements in adult chicken's proximal femora subjected to a Charpy impact test, after removing different trabecular bone core masses to simulate different osteopenic severities. Results We found that removal of core trabecular bone decreased by ~10-fold the cortical strain rate at the side opposite to impact (p Conclusion We conclude that in our in vitro avian model, loss of over 10% of core trabecular bone substantially altered the deformation response of whole bone to impact, which supports the above hypothesis and indicates that integrity of trabecular bone is critical for resisting impact loads.

  16. Determination of dose enhancement in cortical bone substitute material for electron beams

    International Nuclear Information System (INIS)

    Prasad, S.C.

    1991-01-01

    Dose measurements in Witt liquid, which simulates cortical bone, have been compared with dose in water for 6-, 9-, 12-, and 15-MeV electron beams. Measurements were made using a Farmer ionization chamber. The results of the study show dose enhancement in Witt liquid of 5%, 7%, 4%, and 0.4% for 6-, 9-, 12-, and 15 MeV electrons at shallow depths. The dose to a small mass of soft tissue in bone has also been estimated using ionization measurements. The results show a significantly higher dose in bone

  17. Five-year outcome of bone remodelling around implants in the maxillary sinus: assessment of differences between implants placed in autogenous inlay bone blocks and in ungrafted maxilla.

    Science.gov (United States)

    Martuscelli, R; Toti, P; Sbordone, L; Guidetti, F; Ramaglia, L; Sbordone, C

    2014-09-01

    The placement of implants in the posterior maxillary area is considered a reliable procedure, offering recognized rehabilitative advantages. The aim of this study was to evaluate the performance of dental implants placed in the sinus floor augmented with a block autograft by comparing the outcomes over 5 years with those of dental implants positioned in non-augmented bone. This retrospective cohort study included 16 patients who had undergone prosthetic rehabilitation supported by dental implants between 2000 and 2006. One implant per patient was included and assigned to one of two predictor groups: grafted versus ungrafted maxillary sinus. Changes in marginal bone level (MBL) and apical bone level (ABL) over time, at 1, 3, and 5 years, were the primary outcome variables. Appropriate pair-wise comparison tests were performed. No significant differences were seen with regard to ABLs and among times between the grafted group (nine implants) and the ungrafted group (seven implants). Significant marginal bone resorption was found over time, primarily at the buccal aspect, in both study groups. The bone surrounding the apex of dental implants appeared stable after sinus augmentation in the grafted area. The behaviour of the two groups with regard to loss of MBLs over time was very similar. Copyright © 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  18. Cortical bone response to the presence of load-bearing percutaneous osseointegrated prostheses.

    Science.gov (United States)

    Jeyapalina, Sujee; Beck, James Peter; Bachus, Kent N; Bloebaum, Roy D

    2012-09-01

    Although the current percutaneous osseointegrated (OI) prosthetic attachment systems are novel clinical treatments for patients with limb loss, there have only been limited translational studies undertaken to date. To bridge this knowledge gap, from a larger study group of 86 animals that were implanted with a novel percutaneous OI implant construct, 33 sheep were randomly selected from the 0-, 3-, 6-, 9- and 12-month groups for histomorphometric analyses of periprosthetic cortical bone tissue. At necropsy, implanted and nonimplanted limbs were harvested and processed for the evaluation of cortical bone porosity and mineral apposition rate (MAR). The data showed a maximum increase in bone porosity within the first 3 months following implantation and then a progressive reduction in porosity to the baseline steady-state ("Time 0") value by 12 months. The data further verified that the MAR increased during the first 6 months of implantation, reaching a plateau between 6 and 9 months, followed by a progressive decline to the baseline steady state. It was concluded that clinical load bearing and falls precautions, taken during the first 3-6 months following percutaneous OI device implantation surgery, could greatly limit bone fractures during this vulnerable time of increasing cortical bone porosity. Copyright © 2012 Wiley Periodicals, Inc.

  19. Use and preservation methods of bone grafts in small animals

    Directory of Open Access Journals (Sweden)

    Rafael Garabet Agopian

    2016-09-01

    Full Text Available The present review describes the main characteristics of bone grafts used in small animals. Bone grafts are tissues without vasculature, which facilitate the production of new bone cells with osteogenic and osteoinductive factors that lead to the differentiation of cells and structural support for bone marrow. The transplant of a graft is followed by three stages: osteogenesis, or the formation of new bone; osteoinduction, which is the differentiation of cells; and osteoconduction, the process of growth of mesenchymal cells and capillaries that results in new bone formation. The composition of bone grafts may include spongy bone, cortical bone, cortical-spongy bone, cartilage or bone marrow. Grafts can also be classified according to their origin, being autogenous tissue when they are transplanted from the same individual, allogenous (homologous when originating from another individual of the same species, and xenogenous when obtained from a different species.

  20. Machining characteristics of the haversian and plexiform components of bovine cortical bone.

    Science.gov (United States)

    Conward, Michael; Samuel, Johnson

    2016-07-01

    This paper investigates the characteristic differences observed while machining the haversian and plexiform components of a bovine cortical femoral bone. To this end micro-milling slotting experiments are performed on both the components by varying both the cutting velocity and the feed-per-tooth values. The scale of machining is chosen specifically to ensure sensitivity to the microstructural variations in the bone. The material properties of the microstructural components and their size-scale relative to the feed-per-tooth values are seen to dictate the failure mechanisms encountered during machining. The cutting force, surface roughness, and tool wear are all uniquely affected by the plexiform and haversian components of the cortical bone. In general, plexiform bone requires a higher cutting force than the haversian bone. While a higher cutting velocity can lower the surface roughness of haversian bone, it typically results in the most surface damage. The cutting force and surface roughness values for both the components show strain rate sensitivity. The tool wear is seen to be the highest while cutting parallel to the lamellar structures seen in the plexiform bone. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Suppression of autophagy in osteocytes does not modify the adverse effects of glucocorticoids on cortical bone.

    Science.gov (United States)

    Piemontese, Marilina; Onal, Melda; Xiong, Jinhu; Wang, Yiying; Almeida, Maria; Thostenson, Jeff D; Weinstein, Robert S; Manolagas, Stavros C; O'Brien, Charles A

    2015-06-01

    Glucocorticoid excess decreases bone mass and strength in part by acting directly on osteoblasts and osteocytes, but the mechanisms remain unclear. Macroautophagy (herein referred to as autophagy) is a lysosome-based recycling pathway that promotes the turnover of intracellular components and can promote cell function and survival under stressful conditions. Recent studies have shown that glucocorticoids stimulate autophagy in osteocytes, suggesting that autophagy may oppose the negative actions of glucocorticoids on this cell type. To address this possibility, we compared the impact of prednisolone administration on the skeletons of adult mice in which autophagy was suppressed in osteocytes, via deletion of Atg7 with a Dmp1-Cre transgene, to their control littermates. In control mice, prednisolone increased autophagic flux in osteocyte-enriched bone as measured by LC3 conversion, but this change did not occur in the mice lacking Atg7 in osteocytes. Nonetheless, prednisolone reduced femoral cortical thickness, increased cortical porosity, and reduced bone strength to similar extents in mice with and without autophagy in osteocytes. Prednisolone also suppressed osteoblast number and bone formation in the cancellous bone of control mice. As shown previously, Atg7 deletion in osteocytes reduced osteoblast number and bone formation in cancellous bone, but these parameters were not further reduced by prednisolone administration. In cortical bone, prednisolone elevated osteoclast number to a similar extent in both genotypes. Taken together, these results demonstrate that although glucocorticoids stimulate autophagy in osteocytes, suppression of autophagy in this cell type does not worsen the negative impact of glucocorticoids on the skeleton. Published by Elsevier Inc.

  2. Healing of Large Segmental Bone Defect after Implantation of Autogenous Cancellous Bone Graft in Comparison to Hydroxyapatite and 0.5% Collagen Scaffold Combined with Mesenchymal Stem Cells

    Czech Academy of Sciences Publication Activity Database

    Nečas, A.; Proks, P.; Urbanová, L.; Srnec, R.; Stehlík, L.; Crha, M.; Raušer, P.; Plánka, L.; Janovec, J.; Dvořák, M.; Amler, Evžen; Vojtová, L.; Jančář, J.

    2010-01-01

    Roč. 79, č. 4 (2010), s. 607-612 ISSN 0001-7213 R&D Projects: GA MŠk 2B06130 Institutional support: RVO:68378041 Keywords : fracture fixation * bone healing * comminuted fracture Subject RIV: FI - Traumatology, Orthopedics Impact factor: 0.534, year: 2010

  3. Combined estimation of thickness and velocities using ultrasound guided waves: a pioneering study on in vitro cortical bone samples.

    Science.gov (United States)

    Foiret, Josquin; Minonzio, Jean-Gabriel; Chappard, Christine; Talmant, Maryline; Laugier, Pascal

    2014-09-01

    This paper reports for the first time on inverse estimation of several bone properties from guided-wave measurements in human bone samples. Previously, related approaches have focused on ultrasonic estimation of a single bone property at a time. The method is based on two steps: the multi-Lamb mode response is analyzed using the singular value decomposition signal processing method recently introduced in the field, then an identification procedure is run to find thickness and anisotropic elastic properties of the considered specimen. Prior to the measurements on bone, the method is validated on cortical bone-mimicking phantoms. The repeatability and the trueness of the estimated parameters on bone-mimicking phantoms were found around a few percent. Estimation of cortical thickness on bone samples was in good agreement with cortical thickness derived from high-resolution peripheral quantitative computed tomography data analysis of the samples.

  4. Safe Harvesting of Outer Table Parietal Bone Grafts Using an Oscillating Saw and a Bone Scraper : A Refinement of Technique for Harvesting Cortical and "Cancellous"-Like Calvarial Bone

    NARCIS (Netherlands)

    Schortinghuis, Jurjen; Putters, Thomas F.; Raghoebar, Gerry M.

    Calvarial bone is a readily available source of bone for preimplantation augmentation procedures of the alveolar process. However, the calvaria consist mostly of cortical bone, and cancellous bone of the diploic space is scarce. A bone scraper (Safescraper Twist; META, Reggio Emilia, Italy) was used

  5. Mesenchymal stem cells from cortical bone demonstrate increased clonal incidence, potency, and developmental capacity compared to their bone marrow–derived counterparts

    Directory of Open Access Journals (Sweden)

    Daniel Blashki

    2016-08-01

    Full Text Available In this study, we show that matrix dense cortical bone is the more potent compartment of bone than bone marrow as a stromal source for mesenchymal stem cells as isolated from adult rats. Lineage-depleted cortical bone-mesenchymal stem cells demonstrated >150-fold enrichment of colony forming unit–fibroblasts per cell incidence. compared to lineage-depleted bone marrow-mesenchymal stem cells, corresponding to a 70-fold increase in absolute recovered colony forming unit–fibroblasts. The composite phenotype Lin−/CD45−/CD31−/VLA-1+/Thy-1+ enriched for clonogenic mesenchymal stem cells solely from cortical bone–derived cells from which 70% of clones spontaneously differentiated into all lineages of bone, cartilage, and adipose. Both populations generated vascularized bone tissue within subcutaneous implanted collagen scaffolds; however, cortical bone–derived cells formed significantly more osteoid than bone marrow counterparts, quantified by histology. The data demonstrate that our isolation protocol identifies and validates mesenchymal stem cells with superior clonal, proliferative, and developmental potential from cortical bone compared to the bone marrow niche although marrow persists as the typical source for mesenchymal stem cells both in the literature and current pre-clinical therapies.

  6. In situ observation of fracture behavior of canine cortical bone under bending

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Zilan X. [Department of Orthopaedics, Medical University of South Carolina, 96 Jonathan Lucas Street Suite 708 MSC 622, Charleston, SC 29425 (United States); Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States); Xu, Zhi-Hui [Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States); An, Yuehuei H. [Department of Orthopaedics, Medical University of South Carolina, 96 Jonathan Lucas Street Suite 708 MSC 622, Charleston, SC 29425 (United States); Department of Orthopaedic Surgery, Southside Hospital, North Shore-LIJ Health System, 217 East Main Street, Bay Shore, NY 11706 (United States); Li, Xiaodong, E-mail: xl3p@virginia.edu [Department of Mechanical Engineering, University of South Carolina, 300 Main Street, Columbia, SC 29208 (United States); Department of Mechanical and Aerospace Engineering, University of Virginia, 122 Engineer' s Way, Charlottesville, VA 22904 (United States)

    2016-05-01

    Cortical bone provides many important body functions and maintains the rigidness and elasticity of bone. A common failure mode for bone structure is fracture under a bending force. In the current study, the fracture behavior of canine cortical bone under three-point bending was observed in situ using an atomic force microscope (AFM), a scanning electron microscope (SEM), and an optical microscope to examine the fracture process in detail. Nanoindentation was carried out to determine the elastic modulus and hardness of different building blocks of the canine cortical bone. The results have shown that the special structure of Haversian systems has significant effects on directing crack propagation. Although Haversian systems contain previously believed weak points, and micro-cracks initiate within Haversian systems, our findings have demonstrated that macro-cracks typically form around the boundaries of Haversian systems, i.e. the cement lines. Micro-cracks that developed inside Haversian systems have the functions of absorbing and dissipating energy and slow down on expanding when interstitial tissue cannot hold any more pressure, then plastic deformation and fracture occur. - Highlights: • Macro- and micro-cracks occur in unique patterns in the bone fracturing process under a bending force. • Early developed micro-cracks inside Haversian systems absorb and dissipate energy in order to delay fracture initiation. • The mechanical properties of Haverisan systems and its surrounding structures influence the developments of macro- and micro-crack formation. • Previously believed weak spots in the bone matrix are not necessarily the origins of fracture development.

  7. A morphometric and biomechanic comparison of titanium implants inserted in rabbit cortical and cancellous bone.

    Science.gov (United States)

    Sennerby, L; Thomsen, P; Ericson, L E

    1992-01-01

    The removal torques for screw-shaped pure titanium implants inserted in rabbit tibia and the femoral part of the knee joint and the tissue response to these implants, as quantitated with light microscopic morphometry on ground sections, were compared after 6 weeks, 3 months, and 6 months. The bone surrounding the femoral intra-articular implants was mostly cancellous, while cortical bone was formed around the tibial implants. The torque needed to remove the intra-articular implants increased with time, but there was no such increase for the tibial implants. At 6 weeks, significantly less torque was needed to remove the intra-articular implants in spite of the fact that significantly more bone was found in the threads of these implants as compared with the tibial implants. When calculating the amount of bone in threads situated in the cortical and subchondral passage, more was found in the threads of the tibial implants, which corresponded to the higher removal torque. Additional light microscopic observations on implants unscrewed after 12 months in rabbit tibia indicated that rupture occurred between the implant surface and calcified bone. Findings indicate that the resistance to unscrewing is dependent on the amount of compact bone surrounding a titanium implant.

  8. Effect of synthetic cell-binding peptide on the healing of cortical segmental bone defects

    International Nuclear Information System (INIS)

    Cakmak, G.; Bolukbasi, S.; Simsek, A.; Senkoylu, A.; Erdem, O.; Yilmaz, G.

    2006-01-01

    To determine the effect of inorganic bone matric/Pepgen P-15 (ABM/P-15) on the healing of a critical sized segmental defect in a rat radius using a radiological and histological grading system. We carried out this study at the Research Laboratories, Gazi University School of Medicine in 2004. Critical sized segmental defects were created in the radius of 36 Wistar rats. Thirteen defects were filled with ABM/P-15 Flow (gel form), 12 defects were filled with ABM/P-15, and 11 defects were used as a control group. The rats were sacrified at the tenth week, and healing of the defects was evaluated radiographically and histologically. The usage of ABM/P-15 and ABM/P-15 Flow were demonstrated to improve healing of segmental bone defects compared with the control group. Statistical evaluation showed that there were significant differences between control sites, and the sites treated with P-15 and P-15 Flow (p=0.011). The highest radiological and histological grades were achieved by P-15. Segmental cortical bone defects may be treated with ABM/P-15 instead of bone allografts, and autografts. According to the radiological and histological parameters measured in this study, the implantation of ABM/P-15 resulted in optimum healing of the segmental cortical bone defects. Pepgen P-15 has a positive effect on bone healing, without any immunogenic features and disease transmission risk. Therefore, ABM/P-15 can also be used for orthopedic surgery. (author)

  9. Cortical bone growth and maturational changes in dwarf rats induced by recombinant human growth hormone

    Science.gov (United States)

    Martinez, D. A.; Orth, M. W.; Carr, K. E.; Vanderby, R. Jr; Vailas, A. C.

    1996-01-01

    The growth hormone (GH)-deficient dwarf rat was used to investigate recombinant human (rh) GH-induced bone formation and to determine whether rhGH facilitates simultaneous increases in bone formation and bone maturation during rapid growth. Twenty dwarf rats, 37 days of age, were randomly assigned to dwarf plus rhGH (GH; n = 10) and dwarf plus vehicle (n = 10) groups. The GH group received 1.25 mg rhGH/kg body wt two times daily for 14 days. Biochemical, morphological, and X-ray diffraction measurements were performed on the femur middiaphysis. rhGH stimulated new bone growth in the GH group, as demonstrated by significant increases (P < 0.05) in longitudinal bone length (6%), middiaphyseal cross-sectional area (20%), and the amount of newly accreted bone collagen (28%) in the total pool of middiaphyseal bone collagen. Cortical bone density, mean hydroxyapatite crystal size, and the calcium and collagen contents (microgram/mm3) were significantly smaller in the GH group (P < 0.05). Our findings suggest that the processes regulating new collagen accretion, bone collagen maturation, and mean hydroxyapatite crystal size may be independently regulated during rapid growth.

  10. Cortical bone growth and maturational changes in dwarf rats induced by recombinant human growth hormone

    Science.gov (United States)

    Martinez, D. A.; Orth, M. W.; Carr, K. E.; Vanderby, R. Jr; Vailas, A. C.

    1996-01-01

    The growth hormone (GH)-deficient dwarf rat was used to investigate recombinant human (rh) GH-induced bone formation and to determine whether rhGH facilitates simultaneous increases in bone formation and bone maturation during rapid growth. Twenty dwarf rats, 37 days of age, were randomly assigned to dwarf plus rhGH (GH; n = 10) and dwarf plus vehicle (n = 10) groups. The GH group received 1.25 mg rhGH/kg body wt two times daily for 14 days. Biochemical, morphological, and X-ray diffraction measurements were performed on the femur middiaphysis. rhGH stimulated new bone growth in the GH group, as demonstrated by significant increases (P bone length (6%), middiaphyseal cross-sectional area (20%), and the amount of newly accreted bone collagen (28%) in the total pool of middiaphyseal bone collagen. Cortical bone density, mean hydroxyapatite crystal size, and the calcium and collagen contents (microgram/mm3) were significantly smaller in the GH group (P bone collagen maturation, and mean hydroxyapatite crystal size may be independently regulated during rapid growth.

  11. Cortical and trabecular bone are equally affected in rats with renal failure and secondary hyperparathyroidism.

    Science.gov (United States)

    Bajwa, Nikita M; Sanchez, Cheryl P; Lindsey, Richard C; Watt, Heather; Mohan, Subburaman

    2018-02-02

    Changes in mineral metabolism and bone structure develop early in the course of chronic kidney disease and at end-stage are associated with increased risk of fragility fractures. The disruption of phosphorus homeostasis leads to secondary hyperparathyroidism, a common complication of chronic kidney disease. However, the molecular pathways by which high phosphorus influences bone metabolism in the early stages of the disease are not completely understood. We investigated the effects of a high phosphorus diet on bone and mineral metabolism using a 5/6 nephrectomy model of chronic kidney disease. Four-week old rats were randomly assigned into groups: 1) Control with standard diet, 2) Nephrectomy with standard rodent diet, and 3) Nephrectomy with high phosphorus diet. Rats underwent in vivo imaging at baseline, day 14, and day 28, followed by ex vivo imaging. Cortical bone density at the femoral mid-diaphysis was reduced in nephrectomy-control and nephrectomy-high phosphorus compared to control rats. In contrast, trabecular bone mass was reduced at both the lumbar vertebrae and the femoral secondary spongiosa in nephrectomy-high phosphorus but not in nephrectomy-control. Reduced trabecular bone volume adjusted for tissue volume was caused by changes in trabecular number and separation at day 35. Histomorphometry revealed increased bone resorption in tibial secondary spongiosa in nephrectomy-control. High phosphorus diet-induced changes in bone microstructure were accompanied by increased serum parathyroid hormone and fibroblast growth factor 23 levels. Our study demonstrates that changes in mineral metabolism and hormonal dysfunction contribute to trabecular and cortical bone changes in this model of early chronic kidney disease.

  12. Can Cortical Bone Sensitivity be Used as a Practical Indicator of Bone Mineral Density in Postmenopausal Women?

    Directory of Open Access Journals (Sweden)

    Kerem Gün

    2011-08-01

    Full Text Available Aim: Cortical bone pain in patients with osteoporosis is often overlooked in clinical practice. We investigated the relationship between decrease in femur bone mineral density and the local sensitivity in bone cortex of tibia and radius. Patients and Methods: Thirty women with postmenopausal osteoporosis in our outpatient clinic included the study. It was investigated the local sensitivity in bilateral radius and tibia with a standard method and its correlation with femur bone mineral density. Results: The mean age of the patients was 65±8.7 years (43-80 and mean menopause duration was 20±10 years (1-40. The average values of the femoral neck T score and total femur T-score were -3.4±0.7 and -2.6±0.9, respectively. The average local sensitivities of the tibial and radial bone on the right side were 4.6±2.3 and 4.3±2.3, while the average local sensitivities of the tibial and radial bone on the left side were 4.5±2.1 and 4.1±1.4, respectively. We could not find any correlation between decrease in femur bone mineral density and the local sensitivity in bone cortex of the tibia and radius (p>0.05. Conclusion: Percussion initiated the tibial and radial bone sensitivities in patients with postmenopausal osteoporosis method may not be considered as an appropriate clinical evaluation for predicting to bone mineral density. (Turkish Journal of Osteoporosis 2011;17:51-3

  13. Predicting Cortical Bone Strength from DXA and Dental Cone-Beam CT

    Science.gov (United States)

    Hsu, Jui-Ting; Chen, Ying-Ju; Tsai, Ming-Tzu; Lan, Howard Haw-Chang; Cheng, Fu-Chou; Chen, Michael Y. C.; Wang, Shun-Ping

    2012-01-01

    Objective This study compared the capabilities of dual-energy X-ray absorptiometry (DXA) and dental cone-beam computed tomography (CBCT) for predicting the cortical bone strength of rat femurs and tibias. Materials and Methods Specimens of femurs and tibias obtained from 14 rats were first scanned with DXA to obtain the areal bone mineral density (BMD) of the midshaft cortical portion of the bones. The bones were then scanned using dental CBCT to measure the volumetric cortical bone mineral density (vCtBMD) and the cross-sectional moment of inertia (CSMI) for calculating the bone strength index (BSI). A three-point bending test was conducted to measure the fracture load of each femur and tibia. Bivariate linear Pearson analysis was used to calculate the correlation coefficients (r values) among the CBCT measurements, DXA measurements, and three-point bending parameters. Results The correlation coefficients for the associations of the fracture load with areal BMD (measured using DXA), vCtBMD (measured using CBCT), CSMI (measured using CBCT), and BSI were 0.585 (p = 0.028) and 0.532 (p = 0.050) (for the femur and tibia, respectively), 0.638 (p = 0.014) and 0.762 (p = 0.002), 0.778 (p = 0.001) and 0.792 (pfracture loads in rat femurs and tibias. The BSI, which is a combined index of densitometric and geometric parameters, was especially useful. Further clinical studies are needed to validate the predictive value of BSI obtained from CBCT and should include testing on human cadaver specimens. PMID:23226234

  14. Micro-computed tomography of fatigue microdamage in cortical bone using a barium sulfate contrast agent.

    Science.gov (United States)

    Leng, Huijie; Wang, Xiang; Ross, Ryan D; Niebur, Glen L; Roeder, Ryan K

    2008-01-01

    Accumulation of microdamage during fatigue can lead to increased fracture susceptibility in bone. Current techniques for imaging microdamage in bone are inherently destructive and two-dimensional. Therefore, the objective of this study was to image the accumulation of fatigue microdamage in cortical bone using micro-computed tomography (micro-CT) with a barium sulfate (BaSO(4)) contrast agent. Two symmetric notches were machined on the tensile surface of bovine cortical bone beams in order to generate damage ahead of the stress concentrations during four-point bending fatigue. Specimens were loaded to a specified number of cycles or until one notch fractured, such that the other notch exhibited the accumulation of microdamage prior to fracture. Microdamage ahead of the notch was stained in vitro by precipitation of BaSO(4) and imaged using micro-CT. Reconstructed images showed a distinct region of bright voxels around the notch tip or along propagating cracks due to the presence of BaSO(4), which was verified by backscattered electron imaging and energy dispersive spectroscopy. The shape of the stained region ahead of the notch tip was consistent with principal strain contours calculated by finite element analysis. The relative volume of the stained region was correlated with the number of loading cycles by non-linear regression using a power-law. This study demonstrates new methods for the non-destructive and three-dimensional detection of fatigue microdamage accumulation in cortical bone in vitro, which may be useful to gain further understanding into the role of microdamage in bone fragility.

  15. Quantitative CBCT evaluation of maxillary and mandibular cortical bone thickness and density variability for orthodontic miniplate placement.

    Science.gov (United States)

    Rossi, Margherita; Bruno, Giovanni; De Stefani, Alberto; Perri, Alessandro; Gracco, Antonio

    2017-12-01

    To assess whether cortical bone thickness and density vary in relation to age, sex and skeletal pattern at the maxillary and mandibular areas suitable for miniplates placement for orthodontic purposes. CBCT of 92 subjects (42 males and 50 females) with skeletal class I, II or III malocclusion, divided between adolescents and adults, were examined. InVivoDental ® software (Anatomage Inc, USA) was used to measure 34 maxillary areas and 40 mandibular areas per side. Values obtained were then compared between the groups of subjects. Statistical analysis was performed using the non-parametric Wilcoxon-Mann-Whitney rank-sum test for independent samples. No significant differences were found in the cortical bone thickness values between the three skeletal patterns, and according to sex and age. Both maxilla and mandible showed an increase in cortical bone thickness from the anterior towards the posterior regions, and from the alveolar boneto the basal bone. Cortical bone density significantly varied in relation to the subject's age, with adults always showing higher values. Slight clinically significant differences were found between the three skeletal patterns and sex. In terms of cortical bone thickness, age, sex and skeletal pattern do not represent valid decision criteria for the evaluation of the best insertion areas for miniplates, while in terms of cortical bone density, only age is useful as a decision criterion. Copyright © 2017 CEO. Published by Elsevier Masson SAS. All rights reserved.

  16. The effects of glucocorticoid on microarchitecture, collagen, mineral and mechanical properties of sheep femur cortical bone

    DEFF Research Database (Denmark)

    Ding, Ming; Danielsen, Carl Christian; Overgaard, Søren

    2012-01-01

    of 3 months without treatment. Group 3 was left untreated and served as controls. All sheep received a restricted diet with low calcium and phosphorus. At sacrifice, cortical bone samples from the femur midshaft of each sheep were harvested, micro-CT scanned and subjected to three-point bending....... Collagen content was significantly increased in the glucocorticoid-2 compared with the glucocorticoid-1 and control groups. Bone mineral content did not differ between the groups. Neither the three-point bending mechanical properties nor the tensile mechanical properties differed significantly between...... the groups, while there was a trend towards decreasing bending mechanical properties in the glucocorticoid-2 group. In conclusion, 7 months of glucocorticoid treatment with malnutrition had a significant impact on the cortical microarchitecture of the sheep femur midshaft. These observed changes occurred 3...

  17. CD44 deficiency inhibits unloading-induced cortical bone loss through downregulation of osteoclast activity.

    Science.gov (United States)

    Li, Yuheng; Zhong, Guohui; Sun, Weijia; Zhao, Chengyang; Zhang, Pengfei; Song, Jinping; Zhao, Dingsheng; Jin, Xiaoyan; Li, Qi; Ling, Shukuan; Li, Yingxian

    2015-11-04

    The CD44 is cellular surface adhesion molecule that is involved in physiological processes such as hematopoiesis, lymphocyte homing and limb development. It plays an important role in a variety of cellular functions including adhesion, migration, invasion and survival. In bone tissue, CD44 is widely expressed in osteoblasts, osteoclasts and osteocytes. However, the mechanisms underlying its role in bone metabolism remain unclear. We found that CD44 expression was upregulated during osteoclastogenesis. CD44 deficiency in vitro significantly inhibited osteoclast activity and function by regulating the NF-κB/NFATc1-mediated pathway. In vivo, CD44 mRNA levels were significantly upregulated in osteoclasts isolated from the hindlimb of tail-suspended mice. CD44 deficiency can reduce osteoclast activity and counteract cortical bone loss in the hindlimb of unloaded mice. These results suggest that therapeutic inhibition of CD44 may protect from unloading induced bone loss by inhibiting osteoclast activity.

  18. Application of Autogenous Periosteum as a Membrane in Sinus Lifting

    African Journals Online (AJOL)

    2018-01-24

    Jan 24, 2018 ... Keywords: Autogenous periosteum, barrier membrane, new bone formation, ... cases of fracture and provides the nutritional needs of bone.[4] It has been shown by experimental studies that the periosteum contributes positively to osteogenesis and ..... The cell and molecular biology of fracture healing.

  19. Role of microstructure in the aging-related deterioration of the toughness of human cortical bone

    International Nuclear Information System (INIS)

    Nalla, R.K.; Kruzic, J.J.; Kinney, J.H.; Balooch, M.; Ager, J.W.; Ritchie, R.O.

    2006-01-01

    The aging-related deterioration of the fracture properties of bone, coupled with higher life expectancy, is responsible for increasing incidence of bone fracture in the elderly; consequently, an understanding of how these fracture properties degrade with age is essential. In this study, ex vivo fracture experiments have been performed to quantitatively assess the effect of age on human cortical bone in the proximal-distal orientation, i.e., longitudinally along the osteons. Because cortical bone exhibits rising crack-growth resistance with crack extension, the toughness is evaluated in terms of resistance-curve (R-curve) behavior, measured for bone taken from wide range of age groups (34-99 years). Using this approach, both the crack-initiation and crack-growth toughness are determined and are found to deteriorate with age; the initiation toughness decreases some 40% over six decades from 40 to 100 years, while the growth toughness is effectively eliminated over the same age range. The reduction in crack-growth toughness is considered to be associated primarily with a degradation in the degree of extrinsic toughening, in particular, involving crack bridging in the wake of the crack. An examination of the micro-/nano-structural changes accompanying the process of aging, using optical microscopy, X-ray tomography, nanoindentation and Raman spectroscopy, is shown to support such observations

  20. The effect of osteoporosis treatments on fatigue properties of cortical bone tissue

    Directory of Open Access Journals (Sweden)

    Garry R. Brock

    2015-06-01

    Full Text Available Bisphosphonates are commonly prescribed for treatment of osteoporosis. Long-term use of bisphosphonates has been correlated to atypical femoral fractures (AFFs. AFFs arise from fatigue damage to bone tissue that cannot be repaired due to pharmacologic treatments. Despite fatigue being the primary damage mechanism of AFFs, the effects of osteoporosis treatments on fatigue properties of cortical bone are unknown. To examine if fatigue-life differences occur in bone tissue after different pharmacologic treatments for osteoporosis, we tested bone tissue from the femurs of sheep given a metabolic acidosis diet to induce osteoporosis, followed by treatment with a selective estrogen reception modulator (raloxifene, a bisphosphonate (alendronate or zoledronate, or parathyroid hormone (teriparatide, PTH. Beams of cortical bone tissue were created and tested in four-point bending fatigue to failure. Tissue treated with alendronate had reduced fatigue life and less modulus loss at failure compared with other treatments, while tissue treated with PTH had a prolonged fatigue life. No loss of fatigue life occurred with zoledronate treatment despite its greater binding affinity and potency compared with alendronate. Tissue mineralization measured by microCT did not explain the differences seen in fatigue behavior. Increased fatigue life with PTH suggests that current treatment methods for AFF could have beneficial effects for restoring fatigue life. These results indicate that fatigue life differs with each type of osteoporosis treatment.

  1. Mechanotransduction in cortical bone and the role of piezoelectricity: a numerical approach.

    Science.gov (United States)

    Stroe, M C; Crolet, J M; Racila, M

    2013-01-01

    This paper is a contribution to a plausible explanation of the mechanotransduction phenomenon in cortical bone during its remodelling. Our contribution deals only with the mechanical processes and the biological aspects have not been taken into account. It is well known that osteoblasts are able to generate bone in a suitable bony substitute only under fluid action. But the bone created in this manner is not organised to resist specific mechanical stress. Our aim was to suggest the nature of the physical information that can be transmitted - directly or via a biological or biochemical process - to the cell to initiate a cellular activity inducing the reconstruction of the osteon that is best adapted to local mechanical stresses. For this, the cell must have, from our point of view, a good knowledge of its structural environment. But this knowledge exists at the cellular scale while the bone is loaded at the macroscopic scale. This study is based on the SiNuPrOs model that allows exchange of information between the different structural scales of cortical bone. It shows that more than the fluid, the collagen - via its piezoelectric properties - plays an essential role in the transmission of information between the macroscopic and nanoscopic scales. Moreover, this process allows us to explain various dysfunctions and even some diseases.

  2. Effective mechanical properties of diaphyseal cortical bone in the canine femur

    OpenAIRE

    Autefage, André; Palierne, Sophie; Charron, Clémentine; Swider, Pascal

    2012-01-01

    International audience; The effective elastic modulus, yield strength, yield strain, ultimate strength, ultimate strain, strain energy density at yield and strain energy density at ultimate failure of femoral diaphyseal cortical bone were investigated on canine femurs. Four femurs representative of the canine population were selected from four statistically-determined clusters based on increasing size and weight comprising the Toy poodle (5 kg), Poodle (12 kg), German shorthaired pointer (25 ...

  3. Calorie restriction aggravated cortical and trabecular bone architecture in ovariectomy-induced estrogen-deficient rats.

    Science.gov (United States)

    Ahn, Hyejin; Seo, Dong-Hyun; Kim, Han Sung; Choue, Ryowon

    2014-08-01

    We hypothesized that calorie restriction (CR) and estrogen deficiency (ovariectomy [OVX]) would aggravate bone biomarkers and structural parameters in rats. Seven-week-old female Sprague-Dawley rats were randomized to sham-operated groups and fed either an ad libitum diet (SHAM-AL) or a CR diet (SHAM-CR); ovariectomy-operated groups were fed an ad libitum diet (OVX-AL) or a CR diet (OVX-CR). For 8 weeks, the OVX-AL and SHAM-AL groups were fed the same diet, whereas CR groups were fed a diet containing 50% fewer calories. Bone-related biomarkers and structural parameters (OC; deoxypyridinoline [DPD]; N-terminal telopeptide, NTx; architecture and mineralization; and microcomputed tomography images) were analyzed at the end of the experiment. The serum OC levels of calorie-restricted groups (SHAM-CR and OVX-CR) were significantly lower than those of the AL groups (SHAM-AL and OVX-AL) (P calorie-restricted and ovariectomized groups were higher than those of their counterparts (P calorie-restricted groups were higher than those of AL groups (P calorie-restricted and ovariectomized groups had lower values of bone volume to total volume, trabecular number, and bone mineral density, but higher values of trabecular separation than those of their counterparts (P calorie-restricted groups had reduced values of bone volume, mean polar moment of inertia, and cortical thickness compared to the AL groups (P < .05). In conclusion, severe CR with or without OVX during the growth period in rats is equally detrimental to bone; CR has detrimental effects on trabecular and cortical bone; and estrogen deficiency only had an effect on trabecular bone. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Towards assessing cortical bone porosity using low-frequency quantitative acoustics: A phantom-based study.

    Directory of Open Access Journals (Sweden)

    Florian Vogl

    Full Text Available Cortical porosity is a key characteristic governing the structural properties and mechanical behaviour of bone, and its quantification is therefore critical for understanding and monitoring the development of various bone pathologies such as osteoporosis. Axial transmission quantitative acoustics has shown to be a promising technique for assessing bone health in a fast, non-invasive, and radiation-free manner. One major hurdle in bringing this approach to clinical application is the entanglement of the effects of individual characteristics (e.g. geometry, porosity, anisotropy etc. on the measured wave propagation. In order to address this entanglement problem, we therefore propose a systematic bottom-up approach, in which only one bone property is varied, before addressing interaction effects. This work therefore investigated the sensitivity of low-frequency quantitative acoustics to changes in porosity as well as individual pore characteristics using specifically designed cortical bone phantoms.14 bone phantoms were designed with varying pore size, axial-, and radial pore number, resulting in porosities (bone volume fraction between 0% and 15%, similar to porosity values found in human cortical bone. All phantoms were manufactured using laser sintering, measured using axial-transmission acoustics and analysed using a full-wave approach. Experimental results were compared to theoretical predictions based on a modified Timoshenko theory.A clear dependence of phase velocity on frequency and porosity produced by increasing pore size or radial pore number was demonstrated, with the velocity decreasing by between 2-5 m/s per percent of additional porosity, which corresponds to -0.5% to -1.0% of wave speed. While the change in phase velocity due to axial pore number was consistent with the results due to pore size and radial pore number, the relative uncertainties for the estimates were too high to draw any conclusions for this parameter.This work has

  5. Automated classification of mandibular cortical bone on dental panoramic radiographs for early detection of osteoporosis

    Science.gov (United States)

    Horiba, Kazuki; Muramatsu, Chisako; Hayashi, Tatsuro; Fukui, Tatsumasa; Hara, Takeshi; Katsumata, Akitoshi; Fujita, Hiroshi

    2015-03-01

    Findings on dental panoramic radiographs (DPRs) have shown that mandibular cortical index (MCI) based on the morphology of mandibular inferior cortex was significantly correlated with osteoporosis. MCI on DPRs can be categorized into one of three groups and has the high potential for identifying patients with osteoporosis. However, most DPRs are used only for diagnosing dental conditions by dentists in their routine clinical work. Moreover, MCI is not generally quantified but assessed subjectively. In this study, we investigated a computer-aided diagnosis (CAD) system that automatically classifies mandibular cortical bone for detection of osteoporotic patients at early stage. First, an inferior border of mandibular bone was detected by use of an active contour method. Second, regions of interest including the cortical bone are extracted and analyzed for its thickness and roughness. Finally, support vector machine (SVM) differentiate cases into three MCI categories by features including the thickness and roughness. Ninety eight DPRs were used to evaluate our proposed scheme. The number of cases classified to Class I, II, and III by a dental radiologist are 56, 25 and 17 cases, respectively. Experimental result based on the leave-one-out cross-validation evaluation showed that the sensitivities for the classes I, II, and III were 94.6%, 57.7% and 94.1%, respectively. Distribution of the groups in the feature space indicates a possibility of MCI quantification by the proposed method. Therefore, our scheme has a potential in identifying osteoporotic patients at an early stage.

  6. Three-dimensional mapping of cortical bone thickness in subjects with different vertical facial dimensions

    Directory of Open Access Journals (Sweden)

    Mais Medhat Sadek

    2016-10-01

    Full Text Available Abstract Background The purpose of this study was to determine differences in cortical bone thickness among subjects with different vertical facial dimensions using cone beam computed tomography (CBCT. Methods From 114 pre-treatment CBCT scans, 48 scans were selected to be included in the study. CBCT-synthesized lateral cephalograms were used to categorize subjects into three groups based on their vertical skeletal pattern. Cortical bone thickness (CBT at two vertical levels (4 and 7 mm from the alveolar crest were measured in the entire tooth-bearing region in the maxilla and mandible. Results Significant group differences were detected with high-angle subjects having significantly narrower inter-radicular CBT at some sites as compared to average- and low-angle subjects. Conclusions Inter-radicular cortical bone is thinner in high-angle than in average- or low-angle subjects in few selected sites at the vertical height in which mini-implants are commonly inserted for orthodontic anchorage.

  7. Investigation of hyperelastic models for nonlinear elastic behavior of demineralized and deproteinized bovine cortical femur bone.

    Science.gov (United States)

    Hosseinzadeh, M; Ghoreishi, M; Narooei, K

    2016-06-01

    In this study, the hyperelastic models of demineralized and deproteinized bovine cortical femur bone were investigated and appropriate models were developed. Using uniaxial compression test data, the strain energy versus stretch was calculated and the appropriate hyperelastic strain energy functions were fitted on data in order to calculate the material parameters. To obtain the mechanical behavior in other loading conditions, the hyperelastic strain energy equations were investigated for pure shear and equi-biaxial tension loadings. The results showed the Mooney-Rivlin and Ogden models cannot predict the mechanical response of demineralized and deproteinized bovine cortical femur bone accurately, while the general exponential-exponential and general exponential-power law models have a good agreement with the experimental results. To investigate the sensitivity of the hyperelastic models, a variation of 10% in material parameters was performed and the results indicated an acceptable stability for the general exponential-exponential and general exponential-power law models. Finally, the uniaxial tension and compression of cortical femur bone were studied using the finite element method in VUMAT user subroutine of ABAQUS software and the computed stress-stretch curves were shown a good agreement with the experimental data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Osteostatin-coated porous titanium can improve early bone regeneration of cortical bone defects in rats

    NARCIS (Netherlands)

    Van Der Stok, Johan; Lozano, Daniel; Chai, Yoke Chin; Amin Yavari, Saber; Bastidas Coral, Angela P.; Verhaar, Jan A N; Gómez-Barrena, Enrique; Schrooten, Jan; Jahr, Holger; Zadpoor, Amir A.; Esbrit, Pedro; Weinans, Harrie

    2015-01-01

    A promising bone graft substitute is porous titanium. Porous titanium, produced by selective laser melting (SLM), can be made as a completely open porous and load-bearing scaffold that facilitates bone regeneration through osteoconduction. In this study, the bone regenerative capacity of porous

  9. Insulin Resistance and the IGF-I-Cortical Bone Relationship in Children Ages 9 to 13 Years.

    Science.gov (United States)

    Kindler, Joseph M; Pollock, Norman K; Laing, Emma M; Oshri, Assaf; Jenkins, Nathan T; Isales, Carlos M; Hamrick, Mark W; Ding, Ke-Hong; Hausman, Dorothy B; McCabe, George P; Martin, Berdine R; Hill Gallant, Kathleen M; Warden, Stuart J; Weaver, Connie M; Peacock, Munro; Lewis, Richard D

    2017-07-01

    IGF-I is a pivotal hormone in pediatric musculoskeletal development. Although recent data suggest that the role of IGF-I in total body lean mass and total body bone mass accrual may be compromised in children with insulin resistance, cortical bone geometric outcomes have not been studied in this context. Therefore, we explored the influence of insulin resistance on the relationship between IGF-I and cortical bone in children. A secondary aim was to examine the influence of insulin resistance on the lean mass-dependent relationship between IGF-I and cortical bone. Children were otherwise healthy, early adolescent black and white boys and girls (ages 9 to 13 years) and were classified as having high (n = 147) or normal (n = 168) insulin resistance based on the homeostasis model assessment of insulin resistance (HOMA-IR). Cortical bone at the tibia diaphysis (66% site) and total body fat-free soft tissue mass (FFST) were measured by peripheral quantitative computed tomography (pQCT) and dual-energy X-ray absorptiometry (DXA), respectively. IGF-I, insulin, and glucose were measured in fasting sera and HOMA-IR was calculated. Children with high HOMA-IR had greater unadjusted IGF-I (p insulin resistance as a potential suppressor of IGF-I-dependent cortical bone development, though prospective studies are needed. © 2017 American Society for Bone and Mineral Research. © 2017 American Society for Bone and Mineral Research.

  10. Bone loss in the lower leg during 35 days of bed rest is predominantly from the cortical compartment

    OpenAIRE

    Rittweger, Joern; Mekjavić, Igor B.; Eiken, Ola; Pišot, Rado; Biolo, Gianni; Cirillo, Massimo; De Santo, Natale Gaspare; Bilancio, Giancarlo; Šimunič, Boštjan; Narici, Marco

    2013-01-01

    Immobilization-induced bone loss is usually greater in the epiphyses than in the diaphyses. The larger fraction of trabecular bone in the epiphyses than in the diaphyses offers an intuitive explanation to account for this phenomenon. However, recent evidence contradicts this notion and suggests that immobilization-induced bone loss from the distal tibia epiphysis is mainly from the cortical compartment. The aim of this study was to establish whether this pattern of bone loss was a general rul...

  11. Correlation between the thickness of the crestal and buccolingual cortical bone at varying depths and implant stability quotients.

    Directory of Open Access Journals (Sweden)

    Kanthanat Chatvaratthana

    Full Text Available Resonance frequency analysis (RFA is clinically used in dentistry to access the stiffness of dental implants in surrounding bone. However, the clear advantages and disadvantages of this method are still inconclusive. The aim of this study was to investigate and compare implant stability quotient (ISQ values obtained from RFA with parameters obtained from a cone beam computed tomography (CBCT scan of the same region.Nineteen implants (Conelog were inserted in the posterior maxillary and mandibular partially edentulous regions of 16 patients. At the time of implant placement, the ISQ values were obtained using RFA (Osstell. CBCT was used to measure the thickness of the crestal, cortical, buccolingual cortical, and cancellous bone at 3, 6, and 9 mm below the crestal bone level, as indicated by radiographic markers. The ratio of the thickness of the cortical to cancellous bone at varying depths was also calculated and classified into 4 groups (Group 1-4.There was a strong correlation between the crestal cortical bone thickness and ISQ values (P<0.001. The thickness of the buccolingual cortical bone and ratio of the cortical to cancellous bone thickness at 3 mm were significantly related to the ISQ (P = 0.018 and P = 0.034, respectively. Furthermore, the ISQs in Group 1 were the highest compared with those in Group 2 and Group 3, whereas the CBCT parameters at 6 and 9 mm did not have any specific correlation with the ISQ values.This study showed that the ISQ values obtained from RFA highly correlated with the quantity and quality of bone 3 mm below the crestal bone level. The correlation between the ISQ and bone surrounding the implant site was dependent on the depth of measurement. Therefore, RFA can help to predict the marginal bone level, as confirmed in this study.

  12. Mechanical properties of bovine cortical bone based on the automated ball indentation technique and graphics processing method.

    Science.gov (United States)

    Zhang, Airong; Zhang, Song; Bian, Cuirong

    2018-02-01

    Cortical bone provides the main form of support in humans and other vertebrates against various forces. Thus, capturing its mechanical properties is important. In this study, the mechanical properties of cortical bone were investigated by using automated ball indentation and graphics processing at both the macroscopic and microstructural levels under dry conditions. First, all polished samples were photographed under a metallographic microscope, and the area ratio of the circumferential lamellae and osteons was calculated through the graphics processing method. Second, fully-computer-controlled automated ball indentation (ABI) tests were performed to explore the micro-mechanical properties of the cortical bone at room temperature and a constant indenter speed. The indentation defects were examined with a scanning electron microscope. Finally, the macroscopic mechanical properties of the cortical bone were estimated with the graphics processing method and mixture rule. Combining ABI and graphics processing proved to be an effective tool to obtaining the mechanical properties of the cortical bone, and the indenter size had a significant effect on the measurement. The methods presented in this paper provide an innovative approach to acquiring the macroscopic mechanical properties of cortical bone in a nondestructive manner. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Early loading of implants in the atrophic posterior maxilla: lateral sinus lift with autogenous bone and Bio-Oss versus crestal mini sinus lift and 8-mm hydroxyapatite-coated implants. A randomised controlled clinical trial.

    Science.gov (United States)

    Cannizzaro, Gioacchino; Felice, Pietro; Leone, Michele; Viola, Paolo; Esposito, Marco

    2009-01-01

    To evaluate the efficacy of 10- to 16-mm-long implants inserted in maxillary sinuses augmented according to a lateral approach technique with 50% particulated autogenous bone harvested from the oral cavity and 50% Bio-Oss, versus 8-mm-long hydroxyapatite-coated implants placed in crestally augmented sinuses with autogenous bone according to the Cosci technique. All implants were early loaded at 45 days after placement. Forty partially or fully edentulous patients having 3 to 6 mm of residual crestal height and at least 4 mm thickness below the maxillary sinuses (measured on a CT scan) were randomised to receive one to three, 10- to 16-mm-long implants (20 patients) after lateral sinus lifting with 50% anorganic bovine (Bio-Oss) and 50% autogenous bone, or 8-mm-long implants (20 patients) after crestal sinus lifting with autogenous bone. Implants were submerged and left to heal for 45 days. Within 1 week of abutment connection, implants were loaded with screw-retained full acrylic provisional prostheses. Definitive metal-ceramic prostheses were provisionally cemented 45 days after abutment connection. Outcome measures were the number of prosthesis and implant failures, and any complications. In addition, the stability of individual implants was assessed with Osstell and Periotest at abutment connection (baseline) and after 1 year of loading by a blinded outcome assessor. All patients were followed up for 1 year after loading. No patient dropped out. In three patients of the 8-mm implant group, primary stability could not be initially obtained. However, after immediately replacing the unstable implants with implants with a larger diameter, sufficient primary stability was obtained. One implant failed in the short implant group and five implants failed in three patients of the longer implant group. The difference was not statistically significant. There were no differences in complications between groups. However, two major post-operative complications occurred in the

  14. Autogenous Deformation of Concrete

    DEFF Research Database (Denmark)

    Autogenous deformation of concrete can be defined as the free deformation of sealed concrete at a constant temperature. A number of observed problems with early age cracking of high-performance concretes can be attributed to this phenomenon. During the last 10 years , this has led to an increased...... focus on autogenous deformation both within concrete practice and concrete research. Since 1996 the interest has been significant enough to hold international, yearly conferences entirely devoted to this subject. The papers in this publication were presented at two consecutive half-day sessions...... at the American Concrete Institute’s Fall Convention in Phoenix, Arizona, October 29, 2002. All papers have been reviewed according to ACI rules. This publication, as well as the sessions, was sponsored by ACI committee 236, Material Science of Concrete. The 12 presentations from 8 different countries indicate...

  15. Relationships between the anisotropy of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone.

    Science.gov (United States)

    Yamamoto, Kazufumi; Nakatsuji, Tomohiro; Yaoi, Yuichiro; Yamato, Yu; Yanagitani, Takahiko; Matsukawa, Mami; Yamazaki, Kaoru; Matsuyama, Yukihiro

    2012-03-01

    Quantitative ultrasound (QUS) is now widely used for evaluating bone in vivo, because obtained ultrasonic wave properties directly reflect the visco-elasticity. Bone tissue is composed of minerals like hydroxyapatite (HAp) and a collagen matrix. HAp crystallites orientation is thus one parameter of bone elasticity. In this study, we experimentally investigated the anisotropy of ultrasonic wave velocity and the HAp crystallites orientation in the axial-radial and axial-tangential planes in detail, using cylindrical specimens obtained from the cortical bone of three bovine femurs. Longitudinal bulk wave propagation was investigated by using a conventional ultrasonic pulse system. We used the one cycle of sinusoidal pulse which was emitted from wide band transmitter. The nominal frequency of the pulse was 1MHz. First, we investigated the anisotropy of longitudinal wave velocity, measuring the anisotropy of velocity in two planes using cylindrical specimens obtained from identical bone areas. The wave velocity changed due to the rotation angle, showing the maximum value in the direction a little off the bone axis. Moreover, X-ray pole figure measurements also indicated that there were small tilts in the HAp crystallites orientation from the bone axis. The tilt angles were similar to those of the highest velocity direction. There were good correlations between velocity and HAp crystallites orientation obtained in different directions. However, a comparatively low correlation was found in posterior bone areas, which shows the stronger effects of bone microstructure. In the radial-tangential plane, where the HAp crystallites hardly ever align, weak anisotropy of velocity was found which seemed to depend on the bone microstructure. Copyright © 2011 Elsevier B.V. All rights reserved.

  16. Micromotion analysis of different implant configuration, bone density, and crestal cortical bone thickness in immediately loaded mandibular full-arch implant restorations: A nonlinear finite element study.

    Science.gov (United States)

    Sugiura, Tsutomu; Yamamoto, Kazuhiko; Horita, Satoshi; Murakami, Kazuhiro; Kirita, Tadaaki

    2018-02-01

    Excessive micromotion may cause failure of osseointegration between the implant and bone. This study investigated the effects of implant configuration, bone density, and crestal cortical bone thickness on micromotion in immediately loaded mandibular full-arch implant restorations. A finite element model of the edentulous mandible was constructed. Four implants were inserted in two different configurations, which were four parallel implants or tilted distal implants according to the all-on-four concept. Different cancellous bone densities and crestal cortical bone thicknesses were simulated. The framework was made of acrylic resin. A vertical load of 200 N was applied at the cantilever or on the distal implant (noncantilever loading). The maximum extent of micromotion was significantly influenced by the density of cancellous bone and to a lesser extent by implant configuration and the crestal cortical bone thickness. The all-on-four configuration showed less micromotion than the parallel implant configuration in some circumstances. The maximum micromotion detected with noncantilever loading was less than 1/3 of that with cantilever loading. Implant configuration had a limited influence on micromotion. Avoiding cantilever loading during the healing period should effectively reduce the risk of excessive micromotion in patients with low-density cancellous bone and thin crestal cortical bone. © 2017 Wiley Periodicals, Inc.

  17. Organ and tissue level properties are more sensitive to age than osteocyte lacunar characteristics in rat cortical bone

    DEFF Research Database (Denmark)

    Wittig, Nina; Bach-Gansmo, Fiona Linnea; Birkbak, Mie Elholm

    2016-01-01

    of bone on the organ and tissue level, whereas features on the nano- and micrometer scale are much less explored. We investigated the age-related development of organ and tissue level bone properties such as bone volume, bone mineral density, and load to fracture and correlated these with osteocyte...... lacunar properties in rat cortical bone. Femora of 14 to 42-week-old female Wistar rats were investigated using multiple complementary techniques including X-ray micro-computed tomography and biomechanical testing. The body weight, femoral length, aBMD, load to fracture, tissue volume, bone volume...

  18. Dark-field transmission electron microscopy of cortical bone reveals details of extrafibrillar crystals.

    Science.gov (United States)

    Schwarcz, Henry P; McNally, Elizabeth A; Botton, Gianluigi A

    2014-12-01

    In a previous study we showed that most of the mineral in bone is present in the form of "mineral structures", 5-6nm-thick, elongated plates which surround and are oriented parallel to collagen fibrils. Using dark-field transmission electron microscopy, we viewed mineral structures in ion-milled sections of cortical human bone cut parallel to the collagen fibrils. Within the mineral structures we observe single crystals of apatite averaging 5.8±2.7nm in width and 28±19nm in length, their long axes oriented parallel to the fibril axis. Some appear to be composite, co-aligned crystals as thin as 2nm. From their similarity to TEM images of crystals liberated from deproteinated bone we infer that we are viewing sections through platy crystals of apatite that are assembled together to form the mineral structures. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Ultrasonic wave propagation in viscoelastic cortical bone plate coupled with fluids: a spectral finite element study.

    Science.gov (United States)

    Nguyen, Vu-Hieu; Naili, Salah

    2013-01-01

    This work deals with the ultrasonic wave propagation in the cortical layer of long bones which is known as being a functionally graded anisotropic material coupled with fluids. The viscous effects are taken into account. The geometrical configuration mimics the one of axial transmission technique used for evaluating the bone quality. We present a numerical procedure adapted for this purpose which is based on the spectral finite element method (FEM). By using a combined Laplace-Fourier transform, the vibroacoustic problem may be transformed into the frequency-wavenumber domain in which, as radiation conditions may be exactly introduced in the infinite fluid halfspaces, only the heterogeneous solid layer needs to be analysed using FEM. Several numerical tests are presented showing very good performance of the proposed approach. We present some results to study the influence of the frequency on the first arriving signal velocity in (visco)elastic bone plate.

  20. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis).

    Science.gov (United States)

    McGee, Meghan E; Maki, Aaron J; Johnson, Steven E; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2008-02-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. Here we show decreased cortical bone turnover during hibernation with balanced formation and resorption in grizzly bear femurs. Hibernating grizzly bear femurs were less porous and more mineralized, and did not demonstrate any changes in cortical bone geometry or whole bone mechanical properties compared to active grizzly bear femurs. The activation frequency of intracortical remodeling was 75% lower during hibernation than during periods of physical activity, but the normalized mineral apposition rate was unchanged. These data indicate that bone turnover decreases during hibernation, but osteons continue to refill at normal rates. There were no changes in regional variation of porosity, geometry, or remodeling indices in femurs from hibernating bears, indicating that hibernation did not preferentially affect one region of the cortex. Thus, grizzly bears prevent bone loss during disuse by decreasing bone turnover and maintaining balanced formation and resorption, which preserves bone structure and strength. These results support the idea that bears possess a biological mechanism to prevent disuse osteoporosis.

  1. Mechanical test and fractal analysis on anisotropic fracture of cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Yin, Dagang [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044 (China); College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Chen, Bin, E-mail: bchen@cqu.edu.cn [State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044 (China); College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Ye, Wei [College of Aerospace Engineering, Chongqing University, Chongqing 400044 (China); Gou, Jihua [Department of Mechanical and Aerospace Engineering, University of Central Florida, Orlando, FL 32816 (United States); Fan, Jinghong [Division of Mechanical Engineering, Alfred University, Alfred, NY 14802 (United States)

    2015-12-01

    Highlights: • The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. • SEM observation shows that the roughness of the fracture surfaces of the three different directions of the bone are remarkably different. • The fractal dimensions of the different fracture surfaces of the bone are calculated by box-counting method in MATLAB. • The fracture energies of the different fracture directions are calculated based on their fractal models. - Abstract: The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. It is indicated that the fracture energy along the transversal direction of the bone is distinctly larger than those of the longitudinal and radial directions. The fracture surfaces of the three different directions are observed by scanning electron microscope (SEM). It is shown that the roughness of the fracture surface of the transversal direction is obviously larger than those of the fracture surfaces of the longitudinal and radial directions. It is also revealed that the osteons in the bone are perpendicular to the fracture surface of the transversal direction and parallel to the fracture surfaces of the longitudinal and radial directions. Based on these experimental results, the fractal dimensions of the fracture surfaces of different directions are calculated by box-counting method in MATLAB. The calculated results show that the fractal dimension of the fracture surface of the transversal direction is remarkably larger than those of the fracture surfaces of the longitudinal and radial directions. The fracture energies of different directions are also calculated based on their fractal models. It is denoted that the fracture energy of the transversal direction is remarkably larger than those of the longitudinal and radial directions. The calculated results are in

  2. Mechanical test and fractal analysis on anisotropic fracture of cortical bone

    International Nuclear Information System (INIS)

    Yin, Dagang; Chen, Bin; Ye, Wei; Gou, Jihua; Fan, Jinghong

    2015-01-01

    Highlights: • The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. • SEM observation shows that the roughness of the fracture surfaces of the three different directions of the bone are remarkably different. • The fractal dimensions of the different fracture surfaces of the bone are calculated by box-counting method in MATLAB. • The fracture energies of the different fracture directions are calculated based on their fractal models. - Abstract: The mechanical properties of the cortical bone of fresh bovine femora along three different directions are tested through four-point bending experiments. It is indicated that the fracture energy along the transversal direction of the bone is distinctly larger than those of the longitudinal and radial directions. The fracture surfaces of the three different directions are observed by scanning electron microscope (SEM). It is shown that the roughness of the fracture surface of the transversal direction is obviously larger than those of the fracture surfaces of the longitudinal and radial directions. It is also revealed that the osteons in the bone are perpendicular to the fracture surface of the transversal direction and parallel to the fracture surfaces of the longitudinal and radial directions. Based on these experimental results, the fractal dimensions of the fracture surfaces of different directions are calculated by box-counting method in MATLAB. The calculated results show that the fractal dimension of the fracture surface of the transversal direction is remarkably larger than those of the fracture surfaces of the longitudinal and radial directions. The fracture energies of different directions are also calculated based on their fractal models. It is denoted that the fracture energy of the transversal direction is remarkably larger than those of the longitudinal and radial directions. The calculated results are in

  3. Osteoblast-derived WNT16 represses osteoclastogenesis and prevents cortical bone fragility fractures

    Science.gov (United States)

    Movérare-Skrtic, Sofia; Henning, Petra; Liu, Xianwen; Nagano, Kenichi; Saito, Hiroaki; Börjesson, Anna E; Sjögren, Klara; Windahl, Sara H; Farman, Helen; Kindlund, Bert; Engdahl, Cecilia; Koskela, Antti; Zhang, Fu-Ping; Eriksson, Emma E; Zaman, Farasat; Hammarstedt, Ann; Isaksson, Hanna; Bally, Marta; Kassem, Ali; Lindholm, Catharina; Sandberg, Olof; Aspenberg, Per; Sävendahl, Lars; Feng, Jian Q; Tuckermann, Jan; Tuukkanen, Juha; Poutanen, Matti; Baron, Roland; Lerner, Ulf H; Gori, Francesca; Ohlsson, Claes

    2015-01-01

    The WNT16 locus is a major determinant of cortical bone thickness and nonvertebral fracture risk in humans. The disability, mortality and costs caused by osteoporosis-induced nonvertebral fractures are enormous. We demonstrate here that Wnt16-deficient mice develop spontaneous fractures as a result of low cortical thickness and high cortical porosity. In contrast, trabecular bone volume is not altered in these mice. Mechanistic studies revealed that WNT16 is osteoblast derived and inhibits human and mouse osteoclastogenesis both directly by acting on osteoclast progenitors and indirectly by increasing expression of osteoprotegerin (Opg) in osteoblasts. The signaling pathway activated by WNT16 in osteoclast progenitors is noncanonical, whereas the pathway activated in osteoblasts is both canonical and noncanonical. Conditional Wnt16 inactivation revealed that osteoblast-lineage cells are the principal source of WNT16, and its targeted deletion in osteoblasts increases fracture susceptibility. Thus, osteoblast-derived WNT16 is a previously unreported key regulator of osteoclastogenesis and fracture susceptibility. These findings open new avenues for the specific prevention or treatment of nonvertebral fractures, a substantial unmet medical need. PMID:25306233

  4. Age-related changes in cortical bone mass: data from a German female cohort

    International Nuclear Information System (INIS)

    Toledo, V.A. Molina; Jergas, M.

    2006-01-01

    To describe data from digital radiogrammetry (DXR) in an unselected German female cohort over a wide age range. Using a retrospective study design we analyzed radiographs of the hand from 540 German women (aged 5-96 years) using an automated assessment of cortical thickness, metacarpal index (MCI), and estimated cortical bone mineral density (DXR-BMD) on digitized radiographs. Both hands were radiographed in 97 women. In this group DXR-BMD and cortical thickness were significantly higher in the right metacarpals while there was no significant difference in MCI. To study the association with age we differentiated young ( 45 years). In young women all parameters increased significantly with age in a linear fashion (r=0.8 for DXR-BMD, r=0.7 for MCI). In those aged 25-45 years DXR-BMD and MCI were highest (peak bone mass). In women aged 45 or older all parameters decreased with age in an almost linear fashion with an annual change ranging from 0.7% to 0.9%. Our results for an unselected German female cohort indicate that DXR is a reliable, widely available osteodensitometric technique based on the refinement of conventional radiogrammetry. These findings are comparable to those from other studies and represent a valid resource for clinical application and for comparisons with other ethnic groups. (orig.)

  5. Selective laser melting-produced porous titanium scaffolds regenerate bone in critical size cortical bone defects

    NARCIS (Netherlands)

    J. van der Stok (Johan); O.P. van der Jagt (Olav); S. Amin Yavari (Saber); M.F.P. de Haas (Mirthe); J.H. Waarsing (Jan); H. Jahr (Holger); E.M.M. van Lieshout (Esther); P. Patka (Peter); J.A.N. Verhaar (Jan); A.A. Zadpoor (Amir Abbas); H.H. Weinans (Harrie)

    2013-01-01

    textabstractPorous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut

  6. Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain

    Science.gov (United States)

    Pacheco-Costa, Rafael; Davis, Hannah M.; Sorenson, Chad; Hon, Mary C.; Hassan, Iraj; Reginato, Rejane D.; Allen, Matthew R.; Bellido, Teresita; Plotkin, Lilian I.

    2015-01-01

    Connexin43 (Cx43) forms gap junction channels and hemichannels that allow the communication among osteocytes, osteoblasts, and osteoclasts. Cx43 carboxy-terminal (CT) domain regulates channel opening and intracellular signaling by acting as a scaffold for structural and signaling proteins. To determine the role of Cx43 CT domain in bone, mice in which one allele of full length Cx43 was replaced by a mutant lacking the CT domain (Cx43ΔCT/fl) were studied. Cx43ΔCT/fl mice exhibit lower cancellous bone volume but higher cortical thickness than Cx43fl/fl controls, indicating that the CT domain is involved in normal cancellous bone gain but opposes cortical bone acquisition. Further, Cx43ΔCT is able to exert the functions of full length osteocytic Cx43 on cortical bone geometry and mechanical properties, demonstrating that domains other than the CT are responsible for Cx43 function in cortical bone. In addition, parathyroid hormone (PTH) failed to increase endocortical bone formation or energy to failure, a mechanical property that indicates resistance to fracture, in cortical bone in Cx43ΔCT mice with or without osteocytic full length Cx43. On the other hand, bone mass and bone formation markers were increased by the hormone in all mouse models, regardless of whether full length or Cx43ΔCT were or not expressed. We conclude that Cx43 CT domain is involved in proper bone acquisition; and that Cx43 expression in osteocytes is dispensable for some but not all PTH anabolic actions. PMID:26409319

  7. A Piece of the Puzzle: The Bone Health Index of the BoneXpert Software Reflects Cortical Bone Mineral Density in Pediatric and Adolescent Patients.

    Directory of Open Access Journals (Sweden)

    Michael M Schündeln

    Full Text Available Suspected osteopathology in chronically ill children often necessitates the assessment of bone mineral density. The most frequently used methods are dual-energy X-ray-absorption (DXA and peripheral quantitative computed tomography (pQCT. The BoneXpert software provides an automated radiogrammatic method to assess skeletal age from digitalized X-rays of the left hand. Furthermore, the program calculates the Bone Health Index (BHI, a measure of cortical thickness and mineralization, which is obtained from indices of three metacarpal bones. In our study, we analyzed the manner in which BHI information provided by BoneXpert compares with DXA or pQCT measurements in youths.The BHI was retrospectively obtained using digitalized X-rays of the left hand and compared with the results of 203 corresponding DXA readings (Lunar Prodigy, GE Healthcare of the lumbar vertebrae and femur as well as 117 pQCT readings (XCT 900, Stratec of the distal radius.The BHI values showed a strong positive correlation with the DXA readings at each and all lumbar vertebrae (L1 -L4: r = 0.73; P < 0.0001. The age-adjusted Z-score of L1 -L4 and the height-adjusted score showed a positive correlation with the BHI-SDS (standard deviation score, r = 0.23; P < 0.002 and r = 0.27; P < 0.001, respectively. Total bone mineral density, as assessed via pQCT, also positively correlated with the BHI (r = 0.39; P < 0.0001, but the trabecular values displayed only a weak correlation.The BHI obtained using BoneXpert can be a useful parameter in the assessment of bone health in children in most cases. This technique provides observer-independent information on cortical thickness and mineralization based on X-ray imaging of the hands.

  8. Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits

    International Nuclear Information System (INIS)

    Freitas, S.H.; Doria, R.G.S.; Mendonca, F.S.; Santos, M.D.; Moreira, R.; Simoes, R.S.; Camargo, L.M.; Simoes, M.J.; Marques, A.T.C.

    2012-01-01

    A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects. (author)

  9. Glycation of human cortical and cancellous bone captures differences in the formation of Maillard reaction products between glucose and ribose.

    Directory of Open Access Journals (Sweden)

    Grażyna E Sroga

    Full Text Available To better understand some aspects of bone matrix glycation, we used an in vitro glycation approach. Within two weeks, our glycation procedures led to the formation of advanced glycation end products (AGEs at the levels that corresponded to approx. 25-30 years of the natural in vivo glycation. Cortical and cancellous bones from human tibias were glycated in vitro using either glucose (glucosylation or ribose (ribosylation. Both glucosylation and ribosylation led to the formation of higher levels of AGEs and pentosidine (PEN in cancellous than cortical bone dissected from all tested donors (young, middle-age and elderly men and women. More efficient glycation of bone matrix proteins in cancellous bone most likely depended on the higher porosity of this tissue, which facilitated better accessibility of the sugars to the matrix proteins. Notably, glycation of cortical bone from older donors led to much higher AGEs levels as compared to young donors. Such efficient in vitro glycation of older cortical bone could result from aging-related increase in porosity caused by the loss of mineral content. In addition, more pronounced glycation in vivo would be driven by elevated oxidation processes. Interestingly, the levels of PEN formation differed pronouncedly between glucosylation and ribosylation. Ribosylation generated very high levels of PEN (approx. 6- vs. 2.5-fold higher PEN level than in glucosylated samples. Kinetic studies of AGEs and PEN formation in human cortical and cancellous bone matrix confirmed higher accumulation of fluorescent crosslinks for ribosylation. Our results suggest that in vitro glycation of bone using glucose leads to the formation of lower levels of AGEs including PEN, whereas ribosylation appears to support a pathway toward PEN formation. Our studies may help to understand differences in the progression of bone pathologies related to protein glycation by different sugars, and raise awareness for excessive sugar

  10. Biological and physical properties of autogenous vascularized fibular grafts in dogs

    International Nuclear Information System (INIS)

    Goldberg, V.M.; Stevenson, S.; Shaffer, J.W.; Davy, D.; Klein, L.; Zika, J.; Field, G.

    1990-01-01

    The biological and biomechanical properties of normal fibulae, fibulae that had had a sham operation, and both vascularized and non-vascularized autogenous grafts were studied in dogs at three months after the operation. The study was designed to quantify and correlate changes in these properties in orthotopic, stably fixed, weight-bearing grafts and to provide a baseline for additional studies of allografts. The grafts were eight centimeters long and internally fixed. The mechanical properties of the grafts were studied by torsional testing. Metabolic turnover of the grafts was evaluated by preoperative labeling of the dogs with 3H-tetracycline for resorption of bone mineral and with 3H-proline for turnover of collagen. Cortical bone area and porosity were measured. Postoperative formation of bone was evaluated by sequential labeling with fluorochrome. The vascularized grafts resembled the fibulae that had had a sham operation and those that had not had an operation with regard to the total number of osteons and the remodeling process, as measured both morphometrically and metabolically. The vascularized grafts were stronger and stiffer than the non-vascularized grafts and were not different from the bones that had had a sham operation. In contrast, the non-vascularized grafts were smaller, weaker, less stiff, and more porotic, had fewer osteons, and demonstrated increased turnover and resorption compared with the vascularized grafts, the bones that had had a sham operation, and the bones that had not been operated on

  11. Selective laser melting-produced porous titanium scaffolds regenerate bone in critical size cortical bone defects.

    Science.gov (United States)

    Van der Stok, Johan; Van der Jagt, Olav P; Amin Yavari, Saber; De Haas, Mirthe F P; Waarsing, Jan H; Jahr, Holger; Van Lieshout, Esther M M; Patka, Peter; Verhaar, Jan A N; Zadpoor, Amir A; Weinans, Harrie

    2013-05-01

    Porous titanium scaffolds have good mechanical properties that make them an interesting bone substitute material for large bone defects. These scaffolds can be produced with selective laser melting, which has the advantage of tailoring the structure's architecture. Reducing the strut size reduces the stiffness of the structure and may have a positive effect on bone formation. Two scaffolds with struts of 120-µm (titanium-120) or 230-µm (titanium-230) were studied in a load-bearing critical femoral bone defect in rats. The defect was stabilized with an internal plate and treated with titanium-120, titanium-230, or left empty. In vivo micro-CT scans at 4, 8, and 12 weeks showed more bone in the defects treated with scaffolds. Finally, 18.4 ± 7.1 mm(3) (titanium-120, p = 0.015) and 18.7 ± 8.0 mm(3) (titanium-230, p = 0.012) of bone was formed in those defects, significantly more than in the empty defects (5.8 ± 5.1 mm(3) ). Bending tests on the excised femurs after 12 weeks showed that the fusion strength reached 62% (titanium-120) and 45% (titanium-230) of the intact contralateral femurs, but there was no significant difference between the two scaffolds. This study showed that in addition to adequate mechanical support, porous titanium scaffolds facilitate bone formation, which results in high mechanical integrity of the treated large bone defects. Copyright © 2012 Orthopaedic Research Society.

  12. Tomography-Based Quantification of Regional Differences in Cortical Bone Surface Remodeling and Mechano-Response.

    Science.gov (United States)

    Birkhold, Annette I; Razi, Hajar; Duda, Georg N; Checa, Sara; Willie, Bettina M

    2017-03-01

    Bone has an adaptive capacity to maintain structural integrity. However, there seems to be a heterogeneous cortical (re)modeling response to loading at different regions within the same bone, which may lead to inconsistent findings since most studies analyze only one region. It remains unclear if the local mechanical environment is responsible for this heterogeneous response and whether both formation and resorption are affected. Thus, we compared the formation and resorptive response to in vivo loading and the strain environment at two commonly analyzed regions in the mouse tibia, the mid-diaphysis and proximal metaphysis. We quantified cortical surface (re)modeling by tracking changes between geometrically aligned consecutive in vivo micro-tomography images (time lapse 15 days). We investigated the local mechanical strain environment using finite element analyses. The relationship between mechanical stimuli and surface (re)modeling was examined by sub-dividing the mid-diaphysis and proximal metaphysis into 32 sub-regions. In response to loading, metaphyseal cortical bone (re)modeled predominantly at the periosteal surface, whereas diaphyseal (re)modeling was more pronounced at the endocortical surface. Furthermore, different set points and slopes of the relationship between engendered strains and remodeling response were found for the endosteal and periosteal surfaces at the metaphyseal and diaphyseal regions. Resorption was correlated with strain at the endocortical, but not the periosteal surfaces, whereas, formation correlated with strain at all surfaces, except at the metaphyseal periosteal surface. Therefore, besides mechanical stimuli, other non-mechanical factors are likely driving regional differences in adaptation. Studies investigating adaptation to loading or other treatments should consider region-specific (re)modeling differences.

  13. Etelcalcetide (AMG 416), a peptide agonist of the calcium-sensing receptor, preserved cortical bone structure and bone strength in subtotal nephrectomized rats with established secondary hyperparathyroidism.

    Science.gov (United States)

    Li, Xiaodong; Yu, Longchuan; Asuncion, Frank; Grisanti, Mario; Alexander, Shawn; Hensley, Kelly; Han, Chun-Ya; Niu, Qing-Tian; Dwyer, Denise; Villasenor, Kelly; Stolina, Marina; Dean, Charles; Ominsky, Michael S; Ke, Hua Zhu; Tomlinson, James E; Richards, William G

    2017-12-01

    Sustained elevation of parathyroid hormone (PTH) is catabolic to cortical bone, as evidenced by deterioration in bone structure (cortical porosity), and is a major factor for increased fracture risk in chronic kidney disease (CKD). Etelcalcetide (AMG 416), a novel peptide agonist of the calcium-sensing receptor, reduces PTH levels in subtotal nephrectomized (Nx) rats and in hemodialysis patients with secondary hyperparathyroidism (SHPT) in clinical studies; however, effects of etelcalcetide on bone have not been determined. In a rat model of established SHPT with renal osteodystrophy, etelcalcetide or vehicle was administered by subcutaneous (s.c.) injection to subtotal Nx rats with elevated PTH (>750pg/mL) once per day for 6weeks. Sham-operated rats receiving vehicle (s.c.) served as non-SHPT controls. Prior to treatment, significant increases in serum creatinine (2-fold), blood urea nitrogen (BUN, 3-fold), PTH (5-fold), fibroblast growth factor-23 (FGF23; 13-fold) and osteocalcin (12-fold) were observed in SHPT rats compared to non-SHPT controls. Elevations in serum creatinine and BUN were unaffected by treatment with vehicle or etelcalcetide. In contrast, etelcalcetide significantly decreased PTH, FGF23 and osteocalcin, whereas vehicle treatment did not. Cortical bone porosity increased and bone strength decreased in vehicle-treated SHPT rats compared to non-SHPT controls. Cortical bone structure improved and energy to failure was significantly greater in SHPT rats treated with etelcalcetide compared to vehicle. Mineralization lag time and marrow fibrosis were significantly reduced by etelcalcetide. In conclusion, etelcalcetide reduced bone turnover, attenuated mineralization defect and marrow fibrosis, and preserved cortical bone structure and bone strength by lowering PTH in subtotal Nx rats with established SHPT. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Exercise during growth and young adulthood is independently associated with cortical bone size and strength in old Swedish men.

    Science.gov (United States)

    Nilsson, Martin; Sundh, Daniel; Ohlsson, Claes; Karlsson, Magnus; Mellström, Dan; Lorentzon, Mattias

    2014-08-01

    Previous studies have reported an association between exercise during youth and increased areal bone mineral density at old age. The primary aim of this study was to investigate if exercise during growth was independently associated with greater cortical bone size and whole bone strength in weight-bearing bone in old men. The tibia and radius were measured using both peripheral quantitative computed tomography (pQCT) (XCT-2000; Stratec) at the diaphysis and high-resolution pQCT (HR-pQCT) (XtremeCT; Scanco) at the metaphysis to obtain cortical bone geometry and finite element-derived bone strength in distal tibia and radius, in 597 men, 79.9 ± 3.4 (mean ± SD) years old. A self-administered questionnaire was used to collect information about previous and current physical activity. In order to determine whether level of exercise during growth and young adulthood or level of current physical activity were independently associated with bone parameters in both tibia and radius, analysis of covariance (ANCOVA) analyses were used. Adjusting for covariates and current physical activity, we found that men in the group with the highest level of exercise early in life (regular exercise at a competitive level) had higher tibial cortical cross-sectional area (CSA; 6.3%, p strength (failure load: 7.5%, p exercise during growth and young adulthood. Subjects in the group with the highest level of current physical activity had smaller tibial endosteal circumference (EC; 3.6%, p = 0.012) at the diaphysis than subjects with a lower current physical activity, when adjusting for covariates and level of exercise during growth and young adulthood. These findings indicate that exercise during growth can increase the cortical bone size via periosteal expansion, whereas exercise at old age may decrease endosteal bone loss in weight-bearing bone in old men. © 2014 American Society for Bone and Mineral Research.

  15. Edentulation alters material properties of cortical bone in the human craniofacial skeleton: functional implications for craniofacial structure in primate evolution

    Science.gov (United States)

    Dechow, Paul C.; Wang, Qian; Peterson, Jill

    2011-01-01

    Skeletal adaptations to reduced function are an important source of skeletal variation and may be indicative of environmental pressures that lead to evolutionary changes. Humans serve as a model animal to investigate the effects of loss of craniofacial function through edentulation. In the human maxilla, it is known that edentulation leads to significant changes in skeletal structure such as residual ridge resorption and loss of cortical thickness. However, little is known about changes in bone tissue structure and material properties, which are also important for understanding skeletal mechanics but are often ignored. The aims of this study were to determine cortical material properties in edentulous crania and to evaluate differences with dentate crania and thus examine the effects of loss of function on craniofacial structure. Cortical bone samples from fifteen edentulous human skulls were measured for thickness and density. Elastic properties and directions of maximum stiffness were determined by using ultrasonic techniques. These data were compared to those from dentate crania reported in a previous investigation. Cortical bone from all regions of the facial skeleton of edentulous individuals is thinner than in dentate skulls. Elastic and shear moduli, and density are similar or greater in the zygoma and cranial vault of edentulous individuals, while these properties are less in the maxilla. Most cortical bone, especially in edentulous maxillae, has reduced directional orientation. The loss of significant occlusal loads following edentulation may contribute to the change in material properties and the loss of orientation over time during the normal process of bone remodeling. These results suggest that area-specific cortical microstructural changes accompany bone resorption following edentulation. They also suggest that functional forces are important for maintaining bone mass throughout the craniofacial skeleton, even in areas such as the browridges, which

  16. Effects of mechanical loading on cortical defect repair using a novel mechanobiological model of bone healing.

    Science.gov (United States)

    Liu, Chao; Carrera, Robert; Flamini, Vittoria; Kenny, Lena; Cabahug-Zuckerman, Pamela; George, Benson M; Hunter, Daniel; Liu, Bo; Singh, Gurpreet; Leucht, Philipp; Mann, Kenneth A; Helms, Jill A; Castillo, Alesha B

    2018-03-01

    Mechanical loading is an important aspect of post-surgical fracture care. The timing of load application relative to the injury event may differentially regulate repair depending on the stage of healing. Here, we used a novel mechanobiological model of cortical defect repair that offers several advantages including its technical simplicity and spatially confined repair program, making effects of both physical and biological interventions more easily assessed. Using this model, we showed that daily loading (5N peak load, 2Hz, 60 cycles, 4 consecutive days) during hematoma consolidation and inflammation disrupted the injury site and activated cartilage formation on the periosteal surface adjacent to the defect. We also showed that daily loading during the matrix deposition phase enhanced both bone and cartilage formation at the defect site, while loading during the remodeling phase resulted in an enlarged woven bone regenerate. All loading regimens resulted in abundant cellular proliferation throughout the regenerate and fibrous tissue formation directly above the defect demonstrating that all phases of cortical defect healing are sensitive to physical stimulation. Stress was concentrated at the edges of the defect during exogenous loading, and finite element (FE)-modeled longitudinal strain (ε zz ) values along the anterior and posterior borders of the defect (~2200με) was an order of magnitude larger than strain values on the proximal and distal borders (~50-100με). It is concluded that loading during the early stages of repair may impede stabilization of the injury site important for early bone matrix deposition, whereas loading while matrix deposition and remodeling are ongoing may enhance stabilization through the formation of additional cartilage and bone. Published by Elsevier Inc.

  17. Prediction of lumbar spine bone mineral density from the mandibular cortical width in postmenopausal women

    Directory of Open Access Journals (Sweden)

    Ehsan Hekmatin

    2013-01-01

    Full Text Available Background: Osteoporosis is one of the most common bone diseases that is characterized by a generalized reduction of the bone mass. Osteoporotic fractures are associated with morbidity, but can be a predictable condition if early diagnosis is made.The diagnosis is based on the World Health Organization′s (WHO T-score criteria. Panoramic images have been also used to predict low bone mineral density. The aim of the study was to evaluate the prediction of lumbar spine bone mineral density (BMD from the mandibular cortical width in postmenopausal women. Materials and Methods: On the panoramic radiographic images, the mandibular cortical width (MCW was measured by drawing a line parallel to the long axis of the mandible and another line tangential to the inferior border of mandible and a constructed line perpendicular to the tangent intersecting inferior border of mental foramen and analyzed the correlation of recorded MCW with BMD and T-score by using SPSS software and linear regression and bivariate correlation tests. Results: Bivariate correlation showed a significant correlation between BMD and MCW (r = 0.945 (P = 0. 000. There was also a significant correlation between T-score and MCW(r = 0.835 (P = 0. 000. To detect the accurate association between the BMD and MCW and also T-score and MCW, linear regression analyses tests showed two associations to predict the BMD and T-score from MCW with confidence interval of 95%. These associations were as follows: T-score= −7.087 + 1.497 Χ MCW BMD= 0.334 + 0.163 Χ MCW. Conclusion: The MCW is a good index to help the dentists to predict the osteoporosis by panoramic radiographs and have a significant role in patient screening and early diagnosis of osteoporosis.

  18. Lack of deleterious effect of slow-release sodium fluoride treatment on cortical bone histology and quality in osteoporotic patients

    Science.gov (United States)

    Zerwekh, J. E.; Antich, P. P.; Sakhaee, K.; Prior, J.; Gonzales, J.; Gottschalk, F.; Pak, C. Y.

    1992-01-01

    We evaluated the effects of intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate therapy on cortical bone histology, reflection ultrasound velocity (material strength) and back-scattered electron image analysis (BEI) in 26 osteoporotic patients before and following therapy. All measurements were made on transiliac crest bone biopsies obtained before and following 2 years of therapy in each patient. For all 26 patients there were no significant changes in cortical bone histomorphometric parameters. In 15 patients in whom bone material quality was assessed by reflection ultrasound, there was no change in velocity (4000 +/- 227 SD to 4013 +/- 240 m/s). BEI disclosed no mineralization defects or the presence of woven bone. Mean atomic number (density) of bone increased slightly, but significantly (9.261 +/- 0.311 to 9.457 +/- 0.223, P = 0.031). While these changes are less marked than those observed for cancellous bone, they indicate that this form of therapy does not adversely affect cortical bone remodelling.

  19. Propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kang Il [Kangwon National University, Chuncheon (Korea, Republic of); Choi, Bok Kyoung [Maritime Security Research Center, KIOST, Ansan (Korea, Republic of)

    2014-12-15

    The present study aims to investigate the propagation of ultrasonic guided waves in an acrylic plate as a cortical-bone-mimicking phantom. The velocities of the guided waves in a 5-mm-thick acrylic plate were measured by using the axial transmission technique. A pure A0 Lamb mode could be successfully launched in the 5-mm-thick acrylic plate through a time reversal process of Lamb waves, consistent with the fact that the time reversal process can automatically compensate for the dispersive nature of Lamb waves. The experimental velocities of the slow guided wave (SGW) and the time-reversed Lamb wave were found to be in reasonable agreement with the theoretical group velocity of the A0 Lamb mode, suggesting that both the SGW and the time-reversed Lamb wave excited in the 5-mm-thick acrylic plate correspond to the A0 Lamb mode. These results suggest that the time reversal process of Lamb waves can be usefully applied to noninvasive characterization of long cortical bones.

  20. Application of autogenous periosteum as a membrane in sinus lifting ...

    African Journals Online (AJOL)

    Aim: To evaluate the success level of autogenous periosteum in sinus lifting as a barrier membrane which contributes positively to wound healing and is effective in bone formation without the risk of tissue rejection. Materials and Methods: In this study, 32 male New Zealand rabbits were used and were divided into four ...

  1. Assessment of cortical bone fracture resistance curves by fusing artificial neural networks and linear regression.

    Science.gov (United States)

    Vukicevic, Arso M; Jovicic, Gordana R; Jovicic, Milos N; Milicevic, Vladimir L; Filipovic, Nenad D

    2018-02-01

    Bone injures (BI) represents one of the major health problems, together with cancer and cardiovascular diseases. Assessment of the risks associated with BI is nontrivial since fragility of human cortical bone is varying with age. Due to restrictions for performing experiments on humans, only a limited number of fracture resistance curves (R-curves) for particular ages have been reported in the literature. This study proposes a novel decision support system for the assessment of bone fracture resistance by fusing various artificial intelligence algorithms. The aim was to estimate the R-curve slope, toughness threshold and stress intensity factor using the two input parameters commonly available during a routine clinical examination: patients age and crack length. Using the data from the literature, the evolutionary assembled Artificial Neural Network was developed and used for the derivation of Linear regression (LR) models of R-curves for arbitrary age. Finally, by using the patient (age)-specific LR models and diagnosed crack size one could estimate the risk of bone fracture under given physiological conditions. Compared to the literature, we demonstrated improved performances for estimating nonlinear changes of R-curve slope (R 2 = 0.82 vs. R 2 = 0.76) and Toughness threshold with ageing (R 2 = 0.73 vs. R 2 = 0.66).

  2. Nanoscale examination of microdamage in sheep cortical bone using synchrotron radiation transmission x-ray microscopy.

    Directory of Open Access Journals (Sweden)

    Garry R Brock

    Full Text Available Microdamage occurs in bone through repeated and excessive loading. Accumulation of microdamage weakens bone, leading to a loss of strength, stiffness and energy dissipation in the tissue. Imaging techniques used to examine microdamage have typically been limited to the microscale. In the current study microdamage was examined at the nanoscale using transmission x-ray microscopy with an x-ray negative stain, lead-uranyl acetate. Microdamage was generated in notched and unnotched beams of sheep cortical bone (2×2×20 mm, with monotonic and fatigue loading. Bulk sections were removed from beams and stained with lead-uranyl acetate to identify microdamage. Samples were sectioned to 50 microns and imaged using transmission x-ray microscopy producing projection images of microdamage with nanoscale resolution. Staining indicated microdamage occurred in both the tensile and compressive regions. A comparison between monotonic and fatigue loading indicated a statistically significant greater amount of stain present in fatigue loaded sections. Microdamage occurred in three forms: staining to existing bone structures, cross hatch damage and a single crack extending from the notch tip. Comparison to microcomputed tomography demonstrated differences in damage morphology and total damage between the microscale and nanoscale. This method has future applications for understanding the underlying mechanisms for microdamage formation as well as three-dimensional nanoscale examination of microdamage.

  3. Evaluation of cortical bone thickness of mandible with cone beam computed tomography for orthodontic mini implant installation

    Directory of Open Access Journals (Sweden)

    Seyed Hossein Moslemzade

    2014-07-01

    Full Text Available Background: Achieving maximum anchorage without movement of the teeth in anchorage unit has been a great challenge in orthodontics and the success of the treatment plan highly depends on it. In this case, using orthodontic mini-implants can make a huge difference. The objective of this retrospective study was to measure thickness of cortical bone at prospective mini-implant placement sites in mandible in order to understand stability aspects of mini-implant placement by using cone-beam computed tomography (CBCT images. Materials and Methods: Initial 3-dimensional images of 40 adult patients were studied. The cortical bone thickness was obtained at the alveolar processes from canine to second molar at 5 different vertical levels from the cementoenamel junction (CEJ. To determine the cortical bone thickness, tangent lines were drawn buccolingually to the roots in axial section and a third line was drawn from the middle of these two lines, and the cortical bone thickness was measured where the third line crossed the buccal cortex.   Results: Mandibular and buccal cortical bone thicknesses were 0.79 to 2.49 mm, respectively. There was a statistically significant increase from the CEJ to the apex (P<0.001, while this increase was not statically significant at interdental area of teeth #3 and #4. Comparing the 4 mm section in all sites showed significant increase from anterior to posterior. Conclusion: Based on our results, the cortical bone thickness mostly follows a pattern and depends on the interradicular site rather than individual differences.     Key words: Cone-beam computed tomography; orthodontic anchorage procedures

  4. Regional differences in cortical bone organization and microdamage prevalence in Rocky Mountain mule deer.

    Science.gov (United States)

    Skedros, John G; Sybrowsky, Christian L; Parry, Todd R; Bloebaum, Roy D

    2003-09-01

    The limb bones of cursorial mammals may exhibit regional structural/material variations for local mechanical requirements. For example, it has been hypothesized that mineral content (%ash) and secondary osteon population density (OPD) progressively change from proximal (e.g., humerus) to distal (e.g., phalanx), in accordance with corresponding progressive changes in stress and mechanical/metabolic cost of functional use (both greatest in the distal limb). We tested this hypothesis in wild-shot Rocky Mountain mule deer by examining transverse segments from mid-diaphyses of medial proximal phalanges, principal metacarpals, radii, and humeri, as well as the lateral aspects of sixth ribs from each of 11 mature males. Quantified structural parameters included the section modulus (Z), polar moment of inertia (J), cortical area/total area ratio (CA/TA), bone girth, and cortical thickness. In addition, %ash and the prevalence of in vivo microcracks were measured in each bone. Thin sections from seven animals were further examined for OPD and population densities of new remodeling events (NREs). Results showed a significant progressive decrease in %ash from the humerus (75.4% +/- 0.9%) to the phalanx (69.4% +/- 1.1%) (P < 0.0001), with general proximal-to-distal increases in OPD and general decreases in J and Z. Thirteen microcracks were identified in the rib sections, and only two were observed in the limb bones. Although the ribs had considerably greater NREs, no significant differences in NREs were found between the limb bones, indicating that they had similar remodeling rates. Equivalent microcrack prevalence, but nonequivalent structural/material organization, suggests that there are regional adaptations that minimize microcrack production in locations with differences in loading conditions. The progressive proximal-to-distal decrease in %ash (up to 6%); moderate-to-high correlations between OPD, %ash, J, and CA/TA; and additional moderate-to-high correlations of these

  5. Cortical bone trajectory for lumbosacral fixation: penetrating S-1 endplate screw technique: technical note.

    Science.gov (United States)

    Matsukawa, Keitaro; Yato, Yoshiyuki; Kato, Takashi; Imabayashi, Hideaki; Asazuma, Takashi; Nemoto, Koichi

    2014-08-01

    A cortical bone trajectory (CBT) is a new pedicle screw trajectory that maximizes the thread contact with cortical bone surface, providing enhanced screw purchase. Despite the increased use of the CBT in the lumbar spine, little is known about the insertion technique for the sacral CBT. The aim of this study was to introduce a novel sacral pedicle screw trajectory. This trajectory engages with denser bone maximally by the screw penetrating the S-1 superior endplate through a more medial entry point than the traditional technique, and also has safety advantages, with the protrusion of the screw tip into the intervertebral disc space carrying no risk of neurovascular injury. In this study, the CT scans of 50 adults were studied for morphometric measurement of the new trajectory. The entry point was supposed to be the junction of the center of the superior articular process of S-1 and approximately 3 mm inferior to the most inferior border of the inferior articular process of L-5. The direction was straight forward in the axial plane without convergence, angulated cranially in the sagittal plane penetrating the middle of the sacral endplate. The cephalad angle to the sacral endplate, length of trajectory, and safety of the trajectory were investigated. Next, the insertional torque of pedicle screws using this technique was measured intraoperatively in 19 patients and compared with the traditional technique. The mean cephalad angle in these 50 patients was 30.7° ± 5.1°, and the mean length of trajectory was 31.5 ± 3.5 mm. The CT analysis revealed that the penetrating S-1 endplate technique did not cause any neurovascular injury anteriorly in any case. The new technique demonstrated an average of 141% higher insertional torque than the traditional monocortical technique. The penetrating S-1 endplate technique through the medial entry point is suitable for the connection of lumbar CBT, has revealed favorable stability for lumbosacral fixation, and has reduced the

  6. Evaluation of the Cortical Bone Reaction Around of Implants Using a Single-Use Final Drill: A Histologic Study.

    Science.gov (United States)

    Gehrke, Sergio Alexandre

    2015-07-01

    This study was designed to compare the cortical bone reaction following traditional osteotomy or the use of a single-use final drill in the osseointegration of implants in the tibia of rabbits. For this study, 48 conical implants, of standard surface type and design and manufactured by the same company, were inserted into the tibiae of 12 rabbits and removed after 30 or 60 days for histologic analysis. Two test groups were prepared according to the drill sequence used for the osteotomy at the preparation sites: in the control group was used a conventional drill sequence with several uses, whereas the test group (tesG) used a single-use final drill. The bone-to-implant contact and qualitative factors of the resulting cortical bone were assessed. Both techniques produced good implant integration. Differences in the linear bone-to-implant contact were observed between the drilling procedures as time elapsed in vivo, with the tesG appearing to have clinical advantages. Both groups exhibited new bone in quantity and in quality; however, the tesG exhibited a higher level of new bone deposition than the control group. Within the limitations of this study, the findings suggest that the use of a single-use final drill leads to better and faster organization of the cortical bone area during the evaluated period and may avoid the possible problems that can be caused by worn drills.

  7. The incorporation of fluoride and strontium in hydroxyapatite affects the composition, structure, and mechanical properties of human cortical bone.

    Science.gov (United States)

    Riedel, Christoph; Zimmermann, Elizabeth A; Zustin, Jozef; Niecke, Manfred; Amling, Michael; Grynpas, Marc; Busse, Björn

    2017-02-01

    Strontium ranelate and fluoride salts are therapeutic options to reduce fracture risk in osteoporosis. Incorporation of these elements in the physiological hydroxyapatite matrix of bone is accompanied by changes in bone remodeling, composition, and structure. However, a direct comparison of the effectiveness of strontium and fluoride treatment in human cortical bone with a focus on the resulting mechanical properties remains to be established. Study groups are composed of undecalcified specimens from healthy controls, treatment-naïve osteoporosis cases, and strontium ranelate or fluoride-treated osteoporosis cases. Concentrations of both elements were determined using instrumental neutron activation analysis (INAA). Backscattered electron imaging was carried out to investigate the calcium content and the cortical microstructure. In comparison to osteoporotic patients, fluoride and strontium-treated patients have a lower cortical porosity indicating an improvement in bone microstructure. Mechanical properties were assessed via reference point indentation as a measure of bone's resistance to deformation. The strontium-incorporation led to significantly lower total indentation distance values compared to osteoporotic cases; controls have the highest resistance to indentation. In conclusion, osteoporosis treatment with strontium and fluoride showed positive effects on the microstructure and the mechanical characteristics of bone in comparison to treatment-naïve osteoporotic bone. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 433-442, 2017. © 2016 Wiley Periodicals, Inc.

  8. The tensile strength of black bear (Ursus americanus) cortical bone is not compromised with aging despite annual periods of hibernation.

    Science.gov (United States)

    Harvey, Kristin B; Drummer, Thomas D; Donahue, Seth W

    2005-11-01

    Black bears (Ursus americanus) may not develop disuse osteoporosis during long periods of disuse (i.e. hibernation) because they may be able to maintain bone formation. Previously, we found that cortical bone bending strength was not compromised with age in black bears' tibias, despite annual periods of disuse. Here we showed that cortical bone tensile strength (166-198MPa) also does not decrease with age (2-14 years) in black bear tibias. There were also no significant age-related changes in cortical bone porosity in black bear tibias. It is likely that the ability of black bears to maintain bone formation during hibernation keeps bone porosity low (2.3-8.6%) with aging, notwithstanding annual periods of disuse. This low porosity likely preserves ultimate stress with aging. Female bears give birth and nurse during hibernation; however, we found no significant differences between male and female tensile material properties, mineral content, or porosity. Our findings support the idea that black bears, which hibernate 5-7 months annually, have evolved biological mechanisms to mitigate the adverse effects of disuse on bone porosity and strength.

  9. Synchrotron ultraviolet microspectroscopy on rat cortical bone: involvement of tyrosine and tryptophan in the osteocyte and its environment.

    Directory of Open Access Journals (Sweden)

    Stéphane Pallu

    Full Text Available Alcohol induced osteoporosis is characterized by a bone mass decrease and microarchitecture alterations. Having observed an excess in osteocyte apoptosis, we aimed to assess the bone tissue biochemistry, particularly in the osteocyte and its environment. For this purpose, we used a model of alcohol induced osteoporosis in rats. Bone sections of cortical bone were investigated using synchrotron UV-microspectrofluorescence at subcellular resolution. We show that bone present three fluorescence peaks at 305, 333 and 385 nm, respectively corresponding to tyrosine, tryptophan and collagen. We have determined that tyrosine/collagen and tryptophan/collagen ratios were higher in the strong alcohol consumption group. Tryptophan is related to the serotonin metabolism involved in bone formation, while tyrosine is involved in the activity of tyrosine kinases and phosphatases in osteocytes. Our experiment represents the first combined synchrotron UV microspectroscopy analysis of bone tissue with a quantitative biochemical characterization in the osteocyte and surrounding matrix performed separately.

  10. Effects of age and loading rate on equine cortical bone failure.

    Science.gov (United States)

    Kulin, Robb M; Jiang, Fengchun; Vecchio, Kenneth S

    2011-01-01

    Although clinical bone fractures occur predominantly under impact loading (as occurs during sporting accidents, falls, high-speed impacts or other catastrophic events), experimentally validated studies on the dynamic fracture behavior of bone, at the loading rates associated with such events, remain limited. In this study, a series of tests were performed on femoral specimens obtained post-mortem from equine donors ranging in age from 6 months to 28 years. Fracture toughness and compressive tests were performed under both quasi-static and dynamic loading conditions in order to determine the effects of loading rate and age on the mechanical behavior of the cortical bone. Fracture toughness experiments were performed using a four-point bending geometry on single and double-notch specimens in order to measure fracture toughness, as well as observe differences in crack initiation between dynamic and quasi-static experiments. Compressive properties were measured on bone loaded parallel and transverse to the osteonal growth direction. Fracture propagation was then analyzed using scanning electron and scanning confocal microscopy to observe the effects of microstructural toughening mechanisms at different strain rates. Specimens from each horse were also analyzed for dry, wet and mineral densities, as well as weight percent mineral, in order to investigate possible influences of composition on mechanical behavior. Results indicate that bone has a higher compressive strength, but lower fracture toughness when tested dynamically as compared to quasi-static experiments. Fracture toughness also tends to decrease with age when measured quasi-statically, but shows little change with age under dynamic loading conditions, where brittle "cleavage-like" fracture behavior dominates. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Lateral cortical bone thickness of human mandibles in region of mental foramen.

    Science.gov (United States)

    Fernandes, Atson Carlos de Souza; Rossi, Marcelle A; Schaffner, Iuri S; Machado, Laila A; Sampaio, Aline A

    2010-12-01

    We sought to verify the cortical thickness and presence of tooth roots and inferior alveolar canal where miniplates are placed using the Champy technique to treat parasymphyseal fractures between the canine and premolar. We also studied these anatomic features at the same level anteriorly and posteriorly to the mental foramen. A total of 80 dry, normal adult dentate human hemimandibles (40 male and 40 female) were studied. Verification was performed at 3 levels-above (S), below (I), and at the same height as the mental foramen (F). At each level, the thickness and proximity of the tooth roots and inferior alveolar canal were checked at 4 points; two anteriorly (4.5 and 9 mm) and 2 posteriorly (4.5 and 9 mm) to the mental foramen. The cortical bone was significantly thicker at level F (Fa2, 2.37 mm; Fa1, 2.43 mm; Fp1, 2.86 mm; Fp2, 2.89 mm) than the corresponding level S points (Sa2, 2.00 mm; Sa1, 2.11 mm; Sp1, 2.30 mm; Sp2, 2.45 mm) and level I points (Ia2, 2.11 mm; Ia1, 2.17 mm; Ip1, 2.39 mm; Ip2, 2.43 mm). Regarding the thickness and risk of injury, no difference was found between the points at levels S and I, where the miniplates are normally fixed with monocortical screws. No relationship was seen between the points at level F and the tooth roots or inferior alveolar canal. In contrast, a relationship between the points at level S and the tooth root and between the points at level I and the inferior alveolar canal was found. Above and below the mental foramen, the cortical bone for miniscrew anchorage was up to 3 mm thick. At the level of the foramen, the cortical plate will provide better anchorage and the insertion of miniscrews will be free of any risk of injuring the tooth roots or inferior alveolar canal. Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  12. Quantification of stiffness measurement errors in resonant ultrasound spectroscopy of human cortical bone.

    Science.gov (United States)

    Cai, Xiran; Peralta, Laura; Gouttenoire, Pierre-Jean; Olivier, Cécile; Peyrin, Françoise; Laugier, Pascal; Grimal, Quentin

    2017-11-01

    Resonant ultrasound spectroscopy (RUS) is the state-of-the-art method used to investigate the elastic properties of anisotropic solids. Recently, RUS was applied to measure human cortical bone, an anisotropic material with low Q-factor (20), which is challenging due to the difficulty in retrieving resonant frequencies. Determining the precision of the estimated stiffness constants is not straightforward because RUS is an indirect method involving minimizing the distance between measured and calculated resonant frequencies using a model. This work was motivated by the need to quantify the errors on stiffness constants due to different error sources in RUS, including uncertainties on the resonant frequencies and specimen dimensions and imperfect rectangular parallelepiped (RP) specimen geometry. The errors were first investigated using Monte Carlo simulations with typical uncertainty values of experimentally measured resonant frequencies and dimensions assuming a perfect RP geometry. Second, the exact specimen geometry of a set of bone specimens were recorded by synchrotron radiation micro-computed tomography. Then, a "virtual" RUS experiment is proposed to quantify the errors induced by imperfect geometry. Results show that for a bone specimen of ∼1° perpendicularity and parallelism errors, an accuracy of a few percent ( <6.2%) for all the stiffness constants and engineering moduli is achievable.

  13. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Ana Carolina Bergmann de; Henriques, Helene Nara [Postgraduate Program in Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Fernandes, Gustavo Vieira Oliveira [Postgraduate Program in Medical Sciences, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Lima, Inaya; Oliveira, Davi Ferreira de; Lopes, Ricardo Tadeu [Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), RJ (Brazil); Pantaleao, Jose Augusto Soares [Maternal and Child Department, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Granjeiro, Jose Mauro [Department of Cellular and Molecular Biology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Silva, Maria Angelica Guzman [Department of Pathology, Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil)

    2012-03-15

    Purpose: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS). Methods: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T) while the other did not (OVX), those groups were compared to a control group (C) not ovariectomized. Tibolone administration (1 mg/day) began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographs of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at P<0.05%. Results: Tibolone administration was shown to be beneficial only in the densitometric analysis of the femoral head, performing higher optical density compared to OVX. No difference was found in cortical bone thickness. Conclusion: Ovariectomy caused bone loss in the analyzed regions and tibolone administered in high doses over a long period showed not to be fully beneficial, but preserved bone mass in the femoral head. (author)

  14. Cortical and trabecular morphology is altered in the limb bones of mice artificially selected for faster skeletal growth.

    Science.gov (United States)

    Farooq, Saira; Leussink, Shannon; Sparrow, Leah M; Marchini, Marta; Britz, Hayley M; Manske, Sarah L; Rolian, Campbell

    2017-09-05

    Bone strength is influenced by mineral density and macro- and microstructure. Research into factors that contribute to bone morphology and strength has focused on genetic, environmental and morphological factors (e.g., body mass index), but little is known regarding the impact of rates of skeletal elongation on adult skeletal morphology and strength. Using micro-CT, we examined the impact of rates of skeletal elongation on bone cortical and trabecular morphology, and on rates of estrogen-dependent bone loss in the tibia in CD-1 mice, and in mice with accelerated skeletal growth (Longshanks). Groups of adult mice (n = 7/group) were subjected to ovariectomy or sham surgeries, scanned for 6 weeks, and indices of bone morphology were collected. Results show that Longshanks mice had significantly less trabecular bone at skeletal maturity, characterized by fewer, thinner trabeculae, and furthermore lost trabecular bone more slowly in response to ovariectomy. Artificial selection for rapid skeletal growth relative to somatic growth thus had a significant impact on trabecular bone morphology in Longshanks. Our data do not unequivocally demonstrate a causal relationship between rapid bone growth and reduced trabecular bone quality, but suggest that rapid linear bone growth may influence the risk of cancellous bone fragility.

  15. Normocalcemic primary hyperparathyroidism associated with progressive cortical bone loss – A case report

    Directory of Open Access Journals (Sweden)

    Joseph R. Tucci

    2017-12-01

    Full Text Available The existence of normocalcemic primary hyperparathyroidism (NPHP was acknowledged at the Third and Fourth International Proceedings on primary hyperparathyroidism PHPT but data relating to its clinical presentation, natural history, and skeletal status were limited and there was no information nor guidelines as to definitive therapy. Herein are reported biochemical, hormonal, and densitometry data in a postmenopausal woman seen initially for osteoporosis who was found to have increased serum PTH levels and normal serum total and ionized calcium levels without evidence of secondary hyperparathyroidism. Over a seven year period, the patient exhibited continuing preferential cortical bone loss at the one-third site of the radius in the face of relatively stable readings at the lumbar spine and hip that led to a subtotal parathyroidectomy for parathyroid hyperplasia with resultant normalization of serum PTH.

  16. Analysis of cortical bone porosity using synchrotron radiation microtomography to evaluate the effects of chemotherapy

    Science.gov (United States)

    Alessio, R.; Nogueira, L. P.; Salata, C.; Mantuano, A.; Almeida, A. P.; Braz, D.; de Almeida, C. E.; Tromba, G.; Barroso, R. C.

    2015-11-01

    Microporosities play important biologic and mechanical roles on health. One of the side effects caused by some chemotherapy drugs is the induction of amenorrhea, temporary or not, in premenopausal women, with a consequent decrease in estrogen production, which can lead to cortical bone changes. In the present work, the femur diaphysis of rats treated with chemotherapy drugs were evaluated by 3D morphometric parameters using synchrotron radiation microtomography. Control animals were also evaluated for comparison. The 3D tomographic images were obtained at the SYRMEP (SYnchrotron Radiation for MEdical Physics) beamline at the ELETTRA Synchrotron Laboratory in Trieste, Italy. Results showed significant differences in morphometric parameters measured from the 3D images of femur diaphysis of rats.

  17. Cortical bone trajectory screws fixation in lumbar adjacent segment disease: A technique note with case series.

    Science.gov (United States)

    Chen, Chao-Hsuan; Huang, Hsieng-Ming; Chen, Der-Cherng; Wu, Chih-Ying; Lee, Han-Chun; Cho, Der-Yang

    2018-02-01

    Lumbar adjacent segment disease after lumbar fusion surgery often requires surgical intervention. However, subsequent surgical treatment often needs to expose and remove all of the previous instruments. This additional surgery leads to significant post-operative pain, muscular fibrosis, poor wound healing and infection, etc. From October 2015 to March 2016, we collected six cases underwent cortical bone trajectory screws fixation with minimal invasive inter-body cage fusion for lumbar adjacent segment disease. Patients in the study all had improvement after surgery without recurrence or instruments failure during follow-up. The technique negates removal of pre-existing instruments and when combined with minimal invasive fusion surgery, the wound length, blood loss and soft tissue damage could be reduced compared with traditional surgery. We introduce the surgical procedures in detail and wish this technique could be an option for spine surgeons who encounter a similar situation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Modelling of Cortical Bone Tissue as a Fluid Saturated Double-Porous Material - Parametric Study

    Directory of Open Access Journals (Sweden)

    Jana TURJANICOVÁ

    2013-06-01

    Full Text Available In this paper, the cortical bone tissue is considered as a poroelastic material with periodic structure represented at microscopic and mesoscopic levels. The pores of microscopic scale are connected with the pores of mesoscopic scale creating one system of connected network filled with compressible fluid. The method of asymptotic homogenization is applied to upscale the microscopic model of the fluid-solid interaction under a static loading. Obtained homogenized coefficients describe material properties of the poroelastic matrix fractured by fluid-filled pores whose geometry is described at the mesoscopic level. The second-level upscaling provides homogenized poroelastic coefficients relevant on the macroscopic scale. Furthermore, we study the dependence of these coefficients on geometrical parameters on related microscopic and macroscopic scales.

  19. Development and design of a bone-equivalent cortical shell phantom to determine accuracy measures on DXA and PQCT scanners

    International Nuclear Information System (INIS)

    Khoo, B.C.C.; Beck, T.J. Johns; Turk, B.; Price, R.I.

    2004-01-01

    Full text: Hip Structural Analysis (HSA), is an algorithm that computes bone-structural geometry from dual energy X-ray absorptiometry (DXA) derived hip images and may be used in a complementary manner to DXA areal bone mineral density (BMD) for bone strength interpretation. DXA is normally used to facilitate the diagnosis and management of bone metabolic diseases such as osteoporosis. HSA provides a biomechanical interpretation of BMD, using its mass profiles to compute cross-sectional structural geometry. In essence, HSA provides insight into bone structural and biomechanical properties, particularly of long bones, which BMD alone cannot. While conventional (vendor-provided) phantoms calibrate DXA machines for densitometric precision, analogous phantoms for calibrating structural geometry are lacking. This paper describes the design and preliminary testing of a densitometric bone-equivalent cylindrical phantom with 'cortical' shells and 'cancellous' core, and the use of this phantom to do a performance test of structural geometry variables such as cortical thickness, bone width and section modulus derived, from pQCT and DXA scan data. Powdered calcium-sulphate (CSC) was water-mixed in vacuum and cured. This mixture exhibited hydroxyapatite-like DXA photon-attenuation properties with density monotonically related to added water-mass. Its mass and BMD maintained temporal stability (CV%=0.03%, n=4 specimens over 321 d). Using CSC designed for a BMD=1.04g/cm, (for plate-thickness 10mm), a cylindrical phantom with cortical shell thicknesses of 0.5, 1.0, 2.0, 4.0mm, an acrylic-based internal core diameter of 26mm, and an acrylic surrounding 'soft-tissue' were constructed. The phantom was scanned using a DXA scanner (Hologic QDRl000W) and pQCT (Stratec XCT2000, pixel resolution 0.15mm). Selected cortical structural-geometric variables, derived from calculated geometry; pQCT mass-projections, and DXA HSA. In conclusion, dimensions of this novel cortical-shell phantom

  20. Duration-dependent effects of clinically relevant oral alendronate doses on cortical bone toughness in beagle dogs.

    Science.gov (United States)

    Burr, David B; Liu, Ziyue; Allen, Matthew R

    2015-02-01

    Bisphosphonates (BPs) have been shown to significantly reduce bone toughness in vertebrae within one year when given at clinical doses to dogs. Although BPs also reduce toughness in the cortical bone when given at high doses, their effect on cortical bone material properties when given at clinical doses is less clear. In part, this may be due to the use of small sample sizes that were powered to demonstrate differences in bone mineral density rather than the bone's material properties. Our lab has conducted several studies in which dogs were treated with alendronate at a clinically relevant dose. The goal of this study was to examine these published and unpublished data collectively to determine whether there is a significant time-dependent effect of alendronate on toughness of the cortical bone. This analysis seemed particularly relevant given the recent occurrence of atypical femoral fractures in humans. Differences in the toughness of ribs taken from dogs derived from five separate experiments were measured. The dogs were orally administered saline (CON, 1ml/kg/day) or alendronate (ALN) at a clinical dose (0.2mg/kg/day). Treatment duration ranged from 3months to 3years. Groups were compared using ANOVA, and time trends analyzed with linear regression analysis. Linear regressions of the percent difference in toughness between CON and ALN at each time point revealed a significant reduction in toughness with longer exposure to ALN. The downward trend was primarily driven by a downward trend in post-yield toughness, whereas toughness in the pre-yield region was not changed relative to CON. These data suggest that a longer duration of treatment with clinical doses of ALN results in deterioration of cortical bone toughness in a time-dependent manner. As the duration of treatment is lengthened, the cortical bone exhibits increasingly brittle behavior. This may be important in assessing the role that long-term BP treatments play in the risk of atypical fractures of the

  1. Intra- and inter-observer variation in histological criteria used in age at death determination based on femoral cortical bone

    DEFF Research Database (Denmark)

    Lynnerup, N; Thomsen, J L; Frohlich, B

    1998-01-01

    elements as observed on photographic images of cortical bone, in order to assess intra- and inter-observer error. Overall, substantial error was present at the level of identifying and counting secondary osteons, osteon fragments and Haversian canals. Only secondary osteons can be reliably identified...

  2. Relationship among Types of Growth Patterns, Buccolingual Molar Inclination and Cortical Bone Thickness of the Mandible: A CT Scan Study

    Directory of Open Access Journals (Sweden)

    Narendra Shriram Sharma

    2012-01-01

    Conclusion: The results of this study provide evidence that a significant, but complex relationship exists between structures of the mandibular body and types of growth pattern. The morphological features that relate to masticatory function and types of growth pattern are associated with the cortical bone thickness of the mandibular body and the buccolingual inclination of the first and second permanent mandibular molars.

  3. Microstructure and compressive mechanical properties of cortical bone in children with osteogenesis imperfecta treated with bisphosphonates compared with healthy children.

    Science.gov (United States)

    Imbert, Laurianne; Aurégan, Jean-Charles; Pernelle, Kélig; Hoc, Thierry

    2015-06-01

    Osteogenesis imperfecta (OI) is a genetic disorder characterized by a change in bone tissue quality, but little data are available to describe the factors involved at the macroscopic scale. To better understand the effect of microstructure alterations on the mechanical properties at the sample scale, we studied the structural and mechanical properties of six cortical bone samples from children with OI treated with bisphosphonates and compared them to the properties of three controls. Scanning electron microscopy, high resolution computed tomography and compression testing were used to assess these properties. More resorption cavities and a higher osteocyte lacunar density were observed in OI bone compared with controls. Moreover, a higher porosity was measured for OI bones along with lower macroscopic Young's modulus, yield stress and ultimate stress. The microstructure was impaired in OI bones; the higher porosity and osteocyte lacunar density negatively impacted the mechanical properties and made the bone more prone to fracture. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Cortical bone histomorphology of known‐age skeletons from the Kirsten collection, Stellenbosch university, South Africa

    Science.gov (United States)

    Heinrich, Jarred; Beresheim, Amy; Alblas, Mandi

    2016-01-01

    ABSTRACT Objectives Normal human bone tissue changes predictably as adults get older, but substantial variability in pattern and pace remains unexplained. Information is needed regarding the characteristics of histological variables across diverse human populations. Methods Undecalcified thin sections from mid‐thoracic ribs of 213 skeletons (138 M, 75 F, 17–82 years, mean age 48 years), are used to explore the efficacy of an established age‐at‐death estimation method and methodological approach (Cho et al.: J Forensic Sci 47 (2002) 12‐18) and expand on it. The ribs are an age‐balanced sample taken from skeletonized cadavers collected from 1967 to 1999 in South Africa, each with recorded sex, age, cause of death and government‐defined population group (129 “Colored,” 49 “Black,” 35 “White”). Results The Ethnicity Unknown equation performs better than those developed for European‐Americans and African‐Americans, in terms of accuracy and bias. A new equation based solely on the study sample does not improve accuracy. Osteon population densities (OPD) show predicted values, yet secondary osteon areas (On.Ar) are smaller than expected for non‐Black subgroups. Relative cortical area (Ct.Ar/Tt.Ar) is low among non‐Whites. Conclusions Results from this highly diverse sample show that population‐specific equations do not increase estimate precision. While within the published range of error for the method (±24.44 years), results demonstrate a systematic under‐aging of young adults and over‐aging of older adults. The regression approach is inappropriate. The field needs fresh approaches to statistical treatment and to factors behind cortical bone remodeling. Am J Phys Anthropol 160:137–147, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc. PMID:26865244

  5. Applying Full Spectrum Analysis to a Raman Spectroscopic Assessment of Fracture Toughness of Human Cortical Bone.

    Science.gov (United States)

    Makowski, Alexander J; Granke, Mathilde; Ayala, Oscar D; Uppuganti, Sasidhar; Mahadevan-Jansen, Anita; Nyman, Jeffry S

    2017-10-01

    A decline in the inherent quality of bone tissue is a † Equal contributors contributor to the age-related increase in fracture risk. Although this is well-known, the important biochemical factors of bone quality have yet to be identified using Raman spectroscopy (RS), a nondestructive, inelastic light-scattering technique. To identify potential RS predictors of fracture risk, we applied principal component analysis (PCA) to 558 Raman spectra (370-1720 cm -1 ) of human cortical bone acquired from 62 female and male donors (nine spectra each) spanning adulthood (age range = 21-101 years). Spectra were analyzed prior to R-curve, nonlinear fracture mechanics that delineate crack initiation (K init ) from crack growth toughness (K grow ). The traditional ν 1 phosphate peak per amide I peak (mineral-to-matrix ratio) weakly correlated with K init (r = 0.341, p = 0.0067) and overall crack growth toughness (J-int: r = 0.331, p = 0.0086). Sub-peak ratios of the amide I band that are related to the secondary structure of type 1 collagen did not correlate with the fracture toughness properties. In the full spectrum analysis, one principal component (PC5) correlated with all of the mechanical properties (K init : r = - 0.467, K grow : r = - 0.375, and J-int: r = - 0.428; p toughness, namely age and/or volumetric bone mineral density (vBMD), were included in general linear models as covariates, several PCs helped explain 45.0% (PC5) to 48.5% (PC7), 31.4% (PC6), and 25.8% (PC7) of the variance in K init , K grow , and J-int, respectively. Deriving spectral features from full spectrum analysis may improve the ability of RS, a clinically viable technology, to assess fracture risk.

  6. THE EFFECT OF STRAIN RATE ON FRACTURE TOUGHNESS OF HUMAN CORTICAL BONE: A FINITE ELEMENT STUDY

    Science.gov (United States)

    Ural, Ani; Zioupos, Peter; Buchanan, Drew; Vashishth, Deepak

    2011-01-01

    Evaluating the mechanical response of bone under high loading rates is crucial to understanding fractures in traumatic accidents or falls. In the current study, a computational approach based on cohesive finite element modeling was employed to evaluate the effect of strain rate on fracture toughness of human cortical bone. Two-dimensional compact tension specimen models were simulated to evaluate the change in initiation and propagation fracture toughness with increasing strain rate (range: 0.08 to 18 s−1). In addition, the effect of porosity in combination with strain rate was assessed using three-dimensional models of microcomputed tomography-based compact tension specimens. The simulation results showed that bone’s resistance against the propagation of fracture decreased sharply with increase in strain rates up to 1 s−1 and attained an almost constant value for strain rates larger than 1 s−1. On the other hand, initiation fracture toughness exhibited a more gradual decrease throughout the strain rates. There was a significant positive correlation between the experimentally measured number of microcracks and the fracture toughness found in the simulations. Furthermore, the simulation results showed that the amount of porosity did not affect the way initiation fracture toughness decreased with increasing strain rates, whereas it exacerbated the same strain rate effect when propagation fracture toughness was considered. These results suggest that strain rates associated with falls lead to a dramatic reduction in bone’s resistance against crack propagation. The compromised fracture resistance of bone at loads exceeding normal activities indicates a sharp reduction and/or absence of toughening mechanisms in bone during high strain conditions associated with traumatic fracture. PMID:21783112

  7. "Plug" ósseo autógeno para orifícios de trepanação: nota técnica Autogenic bone plug to seal burr holes: technical note

    Directory of Open Access Journals (Sweden)

    JOSUÉ GUIMARÃES GRANHA VIALOGO

    1999-12-01

    Full Text Available Vários materiais são utilizados para ocluir os orifícios de trepanação em neurocirurgia, por motivos variados: para evitar fístula liquórica após trepanações, para auxiliar a fixação do "flap" ósseo e por motivos estéticos, na região frontal. Dentre estes materiais citamos os heterólogos (botões de silicone, miniplacas de metal, cera de osso, metilmetacrilato, gelfoam, cimento de polímero vegetal, cerâmica de hidroxiapatita, e os autólogos (pó de osso originado da trepanação, gordura, músculo, aponeurose. Os materiais heterólogos ou sintéticos podem provocar reação de corpo estranho com erosão da pele e exposição do material, tornando necessária sua retirada, em tempo variável no pós-operatório. Há cerca de três anos, o autor vem utilizando um botão ou "plug" ósseo autólogo, feito com surgicel e o pó de osso proveniente da trepanação, com bom resultado estético eliminando as desconfortáveis depressões cranianas pós-trepanação. Apresentamos a técnica de confecção deste prático `plug ósseo autólogo'. Nas neuroendoscopias, praticamente sanou-se o problema da fístula liquórica e reação de corpo estranho. Encorajamos a utilização deste botão ósseo autólogo em nosso meio, como método eficiente, econômico e biologicamente aceitável para ocluir orifícios cranianos de trepanação.Many neurosurgical procedures can be performed by a single burr hole: neuroendoscopy, microvascular decompression, stereotactic procedures, chronic subdural haematomas. It is technically difficult to suture and close the dura, located at the bottom of such holes, which can lately lead to CSF leakage. On the other hand, the surgical material used to seal the burr holes can be divided in heterogenic (metal screws, silicon plugs, gelfoam, bone wax, metilmetacrilate, hidroxiapatite, and autogenic (fat, aponeurosis, muscle, and bone dust from trephination. The heterogenic group always brings the possibility of

  8. Sex-specific patterns in cortical and trabecular bone microstructure in the Kirsten Skeletal Collection, South Africa.

    Science.gov (United States)

    Beresheim, Amy C; Pfeiffer, Susan K; Grynpas, Marc D; Alblas, Amanda

    2018-02-07

    The purpose of this study was to provide bone histomorphometric reference data for South Africans of the Western Cape who likely dealt with health issues under the apartheid regime. The 206 adult individuals ( n female = 75, n male = 131, mean = 47.9 ± 15.8 years) from the Kirsten Skeletal Collection, U. Stellenbosch, lived in the Cape Town metropole from the late 1960s to the mid-1990s. To study age-related changes in cortical and trabecular bone microstructure, photomontages of mid-thoracic rib cross-sections were quantitatively examined. Variables include relative cortical area (Rt.Ct.Ar), osteon population density (OPD), osteon area (On.Ar), bone volume fraction (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular spacing (Tb.Sp). All cortical variables demonstrated significant relationships with age in both sexes, with women showing stronger overall age associations. Peak bone mass was compromised in some men, possibly reflecting poor nutritional quality and/or substance abuse issues throughout adolescence and early adulthood. In women, greater predicted decrements in On.Ar and Rt.Ct.Ar suggest a structural disadvantage with age, consistent with postmenopausal bone loss. Age-related patterns in trabecular bone microarchitecture are variable and difficult to explain. Except for Tb.Th, there are no statistically significant relationships with age in women. Men demonstrate significant negative correlations between BV/TV, Tb.N, and age, and a significant positive correlation between Tb.Sp and age. This research highlights sex-specific differences in patterns of age-related bone loss, and provides context for discussion of contemporary South African bone health. While the study sample demonstrates indicators of poor bone quality, osteoporosis research continues to be under-prioritized in South Africa. © 2018 Wiley Periodicals, Inc.

  9. Heterogeneity of Necrotic Changes between Cortical and Cancellous Bone in Mandibular Osteoradionecrosis: A Histopathological Analysis of Resection Margin after Segmental Mandibulectomy

    Directory of Open Access Journals (Sweden)

    Masaya Akashi

    2017-01-01

    Full Text Available Background. This study aimed to analyze differences in necrotic changes between cortical and cancellous bone in resection margins after segmental mandibulectomy for advanced mandibular osteoradionecrosis. Methods. Anteroposterior bone specimens from eleven patients who underwent segmental mandibulectomy with simultaneous free fibula flap reconstruction for advanced osteoradionecrosis were analyzed histopathologically for the presence of necrotic bone based on the presence of blood vessels within Haversian canals. Results. Ten of eleven (91% cortices near the inferior border of the mandible at the anterior margins were necrotic. All cancellous bones at the anterior margins were viable. Seven of eleven (64% cortices near the inferior border of the mandible at the posterior margins were necrotic. Three of eleven (27% cancellous bones at the posterior margins were necrotic. Conclusion. Necrotic changes are more prevalent in cortices than in cancellous bones in mandibular osteoradionecrosis, probably due to a decrease of periosteal blood supply caused by radiotherapy.

  10. Intraskeletal variation in human cortical osteocyte lacunar density: Implications for bone quality assessment

    Directory of Open Access Journals (Sweden)

    Randee L. Hunter

    2016-12-01

    Full Text Available Osteocytes and their lacunocanalicular network have been identified as the regulator of bone quality and function by exerting extensive influence over metabolic processes, mechanical adaptation, and mineral homeostasis. Recent research has shown that osteocyte apoptosis leads to a decrease in bone quality and increase in bone fragility mediated through its effects on remodeling. The purpose of this study is to investigate variation in cortical bone osteocyte lacunar density with respect to major factors including sex, age, and intracortical porosity to establish both regional and systemic trends. Samples from the midshaft femur, midshaft rib and distal one-third diaphysis of the radius were recovered from 30 modern cadaveric individuals (15 males and 15 females ranging from 49 to 100 years old. Thick ground undecalcified histological (80 μm cross-sections were made and imaged under bright field microscopy. Osteocyte lacunar density (Ot.Lc.N/B.Ar and intracortical porosity (%Po.Ar were quantified. No significant sex differences in Ot.Lc.N/B.Ar or %Po.Ar were found in any element. Linear regressions demonstrated a significant decrease in osteocyte lacunar density (Ot.Lc.N/B.Ar and increase in intracortical porosity (%Po.Ar with age for the sex-pooled sample in the femur (R2 = 0.208, 0.297 respectively and radius (R2 = 0.108, 0.545 respectively. Age was unable to significantly predict osteocyte lacunar density or intracortical porosity in the rib (R2 = 0.058, 0.114 respectively. Comparisons of regression coefficients demonstrated a systemic trend in the decrease in osteocyte lacunar density (Ot.Lc.N/B.Ar and increase in intracortical porosity (%Po.Ar with age. In each element, intracortical porosity was significantly negatively correlated with lacunar density for which the radius demonstrated the strongest relationship (r = −0.746. Using pore number (Po.N as a proxy for available vascularity to support the osteocyte population, Po

  11. In vitro deposition of hydroxyapatite on cortical bone collagen stimulated by deformation-induced piezoelectricity.

    Science.gov (United States)

    Noris-Suárez, Karem; Lira-Olivares, Joaquin; Ferreira, Ana Marina; Feijoo, José Luis; Suárez, Nery; Hernández, Maria C; Barrios, Esteban

    2007-03-01

    In the present work, we have studied the effect of the piezoelectricity of elastically deformed cortical bone collagen on surface using a biomimetic approach. The mineralization process induced as a consequence of the piezoelectricity effect was evaluated using scanning electron microscopy (SEM), thermally stimulated depolarization current (TSDC), and differential scanning calorimetry (DSC). SEM micrographs showed that mineralization occurred predominantly over the compressed side of bone collagen, due to the effect of piezoelectricity, when the sample was immersed in the simulated body fluid (SBF) in a cell-free system. The TSDC method was used to examine the complex collagen dielectric response. The dielectric spectra of deformed and undeformed collagen samples with different hydration levels were compared and correlated with the mineralization process followed by SEM. The dielectric measurements showed that the mineralization induced significant changes in the dielectric spectra of the deformed sample. DSC and TSDC results demonstrated a reduction of the collagen glass transition as the mineralization process advanced. The combined use of SEM, TSDC, and DSC showed that, even without osteoblasts present, the piezoelectric dipoles produced by deformed collagen can produce the precipitation of hydroxyapatite by electrochemical means, without a catalytic converter as occurs in classical biomimetic deposition.

  12. Extracurricular sports activity around growth spurt and improved tibial cortical bone properties in late adolescence.

    Science.gov (United States)

    Shi, Hui-Jing; Nakamura, Keiko; Kizuki, Masashi; Inose, Tomoko; Seino, Kaoruko; Takano, Takehito

    2006-12-01

    To elucidate whether extracurricular sports activity during rapid growth correlates with improved bone properties in late adolescence, a longitudinal observation was performed among 96 high-school enrollments (46 boys and 50 girls, born in 1981-1982) in metropolitan Tokyo. In each year of high school, tibial cortical speed of sound (TCSOS) was measured by quantitative ultrasonometry, and participation in extracurricular sports activity (ECSA) since primary school was examined by structured questionnaire. We calculated the number of years since peak height velocity (ysPHV) based on annual records of height from 6 to 18 y of age to indicate progression of puberty. The increase in TCSOS during high school in boys (32.5 m/s) was significantly greater than that in girls (5.4 m/s). The magnitude of positive association between ysPHV and TCSOS attenuated gradually over time. ECSA in grades 7-9 in boys and in grades 4-6 in girls were significant predictors of TCSOS throughout high school, independent of potential confounders. The bone benefits of ECSA around the growth spurt are maintainable in subsequent years. The importance of physical activities that are integrated into the ordinary lifestyle of children and adolescents during this crucial period is emphasized.

  13. The effects of embalming using a 4% formalin solution on the compressive mechanical properties of human cortical bone.

    Science.gov (United States)

    Ohman, Caroline; Dall'Ara, Enrico; Baleani, Massimiliano; Van Sint Jan, Serge; Viceconti, Marco

    2008-12-01

    The use of formalin fixed bone tissue is often avoided because of its assumed influence on the mechanical properties of bone. Fixed bone tissue would minimise biological risks and eliminate preservation issues for long duration experimental tests. This study aimed to determine the short- and long-term effects of embalming, using a solution with 4% formalin concentration, on the mechanical properties of human cortical bone. Three-millimetre cylindrical specimens of human cortical bone were extracted from two femoral diaphyses and divided in four groups. The first group was used as control, the remaining three groups were left in the embalming solution for 48 h, 4 week, and 8 week, respectively. Compressive mechanical properties, hardness and ash density were assessed. The last was used to check the homogeneity among the four groups. No significant differences were found among the four groups in yield stress, ultimate stress and hardness. The specimens stored for 8 week in the embalming solution had significant lower Young's modulus (-24%), higher yield strain (+20%) and ultimate strain (+53%) compared to the other groups. On a short-term perspective, embalming did not affect the compressive mechanical properties, nor hardness of human cortical bone, whereas a long-term preservation (8 week) did significantly affect Young's modulus, yield strain and ultimate strain in compression. Preserving bone segments for up to 4 week in an embalming solution with low formalin concentration seems to be an interesting alternative when collecting and/or managing fresh or fresh-frozen bone segments for biomechanical experiments is not possible.

  14. Auditory brainstem and cortical potentials following bone-anchored hearing aid stimulation.

    Science.gov (United States)

    Rahne, Torsten; Ehelebe, Thomas; Rasinski, Christine; Götze, Gerrit

    2010-11-30

    Patients suffering from conductive or mixed hearing loss and Single-Sided Deafness may benefit from implantable hearing devices relying on bone conducted auditory stimulation. However, with only passively cooperative patients, objective methods are needed to estimate the aided and unaided pure-tone audiogram. This study focuses on the feasibility aspect of an electrophysiological determination of the hearing thresholds with bone-anchored hearing aid stimulation. Therefore, 10 normal-hearing subjects were provided with a Baha Intenso (Cochlear Ltd.) which was temporarily connected to the Baha Softband (Cochlear Ltd.). Auditory evoked potentials were measured by auditory stimulation paradigm used in clinical routine. The amplitudes, latencies, and thresholds of the resulting auditory brainstem responses (ABR) and the cortically evoked responses (CAEP) were correlated with the respective responses without the use of the Baha Intenso. The recording of ABR and CAEP by delivering the stimuli to the Baha results in response waveforms which are comparable to those evoked by earphone stimulation and appears appropriate to be measured using the Baha Intenso as stimulator. At the ABR recordings a stimulus artifact at higher stimulation levels and a constant latency shift caused by the Baha Intenso has to be considered. The CAEP recording appeared promising as a frequency specific objective method to approve the fitting of bone-anchored hearing aids. At all measurements, the ABR and CAEP thresholds seem to be consistent with the normal hearing of the investigated participants. Thus, a recording of auditory evoked potentials using a Baha is in general possible if specific limitations are considered. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Periosteal PTHrP regulates cortical bone modeling during linear growth in mice.

    Science.gov (United States)

    Wang, Meina; VanHouten, Joshua N; Nasiri, Ali R; Tommasini, Steven M; Broadus, Arthur E

    2014-07-01

    The modeling of long bone surfaces during linear growth is a key developmental process, but its regulation is poorly understood. We report here that parathyroid hormone-related peptide (PTHrP) expressed in the fibrous layer of the periosteum (PO) drives the osteoclastic (OC) resorption that models the metaphyseal-diaphyseal junction (MDJ) in the proximal tibia and fibula during linear growth. PTHrP was conditionally deleted (cKO) in the PO via Scleraxis gene targeting (Scx-Cre). In the lateral tibia, cKO of PTHrP led to a failure of modeling, such that the normal concave MDJ was replaced by a mound-like deformity. This was accompanied by a failure to induce receptor activator of NF-kB ligand (RANKL) and a 75% reduction in OC number (P ≤ 0.001) on the cortical surface. The MDJ also displayed a curious threefold increase in endocortical osteoblast mineral apposition rate (P ≤ 0.001) and a thickened cortex, suggesting some form of coupling of endocortical bone formation to events on the PO surface. Because it fuses distally, the fibula is modeled only proximally and does so at an extraordinary rate, with an anteromedial cortex in CD-1 mice that was so moth-eaten that a clear PO surface could not be identified. The cKO fibula displayed a remarkable phenotype, with a misshapen club-like metaphysis and an enlargement in the 3D size of the entire bone, manifest as a 40-45% increase in the PO circumference at the MDJ (P ≤ 0.001) as well as the mid-diaphysis (P ≤ 0.001). These tibial and fibular phenotypes were reproduced in a Scx-Cre-driven RANKL cKO mouse. We conclude that PTHrP in the fibrous PO mediates the modeling of the MDJ of long bones during linear growth, and that in a highly susceptible system such as the fibula this surface modeling defines the size and shape of the entire bone. © 2014 Anatomical Society.

  16. Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones.

    Science.gov (United States)

    Sugiyama, Toshihiro; Price, Joanna S; Lanyon, Lance E

    2010-02-01

    In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19 weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2 weeks (approximately 7 min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC+STATIC group were subjected to a peak dynamic load of 11.5 N (40 cycles with 10-s intervals between cycles) superimposed upon a static "pre-load" of 2.0 N. This total load of 13.5 N engendered peak longitudinal strains of approximately 1400 microstrain on the medial surface of the tibia at a middle/proximal site. The right tibiae/fibulae in the STATIC group received the static "pre-load" alone while the NOLOAD group received no artificial loading. After 2 weeks, the animals were sacrificed and both tibiae, fibulae, femora, ulnae and radii analyzed by three-dimensional high-resolution (5 mum) micro-computed tomography (microCT). In the DYNAMIC+STATIC group, the proximal trabecular percent bone volume and cortical bone volume at the proximal and middle levels of the right tibiae as well as the cortical bone volume at the middle level of the right fibulae were markedly greater than the left. In contrast, the left bones in the DYNAMIC+STATIC group showed no differences compared to the left or right bones in the NOLOAD or STATIC group. These microCT data were confirmed by two-dimensional examination of fluorochrome labels in bone sections which showed the predominantly woven nature of the new bone formed in the loaded bones. We conclude that the adaptive response in both cortical and trabecular regions of bones subjected to short periods of dynamic loading, even when this response is sufficiently vigorous to stimulate woven bone formation, is confined to the loaded bones and does not involve changes in other bones that are adjacent, contra-lateral or remote to them. (c) 2009 Elsevier Inc

  17. Hibernation does not reduce cortical bone density, area or second moments of inertia in woodchucks (Marmota monax).

    Science.gov (United States)

    Doherty, Alison H; Frampton, Jason D; Vinyard, Christopher J

    2012-06-01

    Long periods of inactivity in most mammals result in bone loss that may not be completely recoverable during an individual's lifetime regardless of future activity. Prolonged inactivity is normal during hibernation, but it remains uncertain whether hibernating mammals suffer decreased bone properties after hibernation that affects survival. We test the hypothesis that relative cortical area (C(A) ), apparent density, bone area fraction (B.Ar/T.Ar), and moments of inertia do not differ between museum samples of woodchucks (Marmota monax) collected before and after hibernation. We used peripheral quantitative computed tomography to examine bone geometry in the femur, tibia, humerus and mandible. We see little evidence for changes in bone measures with hibernation supporting our hypothesis. In fact, when including subadults to increase sample sizes and controlling age statistically, we observed a trend toward increased bone properties following hibernation. Diaphyses were significantly denser in the humerus, femur, and tibia after hibernation, and relative mandibular cortical area was significantly larger. Similarly, relative mechanical indices were significantly larger in the mandible after hibernation. Although tests of individual measures in many cases were not significantly different prehibernation versus posthibernation, the overall pattern of average increase posthibernation was significant for relative C(A) and densities as well as relative diaphyseal mechanical indices when examining outcomes collectively. The exception to this pattern was a reduction in metaphyseal trabecular bone following hibernation. Individually, only humeral B.Ar/T.Ar was significantly reduced, but the average reduction in trabecular measures post-hibernation was significant when examined collectively. Because the sample included subadults, we suggest that much of the increased bone relates to their continued growth during hibernation. Our results indicate that woodchucks are more

  18. Baseline mineralizing surface determines the magnitude of the bisphosphonate effect on cortical bone mineralization in postmenopausal osteoporotic patients

    Science.gov (United States)

    Misof, B.M.; Blouin, S.; Lueger, S.; Paschalis, E.P.; Recker, R.R.; Phipps, R.; Klaushofer, K.; Roschger, P.

    2017-01-01

    Purpose: To determine the effect of short- or long-term bisphosphonate treatment on cortical bone mineralization density distribution (BMDD). Methods: BMDD was assessed by quantitative backscatter electron imaging in postmenopausal osteoporosis: in paired transiliac biopsy samples (n=36) at baseline and after 3 years risedronate treatment from a clinical study, in transiliac biopsy samples from patients who were treated with either risedronate (n=31) or alendronate (n=68) for 3 to 7 years from an observational study. Outcomes were related to premenopausal reference data (n=73) and to histomorphometric mineralizing surface per bone surface (MS/BS). Results: In the clinical study, patients with lower (below cohort median) MS/BS had normal cortical CaMean at baseline. After 3 years risedronate, their CaMean was not different versus baseline but increased versus reference (+2.9%, p=0.003). Among the groups of the observational study, CaMean did not exceed reference level, was similar for alendronate versus risedronate and similar between 3 to 5 years versus longer than 5 years treatment duration. Conclusion: Baseline bone mineralizing surface appears to be important for the effect of bisphosphonate on cortical bone mineralization. In patients with lower baseline MS/BS, level of mineralization after treatment can exceed reference level. Whether this is beneficial in the long-term is unknown. PMID:28860420

  19. Benefits of mineralized bone cortical allograft for immediate implant placement in extraction sites: an in vivo study in dogs.

    Science.gov (United States)

    Orti, Valérie; Bousquet, Philippe; Tramini, Paul; Gaitan, Cesar; Mertens, Brenda; Cuisinier, Frédéric

    2016-10-01

    The aim of the present study was to evaluate the effectiveness of using a mineralized bone cortical allograft (MBCA), with or without a resorbable collagenous membrane derived from bovine pericardium, on alveolar bone remodeling after immediate implant placement in a dog model. Six mongrel dogs were included. The test and control sites were randomly selected. Four biradicular premolars were extracted from the mandible. In control sites, implants without an allograft or membrane were placed immediately in the fresh extraction sockets. In the test sites, an MBCA was placed to fill the gap between the bone socket wall and implant, with or without a resorbable collagenous membrane. Specimens were collected after 1 and 3 months. The amount of residual particles and new bone quality were evaluated by histomorphometry. Few residual graft particles were observed to be closely embedded in the new bone without any contact with the implant surface. The allograft combined with a resorbable collagen membrane limited the resorption of the buccal wall in height and width. The histological quality of the new bone was equivalent to that of the original bone. The MBCA improved the quality of new bone formation, with few residual particles observed at 3 months. The preliminary results of this animal study indicate a real benefit in obtaining new bone as well as in enhancing osseointegration due to the high resorbability of cortical allograft particles, in comparison to the results of xenografts or other biomaterials (mineralized or demineralized cancellous allografts) that have been presented in the literature. Furthermore, the use of an MBCA combined with a collagen membrane in extraction and immediate implant placement limited the extent of post-extraction resorption.

  20. Development of a strain rate dependent material model of human cortical bone for computer-aided reconstruction of injury mechanisms.

    Science.gov (United States)

    Asgharpour, Zahra; Zioupos, Peter; Graw, Matthias; Peldschus, Steffen

    2014-03-01

    Computer-aided methods such as finite-element simulation offer a great potential in the forensic reconstruction of injury mechanisms. Numerous studies have been performed on understanding and analysing the mechanical properties of bone and the mechanism of its fracture. Determination of the mechanical properties of bones is made on the same basis used for other structural materials. The mechanical behaviour of bones is affected by the mechanical properties of the bone material, the geometry, the loading direction and mode and of course the loading rate. Strain rate dependency of mechanical properties of cortical bone has been well demonstrated in literature studies, but as many of these were performed on animal bones and at non-physiological strain rates it is questionable how these will apply in the human situations. High strain-rates dominate in a lot of forensic applications in automotive crashes and assault scenarios. There is an overwhelming need to a model which can describe the complex behaviour of bone at lower strain rates as well as higher ones. Some attempts have been made to model the viscoelastic and viscoplastic properties of the bone at high strain rates using constitutive mathematical models with little demonstrated success. The main objective of the present study is to model the rate dependent behaviour of the bones based on experimental data. An isotropic material model of human cortical bone with strain rate dependency effects is implemented using the LS-DYNA material library. We employed a human finite element model called THUMS (Total Human Model for Safety), developed by Toyota R&D Labs and the Wayne State University, USA. The finite element model of the human femur is extracted from the THUMS model. Different methods have been employed to develop a strain rate dependent material model for the femur bone. Results of one the recent experimental studies on human femur have been employed to obtain the numerical model for cortical femur. A

  1. Cortical bone resorption rate in elderly persons: Estimates from long-term in vivo measurements of 90Sr in the skeleton

    International Nuclear Information System (INIS)

    Shagina, N.B.; Tolstykh, E.I.; Degteva, M.O.; Anspaugh, L.R.; Napier, Bruce A.

    2012-01-01

    The rate of cortical bone resorption was assessed from long-term in vivo measurements of 90Sr content in the skeleton for men aged 50-80 years and for women 0-30 years after menopause. Measurements of 90Sr were conducted with a whole body counter for residents of the Techa Riverside communities (Southern Urals, Russia), who ingested large amounts of 90Sr as a result of releases of liquid radioactive wastes into the river from the Mayak plutonium facility in early 1950s. The results of this study showed an increase in the rate of cortical bone resorption in both men and women, as based on the use of accidentally ingested 90Sr as a tracer for bone metabolism. In men there was a continuous gradual increase in the rate of cortical bone resorption after 55 years from 2.8 to 4.5%/year by the age of 75 years. In women, there was a doubled increase in the rate of cortical bone resorption after menopause of up to 6%/year; then the rate remained unchanged for 10-12 years with a subsequent gradual decline down to 5-5.5%/year. Comparison of the rate of cortical bone resorption in men and women older than 55 years showed that women expressed significantly higher levels of cortical bone resorption.

  2. Cortical bone resorption rate in elderly persons: Estimates from long-term in vivo measurements of 90Sr in the skeleton

    Energy Technology Data Exchange (ETDEWEB)

    Shagina, N. B.; Tolstykh, E. I.; Degteva, M. O.; Anspaugh, L. R.; Napier, Bruce A.

    2012-06-01

    The rate of cortical bone resorption was assessed from long-term in vivo measurements of 90Sr content in the skeleton for men aged 50-80 years and for women 0-30 years after menopause. Measurements of 90Sr were conducted with a whole body counter for residents of the Techa Riverside communities (Southern Urals, Russia), who ingested large amounts of 90Sr as a result of releases of liquid radioactive wastes into the river from the Mayak plutonium facility in early 1950s. The results of this study showed an increase in the rate of cortical bone resorption in both men and women, as based on the use of accidentally ingested 90Sr as a tracer for bone metabolism. In men there was a continuous gradual increase in the rate of cortical bone resorption after 55 years from 2.8 to 4.5%/year by the age of 75 years. In women, there was a doubled increase in the rate of cortical bone resorption after menopause of up to 6%/year; then the rate remained unchanged for 10-12 years with a subsequent gradual decline down to 5-5.5%/year. Comparison of the rate of cortical bone resorption in men and women older than 55 years showed that women expressed significantly higher levels of cortical bone resorption.

  3. Mechanical properties of radial bone defects treated with autogenous graft covered with hydroxyapatite in rabbit Propriedades mecânicas de defeito de osso radial tratado com enxerto autógeno coberto com nano-hydroxyapatite em coelho

    Directory of Open Access Journals (Sweden)

    Davood Sharifi

    2012-03-01

    Full Text Available PURPOSE: To determine biomechanical property of autogenous bone graft covered with hydroxyapatite in the defect of radial bone in rabbit. METHODS: Eighteen adult male New Zealand white rabbits were used which were divided into three groups (I, II, III of six rabbits each. A segmental bone defect of 10 mm in length was created in the middle of the right radial shaft under general effective anesthesia in all rabbits and were stabilized using mini-plate with four screws. The defects In group I were left as such without filler, whereas in group II the defect were filled up with harvested 10 mm rib bone and in group III the defect were packed with rib bone covered with nano-hydroxyapatite. All rabbits in three groups were divided into two subgroups (one month and three months duration with three rabbits in each one. RESULTS: The mechanical property and the mean load for fracturing normal radial bone was recorded 388.2±6 N whereas it was 72.4±12.8 N for group I in 1 month duration which was recorded 182.4±14.2 N for group II and 211.6±10.4 N for group III at the end of 1 month. These values were 97.6±10.2 N for group I and 324.6±8.2 N for group II and 372.6±17.4 N for group III at the end of three months after implantation. CONCLUSION: Implantation of autologous graft covered with hydroxyapatite indicated to have positive effect in integral formation of qualitative callus at the site of fracture and early re-organization of callus to regain mechanical strength too.OBJETIVO: Determinar as propriedades biomecânicas de enxerto ósseo autógeno coberto com hidroxiapatita em defeito do osso radial em coelhos. MÉTODOS: Foram utilizados 18 coelhos adultos, machos, brancos, Nova Zelândia, distribuídos em três grupos (I, II, III de seis coelhos cada. Um defeito segmentar de 10 mm de comprimento foi criado no meio do eixo radial direito sob anestesia geral efetiva em todos os coelhos e foram fixados usando mini-placa com quatro parafusos. Os

  4. Autogenous tooth transplantation: an alternative to replace extracted tooth

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2015-09-01

    Full Text Available Background: The gold standard treatment to replace missing tooth is dental implants, however, in certain cases, such as in young patients its placement is contraindicated. Autogenous tooth transplantation, which has been widely done in Scandinavian countries for many years, may become a good alternative to overcome this problem. Purpose: This article attempted to provide information about the indication, treatment planning, surgical technique and the successful result of autogenous tooth transplantation. Case: A fifteen year old male patient presented with large caries and periapical disease of his lower left first molar, which was partially erupted and the roots was not fully formed in radiograph. Case management: Autogenous tooth transplantation procedure was performed consisting of extraction of #36, odontectomy of #38 followed by its implantation to socket #36 and fixation of the transplanted tooth to the adjacent teeth. Post operative evaluation was done on regular basis within 18 months period. There was no complaint, the tooth was clinically stable and no evidence of periodontal problem. Serial radiographs showed healing of alveolar bone and periodontal tissue, and the complete root formation was evident by 18 months post operatively. Conclusion: Autogenous tooth transplantation is a potential alternative to replace extracted tooth. Provided that the case be properly planned and operation carefully performed, successful result of this treatment can be achieved.

  5. A viscoelastic, viscoplastic model of cortical bone valid at low and high strain rates.

    Science.gov (United States)

    Johnson, T P M; Socrate, S; Boyce, M C

    2010-10-01

    The stress-strain behavior of cortical bone is well known to be strain-rate dependent, exhibiting both viscoelastic and viscoplastic behavior. Viscoelasticity has been demonstrated in literature data with initial modulus increasing by more than a factor of 2 as applied strain rate is increased from 0.001 to 1500 s(-1). A strong dependence of yield on strain rate has also been reported in the literature, with the yield stress at 250 s(-1) having been observed to be more than twice that at 0.001 s(-1), demonstrating the material viscoplasticity. Constitutive models which capture this rate-dependent behavior from very low to very high strain rates are required in order to model and simulate the full range of loading conditions which may be experienced in vivo; particularly those involving impact, ballistic and blast events. This paper proposes a new viscoelastic, viscoplastic constitutive model which has been developed to meet these requirements. The model is fitted to three sets of stress-strain measurements from the literature and shown to be valid at strain rates ranging over seven orders of magnitude. 2010 Acta Materialia Inc. All rights reserved.

  6. Changes in tissue morphology and collagen composition during the repair of cortical bone in the adult chicken.

    Science.gov (United States)

    Glimcher, M J; Shapiro, F; Ellis, R D; Eyre, D R

    1980-09-01

    An animal model was developed to study the histology and collagen chemistry of healing cortical bone. A hole was cut through the cortex of the mid-shaft of the humerus of the adult chicken, which allowed for repair at a mechanically stable site. After one to two weeks the collagen of the repair tissue, which consisted principally of woven bone, contained almost three times as much hydroxylysine as the collagen of normal adult bone and thus resembled the collagen of embryonic long bones. By eight weeks, when lamellar one predominated, the hydroxylysine content had fallen to normal levels. Type I was the major genetic type of collagen present throughout. No type-II collagen, characteristic of cartilage, was detected; this was consistent with the histological findings. The results established that hydroxylysine-rich type-I collagen can be made by osteoblasts of adult animals as well as by those of embryos and early postnates. In order to understand the biological characteristics of fracture healing, it is vital to study not only the macroscopic organization of the repair tissue but also the chemical properties of its molecular components. The strength of healing fractured bone, and indeed of normal bone, depends largely on the properties of the structural protein collagen. To date, it is not known whether the collagen in healing fractures is the same as that in normal bone, or whether it has distinct chemical features that may suit it for bone repair.

  7. Intra- and inter-observer variation in histological criteria used in age at death determination based on femoral cortical bone

    DEFF Research Database (Denmark)

    Lynnerup, N; Thomsen, J L; Frohlich, B

    1998-01-01

    The microscopic method of age at death determination was introduced by Kerley in 1965. The method, which relies on the quantification of selected elements in cortical bone tissue, has been widely used, and several other researchers have modified or added to the method. Yet, very few studies have...... elements. Until more rigorous definitions of such elements have been agreed upon, the use of microscopical methods must be discouraged as a sole or uncontrolled method of evaluating age at death....

  8. Determination of a tissue-level failure evaluation standard for rat femoral cortical bone utilizing a hybrid computational-experimental method.

    Science.gov (United States)

    Fan, Ruoxun; Liu, Jie; Jia, Zhengbin; Deng, Ying; Liu, Jun

    2018-01-01

    Macro-level failure in bone structure could be diagnosed by pain or physical examination. However, diagnosing tissue-level failure in a timely manner is challenging due to the difficulty in observing the interior mechanical environment of bone tissue. Because most fractures begin with tissue-level failure in bone tissue caused by continually applied loading, people attempt to monitor the tissue-level failure of bone and provide corresponding measures to prevent fracture. Many tissue-level mechanical parameters of bone could be predicted or measured; however, the value of the parameter may vary among different specimens belonging to a kind of bone structure even at the same age and anatomical site. These variations cause difficulty in representing tissue-level bone failure. Therefore, determining an appropriate tissue-level failure evaluation standard is necessary to represent tissue-level bone failure. In this study, the yield and failure processes of rat femoral cortical bones were primarily simulated through a hybrid computational-experimental method. Subsequently, the tissue-level strains and the ratio between tissue-level failure and yield strains in cortical bones were predicted. The results indicated that certain differences existed in tissue-level strains; however, slight variations in the ratio were observed among different cortical bones. Therefore, the ratio between tissue-level failure and yield strains for a kind of bone structure could be determined. This ratio may then be regarded as an appropriate tissue-level failure evaluation standard to represent the mechanical status of bone tissue.

  9. The assessment of trabecular bone parameters and cortical bone strength: a comparison of micro-CT and dental cone-beam CT.

    Science.gov (United States)

    Hsu, Jui-Ting; Wang, Shun-Ping; Huang, Heng-Li; Chen, Ying-Ju; Wu, Jay; Tsai, Ming-Tzu

    2013-10-18

    This study compared the capabilities of micro-computed tomography (micro-CT) and dental cone-beam computed tomography (CBCT) in assessing trabecular bone parameters and cortical bone strength. Micro-CT and CBCT scans were applied to 28 femurs from 14 rats to obtain independent measurements of the volumetric cancellous bone mineral density (vCanBMD) in the femoral head, volumetric cortical bone mineral density (vCtBMD) in the femoral diaphysis, cross-sectional moment of inertia (CSMI), and bone strength index (BSI) (=CSMI×vCtBMD). Five structural parameters of the trabecular bone of the femoral head were calculated from micro-CT images. A three-point bending test was then conducted to measure the fracture load of each femur. Bivariate linear Pearson analysis was conducted to calculate the correlation coefficients (r values) of the micro-CT, dental CBCT, and three-point bending measurements. The statistical analyses showed a strong correlation between vCanBMD values obtained using micro-CT and dental CBCT (r=0.830). There were strong or moderate correlation between vCanBMD measured using dental CBCT and five parameters of trabecular structure measured using micro-CT. Additionally, the results were satisfactory regardless of whether micro-CT or dental CBCT was used to measure the femoral diaphysis vCtBMD (r=0.733 and 0.680, respectively), CSMI (r=0.756 and 0.726, respectively), or BSI (r=0.846 and 0.847, respectively) to predict fracture loads. This study has yielded a new method for using dental CBCT to evaluate bone parameters and bone strength; however, further studies are necessary to validate the use of dental CBCT on humans. © 2013 Elsevier Ltd. All rights reserved.

  10. Disparate effects of mild, moderate, and severe secondary hyperparathyroidism on cancellous and cortical bone in rats with chronic renal insufficiency.

    Science.gov (United States)

    Miller, M A; Chin, J; Miller, S C; Fox, J

    1998-09-01

    The subtotally nephrectomized rat has often been used to investigate the etiology and treatment of secondary hyperparathyroidism (secondaryHPT), but it has been used less frequently to study the effects of secondaryHPT on bone. The recent development of a reliable and specific rat parathyroid hormone (PTH) immunoradiometric assay has provided an opportunity for a thorough investigation of the relationship between circulating, biologically active PTH, and the skeletal abnormalities that occur in chronic renal insufficiency (CRI). Rats were 5/6 nephrectomized (Nx) or sham operated and fed diets with varying levels of Ca and P for 12-14 weeks to induce differing magnitudes of secondaryHPT. Parathyroid gland volume increased by 80%-90% in 5/6 Nx rats in the mild and moderate secondaryHPT groups (2.3- and 7.7-fold higher PTH levels, respectively) and by 3.3-fold in the severe secondaryHPT group (12-fold increase in PTH). The increases in gland volume were caused primarily by cell hyperplasia. Mild secondaryHPT resulted in a 12% decrease in bone mineral density (BMD) across the entire femur, increased osteoclast numbers (N.Oc), unchanged osteoblast numbers (N.Ob), and decreased cancellous bone volume (Cn.BV) in the tibial metaphysis but, apart from increased marrow area, no major changes in cortical bone at the tibio-fibular junction. Moderate secondaryHPT was associated with no changes in femoral BMD, or in tibial Cn.BV, but N.Ob and bone formation rate (BFR) were markedly elevated. Increased periosteal, intracortical, and endocortical BFR and turnover were evident, and contributed to increased cortical porosity (Ct.Po). The changes were exaggerated in the severe secondaryHPT group; BMD was lower in the proximal, but higher in the distal femur, and Cn.BV, N.Ob, N.Oc, and BFR were increased by six-, seven-, three-, and 30-fold, respectively. Endocortical BFR was elevated 31-fold and the extensive Ct.Po (10%) decreased bone strength. However, Ct.Po was not apparent until

  11. Titanium cages versus autogenous iliac crest bone grafts in anterior cervical discectomy and fusion treatment of patients with cervical degenerative diseases: a systematic review and meta-analysis.

    Science.gov (United States)

    Shao, Ming-Hao; Zhang, Fan; Yin, Jun; Xu, Hao-Cheng; Lyu, Fei-Zhou

    2017-05-01

    A systematic review and partial meta-analysis is conducted to compare the efficacy and safety of anterior cervical decompression and fusion procedures employing either rectangular titanium cages or iliac crest autografts in patients suffering from cervical degenerative disc diseases. Medline, PubMed, CENTRAL, and Google Scholar databases were searched up to June 2015, using the key words cervical discectomy; bone transplantation; titanium cages; and iliac crest autografts. Outcomes of interbody fusion rates were compared using odds ratios (ORs) with 95% confidence intervals (CIs). Values of the Japanese Orthopaedic Association score, and visual analog scale before and after operation were also compared. The rate of interbody fusion was similar between patients in the iliac crest autograft and titanium cage groups (pooled OR = 0.33, 95% CI = 0.07 to 1.66, P = .178). The overall analysis showed that patients in the two groups did not have significantly different post-surgery Japanese Orthopaedic Association score (pooled difference in means = -0.05, 95% CI = 0.73 to 0.63, P = .876). Improvement in arm and neck pain scores were assessed with a visual analog scale and differed significantly between patients in the iliac crest autograft and titanium cage groups (pooled difference in means = 0.16, 95% CI = -0.44 to 0.76, P = .610; and pooled difference in means = -0.44, 95% CI = -2.23 to 1.36, P = .634, respectively). Our results suggest that the use of titanium cages constitutes a safe and efficient alternative to iliac crest bone autografts for anterior cervical discectomy with fusion.

  12. Evaluation of “Autogenous Bioengineered Injectable PRF – Tooth graft” combination (ABIT) in reconstruction of maxillary alveolar ridge defects: CBCT volumetric analysis

    OpenAIRE

    Melek, Lydia Nabil; El Said, Marwan M.

    2017-01-01

    Background: Extracted human teeth were suggested as a source for autogenous bone grafts, especially that they have similar chemical composition to bone. In order to accelerate healing of bone graft over the bony defect, numerous techniques utilizing platelet and fibrinogen concentrations have been introduced in the literature. Objectives: To evaluate clinically and radiographically the use of autogenous tooth bone graft material in combination with injectable platelet-rich fibrin for reconstr...

  13. High Insulin Levels in KK-Ay Diabetic Mice Cause Increased Cortical Bone Mass and Impaired Trabecular Micro-Structure

    Directory of Open Access Journals (Sweden)

    Cen Fu

    2015-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a chronic disease characterized by hyperglycemia, hyperinsulinemia and complications, including obesity and osteoporosis. Rodents have been widely used to model human T2DM and investigate its effect on the skeleton. We aimed to investigate skeletal alterations in Yellow Kuo Kondo (KK-Ay diabetic mice displaying high insulin and glucose levels. Bone mineral density (BMD, micro-architecture and bone metabolism-related genes were analyzed. The total femoral areal BMD (aBMD, cortical volumetric BMD (vBMD and thickness were significantly increased in KK-Ay mice, while the trabecular vBMD and mineralized bone volume/tissue volume (BV/TV, trabecular thickness and number were decreased compared to C57BL mice. The expression of both osteoblast-related genes, such as osteocalcin (OC, bone sialoprotein, Type I Collagen, osteonectin, RUNX2 and OSX, and osteoclast-related genes, such as TRAP and TCIRG, were up-regulated in KK-Ay mice. Correlation analyses showed that serum insulin levels were positively associated with aBMD, cortical vBMD and thickness and negatively associated with trabecular vBMD and micro-architecture. In addition, serum insulin levels were positively related to osteoblast-related and osteoclast-related gene expression. Our data suggest that high insulin levels in KK-Ay diabetic mice may increase cortical bone mass and impair trabecular micro-structure by up-regulating osteoblast-and osteoclast-related gene expression.

  14. Prevalent role of porosity and osteonal area over mineralization heterogeneity in the fracture toughness of human cortical bone.

    Science.gov (United States)

    Granke, Mathilde; Makowski, Alexander J; Uppuganti, Sasidhar; Nyman, Jeffry S

    2016-09-06

    Changes in the distribution of bone mineralization occurring with aging, disease, or treatment have prompted concerns that alterations in mineralization heterogeneity may affect the fracture resistance of bone. Yet, so far, studies assessing bone from hip fracture cases and fracture-free women have not reached a consensus on how heterogeneity in tissue mineralization relates to skeletal fragility. Owing to the multifactorial nature of toughening mechanisms occurring in bone, we assessed the relative contribution of heterogeneity in mineralization to fracture resistance with respect to age, porosity, and area fraction of osteonal tissue. The latter parameters were extracted from quantitative backscattered electron imaging of human cortical bone sections following R-curve tests of single-edge notched beam specimens to determine fracture toughness properties. Microstructural heterogeneity was determined as the width of the mineral distribution (bulk) and as the sill of the variogram (local). In univariate analyses of measures from 62 human donors (21 to 101 years), local but not bulk heterogeneity as well as pore clustering negatively correlated with fracture toughness properties. With age as covariate, heterogeneity was a significant predictor of crack initiation, though local had a stronger negative contribution than bulk. When considering all potential covariates, age, cortical porosity and area fraction of osteons explained up to 50% of the variance in bone׳s crack initiation toughness. However, including heterogeneity in mineralization did not improve upon this prediction. The findings of the present work stress the necessity to account for porosity and microstructure when evaluating the potential of matrix-related features to affect skeletal fragility. Published by Elsevier Ltd.

  15. Insertion torque, pull-out strength and cortical bone thickness in contact with orthodontic mini-implants at different insertion angles.

    Science.gov (United States)

    Meira, Thiago Martins; Tanaka, Orlando Motohiro; Ronsani, Maiara Medeiros; Maruo, Ivan Toshio; Guariza-Filho, Odilon; Camargo, Elisa Souza; Maruo, Hiroshi

    2013-12-01

    This study aimed to evaluate biomechanical behaviour of inclined orthodontic mini-implants by analyzing its insertion torque (IT), axial pull-out strength (APS), and cortical bone thickness in contact with mini-implant (CBTC). A total of 102 mini-implants were inserted at 90 degree, 60 degree, and 45 degree to the surface of synthetic bone. Peak IT was measured, and the mini-implants were aligned with the mechanical testing machine to record the APS. The cortical bone thickness in contact with each mini-implant was measured after the pull-out test and the data were subjected to statistical analyses. The 45 degree group had a significantly higher IT compared with the 90 degree group (P Mini-implants that are inserted more inclined to the surface of the bone provide greater IT and an increased contact with the cortical bone. The greater the CBTC, the greater is the APS.

  16. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals

    Science.gov (United States)

    Sprecher, Christoph M.; Schmidutz, Florian; Helfen, Tobias; Richards, R. Geoff; Blauth, Michael; Milz, Stefan

    2015-01-01

    Abstract Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred. The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals. The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis. At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side. This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus. PMID:26705200

  17. Eldecalcitol improves mechanical strength of cortical bones by stimulating the periosteal bone formation in the senescence-accelerated SAM/P6 mice - a comparison with alfacalcidol.

    Science.gov (United States)

    Shiraishi, Ayako; Sakai, Sadaoki; Saito, Hitoshi; Takahashi, Fumiaki

    2014-10-01

    Eldecalcitol (ELD), a 2β-hydroxypropyloxy derivative of 1α,25(OH)2D3, is a potent inhibitor of bone resorption that has demonstrated a greater effect at reducing the risk of fracture in osteoporotic patients than alfacalcidol (ALF). In the present study, we used the senescence-accelerated mouse strain P6 (SAM/P6), which has low bone mass caused by osteoblast dysfunction, to evaluate the effect of ELD on cortical bone in comparison with ALF. Four-month-old SAM/P6 mice were given either ELD (0.025 or 0.05μg/kg) or ALF (0.2 or 0.4μg/kg) by oral gavage 5 times/week for 6 weeks. Both ELD and ALF increased serum calcium (Ca) in a dose-dependent manner. Serum Ca levels in the ELD 0.05μg/kg group were comparable to those of the ALF 0.2μg/kg group. ELD 0.05μg/kg significantly improved the bone biomechanical properties of the femur compared with the vehicle control group (pBone histomorphometry revealed that in the femoral endocortical surface, the suppression of bone resorption parameters (N.Oc/BS) and bone formation parameters (MS/BS) by ELD (0.05μg/kg) was greater than that by ALF (0.2μg/kg). In contrast, in the femoral periosteal surface, ELD 0.05μg/kg significantly increased bone formation parameters (BFR/BS, MS/BS) compared with the vehicle control group (pbone not only by inhibiting endocortical bone resorption but also by stimulating the periosteal bone formation in SAM/P6 mice. This article is part of a Special Issue entitled '16th Vitamin D Workshop'. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Effects of chronic heavy alcohol consumption and endurance exercise on cancellous and cortical bone microarchitecture in adult male rats.

    Science.gov (United States)

    Johnson, Teresa L; Gaddini, Gino; Branscum, Adam J; Olson, Dawn A; Caroline-Westerlind, Kim; Turner, Russell T; Iwaniec, Urszula T

    2014-05-01

    Bone health is influenced by numerous lifestyle factors, including diet and exercise. Alcohol is a major nonessential constituent of diet and has dose- and context-dependent effects on bone. Endurance exercise is associated with increased risk of stress fractures. The purpose of this study was to determine the long-term independent and combined effects of chronic heavy alcohol consumption and endurance exercise (treadmill running) on bone mass and microarchitecture in young adult male Sprague-Dawley rats. Six-month-old male rats were randomized into 4 groups (9 to 13 rats/group): sedentary + control diet, sedentary + ethanol (EtOH) diet, exercise + control diet, or exercise + EtOH diet. EtOH-fed rats consumed a liquid diet (EtOH comprised 35% of caloric intake) ad libitum. Control rats were pair-fed the same diet with isocaloric substitution of EtOH with maltose-dextran. Exercise was conducted on a motorized treadmill (15% grade for 30 minutes) 5 d/wk for 16 weeks. Femur and 12th thoracic vertebra were analyzed for bone mineral content (BMC) and density (BMD) using densitometry and cortical and cancellous bone architecture using microcomputed tomography. EtOH consumption resulted in lower femur length, BMC, and BMD, and lower midshaft femur cortical volume, cortical thickness, and polar moment of inertia. In addition, trabecular thickness was lower in vertebra of EtOH-fed rats. Endurance exercise had no independent effect on any end point evaluated. A significant interaction between endurance exercise and EtOH was detected for several cancellous end points in the distal femur metaphysis. EtOH-consuming rats that exercised had lower distal femur metaphysis bone volume/tissue volume, trabecular connectivity density, and trabecular thickness compared to exercising rats that consumed control diet. The results obtained in this model suggest that chronic heavy alcohol consumption may reduce skeletal integrity by reducing bone size, mass, and density, and by negatively

  19. Cortical Bone Stem Cell Therapy Preserves Cardiac Structure and Function After Myocardial Infarction.

    Science.gov (United States)

    Sharp, Thomas E; Schena, Giana J; Hobby, Alexander R; Starosta, Timothy; Berretta, Remus M; Wallner, Markus; Borghetti, Giulia; Gross, Polina; Yu, Daohai; Johnson, Jaslyn; Feldsott, Eric; Trappanese, Danielle M; Toib, Amir; Rabinowitz, Joseph E; George, Jon C; Kubo, Hajime; Mohsin, Sadia; Houser, Steven R

    2017-11-10

    Cortical bone stem cells (CBSCs) have been shown to reduce ventricular remodeling and improve cardiac function in a murine myocardial infarction (MI) model. These effects were superior to other stem cell types that have been used in recent early-stage clinical trials. However, CBSC efficacy has not been tested in a preclinical large animal model using approaches that could be applied to patients. To determine whether post-MI transendocardial injection of allogeneic CBSCs reduces pathological structural and functional remodeling and prevents the development of heart failure in a swine MI model. Female Göttingen swine underwent left anterior descending coronary artery occlusion, followed by reperfusion (ischemia-reperfusion MI). Animals received, in a randomized, blinded manner, 1:1 ratio, CBSCs (n=9; 2×10 7 cells total) or placebo (vehicle; n=9) through NOGA-guided transendocardial injections. 5-ethynyl-2'deoxyuridine (EdU)-a thymidine analog-containing minipumps were inserted at the time of MI induction. At 72 hours (n=8), initial injury and cell retention were assessed. At 3 months post-MI, cardiac structure and function were evaluated by serial echocardiography and terminal invasive hemodynamics. CBSCs were present in the MI border zone and proliferating at 72 hours post-MI but had no effect on initial cardiac injury or structure. At 3 months, CBSC-treated hearts had significantly reduced scar size, smaller myocytes, and increased myocyte nuclear density. Noninvasive echocardiographic measurements showed that left ventricular volumes and ejection fraction were significantly more preserved in CBSC-treated hearts, and invasive hemodynamic measurements documented improved cardiac structure and functional reserve. The number of EdU + cardiac myocytes was increased in CBSC- versus vehicle- treated animals. CBSC administration into the MI border zone reduces pathological cardiac structural and functional remodeling and improves left ventricular functional reserve

  20. Computed tomography evaluation of autogenous graft in sinus lift surgery; Analise por tomografia computadorizada do enxerto autogeno na cirurgia de 'sinus lift'

    Energy Technology Data Exchange (ETDEWEB)

    Ajzen, Sergio Aron; Moscatiello, Rafael Andrade; Lima, Aida Maria Custodio de; Moscatiello, Vitoria Aparecida Muglia; Helio Kiitiro Yamashita [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Dept. de Diagnostico por Imagem; Mosacatiello, Rafael Muglia; Nishiguchi, Celso Itiro [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Disciplina de Tecnica Operatoria e Cirurgia Experimental; Alves, Maria Teresa de Seixas [Universidade Federal de Sao Paulo (UNIFESP/EPM), SP (Brazil). Disciplina de Anatomia Patologica

    2001-02-01

    The objective was to quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from apheresis or centrifugation using computed tomography. This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months), with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental implant. All patients were submitted to computed tomography examinations prior and six months after sinus lift surgery. Fifty-three maxillary sinuses were operated and divided into three distinct groups: autogenous bone graft, autogenous bone graft in combination with platelet-rich plasma obtained by centrifugation, and autogenous bone graft in combination with platelet-rich plasma obtained by apheresis. The results showed that computed tomography demonstrated bone growth in height and width between the initial and the follow-up computed tomography scans in all three groups. However, no statistical difference was found either for bone height or width. It was concluded that clinical evidence demonstrates the effectiveness of autogenous bone grafts, particularly when used in combination with bone growth factors such as platelet-rich plasma, which allow prosthetic and functional restoration of maxillofacial structures through fixation of dental implants. (author)

  1. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    Science.gov (United States)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  2. Preventing painful age-related bone fractures: Anti-sclerostin therapy builds cortical bone and increases the proliferation of osteogenic cells in the periosteum of the geriatric mouse femur.

    Science.gov (United States)

    Thompson, Michelle L; Chartier, Stephane R; Mitchell, Stefanie A; Mantyh, Patrick W

    2016-01-01

    Age-related bone fractures are usually painful and have highly negative effects on a geriatric patient's functional status, quality of life, and survival. Currently, there are few analgesic therapies that fully control bone fracture pain in the elderly without significant unwanted side effects. However, another way of controlling age-related fracture pain would be to preemptively administer an osteo-anabolic agent to geriatric patients with high risk of fracture, so as to build new cortical bone and prevent the fracture from occurring. A major question, however, is whether an osteo-anabolic agent can stimulate the proliferation of osteogenic cells and build significant amounts of new cortical bone in light of the decreased number and responsiveness of osteogenic cells in aging bone. To explore this question, geriatric and young mice, 20 and 4 months old, respectively, received either vehicle or a monoclonal antibody that sequesters sclerostin (anti-sclerostin) for 28 days. From days 21 to 28, animals also received sustained administration of the thymidine analog, bromodeoxyuridine (BrdU), which labels the DNA of dividing cells. Animals were then euthanized at day 28 and the femurs were examined for cortical bone formation, bone mineral density, and newly borne BrdU+ cells in the periosteum which is a tissue that is pivotally involved in the formation of new cortical bone. In both the geriatric and young mice, anti-sclerostin induced a significant increase in the thickness of the cortical bone, bone mineral density, and the proliferation of newly borne BrdU+ cells in the periosteum. These results suggest that even in geriatric animals, anti-sclerostin therapy can build new cortical bone and increase the proliferation of osteogenic cells and thus reduce the likelihood of painful age-related bone fractures. © The Author(s) 2016.

  3. Bone lead (Pb) content at the tibia is associated with thinner distal tibia cortices and lower volumetric bone density in postmenopausal women

    Science.gov (United States)

    Wong, Andy K.O.; Beattie, Karen A.; Bhargava, Aakash; Cheung, Marco; Webber, Colin E.; Chettle, David R.; Papaioannou, Alexandra; Adachi, Jonathan D.

    2016-01-01

    Conflicting evidence suggests that bone lead or blood lead may reduce areal bone mineral density (BMD). Little is known about how lead at either compartment affects bone structure. This study examined postmenopausal women (N = 38, mean age 76 ± 8, body mass index (BMI): 26.74 ± 4.26 kg/m2) within the Hamilton cohort of the Canadian Multicentre Osteoporosis Study (CaMos), measuring bone lead at 66% of the non-dominant leg and at the calcaneus using 109Cadmium X-ray fluorescence. Volumetric BMD and structural parameters were obtained from peripheral quantitative computed tomography images (200 μm in-plane resolution, 2.3 ± 0.5 mm slice thickness) of the same 66% site and of the distal 4% site of the tibia length. Blood lead was measured using atomic absorption spectrometry and blood-to-bone lead partition coefficients (PBB, log ratio) were computed. Multivariable linear regression examined each of bone lead at the 66% tibia, calcaneus, blood lead and PBB as related to each of volumetric BMD and structural parameters, adjusting for age and BMI, diabetes or antiresorptive therapy. Regression coefficients were reported along with 95% confidence intervals. Higher amounts of bone lead at the tibia were associated with thinner distal tibia cortices (−0.972 (−1.882, −0.061) per 100 μg Pb/g of bone mineral) and integral volumetric BMD (−3.05 (−6.05, −0.05) per μg Pb/g of bone mineral). A higher PBB was associated with larger trabecular separation (0.115 (0.053, 0.178)), lower trabecular volumetric BMD (−26.83 (−50.37, −3.29)) and trabecular number (−0.08 (−0.14, −0.02)), per 100 μg Pb/g of bone mineral after adjusting for age and BMI, and remained significant while accounting for diabetes or use of antiresorptives. Total lead exposure activities related to bone lead at the calcaneus (8.29 (0.11, 16.48)) and remained significant after age and antiresorptives-adjustment. Lead accumulated in bone can have a mild insult on bone structure; but

  4. Bone formation in mono cortical mandibular critical size defects after augmentation with two synthetic nanostructured and one xenogenous hydroxyapatite bone substitute - in vivo animal study.

    Science.gov (United States)

    Dau, Michael; Kämmerer, Peer W; Henkel, Kai-Olaf; Gerber, Thomas; Frerich, Bernhard; Gundlach, Karsten K H

    2016-05-01

    Healing characteristics as well as level of tissue integration and degradation of two different nanostructured hydroxyapatite bone substitute materials (BSM) in comparison with a deproteinized hydroxyapatite bovine BSM were evaluated in an in vivo animal experiment. In the posterior mandible of 18 minipigs, bilateral mono cortical critical size bone defects were created. Randomized augmentation procedures with NanoBone(®) (NHA1), Ostim(®) (NHA2) or Bio-Oss(®) (DBBM) were conducted (each material n = 12). Samples were analyzed after five (each material n = 6) and 8 months (each material n = 6). Defect healing, formation of soft tissue and bone as well as the amount of remaining respective BSM were quantified both macro- and microscopically. For NHA2, the residual bone defect after 5 weeks was significantly less compared to NHA1 or DBBM. There was no difference in residual BSM between NHA1 and DBBM, but the amount in NHA2 was significantly lower. NHA2 also showed the least amount of soft tissue and the highest amount of new bone after 5 weeks. Eight months after implantation, no significant differences in the amount of residual bone defects, in soft tissue or in bone formation were detected between the groups. Again, NHA2 showed significant less residual material than NHA1 and DBBM. We observed non-significant differences in the biological hard tissue response of NHA1 and DBBM. The water-soluble NHA2 initially induced an increased amount of new bone but was highly compressed which may have a negative effect in less stable augmentations of the jaw. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. Does the presence of tumor-induced cortical bone destruction at CT have any prognostic value in newly diagnosed diffuse large B-cell lymphoma?

    NARCIS (Netherlands)

    Adams, Hugo J A; de Klerk, John M H; Fijnheer, Rob; Heggelman, Ben G F; Dubois, Stefan V.; Nievelstein, Rutger A J; Kwee, Thomas C.

    2015-01-01

    Purpose: To determine the prognostic value of tumor-induced cortical bone destruction at computed tomography (CT) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). Materials and methods: This retrospective study included 105 patients with newly diagnosed DLBCL who had undergone CT and bone

  6. Does the presence of tumor-induced cortical bone destruction at CT have any prognostic value in newly diagnosed diffuse large B-cell lymphoma?

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Hugo J.A.; Nievelstein, Rutger A.J.; Kwee, Thomas C. [University Medical Center Utrecht, Department of Radiology and Nuclear Medicine, Utrecht (Netherlands); Klerk, John M.H. de [Meander Medical Center, Department of Nuclear Medicine, Amersfoort (Netherlands); Fijnheer, Rob [Meander Medical Center, Department of Hematology, Amersfoort (Netherlands); Heggelman, Ben G.F. [Meander Medical Center, Department of Radiology, Amersfoort (Netherlands); Dubois, Stefan V. [Meander Medical Center, Department of Pathology, Amersfoort (Netherlands)

    2015-05-01

    To determine the prognostic value of tumor-induced cortical bone destruction at computed tomography (CT) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). This retrospective study included 105 patients with newly diagnosed DLBCL who had undergone CT and bone marrow biopsy (BMB) before R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, Oncovin, and prednisolone) chemo-immunotherapy. Cox regression analyses were used to determine the associations of cortical bone status at CT (absence vs. presence of tumor-induced cortical bone destruction), BMB findings (negative vs. positive for lymphomatous involvement), and dichotomized National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) strata (low risk vs. high risk) with progression-free survival (PFS) and overall survival (OS). Univariate Cox regression analysis indicated that cortical bone status at CT was no significant predictor of either PFS or OS (p = 0.358 and p = 0.560, respectively), whereas BMB findings (p = 0.002 and p = 0.013, respectively) and dichotomized NCCN-IPI risk strata (p = 0.002 and p = 0.003, respectively) were significant predictors of both PFS and OS. In the multivariate Cox proportional hazards model, only the dichotomized NCCN-IPI score was an independent predictive factor of PFS and OS (p = 0.004 and p = 0.003, respectively). The presence of tumor-induced cortical bone destruction at CT was not found to have any prognostic implications in newly diagnosed DLBCL. (orig.)

  7. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone - a feasibility study.

    Science.gov (United States)

    Marcián, Petr; Borák, Libor; Valášek, Jiří; Kaiser, Jozef; Florian, Zdeněk; Wolff, Jan

    2014-12-18

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant geometries and the levels of bone-to-implant contact (BIC) on the surrounding bone. Six mandibular bone segments demonstrating different grades of mandibular bone atrophy and various bone volume fractions (from 0.149 to 0.471) were imaged using a micro-CT device. The acquired bone STL models and implant (Brånemark, Straumann, Ankylos) were merged into a three-dimensional finite elements structure. The mean displacement value for all implants was 3.1 ±1.2 µm. Displacements were lower in the group with a strong BIC. The results indicated that the maximum strain values of cortical and cancellous bone increased with lower bone density. Strain distribution is the first and foremost dependent on the shape of bone and architecture of cancellous bone. The geometry of the implant, thread patterns, grade of bone atrophy and BIC all affect the displacement and micro-strain on the mandible bone. Preoperative finite element analysis could offer improved predictability in the long-term outlook of dental implant restorations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Estimation of femoral bone density from trabecular direct wave and cortical guided wave ultrasound velocities measured at the proximal femur in vivo

    DEFF Research Database (Denmark)

    Barkmann, Reinhard; Dencks, Stefanie; Bremer, Alexander

    2008-01-01

    and of guided waves through cortical bone could be used to estimate BMD. In two centres, Kiel and Odense, we measured time-of-flight (TOF) of waves through the trabecular greater trochanter and cortical intertrochanter as well as a wave through soft tissue only. TOF was adjusted for leg width using ultrasound......Bone mineral density (BMD) of the proximal femur is a predictor of hip fracture risk. We developed a Quantitative Ultrasound (QUS) scanner for measurements at this site with similar performance (FemUS). In this study we tested if ultrasound velocities of direct waves through trabecular bone...

  9. Equipment for measuring autogenous RH-change and autogenous deformation in cement paste and concrete

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard; Jensen, Ole Mejlhede

    1997-01-01

    Equipment for measuring autogenous RH-change and autogenous deformation in cement paste and concrete are presented. The equipment consists of a Rotronic Hygroskop DT including a measuring chamber for measuring autogenous RH-change in cement paste and concrete, a paste dilatometer for measuring...

  10. On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager III, Joel W.; Ritchie, Robert O.

    2010-01-10

    In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the progressive elimination of the bone's capacity for plastic deformation which restricts the intrinsic toughening from the formation 'plastic zones' around crack-like defects. Deep-ultraviolet Raman spectroscopy indicated that this behavior could be related to degradation in the collagen integrity.

  11. Viability of autogenous bone grafts obtained by using bone collectors: histological and microbiological study Viabilidade dos enxertos autógenos obtidos com a utilização de coletores para osso: estudo histológico e microbiológico

    Directory of Open Access Journals (Sweden)

    Alberto Blay

    2003-09-01

    Full Text Available The use of autogenous bone grafts is considered to be the best choice for reconstructive surgery. In the periodontal literature, the utilization of osseous coagulum was suggested by the end of the sixties. The purpose of this study is to consider the use of bone collectors (bone traps as an alternative method for obtaining material to fill small bone imperfections, such as fenestrations and dehiscences. Thirty samples were obtained from bone drilling during fixture installation in patients (13 men and 17 women, with an average age of 54 years requiring treatment at the Department of Periodontology and Implant Dentistry, University of Santo Amaro. These samples were fixed in 10% neutral formaldehyde for 24 hours and subjected to histological preparation, in order to evaluate the presence of viable osteoblasts. In addition, the material was placed in a fluid thioglycolate medium and incubated for 24 hours at 36 ± 1°C in aerobiosis and anaerobiosis. Bacterial growth evaluation was made by using six different culture media (MacConkey agar, blood agar base, mannitol salt agar, Anaerokit LTD medium, Anaerokit LTD - bile medium, Anaerinsol. The results show that, if proper care is taken to prevent saliva contamination during the surgical procedure, this method of collecting autogenous bone may be useful in situations where small amounts of bone are required.A utilização de enxertos autógenos é considerada a melhor opção nos tratamentos cirúrgicos de reconstrução óssea. Na literatura periodontal, a utilização de coágulo ósseo foi sugerida no final da década de 60. O objetivo deste estudo é considerar a utilização de coletores para osso como um método alternativo de se obter osso autógeno para preenchimento de defeitos ósseos como fenestrações e deiscências. Trinta amostras foram obtidas no processo de perfuração do tecido ósseo, durante a instalação de implantes em pacientes (13 homens e 17 mulheres, com média etária de

  12. A numerical study on the propagation of Rayleigh and guided waves in cortical bone according to Mindlin's Form II gradient elastic theory.

    Science.gov (United States)

    Papacharalampopoulos, Alexios; Vavva, Maria G; Protopappas, Vasilios C; Fotiadis, Dimitrios I; Polyzos, Demosthenes

    2011-08-01

    Cortical bone is a multiscale heterogeneous natural material characterized by microstructural effects. Thus guided waves propagating in cortical bone undergo dispersion due to both material microstructure and bone geometry. However, above 0.8 MHz, ultrasound propagates rather as a dispersive surface Rayleigh wave than a dispersive guided wave because at those frequencies, the corresponding wavelengths are smaller than the thickness of cortical bone. Classical elasticity, although it has been largely used for wave propagation modeling in bones, is not able to support dispersion in bulk and Rayleigh waves. This is possible with the use of Mindlin's Form-II gradient elastic theory, which introduces in its equation of motion intrinsic parameters that correlate microstructure with the macrostructure. In this work, the boundary element method in conjunction with the reassigned smoothed pseudo Wigner-Ville transform are employed for the numerical determination of time-frequency diagrams corresponding to the dispersion curves of Rayleigh and guided waves propagating in a cortical bone. A composite material model for the determination of the internal length scale parameters imposed by Mindlin's elastic theory is exploited. The obtained results demonstrate the dispersive nature of Rayleigh wave propagating along the complex structure of bone as well as how microstructure affects guided waves.

  13. The micro-damage process zone during transverse cortical bone fracture: No ears at crack growth initiation.

    Science.gov (United States)

    Willett, Thomas; Josey, David; Lu, Rick Xing Ze; Minhas, Gagan; Montesano, John

    2017-10-01

    Apply high-resolution benchtop micro-computed tomography (micro-CT) to gain greater understanding and knowledge of the formation of the micro-damage process zone formed during traverse fracture of cortical bone. Bovine cortical bone was cut into single edge notch (bending) fracture testing specimens with the crack on the transverse plane and oriented to grow in the circumferential direction. We used a multi-specimen technique and deformed the specimens to various individual secant modulus loss levels (P-values) up to and including maximum load (Pmax). Next, the specimens were infiltrated with a BaSO 4 precipitation stain and scanned at 3.57-μm isotropic voxel size using a benchtop high resolution-micro-CT. Measurements of the micro-damage process zone volume, width and height were made. These were compared with the simple Irwin's process zone model and with finite element models. Electron and confocal microscopy confirmed the formation of BaSO 4 precipitate in micro-cracks and other porosity, and an interesting novel mechanism similar to tunneling. Measurable micro-damage was detected at low P values and the volume of the process zone increased according to a second order polynomial trend. Both width and height grew linearly up to Pmax, at which point the process zone cross-section (perpendicular to the plane of the crack) was almost circular on average with a radius of approximately 550µm (approximately one quarter of the unbroken ligament thickness) and corresponding to the shape expected for a biological composite under plane stress conditions. This study reports details of the micro-damage fracture process zone previously unreported for cortical bone. High-resolution micro-CT enables 3D visualization and measurement of the process zone and confirmation that the crack front edge and process zone are affected by microstructure. It is clear that the process zone for the specimens studied grows to be meaningfully large, confirming the need for the J

  14. Mitochondrial point mutation m.3243A > G associates with lower bone mineral density, thinner cortices and reduced bone strength

    DEFF Research Database (Denmark)

    Langdahl, Jakob Høgild; Frederiksen, Anja Lisbeth; Hansen, Stinus Jørn

    2017-01-01

    turnover markers (BTM) P1NP and CTX were measured. Cases and controls were well matched except for body weight, which was lower in cases (63.6 kg ± 18.1 vs. 74.6 kg ± 14.8, p ..., total hip and femoral neck in cases. Mean lumbar spine, total hip and femoral neck T-scores were -1.5, -1.3 and -1.6 in cases, respectively, and -0.8, -0.3 and -0.7 in controls (all p  G mutation was associated with lower bone mineral density, cortical but not trabecular density...

  15. Influence of the cutting edge angle of a titanium instrument on chip formation in the machining of trabecular and cortical bone.

    Science.gov (United States)

    von See, Constantin; Stoetzer, Marcus; Ruecker, Martin; Wagner, Max; Schumann, Paul; Gellrich, Nils-Claudius

    2014-01-01

    The placement of self-tapping implants is associated with microfractures and the formation of bone chips along the cutting flutes. This study was conducted to investigate the effect of different cutting edge angles on chip formation during the machining of trabecular and cortical bone using instruments with a rough titanium surface. Mandibular cortical and trabecular bone specimens were obtained from freshly slaughtered domestic pigs. A predefined thrust force was applied to the specimens. Four specially designed cutting instruments that simulated dental implants and had a rough titanium surface were allowed to complete one full revolution at cutting edge angles of 55, 65, 75, and 85 degrees, respectively. Torque and thrust were measured during the cutting process. Bone chips were measured and weighed under a microscope. Different cutting edge angles did not lead to significant differences in torque. The lowest torque values were measured when the cutting edges were positioned at 65 degrees in trabecular bone and at 85 degrees in cortical bone. Bone chips were significantly larger and heavier at angles of 55 and 65 degrees than at angles of 75 and 85 degrees in trabecular bone. Instruments with a rough titanium surface show considerable angle-dependent differences in chip formation. In addition to bone density, the angle of the cutting edges should be taken into consideration during the placement of dental implants. Good results were obtained when the cutting edges were positioned at an angle of 65 degrees. This angle can have positive effects on osseointegration.

  16. Effect of Loading Rate and Orientation on the Compressive Response of Human Cortical Bone

    Science.gov (United States)

    2014-05-01

    subchondral bone of the femoral head (44) (the metaphyseal section), which is located between the diaphysis and the epiphysis in the proximal femur...are different from the properties of the diaphysis (45). Regarding the tibia bone, the metaphyseal (46) and subchondral (39) bones in the proximal...45. Lotz, J. C.; Gerhart, T. N.; Hayes, W. C. Mechanical Properties of Metaphyseal Bone in the Proximal Femur. Journal of Biomechanics 1991, 24 (5

  17. Inflammatory response and bone healing capacity of two porous calcium phosphate ceramics in critical size cortical bone defects.

    Science.gov (United States)

    Chatterjea, Anindita; van der Stok, Johan; Danoux, Charlène B; Yuan, Huipin; Habibovic, Pamela; van Blitterswijk, Clemens A; Weinans, Harrie; de Boer, Jan

    2014-05-01

    In the present study, two open porous calcium phosphate ceramics, β-tricalcium phosphate (β-TCP), and hydroxyapatite (HA) were compared in a critical-sized femoral defect in rats. Previous comparisons of these two ceramics showed significantly greater osteoinductive potential of β-TCP upon intramuscular implantation and a better performance in a spinal fusion model in dogs. Results of the current study also showed significantly more bone formation in defects grafted with β-TCP compared to HA; however, both the ceramics were not capable of increasing bone formation to such extend that it bridges the defect. Furthermore, a more pronounced degradation of β-TCP was observed as compared to HA. Progression of inflammation and initiation of new bone formation were assessed for both materials at multiple time points by histological and fluorochrome-based analyses. Until 12 days postimplantation, a strong inflammatory response in absence of new bone formation was observed in both ceramics, without obvious differences between the two materials. Four weeks postimplantation, signs of new bone formation were found in both β-TCP and HA. At 6 weeks, inflammation had subsided in both ceramics while bone deposition continued. In conclusion, the two ceramics differed in the amount of bone formed after 8 weeks of implantation, whereas no differences were found in the duration of the inflammatory phase after implantation or initiation of new bone formation. Copyright © 2013 Wiley Periodicals, Inc.

  18. Toughness and damage susceptibility in human cortical bone is proportional to mechanical inhomogeneity at the osteonal-level.

    Science.gov (United States)

    Katsamenis, Orestis L; Jenkins, Thomas; Thurner, Philipp J

    2015-07-01

    Limitations associated with current clinical fracture risk assessment tools highlight the need for increased understanding of the fracture mechanisms of the bone and, ideally, a means of assessing this in vivo. Being a multi-layered hierarchical structure, the overall properties of the bone are dictated by its structural and compositional properties over multiple length scales. In this study, we investigate the osteonal-, micro- and tissue-level mechanical behaviour of cortical bone tissue samples from young and elderly donors through atomic force microscope (AFM) cantilever-based nanoindentation, reference point microindentation (RPI) and fracture toughness experiments respectively. We demonstrate that bone's fracture toughness and crack growth resistance at the tissue-level are significantly correlated to damage susceptibility at the micro-level, and mechanical inhomogeneity between lamellae and interlamellar areas at the osteonal-level. In more detail, reduced nanoelasticity inhomogeneity of lamellar/interlamellar layers within the osteons correlated to increased indentation depth at the micro-level and an overall reduction in crack-growth toughness and fracture toughness of the tissue. Our data also suggest that deterioration of bone's mechanical properties is expressed concurrently at these three levels, and that mechanical inhomogeneity between the principal structural units of the cortical tissue holds a key role on bone's toughness behaviour. We hypothesise that the reduction in nanoelasticity inhomogeneity is--at least to some extent--responsible for the inability of the microstructure to effectively adapt to the applied load, e.g. by redistributing strains, in a non-catastrophic manner preventing damage formation and propagation. Our hypothesis is further supported by synchrotron radiation micro-computed tomography (SRμCT) data, which show that failure of tougher bone specimens is governed by increased deflection of the crack path and broadly spread

  19. Evaluation of autogenous PRGF+β-TCP with or without a collagen membrane on bone formation and implant osseointegration in large size bone defects. A preclinical in vivo study.

    Science.gov (United States)

    Batas, Leonidas; Stavropoulos, Andreas; Papadimitriou, Serafim; Nyengaard, Jens R; Konstantinidis, Antonios

    2016-08-01

    The aim of this study was to evaluate whether the adjunctive use of a collagen membrane enhances bone formation and implant osseointegration in non-contained defects grafted with chair-side prepared autologous platelet-rich growth factor (PRGF) adsorbed on a β-TCP particulate carrier. Large box-type defects (10 × 6 mm; W × D) were prepared in the edentulated and completely healed mandibles of six Beagles dogs. An implant with moderately rough surface was placed in the center of each defect leaving the coronal 6 mm of the implant not covered with bone. The remaining defect space was then filled out with chair-side prepared autologous PRGF adsorbed on β-TCP particles and either covered with a collagen membrane (PRGF/β-TCP+CM) (6 defects) or left without a membrane (PRGF/β-TCP) (5 defects). Histology 4 months post-op showed new lamellar and woven bone formation encompassing almost entirely the defect and limited residual β-TCP particles. Extent of osseointegration of the previously exposed portion of the implants varied, but in general was limited. Within the defect, new mineralized bone (%) averaged 43.2 ± 9.86 vs. 39.9 ± 13.7 in the PRGF/β-TCP+CM and PRGF/β-TCP group (P = 0.22) and relative mineralized bone-to-implant contact (%) averaged 26.2 ± 16.45 vs. 35.91 ± 24.45, respectively (P = 0.5). First, bone-to-implant contact from the implant top was 4.1 ± 1.5 and 3.2 ± 2.3 (P = 0.9), in the PRGF/β-TCP+CM and PRGF/β-TCP group, respectively. Implantation of chair-side prepared autologous PRGF adsorbed on a β-TCP carrier in non-contained peri-implant defects resulted in large amounts of bone regeneration, but osseointegration was limited. Provisions for GBR with a collagen membrane did not significantly enhance bone regeneration or implant osseointegration. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Molt performance and bone density of cortical, medullary, and cancellous bone in laying hens during feed restriction or alfalfa-based feed molt.

    Science.gov (United States)

    Kim, W K; Donalson, L M; Bloomfield, S A; Hogan, H A; Kubena, L F; Nisbet, D J; Ricke, S C

    2007-09-01

    A study was conducted to evaluate the effects of alfalfa-based molt diets on molting performance and bone qualities. A total of 36 Single Comb White Leghorn hens were used for the study. There were 6 treatments: pretrial control (PC), fully fed (FF), feed withdrawal (FW), 90% alfalfa:10% layer ration (A90), 80% alfalfa:20% layer ration (A80), and 70% alfalfa:30% layer ration (A70). For the PC treatment, hens were euthanized by CO(2) gas, and bones were collected before molt was initiated. At the end of the 9-d molt period, hens were euthanized, and femurs and tibias were collected to evaluate bone qualities by peripheral quantitative computed tomography, mechanical testing, and conventional ash weights. The hens fed alfalfa-based molt diets and FW stopped laying eggs within 5 d after molt started, and all hens in these groups had reduced ovary weights compared with those of the FF hens. In the FW and A90 groups, total femur volumetric bone mineral densities (vBMD) at the midshaft were significantly lower, but those of the A80 and A70 groups were not significantly different from the values for the PC and FF hens. In cortical bone density, the midshaft tibial vBMD were significantly higher for FF and A70 hens than for PC hens. The medullary bone densities at the midshaft femur or tibia of the FW, A90, A80, and A70 hens were reduced compared with those of the PC hens. Femur cancellous densities at the distal femur for the FW and A90 hens were significantly reduced compared with those of the PC and FF hens. The FW, A80, and A70 hens yielded significantly higher elastic moduli, and the A80 hens had higher ultimate stress compared with the PC hens, suggesting that the mechanical integrity of the midshaft bone was maintained even though the medullary vBMD was reduced. These results suggest that alfalfa-based molt diets exhibit molt performance similar to FW, that medullary and cancellous bones are labile bone compartments during molting, and that alfalfa-based molt diets

  1. Predicting Hip Fracture Type With Cortical Bone Mapping (CBM) in the Osteoporotic Fractures in Men (MrOS) Study.

    Science.gov (United States)

    Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Ewing, Susan K; Cawthon, Peggy M; Black, Dennis M; Poole, Kenneth E S

    2015-11-01

    Hip fracture risk is known to be related to material properties of the proximal femur, but fracture prediction studies adding richer quantitative computed tomography (QCT) measures to dual-energy X-ray (DXA)-based methods have shown limited improvement. Fracture types have distinct relationships to predictors, but few studies have subdivided fracture into types, because this necessitates regional measurements and more fracture cases. This work makes use of cortical bone mapping (CBM) to accurately assess, with no prior anatomical presumptions, the distribution of properties related to fracture type. CBM uses QCT data to measure the cortical and trabecular properties, accurate even for thin cortices below the imaging resolution. The Osteoporotic Fractures in Men (MrOS) study is a predictive case-cohort study of men over 65 years old: we analyze 99 fracture cases (44 trochanteric and 55 femoral neck) compared to a cohort of 308, randomly selected from 5994. To our knowledge, this is the largest QCT-based predictive hip fracture study to date, and the first to incorporate CBM analysis into fracture prediction. We show that both cortical mass surface density and endocortical trabecular BMD are significantly different in fracture cases versus cohort, in regions appropriate to fracture type. We incorporate these regions into predictive models using Cox proportional hazards regression to estimate hazard ratios, and logistic regression to estimate area under the receiver operating characteristic curve (AUC). Adding CBM to DXA-based BMD leads to a small but significant (p fracture, with AUC increasing from 0.78 to 0.79, assessed using leave-one-out cross-validation. For specific fracture types, the improvement is more significant (p trochanteric fractures and 0.76 to 0.82 for femoral neck fractures. In contrast, adding DXA-based BMD to a CBM-based predictive model does not result in any significant improvement. © 2015 The Authors. Journal of Bone and Mineral Research

  2. Influence and evolution mechanism of different sharpness contact forms to mechanical property of cortical bone by nanoindentation

    Directory of Open Access Journals (Sweden)

    Xingdong Sun

    2018-03-01

    Full Text Available Based on different damage forms of various contact forms to bone, the mechanical response and mechanism were investigated by nanoindentation under different sharpness contact forms. For the purpose of simulating the different sharpness contact forms, two kinds of indenters were used in experiments and finite elements simulations. Through nanoindentation experiments, it was concluded that the residual depth of sharp indenter was bigger than that of blunt indenter with small penetration depth. However, the contrary law was obtained with bigger penetration depth. There was a turning point of transition from blunt tendency to sharp tendency. By calculation, it was concluded that the sharper the indenter was, the bigger the proportion of plastic energy in total energy was. Basically, results of finite elements simulation could correspond with the experimental conclusions. By the observation of FE-SEM, the surface of cortical bone compressed was more seriously directly below the blunt indenter than the lateral face. For the berkovich indenter, the surface of indentation compressed was less directly below the indenter, but seriously on three lateral faces. This research may provide some new references to the studies of bone fracture mechanism in different load patterns in the initial press-in stage and offer new explanation for bone trauma diagnosis in clinical treatment and criminal investigation.

  3. Influence and evolution mechanism of different sharpness contact forms to mechanical property of cortical bone by nanoindentation

    Science.gov (United States)

    Sun, Xingdong; Guo, Yue; Li, Lijia; Liu, Zeyang; Wu, Di; Shi, Dong; Zhao, Hongwei; Zhang, Shizhong

    2018-03-01

    Based on different damage forms of various contact forms to bone, the mechanical response and mechanism were investigated by nanoindentation under different sharpness contact forms. For the purpose of simulating the different sharpness contact forms, two kinds of indenters were used in experiments and finite elements simulations. Through nanoindentation experiments, it was concluded that the residual depth of sharp indenter was bigger than that of blunt indenter with small penetration depth. However, the contrary law was obtained with bigger penetration depth. There was a turning point of transition from blunt tendency to sharp tendency. By calculation, it was concluded that the sharper the indenter was, the bigger the proportion of plastic energy in total energy was. Basically, results of finite elements simulation could correspond with the experimental conclusions. By the observation of FE-SEM, the surface of cortical bone compressed was more seriously directly below the blunt indenter than the lateral face. For the berkovich indenter, the surface of indentation compressed was less directly below the indenter, but seriously on three lateral faces. This research may provide some new references to the studies of bone fracture mechanism in different load patterns in the initial press-in stage and offer new explanation for bone trauma diagnosis in clinical treatment and criminal investigation.

  4. Simulation of acoustic guided wave propagation in cortical bone using a semi-analytical finite element method.

    Science.gov (United States)

    Pereira, Daniel; Haiat, Guillaume; Fernandes, Julio; Belanger, Pierre

    2017-04-01

    Axial transmission techniques have been extensively studied for cortical bone quality assessment. However, the modeling of ultrasonic guided waves propagation in such a complex medium remains challenging. The aim of this paper is to develop a semi-analytical finite element method to simulate the propagation of guided waves in an irregular, multi-layer, and heterogeneous bone cross-section modeled with anisotropic and viscoelastic material properties. The accuracy of the simulations was verified against conventional time-domain three-dimensional finite element. The method was applied in the context of axial transmission in bone to investigate the feasibility of first arrival signal (FAS) to monitor degradation of intracortical properties at low frequency. Different physiopathological conditions for the intracortical region, varying from healthy to osteoporotic, were monitored through FAS velocity using a 10-cycle tone burst excitation centered at 32.5 kHz. The results show that the variation in FAS velocity is mainly associated with four of the eight modes supported by the waveguide, varying with velocity values between 550 and 700 m/s along the different scenarios. Furthermore, the FAS velocity is shown to be associated with the group velocity of the mode with the highest relative amplitude contribution at each studied scenario. However, because of the evolution of the mode with the highest contribution, the FAS velocity is shown to be limited to discriminate intracortical bone properties at low frequency.

  5. Cortical and trabecular bone at the radius and tibia in male and female adolescents with Down syndrome: a peripheral quantitative computed tomography (pQCT) study.

    Science.gov (United States)

    González-Agüero, A; Vicente-Rodríguez, G; Gómez-Cabello, A; Casajús, J A

    2013-03-01

    We aimed to describe the structure and strength of the tibia and radius of adolescents with Down syndrome. We observed that despite higher levels of volumetric bone mineral density in determined skeletal sites, they are at higher risk of developing osteoporotic fractures in the future due to their lower bone strength indexes. The aims of the study were to describe the cortical and trabecular volumetric bone mineral density (vBMD), bone mineral content (BMC), area, and bone strength in adolescents with Down syndrome (DS) and to compare them with adolescents without disabilities. Thirty adolescents (11 girls) with DS and 28 without disabilities (10 girls) participated in the study. Peripheral quantitative computed tomography measurements were taken at proximal and distal sites of the tibia and radius. Values of total, trabecular, and cortical BMC; vBMD; and area were obtained of each scan. Cortical thickness and endosteal and periosteal circumferences were also measured, and different bone strength indexes were calculated. Student's t tests were applied between groups. The DS group showed greater vBMD at distal radius, BMC at proximal radius, and total and cortical vBMD at proximal tibia. The non-DS group showed higher total and trabecular area at the distal radius and total, cortical, and trabecular BMC and area at distal tibia. Higher values of periosteal and endosteal circumference and bone strength were also found in non-DS group. From these results, it can be believed that even with higher vBMD in determined skeletal sites, adolescents with DS are at higher risk of suffering bone fractures due to an increased fragility by lower resistance to load bending or torsion.

  6. Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly; Zimmermann, Elizabeth; Schaible, Eric; Tang, Simon; Alliston, Tamara; Ritchie, Robert

    2011-08-19

    Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and properties of human cortical bone over a range of characteristic (nano to macro) length-scales, following x-­ray exposures up to 630 kGy. Macroscopically, bone strength, ductility and fracture resistance are seen to be progressively degraded with increasing irradiation levels. At the micron-­scale, fracture properties, evaluated using in-situ scanning electron microscopy and synchrotron x-ray computed micro-tomography, provide mechanistic information on how cracks interact with the bone-matrix structure. At sub-micron scales, strength properties are evaluated with in-situ tensile tests in the synchrotron using small-/wide-angle x-ray scattering/diffraction, where strains are simultaneously measured in the macroscopic tissue, collagen fibrils and mineral. Compared to healthy bone, results show that the fibrillar strain is decreased by ~40% following 70 kGy exposures, consistent with significant stiffening and degradation of the collagen. We attribute the irradiation-­induced deterioration in mechanical properties to mechanisms at multiple length-scales, including changes in crack paths at micron-­scales, loss of plasticity from suppressed fibrillar sliding at sub-­micron scales, and the loss and damage of collagen at the nano-­scales, the latter being assessed using Raman and Fourier-Transform-Infrared spectroscopy and a fluorometric assay.

  7. Use and preservation methods of bone grafts in small animals

    Directory of Open Access Journals (Sweden)

    Rafael Garabet Agopian

    2016-09-01

    Full Text Available http://dx.doi.org/10.5007/2175-7925.2016v29n3p11 The present review describes the main characteristics of bone grafts used in small animals. Bone grafts are tissues without vasculature, which facilitate the production of new bone cells with osteogenic and osteoinductive factors that lead to the differentiation of cells and structural support for bone marrow. The transplant of a graft is followed by three stages: osteogenesis, or the formation of new bone; osteoinduction, which is the differentiation of cells; and osteoconduction, the process of growth of mesenchymal cells and capillaries that results in new bone formation. The composition of bone grafts may include spongy bone, cortical bone, cortical-spongy bone, cartilage or bone marrow. Grafts can also be classified according to their origin, being autogenous tissue when they are transplanted from the same individual, allogenous (homologous when originating from another individual of the same species, and xenogenous when obtained from a different species.

  8. Polímero derivado de mamona acrescido de cálcio, associado ou não à medula óssea autógena na reparação de falhas ósseas Castor oil plant polymer and calcium associated or not to autogenous bone marrow in bone gaps repair

    Directory of Open Access Journals (Sweden)

    Ricardo Junqueira Del Carlo

    2003-12-01

    ítio heterotópico, o implante foi incapaz de osteoindução e histologicamente, em ambos os sítios de implantação foram identificadas células gigantes e tecido fibroso envolvente.In order to evaluate tissue repair after the use of castor oil polymer implant additioned with 40% sodium carbonate, isolated or associated to autogenous bone marrow in heterotopic site and in experimental bone gaps in radii of rabbits, 30 White New Zealand rabbits were submitted to bilateral radial ostectomy. In 15 rabbits the bone gap of the right side was filled with polymer cylinders (group P of similar size of the gaps; the remaining rabbits received autogenous bone marrow with the implant (group M. The bone defects of the left limb did not receive any treatment and served as control. Six rabbits received 6 implants in the Rectus abdominus muscle (heterotopic site and in three of these rabbits the implants was associated with bone marrow. In the radiographic study both groups presented increased radiopacity at the implant site without bone axis deviation or resorption of the receptor bone ends. Group P presented irregular calcification areas at the peripheral region and over the polymer. Group M presented a more intense, regular and precocious radiopacity pattern in relation to group P. In microscopical evaluation there was evidence of immature bone tissue formation tending to organize itself, isolated sprouts of neoformed bone over the polymer and its superficial pores. It was concluded that implant allows osteogenenesis and osteoconduction in bone gaps, and bone formation was progressive, especially when additioned bone marrow aspirate; there was capillary, perivascular tissue and osteoprogenitor cells migrating into the pores; with fibrovascular tissue permeating implant surface; implants incorporation was slowly and was found incomplete until 9 weeks; the implant was able to induce foreign body reaction without toxic or secondary reactions to its presence. In heterotopic and orthotopic

  9. Accounting for beta-particle energy loss to cortical bone via paired-image radiation transport (PIRT)

    International Nuclear Information System (INIS)

    Shah, Amish P.; Rajon, Didier A.; Patton, Phillip W.; Jokisch, Derek W.; Bolch, Wesley E.

    2005-01-01

    Current methods of skeletal dose assessment in both medical physics (radionuclide therapy) and health physics (dose reconstruction and risk assessment) rely heavily on a single set of bone and marrow cavity chord-length distributions in which particle energy deposition is tracked within an infinite extent of trabecular spongiosa, with no allowance for particle escape to cortical bone. In the present study, we introduce a paired-image radiation transport (PIRT) model which provides a more realistic three-dimensional (3D) geometry for particle transport in the skeletal site at both microscopic and macroscopic levels of its histology. Ex vivo CT scans were acquired of the pelvis, cranial cap, and individual ribs excised from a 66-year male cadaver (BMI of 22.7 kg m -2 ). For the three skeletal sites, regions of trabecular spongiosa and cortical bone were identified and segmented. Physical sections of interior spongiosa were taken and subjected to microCT imaging. Voxels within the resulting microCT images were then segmented and labeled as regions of bone trabeculae, endosteum, active marrow, and inactive marrow through application of image processing algorithms. The PIRT methodology was then implemented within the EGSNRC radiation transport code whereby electrons of various initial energies are simultaneously tracked within both the ex vivo CT macroimage and the CT microimage of the skeletal site. At initial electron energies greater than 50-200 keV, a divergence in absorbed fractions to active marrow are noted between PIRT model simulations and those estimated under existing techniques of infinite spongiosa transport. Calculations of radionuclide S values under both methodologies imply that current chord-based models may overestimate the absorbed dose to active bone marrow in these skeletal sites by 0% to 27% for low-energy beta emitters ( 33 P, 169 Er, and 177 Lu), by ∼4% to 49% for intermediate-energy beta emitters ( 153 Sm, 186 Re, and 89 Sr), and by ∼14% to

  10. Microstructural and Photoacoustic Infrared Spectroscopic Studies of Human Cortical Bone with Osteogenesis Imperfecta

    Science.gov (United States)

    Gu, Chunju; Katti, Dinesh R.; Katti, Kalpana S.

    2016-04-01

    The molecular basis of bone disease osteogenesis imperfecta (OI) and the mineralization of hydroxyapatite in OI bone have been of significant research interest. To further investigate the mechanism of OI disease and bone mineralization, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and x-ray diffraction (XRD) are used in the present study to describe the structural and compositional differences between OI and healthy bone. OI bone exhibits more porous, fibrous features, abnormal collagen fibrils, and abnormal mineral deposits. Likewise, photoacoustic-FTIR experiments indicate an aberrant collagen structure and an altered mineral structure in OI. In contrast, there is neither significant difference in the non-collagenous proteins (NCPs) composition observed nor apparent change in the crystal structure between OI and healthy bone minerals as shown in XRD and energy-dispersive x-ray spectroscopy (EDS) results. This observation indicates that the biomineralization process is more controlled by the bone cells and non-collagenous phosphorylated proteins. The present study also confirms that there is an orientational influence on the stoichiometry of the mineral in OI bone. Also, a larger volume of the hydrated layer in the transverse plane than the longitudinal plane of the mineral crystal structure is proposed. The appearance of a new C-S band in the FTIR spectra in OI bone suggests the substitution of glycine by cysteine in collagen molecules or/and an increased amount of cysteine-rich osteonectin that relates to mineral nucleation and mineral crystal formation.

  11. Correlation between longitudinal, circumferential, and radial moduli in cortical bone: effect of mineral content.

    Science.gov (United States)

    Macione, J; Depaula, C A; Guzelsu, N; Kotha, S P

    2010-07-01

    Previous studies indicate that changes in the longitudinal elastic properties of bone due to changes in mineral content are related to the longitudinal strength of bone tissue. Changes in mineral content are expected to affect bone tissue mechanical properties along all directions, albeit to different extents. However, changes in tissue mechanical properties along the different directions are expected to be correlated to one another. In this study, we investigate if radial, circumferential, and longitudinal moduli are related in bone tissue with varying mineral content. Plexiform bovine femoral bone samples were treated in fluoride ion solutions for a period of 3 and 12 days to obtain bones with 20% and 32% lower effective mineral contents. Transmission ultrasound velocities were obtained in the radial, circumferential, and longitudinal axes of bone and combined with measured densities to obtain corresponding tensorial moduli. Results indicate that moduli decreased with fluoride ion treatments and were significantly correlated to one another (r(2) radial vs. longitudinal = 0.80, r(2) circumferential vs. longitudinal = 0.90, r(2) radial vs. circumferential = 0.85). Densities calculated from using ultrasound parameters, acoustic impedance and transmission velocities, were moderately correlated to those measured by the Archimedes principle (r(2)=0.54, p<0.01). These results suggest that radial and circumferential ultrasound measurements could be used to determine the longitudinal properties of bone and that ultrasound may not be able to predict in vitro densities of bones containing unbonded mineral. Published by Elsevier Ltd.

  12. Vitamin D supplementation prevents hypocalcemia and cortical bone loss associated with chronic feeding in female mice

    Science.gov (United States)

    Dietary cholecalciferol supplementation alone or combined with calcium has shown great promise in improving bone health, which has been attributed to endocrine actions involved in calcium regulation and/or paracrine/autocrine actions within bone. Indeed, we and others have suggested that dietary su...

  13. Effect of long-term preservation on the mechanical properties of cortical bone in goats

    NARCIS (Netherlands)

    van Haaren, Emil H.; van der Zwaard, Babette C.; van der Veen, Albert J.; Heyligers, Ide C.; Wuisman, Paul I. J. M.; Smit, Theo H.

    2008-01-01

    Bones used in mechanical studies are frequently harvested from human cadavers that have been embalmed in a buffered formaldehyde solution. It has been reported that formaldehyde fixation or freezing hardly affects the mechanical properties of bone after a storage period of several weeks. However,

  14. Effect of long-term preservation on the mechanical properties of cortical bone in goats

    NARCIS (Netherlands)

    van Haaren, E.H.; van der Zwaard, B.C.; van der Veen, A.J.; Heyligers, I.C.; Wuisman, P.I.J.M.; Smit, T.H.

    2008-01-01

    BACKGROUND AND PURPOSE: Bones used in mechanical studies are frequently harvested from human cadavers that have been embalmed in a buffered formaldehyde solution. It has been reported that formaldehyde fixation or freezing hardly affects the mechanical properties of bone after a storage period of

  15. Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone

    Directory of Open Access Journals (Sweden)

    Mick E.

    2015-09-01

    Full Text Available Bone specimens obtained for biomechanical experiments are fresh-frozen for storage to slow down tissue degradation and autolysis in long-term storage. Alternatively, due to infectious risks related to the fresh tissues, fixative agents are commonly used. However, fixatives will likely change the mechanical properties of bone. Existing studies on this issue gave controversial results that are hardly comparable due to a variety of measurement approaches. For this reason, the influence of ethanol and a formalin-based fixative agent was evaluated on the mechanical properties of human cortical bone specimens by means of four-point-bending tests. 127 prismatic specimens with rectangular cross sections (2.5 x 2.5 x 20 mm3 were obtained from different regions of two fresh human femora (medial, lateral, dorsal, ventral. Specimens were either fixed in ethanol or in a mixed formalin solution or frozen following a given scheme. After two weeks of storage the samples were re-hydrated in isotonic saline and subsequently tested mechanically. The elastic bending modulus and ultimate bending strength were computed considering the actual dimensions of each specific specimen. For statistical analysis a one-way-ANOVA and an LSD post-hoc-test were performed. For ultimate bending strength no significant differences due to formalin or ethanol fixation, as compared to unfixed-fresh bone specimens could be found. And only for few cases significant differences in elastic bending modulus were observed when the two bones were evaluated separately. Since more differences of significant level due to the anatomical region of the samples were determined, the original location seems to have more influence on the evaluated mechanical properties than the method of (chemical fixation. Consequently, ethanol and the mixed formalin solution can be recommended as a fixation agent for samples in biomechanical testing, if these samples are rinsed in isotonic saline prior to static

  16. Age-related changes in the plasticity and toughness of human cortical bone at multiple length-scales

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Schaible, Eric; Bale, Hrishikesh; Barth, Holly D.; Tang, Simon Y.; Reichert, Peter; Busse, Bjoern; Alliston, Tamara; Ager III, Joel W.; Ritchie, Robert O.

    2011-08-10

    The structure of human cortical bone evolves over multiple length-scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at nearmillimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone’s toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) at structural-scales typically below a micron and extrinsically (i.e., during crack growth) through mechanisms (e.g., crack deflection/bridging) generated at larger structural-scales. Biological factors such as aging lead to a markedly increased fracture risk, which is often associated with an age-related loss in bone mass (bone quantity). However, we find that age-related structural changes can significantly degrade the fracture resistance (bone quality) over multiple lengthscales. Using in situ small-/wide-angle x-ray scattering/diffraction to characterize sub-micron structural changes and synchrotron x-ray computed tomography and in situ fracture-toughness measurements in the scanning electron microscope to characterize effects at micron-scales, we show how these age-related structural changes at differing size-scales degrade both the intrinsic and extrinsic toughness of bone. Specifically, we attribute the loss in toughness to increased non-enzymatic collagen cross-linking which suppresses plasticity at nanoscale dimensions and to an increased osteonal density which limits the potency of crack-bridging mechanisms at micron-scales. The link between these processes is that the increased stiffness of the cross-linked collagen requires energy to be absorbed by “plastic” deformation at higher structural levels, which occurs by the process of microcracking.

  17. Effect of stainless steel and titanium low-contact dynamic compression plate application on the vascularity and mechanical properties of cortical bone after fracture.

    Science.gov (United States)

    Jain, R; Podworny, N; Hearn, T; Anderson, G I; Schemitsch, E H

    1997-10-01

    Comparison of the effect of stainless steel and titanium low-contact dynamic compression plate application on the vascularity and mechanical properties of cortical bone after fracture. Randomized, prospective. Orthopaedic research laboratory. Ten large (greater than twenty-five kilogram) adult dogs. A short, midshaft spiral tibial fracture was created, followed by lag screw fixation and neutralization with an eight-hole, 3.5-millimeter, low-contact dynamic compression plate (LCDCP) made of either 316L stainless steel (n = five) or commercially pure titanium (n = five). After surgery, animals were kept with unrestricted weight-bearing in individual stalls for ten weeks. Cortical bone blood flow was assessed by laser Doppler flowmetry using a standard metalshafted probe (Periflux Pf303, Perimed, Jarfalla, Sweden) applied through holes in the custom-made LCDCPs at five sites. Bone blood flow was determined at four times: (a) prefracture, (b) postfracture, (c) postplating, and (d) ten weeks postplating. After the dogs were killed, the implant was removed and both the treated tibia and contralateral tibia were tested for bending stiffness and load to failure. Fracture creation decreased cortical perfusion in both groups at the fracture site (p = 0.02). The application of neither stainless steel nor titanium LCDCPs further decreased cortical bone blood flow after fracture creation. However, at ten weeks postplating, cortical perfusion significantly increased compared with acute postplating levels in the stainless steel (p = 0.003) and titanium (p = 0.001) groups. Cortical bone blood flow ten weeks postplating was not significantly different between the titanium group and the stainless steel group. Biomechanical tests performed on the tibiae with the plates removed did not reveal any differences in bending stiffness nor load required to cause failure between the two groups. Both titanium and stainless steel LCDCPs were equally effective in allowing revascularization, and

  18. Irradiation conditions for fiber laser bonding of HAp-glass ceramics with bovine cortical bone.

    Science.gov (United States)

    Tadano, Shigeru; Yamada, Satoshi; Kanaoka, Masaru

    2014-01-01

    Orthopedic implants are widely used to repair bones and to replace articulating joint surfaces. It is important to develop an instantaneous technique for the direct bonding of bone and implant materials. The aim of this study was to develop a technique for the laser bonding of bone with an implant material like ceramics. Ceramic specimens (10 mm diameter and 1 mm thickness) were sintered with hydroxyapatite and MgO-Al2O3-SiO2 glass powders mixed in 40:60 wt% proportions. A small hole was bored at the center of a ceramic specimen. The ceramic specimen was positioned onto a bovine bone specimen and a 5 mm diameter area of the ceramic specimen was irradiated using a fiber laser beam (1070-1080 nm wavelength). As a result, the bone and the ceramic specimens bonded strongly under the irradiation conditions of a 400 W laser power and a 1.0 s exposure time. The maximum shear strength was 5.3 ± 2.3 N. A bonding substance that penetrated deeply into the bone specimen was generated around the hole in the ceramic specimen. On using the fiber laser, the ceramic specimen instantaneously bonded to the bone specimen. Further, the irradiation conditions required for the bonding were investigated.

  19. The Content of the 14 Metals in Cancellous and Cortical Bone of the Hip Joint Affected by Osteoarthritis

    Science.gov (United States)

    Zioła-Frankowska, Anetta; Kubaszewski, Łukasz; Dąbrowski, Mikołaj; Kowalski, Artur; Rogala, Piotr; Strzyżewski, Wojciech; Łabędź, Wojciech; Kanicky, Viktor

    2015-01-01

    The aim of the study was to determine the content of particular elements Ca, Mg, P, Na, K, Zn, Cu, Fe, Mo, Cr, Ni, Ba, Sr, and Pb in the proximal femur bone tissue (cancellous and cortical bone) of 96 patients undergoing total hip replacement for osteoarthritis using ICP-AES and FAAS analytical techniques. The interdependencies among these elements and their correlations depended on factors including age, gender, place of residence, tobacco consumption, alcohol consumption, exposure to environmental pollution, physical activity, and type of degenerative change which were examined by statistical and chemometric methods. The factors that exerted the greatest influence on the elements in the femoral head and neck were tobacco smoking (higher Cr and Ni content in smokers), alcohol consumption (higher concentrations of Ni, Cu in people who consume alcohol), and gender (higher Cu, Zn, and Ni concentrations in men). The factors influencing Pb accumulation in bone tissue were tobacco, alcohol, gender, and age. In primary and secondary osteoarthritis of the hip, the content and interactions of elements are different (mainly those of Fe and Pb). There were no significant differences in the concentrations of elements in the femoral head and neck that could be attributed to residence or physical activity. PMID:26357659

  20. Three-Dimensional Analysis of the Contact Pattern between the Cortical Bone and Femoral Prosthesis after Cementless Total Hip Arthroplasty

    Directory of Open Access Journals (Sweden)

    Hiroshi Wada

    2016-01-01

    Full Text Available The cementless stem Excia (B. Braun, Melsungen, Germany implant has a rectangular cross-sectional shape with back-and-forth flanges and a plasma-sprayed, dicalcium phosphate dihydrate coating from the middle to proximal portion to increase initial fixation and early bone formation. Here, the conformity of the Excia stem to the femoral canal morphology was three-dimensionally assessed using computed tomography. Forty-three patients (45 hips were examined after primary total hip arthroplasty with a mean follow-up of 27 ± 3 months (range: 24–36 months. Spot welds occurred at zone 2 in 16 hips and at zone 6 in 24 hips, with 83% (20/24 hips of those occurring within 3 months after surgery. First- (n=12 hips, second- (n=32, and third- (n=1 degree stress shielding were observed. The stem was typically in contact with the cortical bone in the anterolateral mid-portion (100% and posteromedial distal portions (85%. Stress shielding did not progress, even in cases where the stems were in contact with the distal portions. The anterior flange was in contact with the bone in all cases. The stability of the mid-lateral portion with the dicalcium phosphate dihydrate coating and the anterior flange may have inhibited the progression of stress shielding beyond the second degree.

  1. Compromised cortical bone compartment in type 2 diabetes mellitus patients with microvascular disease

    DEFF Research Database (Denmark)

    Shanbhogue, Vikram Vinod; Hansen, Stinus; Nielsen, Morten Frost Munk

    2016-01-01

    OBJECTIVE AND DESIGN: Patients with type 2 diabetes mellitus (T2D) have an increased fracture risk despite a normal or elevated bone mineral density (BMD). The aim of this cross-sectional in vivo study was to assess parameters of peripheral bone microarchitecture, estimated bone strength and bone...... remodeling in T2D patients with and without diabetic microvascular disease (MVD+ and MVD- respectively) and to compare them with healthy controls. METHODS: Fifty-one T2D patients (MVD+ group: n=25) were recruited from Funen Diabetic Database and matched for age, sex and height with 51 healthy subjects. High...... deficits are not a characteristic of all T2D patients but of a subgroup characterized by the presence of microvascular complications. Whether this influences fracture rates in these patients needs further investigation....

  2. Segmentation of nanotomographic cortical bone images for quantitative characterization of the osteoctyte lacuno-canalicular network

    Energy Technology Data Exchange (ETDEWEB)

    Ciani, A.; Kewish, C. M. [Synchrotron Soleil, L’Orme des Merisiers, 91192 Saint-Aubin (France); Guizar-Sicairos, M.; Diaz, A.; Holler, M. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Pallu, S.; Achiou, Z.; Jennane, R.; Toumi, H.; Lespessailles, E. [Univ Orléans, I3MTO, Ea 4708, 45000 Orléans (France)

    2016-01-28

    A newly developed data processing method able to characterize the osteocytes lacuno-canalicular network (LCN) is presented. Osteocytes are the most abundant cells in the bone, living in spaces called lacunae embedded inside the bone matrix and connected to each other with an extensive network of canals that allows for the exchange of nutrients and for mechanotransduction functions. The geometrical three-dimensional (3D) architecture is increasingly thought to be related to the macroscopic strength or failure of the bone and it is becoming the focus for investigating widely spread diseases such as osteoporosis. To obtain 3D LCN images non-destructively has been out of reach until recently, since tens-of-nanometers scale resolution is required. Ptychographic tomography was validated for bone imaging in [1], showing clearly the LCN. The method presented here was applied to 3D ptychographic tomographic images in order to extract morphological and geometrical parameters of the lacuno-canalicular structures.

  3. Parametric study of control mechanism of cortical bone remodeling under mechanical stimulus

    Science.gov (United States)

    Wang, Yanan; Qin, Qing-Hua

    2010-03-01

    The control mechanism of mechanical bone remodeling at cellular level was investigated by means of an extensive parametric study on a theoretical model described in this paper. From a perspective of control mechanism, it was found that there are several control mechanisms working simultaneously in bone remodeling which is a complex process. Typically, an extensive parametric study was carried out for investigating model parameter space related to cell differentiation and apoptosis which can describe the fundamental cell lineage behaviors. After analyzing all the combinations of 728 permutations in six model parameters, we have identified a small number of parameter combinations that can lead to physiologically realistic responses which are similar to theoretically idealized physiological responses. The results presented in the work enhanced our understanding on mechanical bone remodeling and the identified control mechanisms can help researchers to develop combined pharmacological-mechanical therapies to treat bone loss diseases such as osteoporosis.

  4. Lag screw fixation of dorsal cortical stress fractures of the third metacarpal bone in 116 racehorses.

    Science.gov (United States)

    Jalim, S L; McIlwraith, C W; Goodman, N L; Anderson, G A

    2010-10-01

    The effectiveness and best method to manage dorsal cortical stress fractures is not clear. This study was performed to evaluate the success of lag screw fixation of such fractures in a population of Thoroughbred racehorses. Lag screw fixation of dorsal cortical stress fractures is an effective surgical procedure allowing racehorses to return to their preoperative level of performance. The records of 116 racehorses (103 Thoroughbreds) admitted to Equine Medical Centre, California between 1986 and 2008 were assessed. Information obtained from medical records included subject details, limb(s) affected, fracture configuration, length of screw used in repair and presence of concurrent surgical procedures performed. Racing performance was evaluated relative to these factors using Fisher's exact test and nonparametric methods with a level of significance of Phorses, 83% raced preoperatively and 83% raced post operatively, with 63% having ≥5 starts. There was no statistically significant association between age, gender, limb affected, fracture configuration or presence of concurrent surgery and likelihood of racing post operatively or of having 5 or more starts. The mean earnings per start and the performance index for the 3 races following surgery were lower compared to the 3 races prior to surgery; however, 29 and 45% of horses either improved or did not change their earnings per start and performance index, respectively. Data show that lag screw fixation is successful at restoring ability to race in horses suffering from dorsal cortical stress fractures. © 2010 EVJ Ltd.

  5. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone - a feasibility study

    NARCIS (Netherlands)

    Marcián, P.; Borák, L.; Valášek, J.; Kaiser, J.; Florian, Z.; Wolff, J.

    2014-01-01

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant

  6. Finite element analysis of dental implant loading on atrophic and non-atrophic cancellous and cortical mandibular bone – a feasibility study

    NARCIS (Netherlands)

    Marcian, P.; Borak, L.; Valasek, J.; Kaiser, J.; Florian, Z.; Wolff, J.E.H.

    2014-01-01

    The first aim of this study was to assess displacements and micro-strain induced on different grades of atrophic cortical and trabecular mandibular bone by axially loaded dental implants using finite element analysis (FEA). The second aim was to assess the micro-strain induced by different implant

  7. Histologic Evaluation of Wound Healing After Ridge Preservation With Cortical, Cancellous, and Combined Cortico-Cancellous Freeze-Dried Bone Allograft: A Randomized Controlled Clinical Trial.

    Science.gov (United States)

    Demetter, Randy S; Calahan, Blaine G; Mealey, Brian L

    2017-09-01

    Cortical and cancellous mineralized freeze-dried bone allografts (FDBA) are available for use in alveolar ridge preservation after tooth extraction. There are currently no data regarding use of a combination 50%/50% cortico-cancellous FDBA compared with a 100% cortical or 100% cancellous FDBA in ridge preservation. The primary objective of this study is to dimensionally and histologically evaluate healing after ridge preservation in non-molar sites using 50%/50% cortico-cancellous FDBA versus 100% cortical and 100% cancellous FDBA. Sixty-six patients requiring extraction of a non-molar tooth were enrolled and randomized into three groups to receive ridge preservation with the following: 1) 100% cortical FDBA; 2) 100% cancellous FDBA; or 3) 50%/50% cortico-cancellous FDBA. After 18 to 20 weeks of healing, a biopsy was harvested, and an implant was placed. The alveolar ridge was measured pre- and postoperatively to evaluate change in ridge height and width. Percentages of vital bone, residual graft, and connective tissue (CT)/other were determined via histomorphometric analysis. Histomorphometric analysis revealed no significant differences among groups regarding percentage of vital bone or CT/other. The 100% cortical FDBA group had significantly greater residual graft material (P = 0.04). Dimensional analysis revealed no significant between-group differences in any parameter measured. To the best knowledge of the authors, this study offers the first histologic evidence demonstrating no significant difference in vital bone formation or dimensional changes among 50%/50% cortico-cancellous FDBA, 100% cortical FDBA, and 100% cancellous FDBA when used in ridge preservation of non-molar tooth sites.

  8. Autogenous shrinkage, speciality of high performance concretes

    OpenAIRE

    Vogrič, Nina

    2014-01-01

    Autogenous shrinkage is a consequence of self dessication in pores of hardened cement paste and is, at high performance concrete significantly greater than that of the ordinary concretes, mainly due to low water to cement ratio. In the graduation thesis we examined the main mechanisms that cause autogenous shrinkage. It can be reduced by internal curinginternal water reservoirs. As internal water reservoirs we used pre-soaked expanded clay Liapor. On specimens, in which we replaced 12 % of ag...

  9. Plasma rico em plaquetas associado ou não ao osso esponjoso autógeno no reparo de falhas ósseas experimentais Platelet rich plasma associated or not to autogenous bone graft on the reparation of experimental bone defects in the rabbits cranium

    Directory of Open Access Journals (Sweden)

    Paloma Sayegh Arreguy Silva

    2009-02-01

    do tipo corpo estranho, que atuou negativamente na fase inicial de reparação.The present study evaluated autogenous platelet rich plasma's (PRP influence on the reparation process of four bone defects made on rabbit's skull, associated or not to autogenous bone graft (EOE. Defect I received PRP only; defect II received 3mg of EOE only; defect III received EOE associated to PRP; defect IV was left to heal naturally, serving as control. After each surgery the animals were randomly divided into three groups that were euthanized at 30, 60 and 90 days. In the mesoscopic evaluation bone ingrowth started from the defect's borders to the center and from the bottom to the surface for all observation times on the control (VI and PRP only (I groups. In the groups treated with EOE only (II and EOE associated to PRP (III new bone was observed in the center of the defects. Radiographic analysis showed greater central radiopacity for groups treated with EOE only (II and EOE associated to PRP (III at all observation times. Microscopically in the group treated with EOE associated to PRP (III at 30 days the graft was indistinguishable from new bone present on the border of the defect, associated to a moderate quantity of a very vascularized and cellular fibrous connective tissue. This tissue showed an extracelular eosinophilic amorphous foamy material, associated to an inflammatory process constituted by lymphocytes and in less number by macrophages and multinucleated giant cells that may have negatively influenced early bone formation. At 60 and 90 days occasional spots of lymphocytic inflammation were observed. Both treatments, PRP associated or not to EOE, were similar for the bone ingrowth at the final time of observation; the graft used alone determined early bone reparation and thromboplastine used for the platelet gel formation incited a foreign body-like reaction that acted negatively on the initial reparation.

  10. A new method to determine cortical bone thickness in CT images using a hybrid approach of parametric profile representation and local adaptive thresholds: Accuracy results.

    Directory of Open Access Journals (Sweden)

    Oleg Museyko

    Full Text Available Cortical bone is an important contributor to bone strength and is pivotal to understand the etiology of osteoporotic fractures and the specific mechanisms of antiosteoporotic treatment regimen. 3D computed tomography (CT can be used to measure cortical thickness, density, and mass in the proximal femur, lumbar vertebrae, and distal forearm. However, the spatial resolution of clinical whole body CT scanners is limited by radiation exposure; partial volume artefacts severely impair the accurate assessment of cortical parameters, in particular in locations where the cortex is thin such as in the lumbar vertebral bodies or in the femoral neck.Model-based deconvolution approaches recover the cortical thickness by numerically deconvolving the image along 1D profiles using an estimated scanner point spread function (PSF and a hypothesized uniform cortical bone mineral density (reference density. In this work we provide a new essentially analytical unique solution to the model-based cortex recovery problem using few characteristics of the measured profile and thus eliminate the non-linear optimization step for deconvolution. Also, the proposed approach allows to get rid of the PSF in the model and reduces sensitivity to errors in the reference density. Additionally, run-time and memory effective computation of cortical thickness was achieved with the help of a lookup table.The method accuracy and robustness was validated and compared to that of a deconvolution approach recently proposed for cortical bone and of the 50% relative threshold technique: in a simulated environment with noise and various error levels in the reference density and using CT acquisitions of the European Forearm Phantom (EFP II, a modification of a widely used anthropomorphic standard of cortical and trabecular bone compartments that was scanned with various scan protocols.Results of simulations and of phantom data analysis verified the following properties of the new method: 1

  11. Curcumin deteriorates trabecular and cortical bone in mice bearing metastatic Lewis lung carcinoma

    Science.gov (United States)

    Bone is a major target of metastasis for many malignancies; curcumin has been studied for its role in cancer prevention including early phase clinical trials for its efficacy and safe use with cancer patients. The present study investigated the effects of dietary supplementation with curcumin (2% a...

  12. Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

    Science.gov (United States)

    The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

  13. Velocity dispersion of guided waves propagating in a free gradient elastic plate: application to cortical bone.

    Science.gov (United States)

    Vavva, Maria G; Protopappas, Vasilios C; Gergidis, Leonidas N; Charalambopoulos, Antonios; Fotiadis, Dimitrios I; Polyzos, Demosthenes

    2009-05-01

    The classical linear theory of elasticity has been largely used for the ultrasonic characterization of bone. However, linear elasticity cannot adequately describe the mechanical behavior of materials with microstructure in which the stress state has to be defined in a non-local manner. In this study, the simplest form of gradient theory (Mindlin Form-II) is used to theoretically determine the velocity dispersion curves of guided modes propagating in isotropic bone-mimicking plates. Two additional terms are included in the constitutive equations representing the characteristic length in bone: (a) the gradient coefficient g, introduced in the strain energy, and (b) the micro-inertia term h, in the kinetic energy. The plate was assumed free of stresses and of double stresses. Two cases were studied for the characteristic length: h=10(-4) m and h=10(-5) m. For each case, three subcases for g were assumed, namely, g>h, gguided waves were numerically obtained and compared with the Lamb modes. The results indicate that when g was not equal to h (i.e., g not equal h), microstructure affects mode dispersion by inducing both material and geometrical dispersion. In conclusion, gradient elasticity can provide supplementary information to better understand guided waves in bones.

  14. Phase velocity estimation technique based on adaptive beamforming for ultrasonic guided waves propagating along cortical long bones

    Science.gov (United States)

    Okumura, Shigeaki; Nguyen, Vu-Hieu; Taki, Hirofumi; Haïat, Guillaume; Naili, Salah; Sato, Toru

    2017-07-01

    The axial transmission technique, which is used to estimate the phase velocity of an ultrasonic guided wave propagating along cortical bone is a promising tool for bone quality assessment. Lamb waves are ultrasonic guided waves that consist of multiple modes. The number of existing modes and the signal-to-noise ratio required for phase velocity estimation depend on the frequency of the signal. Hence, we employ an adaptive beamforming technique with spatial averaging to control signal-to-noise ratio and resolution by situating subarrays within the full array. Because the determination of the optimal size for spatial averaging is difficult, we propose a new algorithm that does not require a specific size with a new false-phase-velocity rejection technique. Using a 2.0-mm-thick copper plate, the proposed method accurately estimates phase velocity with fitting errors of 0.26 and 1.3%, as shown by simulation and experimental results, respectively. The measurement frequency ranges are more than twice wider than those measured by the conventional method.

  15. Comparison of dose calculation algorithms in slab phantoms with cortical bone equivalent heterogeneities

    International Nuclear Information System (INIS)

    Carrasco, P.; Jornet, N.; Duch, M. A.; Panettieri, V.; Weber, L.; Eudaldo, T.; Ginjaume, M.; Ribas, M.

    2007-01-01

    To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect transistors (MOSFETs), plane parallel and cylindrical ionization chambers, and beam profiles with films. The MC code used for the simulations was the PENELOPE code. Three different field sizes (10x10, 5x5, and 2x2 cm 2 ) were studied in two phantom configurations and a bone equivalent material. These two phantom configurations contained heterogeneities of 5 and 2 cm of bone, respectively. We analyzed the performance of four correction-based algorithms and one based on convolution superposition. The correction-based algorithms were the Batho, the Modified Batho, the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system (TPS), and the Helax-TMS Pencil Beam from the Helax-TMS (Nucletron) TPS. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. All the correction-based calculation algorithms underestimated the dose inside the bone-equivalent material for 18 MV compared to MC simulations. The maximum underestimation, in terms of root-mean-square (RMS), was about 15% for the Helax-TMS Pencil Beam (Helax-TMS PB) for a 2x2 cm 2 field inside the bone-equivalent material. In contrast, the Collapsed Cone algorithm yielded values around 3%. A more complex behavior was found for 6 MV where the Collapsed Cone performed less well, overestimating the dose inside the heterogeneity in 3%-5%. The rebuildup in the interface bone-water and the penumbra shrinking in high-density media were not predicted by any of the calculation algorithms except the Collapsed Cone, and only the MC simulations matched the experimental values within

  16. Comparison of dose calculation algorithms in slab phantoms with cortical bone equivalent heterogeneities.

    Science.gov (United States)

    Carrasco, P; Jornet, N; Duch, M A; Panettieri, V; Weber, L; Eudaldo, T; Ginjaume, M; Ribas, M

    2007-08-01

    To evaluate the dose values predicted by several calculation algorithms in two treatment planning systems, Monte Carlo (MC) simulations and measurements by means of various detectors were performed in heterogeneous layer phantoms with water- and bone-equivalent materials. Percentage depth doses (PDDs) were measured with thermoluminescent dosimeters (TLDs), metal-oxide semiconductor field-effect transistors (MOSFETs), plane parallel and cylindrical ionization chambers, and beam profiles with films. The MC code used for the simulations was the PENELOPE code. Three different field sizes (10 x 10, 5 x 5, and 2 x 2 cm2) were studied in two phantom configurations and a bone equivalent material. These two phantom configurations contained heterogeneities of 5 and 2 cm of bone, respectively. We analyzed the performance of four correction-based algorithms and one based on convolution superposition. The correction-based algorithms were the Batho, the Modified Batho, the Equivalent TAR implemented in the Cadplan (Varian) treatment planning system (TPS), and the Helax-TMS Pencil Beam from the Helax-TMS (Nucletron) TPS. The convolution-superposition algorithm was the Collapsed Cone implemented in the Helax-TMS. All the correction-based calculation algorithms underestimated the dose inside the bone-equivalent material for 18 MV compared to MC simulations. The maximum underestimation, in terms of root-mean-square (RMS), was about 15% for the Helax-TMS Pencil Beam (Helax-TMS PB) for a 2 x 2 cm2 field inside the bone-equivalent material. In contrast, the Collapsed Cone algorithm yielded values around 3%. A more complex behavior was found for 6 MV where the Collapsed Cone performed less well, overestimating the dose inside the heterogeneity in 3%-5%. The rebuildup in the interface bone-water and the penumbra shrinking in high-density media were not predicted by any of the calculation algorithms except the Collapsed Cone, and only the MC simulations matched the experimental values

  17. k-space sampling optimization for ultrashort TE imaging of cortical bone: applications in radiation therapy planning and MR-based PET attenuation correction.

    Science.gov (United States)

    Hu, Lingzhi; Su, Kuan-Hao; Pereira, Gisele C; Grover, Anu; Traughber, Bryan; Traughber, Melanie; Muzic, Raymond F

    2014-10-01

    The ultrashort echo-time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k-space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone-enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR. An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2(∗) = 1/T2(∗), was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone-enhanced image quality, image noise, water fraction, and R2(∗) of cortical bone. A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2(∗) of human skull was measured as 0.2-0.3 ms(-1) depending on the specific region, which is more than ten times greater than the R2(∗) of soft tissue. The water fraction in human skull was measured to be 60%-80%, which is significantly less than the >90% water fraction in brain. High-quality, bone-enhanced images can be generated

  18. k-space sampling optimization for ultrashort TE imaging of cortical bone: Applications in radiation therapy planning and MR-based PET attenuation correction

    International Nuclear Information System (INIS)

    Hu, Lingzhi; Traughber, Melanie; Su, Kuan-Hao; Pereira, Gisele C.; Grover, Anu; Traughber, Bryan; Muzic, Raymond F. Jr.

    2014-01-01

    Purpose: The ultrashort echo-time (UTE) sequence is a promising MR pulse sequence for imaging cortical bone which is otherwise difficult to image using conventional MR sequences and also poses strong attenuation for photons in radiation therapy and PET imaging. The authors report here a systematic characterization of cortical bone signal decay and a scanning time optimization strategy for the UTE sequence through k-space undersampling, which can result in up to a 75% reduction in acquisition time. Using the undersampled UTE imaging sequence, the authors also attempted to quantitatively investigate the MR properties of cortical bone in healthy volunteers, thus demonstrating the feasibility of using such a technique for generating bone-enhanced images which can be used for radiation therapy planning and attenuation correction with PET/MR. Methods: An angularly undersampled, radially encoded UTE sequence was used for scanning the brains of healthy volunteers. Quantitative MR characterization of tissue properties, including water fraction and R2 ∗ = 1/T2 ∗ , was performed by analyzing the UTE images acquired at multiple echo times. The impact of different sampling rates was evaluated through systematic comparison of the MR image quality, bone-enhanced image quality, image noise, water fraction, and R2 ∗ of cortical bone. Results: A reduced angular sampling rate of the UTE trajectory achieves acquisition durations in proportion to the sampling rate and in as short as 25% of the time required for full sampling using a standard Cartesian acquisition, while preserving unique MR contrast within the skull at the cost of a minimal increase in noise level. The R2 ∗ of human skull was measured as 0.2–0.3 ms −1 depending on the specific region, which is more than ten times greater than the R2 ∗ of soft tissue. The water fraction in human skull was measured to be 60%–80%, which is significantly less than the >90% water fraction in brain. High-quality, bone

  19. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs.

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Bunnell, Kevin; Auger, Janene; Black, Hal L; Donahue, Seth W

    2009-07-22

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.

  20. The effect of pilot hole size on the insertion torque and pullout strength of self-tapping cortical bone screws in osteoporotic bone.

    Science.gov (United States)

    Battula, Suneel; Schoenfeld, Andrew J; Sahai, Vivek; Vrabec, Gregory A; Tank, Jason; Njus, Glen O

    2008-04-01

    All surgical screws can experience failure if the torsional, tensile, and flexion loads exerted on the screws are excessively high. The use of self-tapping screws (STS) results in higher insertion torques (IT) as these screws cut their own threads in the pilot hole drilled in the bone. In this study, the torque for inserting the STS into an osteoporotic bone block for different pilot hole sizes (PHS) was measured and the pullout strength (PS) for extraction of the screws was determined for different depths of insertion, 0 mm, 1 mm, and 2 mm beyond the far cortex. Seventy-two Synthes stainless steel STS (40 mm length and 3.5 mm diameter) were inserted into pilot holes of sizes 2.55 (A: 73% OD), 2.50 (B: 71.5%), 2.45 (C: 70%), and 2.8 mm (D: 80%). Using a digital torque screwdriver, screws were inserted to 0 mm, 1 mm or 2 mm past the far cortex. Pullout tests were conducted with an Instron materials testing system. Analysis of variance and Student-Neuman-Keuls tests were performed to determine the effect of DOI and PHS on the loading energy, PS, and IT. Results demonstrated that IT of the screws inserted into pilot holes A, B, and C were higher than those in D. It was also observed that PS and loading energy for 1 mm and 2 mm penetration past the far cortex were higher than those for 0 mm regardless of PHS. This study also found that an increase in PHS to 2.8 mm will reduce IT but will also reduce the PS relative to a PHS of 2.5 mm, the current standard for 3.5 mm screws. The results of previously published studies regarding the effect of pilot hole size on PS in healthy cortical bone cannot be applied to the osteoporotic environment. The findings presented in this research support using PHS no larger than 71.5% of the screw outer diameter (i.e., pilot hole size of 2.5 mm for 3.5 mm screws) and inserting screws at least 2 mm beyond the far cortex to maximize PS and minimize iatrogenic damage in osteoporotic bone.

  1. Cortical Bone Mineralization in the Human Femoral Neck in Cases and Controls from Synchrotron Radiation Study.

    Science.gov (United States)

    Wu, Yan; Zhou, Liangqiang; Bergot, Catherine; Peyrin, Françoise; Bousson, Valérie

    2015-09-01

    To compare the degree and distribution of mineralization in femoral neck cortex from 23 women with hip fractures (age 65-96 years) and 17 female controls (age 72-103 years), we obtained 3D data by synchrotron radiation microtomography (SRμCT). Variables were degree of mineralization of bone (DMB) in total cortex (cDMBSRMEAN), osteons (oDMBSRMEAN), and pure interstitial tissue (intDMBSRMEAN). The cortex on SRμCT images was divided into nine to twelve 50-μm zones from the periosteum to the endosteum; cDMBSRMEAN, oDMBSRMEAN, and intDMBSRMEAN were measured in each zone. We used descriptive statistics and t tests, general linear model analyses to compare DMBSR values across zones and individuals, one-way analysis of variance for within-group comparisons of zones. In patients, the variance of mineral content value was not different than in controls, but mean values of degree of mineralization varied across zones. These cross-sectional data suggest that bone fragility may be related to a greater heterogeneity of the distribution of mineralization in femoral neck cortex.

  2. Instrumental neutron-activation analysis applications in the age dynamics assessment of Ca, Cl, K, Mg. Mn, Na, P, and Sr contents in the human cortical bone

    International Nuclear Information System (INIS)

    Zaichick, V.

    2003-01-01

    Full text: Senile osteoporosis and particularly osteoporosis among postmenopausal women represents an urgent problem of modern medicine. One of the main osteoporosis symptoms is a decrease in both bone mineral density and subsequent bone strength. The upper extremity of the femur in humans is a particularly vulnerable section of the skeleton, being subject to fracture and necrosis and to destruction of its cartilage. Iliac crest biopsies are commonly taken clinically on patients. It is known that the control of the mineral component providing bone strength is a good indicator to detect bone diseases like osteoporosis. Despite this, changes of chemical element contents occurring with age in the femoral head and the iliac crest of female and male separately have been little studied, but in iliac cortical bone have not been studied at all. The effect of age and sex on chemical element contents in intact cortical bone of femoral neck and iliac crest of 81 relatively healthy 15-55 years old women (n=36) and men (n=45) was investigated. All subjects had died suddenly and bone samples were obtained at necropsy from the right side of bodies within twenty-four hours after death. A tool made of titanium and plastic was used to clear samples from soft tissues and blood and to cut cortical part of bone. The IAEA and NIST reference materials (H-5 animal bone and SRM1486 bone meal) were used to estimate the precision and accuracy of results. Contents of Ca, Cl, K, Mg> Mn, Na, P, and Sr in intact bone samples were determined by instrumental neutron activation analysis using short-lived radionuclides. Our means data for each element of reference materials were within the certified 95 % confidence interval, and indicate an acceptable accuracy of the obtained results. No age- and sex-related differences in the cortical femoral neck composition were detected. Mean values (M±S.E.M.) of Ca, Cl, K, Mg, Mn, Na, P, and Sr mass fractions (on dry weight basis) for female and male all

  3. History of amenorrhoea compromises some of the exercise-induced benefits in cortical and trabecular bone in the peripheral and axial skeleton: a study in retired elite gymnasts.

    Science.gov (United States)

    Ducher, G; Eser, P; Hill, B; Bass, S

    2009-10-01

    Female gymnasts frequently present with overt signs of hypoestrogenism, such as late menarche or menstrual dysfunction. The objective was to investigate the impact of history of amenorrhoea on the exercise-induced skeletal benefits in bone geometry and volumetric density in retired elite gymnasts. 24 retired artistic gymnasts, aged 17-36 years, who had been training for at least 15 h/week at the peak of their career and had been retired for 3-18 years were recruited. They had not been engaged in more than 2 h/week of regular physical activity since retirement. Former gymnasts who reported history of amenorrhoea ('AME', n=12: either primary or secondary amenorrhoea) were compared with former gymnasts ('NO-AME', n=12) and controls ('C', n=26) who did not report history of amenorrhoea. Bone mineral content (BMC), total bone area (ToA) and total volumetric density (ToD) were measured by pQCT at the radius and tibia (4% and 66%). Trabecular volumetric density (TrD) and bone strength index (BSI) were measured at the 4% sites. Cortical area (CoA), cortical thickness (CoTh), medullary area (MedA), cortical volumetric density (CoD), stress-strain index (SSI) and muscle and fat area were measured at the 66% sites. Spinal BMC, areal BMD and bone mineral apparent density (BMAD) were measured by DXA. Menarcheal age was delayed in AME when compared to NO-AME (16.4+/-0.5 years vs. 13.3+/-0.4 years, pdensity and bone strength in the peripheral skeleton were found in former gymnasts without a history of menstrual dysfunction but not in those who reported either primary or secondary amenorrhoea. History of amenorrhoea may have compromised some of the skeletal benefits associated with high-impact gymnastics training.

  4. 30 CFR 35.20 - Autogenous-ignition temperature test.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Autogenous-ignition temperature test. 35.20... Autogenous-ignition temperature test. (a) Purpose. The purpose of this test, referred to hereinafter as the ignition-temperature test, is to determine the lowest autogenous-ignition temperature of a hydraulic fluid...

  5. Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

    Energy Technology Data Exchange (ETDEWEB)

    Meema, S.; Meema, H.E.

    1982-08-01

    Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scores were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed.

  6. Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

    International Nuclear Information System (INIS)

    Meema, S.; Meema, H.E.

    1982-01-01

    Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scores were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed. (orig.)

  7. Effects of mineral content on the fracture properties of equine cortical bone in double-notched beams.

    Science.gov (United States)

    McCormack, Jordan; Stover, Susan M; Gibeling, Jeffery C; Fyhrie, David P

    2012-06-01

    We recently developed a method to measure cortical bone fracture initiation toughness using a double-notched beam in four-point bending. This method was used to test the hypothesis that mineralization around the two notch roots is correlated with fracture toughness and crack extension (physical damage). Total energy absorbed to failure negatively correlated with average mineralization of the beam (r(2)=0.62), but not with notch root mineralization. Fracture initiation toughness was positively correlated to mineralization at the broken notch root (r(2)=0.34). Crack length extension at the unbroken notch was strongly negatively correlated with the average mineralization of the notch roots (r(2)=0.81) whereas crack length extension at the broken notch did not correlate with any of the mineralization measurements. Mineralization at the notch roots and the average mineralization contributed independently to the mechanical and damage properties. The data are consistent with a hypothesis that a) high notch root mineralization results in less stable crack length extension but high force to initiate unstable crack propagation while b) higher average mineralization leads to low post-yield (and total) energy absorption to failure. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Acute development of cortical porosity and endosteal naïve bone formation from the daily but not weekly short-term administration of PTH in rabbit.

    Directory of Open Access Journals (Sweden)

    Hiroshi Yamane

    Full Text Available Teriparatide [human parathyroid hormone (1-34], which exerts an anabolic effect on bone, is used for the treatment of osteoporosis in patients who are at a high risk for fracture. That the once-daily administration of teriparatide causes an increase in cortical porosity in animal models and clinical studies has been a matter of concern. However, it is not well documented that the frequency of administration and/or the total dose of teriparatide affect the cortical porosity. The present study developed 4 teriparatide regimens [20 μg/kg/day (D20, 40 μg/kg/day (D40, 140 μg/kg/week (W140 and 280 μg/kg/week (W280] in the rabbit as a model animal with a well-developed Haversian system and osteons. The total weekly doses were equivalent in the low-dose groups (D20 and W140 and in the high-dose groups (D40 and W280. After the short-term (1 month administration of TPDT, micro-CT, histomorphometry and three-dimensional second harmonic generation (3D-SHG imaging to visualize the bone collagen demonstrated that daily regimens but not weekly regimens were associated with the significant development of cortical porosity and endosteal naïve bone formation by marrow fibrosis. We concomitantly monitored the pharmacokinetics of the plasma teriparatide levels as well as the temporal changes in markers of bone formation and resorption. The analyses in the present study suggested that the daily repeated administration of teriparatide causes more deleterious changes in the cortical microarchitecture than the less frequent administration of higher doses. The findings of the present study may have some implications for use of teriparatide in clinical treatment.

  9. Comparison of interradicular distances and cortical bone thickness in Thai patients with class I and class II skeletal patterns using cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Khumsarn, Nattida [Dental Division of Lamphun Hospital, Lamphun (Thailand); Patanaporn, Virush; Janhom, Apirum; Jotikasthira, Dhirawat [Faculty of Dentistry, Chiang Mai University, Chiang Mai (Thailand)

    2016-06-15

    This study evaluated and compared interradicular distances and cortical bone thickness in Thai patients with Class I and Class II skeletal patterns, using cone-beam computed tomography (CBCT). Pretreatment CBCT images of 24 Thai orthodontic patients with Class I and Class II skeletal patterns were included in the study. Three measurements were chosen for investigation: the mesiodistal distance between the roots, the width of the buccolingual alveolar process, and buccal cortical bone thickness. All distances were recorded at five different levels from the cementoenamel junction (CEJ). Descriptive statistical analysis and t-tests were performed, with the significance level for all tests set at p<0.05. Patients with a Class II skeletal pattern showed significantly greater maxillary mesiodistal distances (between the first and second premolars) and widths of the buccolingual alveolar process (between the first and second molars) than Class I skeletal pattern patients at 10 mm above the CEJ. The maxillary buccal cortical bone thicknesses between the second premolar and first molar at 8 mm above the CEJ in Class II patients were likewise significantly greater than in Class I patients. Patients with a Class I skeletal pattern showed significantly wider mandibular buccolingual alveolar processes than did Class II patients (between the first and second molars) at 4, 6, and 8 mm below the CEJ. In both the maxilla and mandible, the mesiodistal distances, the width of the buccolingual alveolar process, and buccal cortical bone thickness tended to increase from the CEJ to the apex in both Class I and Class II skeletal patterns.

  10. The fracture toughness of small animal cortical bone measured using arc-shaped tension specimens: Effects of bisphosphonate and deproteinization treatments.

    Science.gov (United States)

    Hunckler, Michael D; Chu, Ethan D; Baumann, Andrew P; Curtis, Tyler E; Ravosa, Matthew J; Allen, Matthew R; Roeder, Ryan K

    2017-12-01

    Small animal models, and especially transgenic models, have become widespread in the study of bone mechanobiology and metabolic bone disease, but test methods for measuring fracture toughness on multiple replicates or at multiple locations within a single small animal bone are lacking. Therefore, the objective of this study was to develop a method to measure cortical bone fracture toughness in multiple specimens and locations along the diaphysis of small animal bones. Arc-shaped tension specimens were prepared from the mid-diaphysis of rabbit ulnae and loaded to failure to measure the radial fracture toughness in multiple replicates per bone. The test specimen dimensions, crack length, and maximum load met requirements for measuring the plane strain fracture toughness. Experimental groups included a control group, bisphosphonate treatment group, and an ex vivo deproteinization treatment following bisphosphonate treatment (5 rabbits/group and 15 specimens/group). The fracture toughness of ulnar cortical bone from rabbits treated with zoledronic acid for six months exhibited no difference compared with the control group. Partially deproteinized specimens exhibited significantly lower fracture toughness compared with both the control and bisphosphonate treatment groups. The deproteinization treatment increased tissue mineral density (TMD) and resulted in a negative linear correlation between the measured fracture toughness and TMD. Fracture toughness measurements were repeatable with a coefficient of variation of 12-16% within experimental groups. Retrospective power analysis of the control and deproteinization treatment groups indicated a minimum detectable difference of 0.1MPa·m 1/2 . Therefore, the overall results of this study suggest that arc-shaped tension specimens offer an advantageous new method for measuring the fracture toughness in small animal bones. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Decreased bone turnover with balanced resorption and formation prevent cortical bone loss during disuse (hibernation) in grizzly bears (Ursus arctos horribilis)

    OpenAIRE

    McGee, Meghan E.; Maki, Aaron J.; Johnson, Steven E.; Lynne Nelson, O.; Robbins, Charles T.; Donahue, Seth W.

    2007-01-01

    Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. ...

  12. Ratio between mature and immature enzymatic cross-links correlates with post-yield cortical bone behavior: An insight into greenstick fractures of the child fibula.

    Science.gov (United States)

    Berteau, Jean-Philippe; Gineyts, Evelyne; Pithioux, Martine; Baron, Cécile; Boivin, Georges; Lasaygues, Philippe; Chabrand, Patrick; Follet, Hélène

    2015-10-01

    As a determinant of skeletal fragility, the organic matrix is responsible for the post-yield and creep behavior of bone and for its toughness, while the mineral apatite acts on stiffness. Specific to the fibula and ulna in children, greenstick fractures show a plastic in vivo mechanical behavior before bone fracture. During growth, the immature form of collagen enzymatic cross-links gradually decreases, to be replaced by the mature form until adolescence, subsequently remaining constant throughout adult life. However, the link between the cortical bone organic matrix and greenstick fractures in children remains to be explored. Here, we sought to determine: 1) whether plastic bending fractures can occur in vitro, by testing cortical bone samples from children's fibula and 2) whether the post-yield behavior (ωp plastic energy) of cortical bone before fracture is related to total quantity of the collagen matrix, or to the quantity of mature and immature enzymatic cross-links and the quantity of non-enzymatic cross-links. We used a two-step approach; first, a 3-point microbending device tested 22 fibula machined bone samples from 7 children and 3 elderly adults until fracture. Second, biochemical analysis by HPLC was performed on the sample fragments. When pooling two groups of donors, children and elderly adults, results show a rank correlation between total energy dissipated before fracture and age and a linear correlation between plastic energy dissipated before fracture and ratio of immature/mature cross-links. A collagen matrix with more immature cross-links (i.e. a higher immature/mature cross-link ratio) is more likely to plastically deform before fracture. We conclude that this ratio in the sub-nanostructure of the organic matrix in cortical bone from the fibula may go some way towards explaining the variance in post-yield behavior. From a clinical point of view, therefore, our results provide a potential explanation of the presence of greenstick fractures in

  13. Identification of microcracks caused by autogenous shrinkage

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; Guang, Ye

    2005-01-01

    Detection and quantification of microcracks caused by restrained autogenous shrinkage in high-performance concrete is difficult. Available techniques either lack the required resolution or may cause further cracks indistinguishable from the original ones. The new technique presented in this paper...

  14. Autogenous Phenomena in Cement-Based Materials

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2005-01-01

    Denne afhandling er skrevet med henblik på opnåelse af den danske doktorgrad i teknik, dr.techn. Den vedrører autogene fænomener i cementbaserede materialer – primært deformation og ændring af den relative luftfugtighed (RF). I afhandlingen er det belyst, hvordan betydningen af disse fænomener bl...

  15. Autogenous Phenomena in Cement-Based Materials

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    Denne afhandling er skrevet med henblik på opnåelse af den danske doktorgrad i teknik, dr.techn. Den vedrører autogene fænomener i cementbaserede materialer – primært deformation og ændring af den relative luftfugtighed (RF). I afhandlingen er det belyst, hvordan betydningen af disse fænomener bl...

  16. MRI of the temporo-mandibular joint: which sequence is best suited to assess the cortical bone of the mandibular condyle? A cadaveric study using micro-CT as the standard of reference

    Energy Technology Data Exchange (ETDEWEB)

    Karlo, Christoph A. [University Hospital Zurich, Department of Diagnostic and Interventional Radiology, Zurich (Switzerland); University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); Patcas, Raphael; Signorelli, Luca; Mueller, Lukas [University of Zurich, Clinic for Orthodontics and Pediatric Dentistry, Center of Dental Medicine, Zurich (Switzerland); Kau, Thomas; Watzal, Helmut; Kellenberger, Christian J. [University Children' s Hospital Zurich, Department of Diagnostic Imaging, Zurich (Switzerland); Ullrich, Oliver [University of Zurich, Institute of Anatomy, Faculty of Medicine, Zurich (Switzerland); Luder, Hans-Ulrich [University of Zurich, Section of Orofacial Structures and Development, Center of Dental Medicine, Zurich (Switzerland)

    2012-07-15

    To determine the best suited sagittal MRI sequence out of a standard temporo-mandibular joint (TMJ) imaging protocol for the assessment of the cortical bone of the mandibular condyles of cadaveric specimens using micro-CT as the standard of reference. Sixteen TMJs in 8 human cadaveric heads (mean age, 81 years) were examined by MRI. Upon all sagittal sequences, two observers measured the cortical bone thickness (CBT) of the anterior, superior and posterior portions of the mandibular condyles (i.e. objective analysis), and assessed for the presence of cortical bone thinning, erosions or surface irregularities as well as subcortical bone cysts and anterior osteophytes (i.e. subjective analysis). Micro-CT of the condyles was performed to serve as the standard of reference for statistical analysis. Inter-observer agreements for objective (r = 0.83-0.99, P < 0.01) and subjective ({kappa} = 0.67-0.88) analyses were very good. Mean CBT measurements were most accurate, and cortical bone thinning, erosions, surface irregularities and subcortical bone cysts were best depicted on the 3D fast spoiled gradient echo recalled sequence (3D FSPGR). The most reliable MRI sequence to assess the cortical bone of the mandibular condyles on sagittal imaging planes is the 3D FSPGR sequence. (orig.)

  17. MRI of the temporo-mandibular joint: which sequence is best suited to assess the cortical bone of the mandibular condyle? A cadaveric study using micro-CT as the standard of reference

    International Nuclear Information System (INIS)

    Karlo, Christoph A.; Patcas, Raphael; Signorelli, Luca; Mueller, Lukas; Kau, Thomas; Watzal, Helmut; Kellenberger, Christian J.; Ullrich, Oliver; Luder, Hans-Ulrich

    2012-01-01

    To determine the best suited sagittal MRI sequence out of a standard temporo-mandibular joint (TMJ) imaging protocol for the assessment of the cortical bone of the mandibular condyles of cadaveric specimens using micro-CT as the standard of reference. Sixteen TMJs in 8 human cadaveric heads (mean age, 81 years) were examined by MRI. Upon all sagittal sequences, two observers measured the cortical bone thickness (CBT) of the anterior, superior and posterior portions of the mandibular condyles (i.e. objective analysis), and assessed for the presence of cortical bone thinning, erosions or surface irregularities as well as subcortical bone cysts and anterior osteophytes (i.e. subjective analysis). Micro-CT of the condyles was performed to serve as the standard of reference for statistical analysis. Inter-observer agreements for objective (r = 0.83-0.99, P < 0.01) and subjective (κ = 0.67-0.88) analyses were very good. Mean CBT measurements were most accurate, and cortical bone thinning, erosions, surface irregularities and subcortical bone cysts were best depicted on the 3D fast spoiled gradient echo recalled sequence (3D FSPGR). The most reliable MRI sequence to assess the cortical bone of the mandibular condyles on sagittal imaging planes is the 3D FSPGR sequence. (orig.)

  18. A biomechanical comparison of headless tapered variable pitch and AO cortical bone screws for fixation of a simulated slab fracture in equine third carpal bones.

    Science.gov (United States)

    Bueno, Aloisio C D; Galuppo, Larry D; Taylor, Kenneth T; Jensen, David G; Stover, Susan M

    2003-01-01

    To compare the mechanical shear strengths and stiffnesses obtained from in vitro testing of a simulated complete third carpal bone (C3) frontal plane radial facet slab fracture (osteotomy) stabilized with either a 4/5 Acutrak (AT) compression screw or a 4.5-mm AO cortical bone (AO) screw inserted in lag fashion. Drilling, tapping, and screw insertion torques, forces, and times also were compared between AT and AO implants. In vitro biomechanical assessment of site preparation, screw insertion, and shear failure test variables of bone screw stabilized simulated C3 slab fracture in paired cadaveric equine carpi. Eight pairs of cadaveric equine C3 without orthopedic abnormalities. Standardized simulated C3 slab fractures were repaired with either AO or AT screws (AO/C3 and AT/C3 groups, respectively). Drilling, tapping, and screw insertion torques, forces, and times were measured with a materials testing machine for each screw type. Repaired specimens were tested in axially oriented shear until failure. Paired Students t-tests were used to assess differences between site preparation, screw insertion, and shear testing variables. Significance was set at P bone fragment measurements of the standardized simulated C3 slab fractures created for AO or AT screws. There were no significant differences for mean and maximum drilling torques; however, the tapered AT drill had greater maximum drilling force compared with the 3.2-mm and 4.5-mm AO drill bits. Mean insertion torque and force measured from the self-tapping AT screw were not significantly different compared with the 4.5-mm AO tap. There were no significant differences in maximum screw torque among constructs. Total procedure time was significantly longer for the AT group (5.8 +/- 1.6 minutes) compared with the AO group (2.9 +/- 1.1 minutes; P =.001). AT stabilized specimens had significantly greater mean +/- SD initial shear stiffness (3.64 +/- 1.08 kN/mm) than AO specimens (1.64 +/- 0.73 kN/mm; P =.005). All other

  19. Results of screw fixation combined with cortical drilling for treatment of dorsal cortical stress fractures of the third metacarpal bone in 56 Thoroughbred racehorses

    International Nuclear Information System (INIS)

    Dallap, B.L.; Bramlage, L.R.; Embertson, R.M.

    1999-01-01

    The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty-six Thoroughbred racehorses were treated surgically for stress fracture of MCIII with screw fixation and cortical drilling. Stress fractures occurred primarily in the left front limb of the male 3-year-olds, in the dorsolateral cortex of the middle third of MCIII. Ninety-seven percent of the fractures travelled in a dorsodistal to palmaroproximal direction. Median period to screw removal was 2.0 months. Evaluation at time of screw removal revealed 98% of single stress fractures of the left front limb were healed radiographically. Median period to resume training was 2.75 months (single stress fractures); median period to race was 7.62 months. There was no statistically significant difference in earnings/start before and after surgical intervention. Of the 63 fractures treated, two recurred. There were no catastrophic failures, and no incisional infections

  20. USO DO ENXERTO ÓSSEO CORTICAL BOVINO CONSERVADO EM GLICERINA A 98% NA OSTEOTOMIA FEMORAL EM GATOS USE BOVINE CORTICAL BONE, PRESERVED IN 98% GLICERIN IN FEMORAL OSTEOTOMY IN CATS.

    Directory of Open Access Journals (Sweden)

    Lucia Helena de Carvalho Penha

    2008-12-01

    . The objective of this study was to evaluate clinically and radiographically the efficacy of xenografts as a substitute for methalic implants. Animals were divided into two groups: five young cats and five adult cats. Clinically, the weight-bearing on the operated limb was observed the day after surgery in all animals, with complete remission of lameness at 15 days and bone union in 16.6 weeks. In five young animals, in two of them, the grafts were fractured carrying a serious bone bending without fracture of feline femur. In the last two young cats, remodeling was noted in mean time of 75 days or 10.7 weeks. In five adult cats, all of them suffered overriding of the fragments of osteotomized bone with various degrees, where two cases were considered severe cases dut to fracture of feline femur without bone bending. In the three remaining animals with slightly overriding, one was a case of delayed union, one suffered tow surgical procedures due to graft fracture and one did not show a radiographic exuberant bone callus, with remodeling at 110 days. The use of the bonive xenograft preserved in 98% glycerol in young and adult cats used as intramedularry nails was perfectly employed, offering mechanical support in time of bone consolidation in all of 10 animals.

    KEY WORDS: Cortical bovine graft, cats, femur, fracture, osteotomy.

  1. Regenerative capacity of augmented bone in rat calvarial guided bone augmentation model.

    Science.gov (United States)

    Kubota, Tatsuya; Hasuike, Akira; Ozawa, Yasumasa; Yamamoto, Takanobu; Tsunori, Katsuyoshi; Yamada, Yutaka; Sato, Shuichi

    2017-04-01

    Guided bone regeneration (GBR) is the most widely used technique to regenerate and augment bones. Even though augmented bones (ABs) have been examined histologically in many studies, few studies have been conducted to examine the biological potential of these bones and the healing dynamics following their use. Moreover, whether the bone obtained from the GBR procedure possesses the same functions as the existing autogenous bone is uncertain. In particular, little attention has been paid to the regenerative ability of GBR bone. Therefore, the present study histologically evaluated the regenerative capacity of AB in the occlusive space of a rat guided bone augmentation (GBA) model. The calvaria of 30 rats were exposed, and plastic caps were placed on the right of the calvaria in 10 of the 30 rats. After a 12-week healing phase, critical-sized calvarial bone defects (diameter: 5.0 mm) were trephined into the dorsal parietal bone on the left of the calvaria. Bone particles were harvested from the AB or the cortical bone (CB) using a bone scraper and transplanted into the critical defects. The newly generated bone at the defects' edge was evaluated using micro-computed tomography (micro-CT) and histological sections. In the micro-CT analysis, the radiopacity in both the augmented and the CB groups remained high throughout the observational period. In the histological analysis, the closure rate of the CB was significantly higher than in the AB group. The numbers of cells positive for runt-related transcription factor 2 (Runx2) and tartrate-resistant acid phosphatase (TRAP) in the AB group were larger than in the CB group. The regenerative capacity of AB in the occlusive space of the rat GBA model was confirmed. Within the limitations of this study, the regenerative ability of the AB particulate transplant was inferior to that of the CB particulate transplant.

  2. Hard and Soft Tissue Management of a Localized Alveolar Ridge Atrophy with Autogenous Sources and Biomaterials: A Challenging Clinical Case

    Directory of Open Access Journals (Sweden)

    C. Maiorana

    2016-01-01

    Full Text Available Particularly in the premaxillary area, the stability of hard and soft tissues plays a pivotal role in the success of the rehabilitation from both a functional and aesthetic aspect. The present case report describes the clinical management of a localized alveolar ridge atrophy in the area of the upper right canine associated with a thin gingival biotype with a lack of keratinized tissue. An autogenous bone block harvested from the chin associated with heterologous bone particles was used to replace the missing bone, allowing for a prosthetic driven implant placement. Soft tissues deficiency was corrected by means of a combined epithelialized and subepithelial connective tissue graft. The 3-year clinical and radiological follow-up demonstrated symmetric gingival levels of the upper canines, with physiological peri-implant probing depths and bone loss. Thus, the use of autogenous tissues combined with biomaterials might be considered a reliable technique in case of highly aesthetic demanding cases.

  3. Uso de enxerto ósseo homólogo estrutural cortical em cirurgias de reconstrução femoral Use of cortical structural homologous bone graft in femoral reconstructive surgery

    Directory of Open Access Journals (Sweden)

    Milton Valdomiro Roos

    2010-01-01

    periprotéticas é uma boa opção de tratamento em casos selecionados, permitindo resultados clínicos e radiográficos satisfatórios.OBJECTIVE: To perform a clinical and radiographic assessment of patients submitted to cortical structural homologous bone graftsurgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty and periprosthetic fractures. METHODS: A retrospective study with 27 patients submitted to surgical treatment for femoral reconstruction following mechanical failure of total hip arthroplasty (12 cases and periprosthetic fractures (15 cases, using cortical structural homologous bone graft and cemented implants, in the period of June 1999 to February 2008 was performed. Of these, 21 fulfilled the criteria required for this study. Patients were submitted to a pre and postoperative clinical assessment according to Harris Hip Score. Pre-operative, immediate and late postoperative radiographs were also evaluated by comparing fracture consolidation, radiographic signs of graft integration, changes in bone stock and femoral bone quality, as well as femoral alignment. RESULTS: Nine patients (42.9% were submitted to femoral reconstruction following mechanical failure of total hip arthroplasty. The other 12 cases (57.1%, were submitted to femoral reconstruction following periprosthetic fracture. Results were considered satisfactory in 85.7% and unsatisfactory in 14.3% of cases. Radiographic signs of graft integration to the host's bone were seen in all cases. There was an increase of bone stock in 90.5% of hip reconstructions, according to cortical index measurement. Furthermore, changes in femoral bone quality were considered good in 66.7% of cases. CONCLUSION: The use of cortical structural homologous bone grafts for both femoral reconstructive surgeries of total hip arthroplasty and periprosthetic fractures is a good treatment option for selected cases, allowing for satisfactory clinical and radiographic results.

  4. The Influence of High-Impact Exercise on Cortical and Trabecular Bone Mineral Content and 3D Distribution Across the Proximal Femur in Older Men: A Randomized Controlled Unilateral Intervention.

    Science.gov (United States)

    Allison, Sarah J; Poole, Kenneth E S; Treece, Graham M; Gee, Andrew H; Tonkin, Carol; Rennie, Winston J; Folland, Jonathan P; Summers, Gregory D; Brooke-Wavell, Katherine

    2015-09-01

    Regular exercisers have lower fracture risk, despite modest effects of exercise on bone mineral content (BMC). Exercise may produce localized cortical and trabecular bone changes that affect bone strength independently of BMC. We previously demonstrated that brief, daily unilateral hopping exercises increased femoral neck BMC in the exercise leg versus the control leg of older men. This study evaluated the effects of these exercises on cortical and trabecular bone and its 3D distribution across the proximal femur, using clinical CT. Fifty healthy men had pelvic CT scans before and after the exercise intervention. We used hip QCT analysis to quantify BMC in traditional regions of interest and estimate biomechanical variables. Cortical bone mapping localized cortical mass surface density and endocortical trabecular density changes across each proximal femur, which involved registration to a canonical proximal femur model. Following statistical parametric mapping, we visualized and quantified statistically significant changes of variables over time in both legs, and significant differences between legs. Thirty-four men aged mean (SD) 70 (4) years exercised for 12-months, attending 92% of prescribed sessions. In traditional regions of interest, cortical and trabecular BMC increased over time in both legs. Cortical BMC at the trochanter increased more in the exercise than control leg, whereas femoral neck buckling ratio declined more in the exercise than control leg. Across the entire proximal femur, cortical mass surface density increased significantly with exercise (2.7%; p 6%) at anterior and posterior aspects of the femoral neck and anterior shaft. Endocortical trabecular density also increased (6.4%; p 12% at the anterior femoral neck, trochanter, and inferior femoral head. Odd impact exercise increased cortical mass surface density and endocortical trabecular density, at regions that may be important to structural integrity. These exercise-induced changes were

  5. Hard and Soft Tissue Management of a Localized Alveolar Ridge Atrophy with Autogenous Sources and Biomaterials: A Challenging Clinical Case

    OpenAIRE

    C. Maiorana; D. Andreoni; P. P. Poli

    2016-01-01

    Particularly in the premaxillary area, the stability of hard and soft tissues plays a pivotal role in the success of the rehabilitation from both a functional and aesthetic aspect. The present case report describes the clinical management of a localized alveolar ridge atrophy in the area of the upper right canine associated with a thin gingival biotype with a lack of keratinized tissue. An autogenous bone block harvested from the chin associated with heterologous bone particles was used to re...

  6. Avaliação radiográfica da absorção de parafusos de osso cortical bovino com bone morphogenetic protein (BMP inseridos em úmero de cão

    Directory of Open Access Journals (Sweden)

    Cássio Ricardo Auada Ferrigno

    2005-02-01

    Full Text Available Allografts are produced from natural sources and have been used in orthopedic repair procedures for a long time in humans and animals. Since 1952, hundreds of orthopedic surgeries have been performed with success using donated tissues and materials from bone banks. The purpose of the present study was to verify the absorption time of xenografts screws made of bovine cortical bone, inserted in the greater tubercule. The humerus of seven dogs in comparison with stainless steel screws. The results showed that screws made from bovine cortical bone used in the humerus of dogs were incorporated within a period of 30 to 60 days with no severe periosteum reaction.

  7. Textural versus electrostatic exclusion-enrichment effects in the effective chemical transport within the cortical bone: a numerical investigation.

    Science.gov (United States)

    Lemaire, T; Kaiser, J; Naili, S; Sansalone, V

    2013-11-01

    Interstitial fluid within bone tissue is known to govern the remodelling signals' expression. Bone fluid flow is generated by skeleton deformation during the daily activities. Due to the presence of charged surfaces in the bone porous matrix, the electrochemical phenomena occurring in the vicinity of mechanosensitive bone cells, the osteocytes, are key elements in the cellular communication. In this study, a multiscale model of interstitial fluid transport within bone tissues is proposed. Based on an asymptotic homogenization method, our modelling takes into account the physicochemical properties of bone tissue. Thanks to this multiphysical approach, the transport of nutrients and waste between the blood vessels and the bone cells can be quantified to better understand the mechanotransduction of bone remodelling. In particular, it is shown that the electrochemical tortuosity may have stronger implications in the mass transport within the bone than the purely morphological one. Copyright © 2013 John Wiley & Sons, Ltd.

  8. Histomorphometric Assessment of Cancellous and Cortical Bone Material Distribution in the Proximal Humerus of Normal and Osteoporotic Individuals: Significantly Reduced Bone Stock in the Metaphyseal and Subcapital Regions of Osteoporotic Individuals.

    Science.gov (United States)

    Sprecher, Christoph M; Schmidutz, Florian; Helfen, Tobias; Richards, R Geoff; Blauth, Michael; Milz, Stefan

    2015-12-01

    Osteoporosis is a systemic disorder predominantly affecting postmenopausal women but also men at an advanced age. Both genders may suffer from low-energy fractures of, for example, the proximal humerus when reduction of the bone stock or/and quality has occurred.The aim of the current study was to compare the amount of bone in typical fracture zones of the proximal humerus in osteoporotic and non-osteoporotic individuals.The amount of bone in the proximal humerus was determined histomorphometrically in frontal plane sections. The donor bones were allocated to normal and osteoporotic groups using the T-score from distal radius DXA measurements of the same extremities. The T-score evaluation was done according to WHO criteria. Regional thickness of the subchondral plate and the metaphyseal cortical bone were measured using interactive image analysis.At all measured locations the amount of cancellous bone was significantly lower in individuals from the osteoporotic group compared to the non-osteoporotic one. The osteoporotic group showed more significant differences between regions of the same bone than the non-osteoporotic group. In both groups the subchondral cancellous bone and the subchondral plate were least affected by bone loss. In contrast, the medial metaphyseal region in the osteoporotic group exhibited higher bone loss in comparison to the lateral side.This observation may explain prevailing fracture patterns, which frequently involve compression fractures and certainly has an influence on the stability of implants placed in this medial region. It should be considered when planning the anchoring of osteosynthesis materials in osteoporotic patients with fractures of the proximal humerus.

  9. Bone grafting options in children.

    Science.gov (United States)

    Betz, Randal R; Lavelle, William F; Samdani, Amer F

    2010-08-01

    Retrospective review of the literature. To review the current literature as well as recent trends in bone grafting techniques available for children. The currently accepted gold standard in bone grafting for adolescent idiopathic scoliosis (AIS) is autogenous iliac crest. Due to questions concerning complications such as donor site pain, other options have been explored, including various allograft sources, demineralized bone matrix, and bone morphogenetic protein. A review of the current medical literature was completed and additional case examples are presented. A review of the literature reveals that up to 31% of patients have persistent pain at 2 years post surgery when autogenous iliac crest bone graft is harvested. Allograft supplementation of local autograft has been demonstrated in the literature to be as effective as autogenous iliac crest bone grafting in contributing to a successful posterior spinal fusion in patients with AIS. Modern demineralized bone matrix formulations have been found in both animal models as well as in a recent retrospective clinical review to contribute to a successful posterior spinal fusion in AIS. Bone morphogenetic protein has been shown to contribute to a successful posterior spinal fusion in complex pediatric spinal deformity patients. At 2 years follow-up, patients who underwent a posterior instrumented spinal fusion that was not augmented with any bone graft appear to have successful spinal fusions. Although autogenous iliac bone graft remains the benchmark to which bone grafting materials are compared, other options including the placement of no bone graft at all provides similar fusion rates in patients with AIS.

  10. Assessment of bone repair in critical-size defect in the calvarium of rats after the implantation of tricalcium phosphate beta (β-TCP).

    Science.gov (United States)

    de Freitas Silva, Leonardo; de Carvalho Reis, Erik Neiva Ribeiro; Barbara, Tânia Aparecida; Bonardi, João Paulo; Garcia, Idelmo Rangel; de Carvalho, Paulo Sérgio Perri; Ponzoni, Daniela

    2017-07-01

    Evaluating the osteoconductive property of tricalcium phosphate beta (β-TCP) in comparison to that of inorganic bovine bone for repair in a critical-size defect in the rat calvarium. Critical-size defects of 7mm were made with a trephine in the calvaria of 48 Wistar rats. The animals were divided into four groups, and the defects in each group were filled with tricalcium phosphate beta (β-TCP), inorganic bovine bone (Bio-Oss), autogenous bone, or left empty. The animals were euthanized at two different time points (30 and 60days post-operation). All defects were recovered with a absorbable membrane of bovine cortical bone. Histological, histometric, and immunohistochemical (osteocalcin) assessments were carried out at 30 and 60days post-operation. At 30days post-operation, all groups showed areas of bone formation, predominantly when autogenous grafts were used. However, there were no statistically significant differences between the treatment groups (p>0.05). After 60days, there were similarities in the bone formation patterns between the β-TCP (26.32±) and Bio-Oss (17.35±) groups (p=0.549). In terms of the immunohistochemical assessment of osteocalcin, the clot group showed light to moderate staining at 30 and 60days. The autogenous group showed moderate staining at 30days and moderate to intense staining after 60days. The Bio-Oss group showed light to moderate staining after 30days and intense staining at 60days. The β-TCP group showed moderate staining at 30 and 60days post-operation. β-TCP is a good osteoconductive material with similar effects to those of inorganic bovine bone graft and is suitable for utilization in the repair of bone defects. Copyright © 2017 Elsevier GmbH. All rights reserved.

  11. Raman spectral markers of collagen denaturation and hydration in human cortical bone tissue are affected by radiation sterilization and high cycle fatigue damage.

    Science.gov (United States)

    Flanagan, Christopher D; Unal, Mustafa; Akkus, Ozan; Rimnac, Clare M

    2017-11-01

    Thermal denaturation and monotonic mechanical damage alter the organic and water-related compartments of cortical bone. These changes can be detected using Raman spectroscopy. However, less is known regarding Raman sensitivity to detect the effects of cyclic fatigue damage and allograft sterilization doses of gamma radiation. To determine if Raman spectroscopic biomarkers of collagen denaturation and hydration are sensitive to the effects of (a) high cycle fatigue damage and (b) 25kGy irradiation. Unirradiated and gamma-radiation sterilized human cortical bone specimens previously tested in vitro under high-cycle (> 100,000 cycles) fatigue conditions at 15MPa, 25MPa, 35MPa, 45MPa, and 55MPa cyclic stress levels were studied. Cortical bone Raman spectral profiles from wavenumber ranges of 800-1750cm -1 and 2700-3800cm -1 were obtained and compared from: a) non-fatigue vs fatigue fracture sites and b) radiated vs. unirradiated states. Raman biomarker ratios 1670/1640 and 3220/2949, which reflect collagen denaturation and organic matrix (mainly collagen)-bound water, respectively, were assessed. One- and two-way ANOVA analyses were utilized to identify differences between groups along with interaction effects between cyclic fatigue and radiation-induced damage. Cyclic fatigue damage resulted in increases in collagen denaturation (1670/1640: 1.517 ± 0.043 vs 1.579 ± 0.021, p collagen denaturation (r = 0.514, p collagen)-bound water. A Raman measure of collagen denaturation was sensitive to cyclic fatigue damage but not 25kGy irradiation. Collagen denaturation was correlated with organic matrix-bound water, suggesting that denaturation of collagen to gelatinous form may expose more binding sites to water by unwinding the triple alpha chains. This research may eventually be useful to help identify allograft quality and more appropriately match donors to recipients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Location of the Mandibular Canal and Thickness of the Occlusal Cortical Bone at Dental Implant Sites in the Lower Second Premolar and First Molar

    OpenAIRE

    Hsu, Jui-Ting; Huang, Heng-Li; Fuh, Lih-Jyh; Li, Rou-Wei; Wu, Jay; Tsai, Ming-Tzu; Shen, Yen-Wen; Tu, Ming-Gene

    2013-01-01

    The objective of this study was to evaluate the location of the mandibular canal and the thickness of the occlusal cortical bone at dental implant sites in the lower second premolar and lower first molar by using dental cone-beam computed tomography (CBCT). Seventy-nine sites (47 second premolar and 32 first molar sites) were identified in the dental CBCT examinations of 47 patients. In this study, 4 parameters were measured: (1) MC?the distance from the mandibular canal to the upper border o...

  13. Age-related changes in collagen properties and mineralization in cancellous and cortical bone in the porcine mandibular condyle

    NARCIS (Netherlands)

    Willems, N.M.B.K.; Langenbach, G.E.J.; Everts, V.; Mulder, L.; Grünheid, T.; Bank, R.A.; Zentner, A.; Eijden, T.M.G.J. van

    2010-01-01

    Collagen is an important constituent of bone, and it has been suggested that changes in collagen and mineral properties of bone are interrelated during growth. The aim of this study was to quantify age-related changes in collagen properties and the degree of mineralization of bone (DMB). The DMB in

  14. Autologous grafts of double-strut fibular cortical bone plate to treat the fractures and defects of distal femur: a case report and review of literature

    Directory of Open Access Journals (Sweden)

    CHEN Xu

    2012-02-01

    Full Text Available 【Abstract】We reported a 23-year-old man who was involved in a high-speed motorcycle accident. He sustained a closed fracture at the right distal femur. The primary fracture happened on February 2008. He underwent open reduction and internal fixation with cloverleaf plate. And one hundred days after the surgery, the proximal screws were pulled-out, but the bone union was not achieved. Treatment consisted of exchanging the cloverleaf plate with a locking compression plate and using an auto-iliac bone graft to fill the nonunion gap. In July 2009, the patient had a sharp pain in the right lower limb. The X-ray revealed that the plate implanted last year was broken, causing a nonunion at the fracture site. Immediately the plate and screws were removed and an intramedullary nail was inserted reversely from the distal femur as well as a 7 cm long bone from the right fibula was extracted and longitudinally split into two pieces to construct cortical bone plates. Then we placed them laterally and medially to fracture site, drilled two holes respectively, and fastened them with suture. We carried on auto-iliac bone grafting with the nonunion bone grafts. The follow-up at 15 months after operation showed that the treatment was successful, X-ray confirmed that there was no rotation and no angular or short deformity. We briefly reviewed the literature regarding such an unusual presentation and discussed in details the possible etiology and the advantages of autologous double-strut fibular grafts to cope with such an intractable situation. Key words: Femur; Transplantation, autologous; Bone screws

  15. A new implementation of digital X-ray radiogrammetry and reference curves of four indices of cortical bone for healthy European adults

    DEFF Research Database (Denmark)

    Thodberg, Hans Henrik; Böttcher, Joachim; Lomholt, Jens

    2016-01-01

    . PURPOSE: The digital X-ray radiogrammetry (DXR) method has been shown to be efficient for diagnosis of osteoporosis and for assessment of progression of rheumatoid arthritis. The aim of this work is to present a new DXR implementation and reference curves of four indices of cortical bone and to compare...... their relative SDs in healthy subjects at fixed age and gender. MATERIALS AND METHODS: A total of 1662 hand radiographs of healthy subjects of age 9-100 years were collected in Jena in 2001-2005. We also used a longitudinal study of 116 Danish children born in 1952 with on average 11 images taken over the age...... range 7 to 40 years. The new DXR method reconstructs the whole metacarpal contour so that the metacarpal lengths can be measured and used in two of the indices. The new DXR method automatically validates 97 % of the images and is implemented as a local server for PACS users. RESULTS: The Danish bone...

  16. Elastic-plastic fracture toughness and rising JR-curve behavior of cortical bone is partially protected from irradiation-sterilization-induced degradation by ribose protectant.

    Science.gov (United States)

    Woodside, Mitchell; Willett, Thomas L

    2016-12-01

    This study tested the hypothesis that pre-treating cortical bone with ribose would protect the rising fracture resistance curve behavior and crack initiation fracture toughness of both bovine and human cortical bone from the degrading effects of γ-irradiation sterilization. A ribose pre-treatment (1.8 M for bovine, and 1.2 M for human, in PBS at 60 °C for 24 h) was applied to single-edge notched bending fracture specimens prior to sterilization with a 33 kGy dose of γ-irradiation. Fracture resistance curves were generated with a single specimen method using an optical crack length measurement technique. The effect of the treatment on overall fracture resistance behavior, crack initiation fracture toughness, and tearing modulus was compared with non-irradiated and conventionally irradiation sterilized controls. Hydrothermal isometric tension testing was used to examine collagen network connectivity and thermal stability to explore relationships between collagen network quality and fracture resistance. The ribose pre-treatment successfully protected the crack growth initiation fracture toughness of bovine and human bone by 32% and 63%, respectively. The rising JR-curve behavior was also partially protected. Furthermore, collagen connectivity and thermal stability followed similar patterns to those displayed by fracture toughness. This paper demonstrates that the fracture toughness of irradiation-sterilized bone tissue can be partially protected with a ribose pre-treatment. This new approach shows potential for the production and clinical application of sterilized allografts with improved mechanical performance and durability. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Autogenous Deformation and Change of the Relative Humidity in Silica Fume-Modified Cement Paste

    DEFF Research Database (Denmark)

    Jensen, Ole mejlhede; Hansen, Per Freiesleben

    1996-01-01

    Even during sealed curing and at a constant temperature a hardening cement paste will deform and the relative humidity within its pores will lower. This autogenous deformation and autogenous relative humidity change may be so significant that the cement paste cracks if the deformation is restrained....... This article focuses on the influence of silica fume addition on autogenous deformation and autogenous relative humidity change. Continuous measurement of autogenous deformation and autogenous relative humidity change for more than 1 year and 1« years, respectively, was performed. The investigations show...... thatsilica fume addition markedly increases the autogenous shrinkage as well as the autogenous relative humidity change....

  18. Location of the Mandibular Canal and Thickness of the Occlusal Cortical Bone at Dental Implant Sites in the Lower Second Premolar and First Molar

    Directory of Open Access Journals (Sweden)

    Jui-Ting Hsu

    2013-01-01

    Full Text Available The objective of this study was to evaluate the location of the mandibular canal and the thickness of the occlusal cortical bone at dental implant sites in the lower second premolar and lower first molar by using dental cone-beam computed tomography (CBCT. Seventy-nine sites (47 second premolar and 32 first molar sites were identified in the dental CBCT examinations of 47 patients. In this study, 4 parameters were measured: (1 MC—the distance from the mandibular canal to the upper border of the mandible; (2 CD—the distance from the mandibular canal to the buccal border of the mandible; (3 MD—the distance from the mandibular canal to the lingual border of the mandible; (4 TC—the thickness of the cortical bone at the occlusal side. A statistical analysis was employed to compare the size and differences between these 4 parameters at the lower second premolar and lower first molar. Regarding the MC and MD, the experimental results showed no statistical difference between the first molar and second premolar. However, the TC for the second premolar was greater than that of the first molar. Thus, careful consideration is necessary in choosing the size of and operation type for dental implants.

  19. Intrinsic mechanical behavior of femoral cortical bone in young, osteoporotic and bisphosphonate-treated individuals in low- and high energy fracture conditions

    Science.gov (United States)

    Zimmermann, Elizabeth A.; Schaible, Eric; Gludovatz, Bernd; Schmidt, Felix N.; Riedel, Christoph; Krause, Matthias; Vettorazzi, Eik; Acevedo, Claire; Hahn, Michael; Püschel, Klaus; Tang, Simon; Amling, Michael; Ritchie, Robert O.; Busse, Björn

    2016-02-01

    Bisphosphonates are a common treatment to reduce osteoporotic fractures. This treatment induces osseous structural and compositional changes accompanied by positive effects on osteoblasts and osteocytes. Here, we test the hypothesis that restored osseous cell behavior, which resembles characteristics of younger, healthy cortical bone, leads to improved bone quality. Microarchitecture and mechanical properties of young, treatment-naïve osteoporosis, and bisphosphonate-treated cases were investigated in femoral cortices. Tissue strength was measured using three-point bending. Collagen fibril-level deformation was assessed in non-traumatic and traumatic fracture states using synchrotron small-angle x-ray scattering (SAXS) at low and high strain rates. The lower modulus, strength and fibril deformation measured at low strain rates reflects susceptibility for osteoporotic low-energy fragility fractures. Independent of age, disease and treatment status, SAXS revealed reduced fibril plasticity at high strain rates, characteristic of traumatic fracture. The significantly reduced mechanical integrity in osteoporosis may originate from porosity and alterations to the intra/extrafibrillar structure, while the fibril deformation under treatment indicates improved nano-scale characteristics. In conclusion, losses in strength and fibril deformation at low strain rates correlate with the occurrence of fragility fractures in osteoporosis, while improvements in structural and mechanical properties following bisphosphonate treatment may foster resistance to fracture during physiological strain rates.

  20. Autogenic training as a therapy for adjustment disorder in adolescents

    Directory of Open Access Journals (Sweden)

    Jojić Boris R.

    2005-01-01

    Full Text Available INTRODUCTION Autogenic training is a widespread technique used in psychotherapy. The British school of autogenic training cites a large list of diseases, health states, and life changes, in which autogenic training can be of help. We wanted to explore the application of autogenic training as a therapy for adjustment disorder in adolescents. The sample consisted of a homogeneous group of 31 individuals, with an average age of 17.3±0.2 years, who were diagnosed with adjustment disorder, F 43.2, in accordance with ICD 10 search criteria. OBJECTIVE The aim of our work was to figure out the influence of autogenic training on adjustment disorder, through biophysical and biochemical indicators, and to research the efficacy of autogenic training as a therapy for adjustment disorder in adolescents. METHOD We observed adjustment disorder indicators and their changes in three phases, using initial, final, and control values, which we measured immediately before the beginning, immediately after the completion, and six months after the completion, of the practical course in autogenic training. We measured systolic and diastolic arterial blood pressure, brachial pulse rates, cortisol levels in plasma, cholesterol levels in blood, as well as glucose concentrations. During that period, autogenic training was employed as the sole therapy. RESULTS The study confirmed our preliminary assumptions. The measurements we performed showed that arterial blood pressure, pulse rates, cholesterol and cortisol concentrations, after the application of autogenic training among adolescents suffering from adjustment disorder, were lower than the initial values. They remained lower even six months after the completion of the practical course in autogenic training. CONCLUSION We concluded that autogenic training significantly decreases the values of physiological indicators of adjustment disorder, diminishes the effects of stress in an individual, and eases the adaptation of

  1. In Situ Mechanical Behavior of Mineral Crystals in Human Cortical Bone under Compressive Load Using Synchrotron X-Ray Scattering Techniques

    Science.gov (United States)

    Giri, Bijay; Almer, Jon D.; Dong, X. Neil; Wang, Xiaodu

    2012-01-01

    Mineral crystals, the major strength-bearing component of bone, are aligned in longitudinal bone with (00l) axes preferentially along the longitudinal axis, which in concert with crystal anisotropy leads to macroscopic anisotropy in mechanical behavior. Thus, it is of great interest to delineate the contributions of different subsets of mineral crystals as a function of orientation, on the bulk mechanical behavior of bone. Using a unique synergistic approach combining a progressive loading scheme and synchrotron X-ray scattering techniques, human cortical bone specimens were loaded in compression to examine the in situ mechanical behavior of mineral crystals as the function of orientation. The orientation distribution of mineral crystals was quantitatively estimated by measuring the X-ray diffraction intensity from the crystallographic (002) plane in different orientations. In addition, the average longitudinal (c-axis), transverse (a-axis), and shear strains of the subset of mineral crystals aligned in each orientation were determined by measuring the lattice deformation in the crystals normal to three distinct crystallographic planes (i.e. 002, 310, and 213). The experimental results indicated that the in situ strain and stress of mineral crystals varied with orientation. The normal strain and stress exerted on the longitudinally aligned mineral crystals were markedly greater than those on the transversely oriented crystals, whereas the shear stress reached a maximum for the crystals aligned in ±30° with respect to the loading direction, which coincided with the long axis of bone. The maximum principal strain and stress were observed in the mineral crystals oriented along the loading axis, with a similar trend observed in the maximum shear strain and stress. By examining their in situ behavior, the contribution of mineral crystals to load bearing and the bulk behavior of bone are discussed. PMID:22982959

  2. Investigation, sensitivity analysis, and multi-objective optimization of effective parameters on temperature and force in robotic drilling cortical bone.

    Science.gov (United States)

    Tahmasbi, Vahid; Ghoreishi, Majid; Zolfaghari, Mojtaba

    2017-11-01

    The bone drilling process is very prominent in orthopedic surgeries and in the repair of bone fractures. It is also very common in dentistry and bone sampling operations. Due to the complexity of bone and the sensitivity of the process, bone drilling is one of the most important and sensitive processes in biomedical engineering. Orthopedic surgeries can be improved using robotic systems and mechatronic tools. The most crucial problem during drilling is an unwanted increase in process temperature (higher than 47 °C), which causes thermal osteonecrosis or cell death and local burning of the bone tissue. Moreover, imposing higher forces to the bone may lead to breaking or cracking and consequently cause serious damage. In this study, a mathematical second-order linear regression model as a function of tool drilling speed, feed rate, tool diameter, and their effective interactions is introduced to predict temperature and force during the bone drilling process. This model can determine the maximum speed of surgery that remains within an acceptable temperature range. Moreover, for the first time, using designed experiments, the bone drilling process was modeled, and the drilling speed, feed rate, and tool diameter were optimized. Then, using response surface methodology and applying a multi-objective optimization, drilling force was minimized to sustain an acceptable temperature range without damaging the bone or the surrounding tissue. In addition, for the first time, Sobol statistical sensitivity analysis is used to ascertain the effect of process input parameters on process temperature and force. The results show that among all effective input parameters, tool rotational speed, feed rate, and tool diameter have the highest influence on process temperature and force, respectively. The behavior of each output parameters with variation in each input parameter is further investigated. Finally, a multi-objective optimization has been performed considering all the

  3. The application of heat-deproteinization to the morphological study of cortical bone: A contribution to the knowledge of the osteonal structure.

    Science.gov (United States)

    Pazzaglia, Ugo E; Congiu, Terenzio; Basso, Petra; Alessandri, Ivano; Cucca, Lucia; Raspanti, Mario

    2016-08-01

    Observation of heat-deproteinized cortical bone specimens in incident light enabled the high definition documentation of the osteonal pattern of diaphyseal Haversian bone. This prompted a study to compare these images with those revealed by polarized light microscopy, carried out either on decalcified or thin, undecalcified, resin-embedded sections. Different bone processing methods can reveal structural aspects of the intercellular matrix, depending on the light diffraction mode: birefringency in decalcified sections can be ascribed to the collagen fibrils orientation alone; in undecalcified sections, to both the ordered layout of collagen and the inorganic phase; in the heat-deproteinized samples, exclusively to the hydroxyapatite crystals aggregation mode. The elemental chemical analysis documented low content of carbon and hydrogen, no detectable levels of nitrogen and significantly higher content of calcium and phosphorus in heat-deproteinized samples, as compared with dehydrated controls. In both samples, the X-ray diffraction (XRD) pattern did not show any significant difference in pattern of hydroxyapatite, with no peaks of any possible decomposition phases. Scanning electron microscopic (SEM) morphology of heat-deproteinized samples could be documented with the fracturing technique facilitated by the bone brittleness. The structure of crystal aggregates, oriented in parallel and with marks of time periods, was documented. Comparative study of deproteinized and undecalcified samples showed that the matrix inorganic phase did not undergo a coarse grain thermal conversion until it reached 500°C, maintaining the original crystals structure and orientation. Incident light stereomicroscopy, combined with SEM analysis of deproteinized bone fractured surfaces, is a new enforceable technique which can be used in morphometric studies to improve the understanding of the osteonal dynamics. Microsc. Res. Tech. 79:691-699, 2016. © 2016 Wiley Periodicals, Inc. © 2016

  4. L-line x-ray fluorescence of cortical bone lead compared with the CaNa2EDTA test in lead-toxic children: public health implications

    International Nuclear Information System (INIS)

    Rosen, J.F.; Markowitz, M.E.; Bijur, P.E.; Jenks, S.T.; Wielopolski, L.; Kalef-Ezra, J.A.; Slatkin, D.N.

    1989-01-01

    Mild to moderate lead toxicity (blood lead, 25-55 micrograms/dl) is a preventable pediatric illness affecting several million preschool children (lead-toxic children) in the United States. In-hospital lead-chelation treatment is predicated upon a positive CaNa 2 EDTA test, which is difficult to perform and impractical in large populations. After the development of an L-line x-ray fluorescence technique (LXRF) that measures cortical bone lead content safely, rapidly, and noninvasively, this study was initiated in lead-toxic children to compare LXRF with the CaNa 2 EDTA test. Moreover, LXRF provided the opportunity to quantify bone lead content. From blood lead and LXRF alone, 90% of lead-toxic children were correctly classified as being CaNa 2 EDTA-positive or -negative. In 76% of 59 lead-toxic children, bone lead values measured by LXRF were equal to or greater than those measured in normal and industrially exposed adults. These results indicate that LXRF may be capable of replacing the CaNa 2 EDTA test. When considered with the known neurotoxic effects on children of low levels of exposure to lead, these results also suggest that either an excessively narrow margin of safety or insufficient safety is provided by present U.S. guidelines, which classify an elevated blood lead concentration as 25 micrograms/dl or greater

  5. Computed tomography to evaluate the association of fragmented heterolog cortical bone and methylmethacrylate to repare segmental bone defect produced in tibia of rabbits; Tomografia computadorizada da matriz ossea mineralizada heterologa fragmentada e metilmetacrilato na reparacao de falhas osseas segmentares produzidas em tibia de coelhos

    Energy Technology Data Exchange (ETDEWEB)

    Freitas, S.H. [Universidade Federal de Sao Paulo (USP), SP (Brazil); Doria, R.G.S. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos; Mendonca, F.S.; Santos, M.D.; Moreira, R. [Universidade de Cuiaba, MT (Brazil). Faculdade de Medicina Veterinaria; Simoes, R.S. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Hospital Universitario; Camargo, L.M.; Simoes, M.J. [Universidade Federal de Sao Paulo (USP), SP (Brazil). Escola Paulista de Medicina; Marques, A.T.C. [Universidade de Cuiaba, MT (Brazil). Faculdade de Odontologia

    2012-11-15

    A 6mm segmental defect was performed on the metaphyseal region of the tibia of 12 rabbits and the autoclaved fragmented heterolog cortical bone conserved in glycerin (98%) and methylmethacrylate was used as a bone graft for the reconstruction. The graft was placed in the receptor bed and its integration was evaluated by computed tomography after 30, 60 and 90 days. There was gradual bone graft incorporation in the receptor bed during the time in 100% of the cases. Fragmented cortical bone heterograft and methylmethacrylate was biologically compatible and promotes bone defect reparation without signs of infection, migration and or rejection, featuring a new option of osseous substitute to fill in bone defects. (author)

  6. Comparative study of two autogenous graft techniques using piezosurgery for sinus lifting.

    Science.gov (United States)

    Camargo Filho, Geraldo Prestes de; Corrêa, Luciana; Costa, Claudio; Pannuti, Claudio Mendes; Schmelzeisen, Rainer; Luz, João Gualberto de Cerqueira

    2010-12-01

    Maxillary sinus lifting is a technique, in which, a possible complication is sinus membrane perforation. The aim of this study was to compare two techniques using ultrasound surgery to perform autogenous graft for maxillary sinus lifting. Ten rabbits were used in the study, one of them did not undergo surgery. The other nine rabbits had their maxillary sinuses filled with autogenous bone grafts collected from the external skull diploe in particulate form on the right side, and shaved on the left side, both with ultrasonic device. Data on bone density in left and right maxillary sinus, obtained by computed tomography in transverse and longitudinal sections, recorded 90 days after the grafts, were statistically compared. There were no statistically significant differences between the two techniques that used shaved and particulate bone collected by means of ultrasonic device from rabbit skulls. Assessment of operative procedures led to the conclusion that piezoelectric ultrasound was shown to be a safe tool in the surgical approach to the maxillary sinus of rabbits, allowing sinus membrane integrity to be maintained during surgical procedures.

  7. Decoupling allogenic and autogenic processes in experimental stratigraphy

    Science.gov (United States)

    Kim, W.

    2009-12-01

    At the heart of interpreting the history of Earth surface evolution preserved in the sedimentary record is decoupling environmental (allogenic) forcing from internally generated (autogenic) “noise.” One of the major stumbling blocks for distinguishing allogenic and autogenic origins in the stratigraphic record lies in the lack of quantitative understanding on autogenic processes. So far no existing computational models can explicitly model geomorphic self-organization. However, flume studies with sediment and water, which clearly show self-organized, internally driven sediment transport processes, do give the opportunity to model and investigate autogenic processes under controlled boundary conditions. I present data from two recent experiments performed in the Experimental EarthScape (XES) subsiding basin at St. Anthony Falls Laboratory, University of Minnesota. Evolution of experimental deltas in XES performed in 2002 and 2005 showed 1) clear cyclic alternations of autogenic fluvial sediment storage and release associated with changes in the fluvial planform pattern and 2) changes in time and event size of the autogenic processes by interaction with external controls e.g., tectonics. Comparing the experimental data conducted under either no or active relative base-level rise, I further explore the effects of coupling autogenic processes with environmental forcing.

  8. Relationship Between Femur Bone Mineral Density, Body Mass Index and Dental Panoramic Mandibular Cortical Width in Diagnosis of Elderly Postmenopausal Women With Osteoporosis

    Science.gov (United States)

    Devi B.K., Yashoda; Rakesh, N.; Reddy, Sujatha S.; Santana, N.; Shetty, Naresh

    2014-01-01

    Objectives: To measure and determine mandibular cortical width (MCW) on the panoramic radiographs, to evaluate the usefulness of the method in identifying postmenopausal women with low femoral bone mineral densities (f- BMD) and to correlate the radiographic findings on panoramic radiographs with the f-BMD assessed by dual X-ray absorptiometry (DXA) to predict the efficacy of the radiographic method in diagnosing osteoporosis. Materials and Methods: One hundred and twenty postmenopausal women (60 normal and 60 osteoporotic) in the age group of 50-75 y with f-BMD assessed by DXA had undergone panoramic radiographic examination. The patients were classified as normal (T-score ≥ -1.0) and osteoporotic (T-score ≤ -2.5). MCW on panoramic radiographs was measured bilaterally at the mental foramen region with a caliper and their mean was used as the exposure measure in the analysis. Results: Student t-test showed that mean f-BMD, BMI and MCW was found be less in osteoporotic patients as compared to normal group with a statistically significant p-value fractures. Mandibular inferior cortical width at the mental foramen region could be used to identify postmenopausal women with low f- BMD. Hence, dental panoramic radiographs serve as a useful screening tool for early diagnosis of osteoporotic fractures. PMID:25302265

  9. Mechanically-induced osteogenesis in the cortical bone of pre- to peripubertal stage and peri- to postpubertal stage mice

    Directory of Open Access Journals (Sweden)

    Plochocki Jeffrey H

    2009-06-01

    Full Text Available Abstract Background Exercise during postnatal development plays a key role in determining adult bone mass and reducing the risk of fracture and osteoporosis later in life. However, the relationship between mechanically-induced osteogenesis and age is unclear. Elevated levels of estrogen during puberty may inhibit periosteal bone formation. Thus, magnitudes of mechanically-induced osteogenesis may be vary with pubertal state. Methods The present study uses a murine model to examine age-related changes in bone formation at the femoral midshaft with voluntary exercise. Pre- to peripubertal mice aged 3 weeks and peri- to postpubertal mice aged 7 weeks were randomly divided into sedentary and exercised groups and subjected to histomorphometric comparison after 4 weeks of treatment. Results Results of the experiment indicate that exercise significantly increased osteogenesis on the periosteal and endocortical surface of the mice in the older age group (P P Conclusion These findings suggest that the amount and location of mechanically-induced osteogenesis differs by age during skeletal development. Late adolescence may be the optimal time to accrue bone mass and maximize bone strength.

  10. Mecânica e microbiologia de placas produzidas a partir de osso cortical bovino, conservadas em diferentes meios Mechanic and microbiology of plates produced from bovine cortical bone, conserved in several means

    Directory of Open Access Journals (Sweden)

    Edson Vilela de Melo Filho

    2011-04-01

    Full Text Available Objetivou-se com este trabalho avaliar a resistência mecânica de placas ósseas produzidas a partir de osso cortical bovino, conservadas em diferentes meios, e a eficiência desses meios em inibir o crescimento de microrganismos. Foram utilizadas 168 placas confeccionadas a partir de tíbia bovina e conservadas em glicerina a 98%, solução salina a 150%, solução de açúcar a 300%, líquido de Dakin, congeladas em N2L a -196°C, ou esterilizadas em óxido de etileno. Após reidratação em solução de cloreto de sódio a 0,9% por seis horas, elas foram submetidas a ensaios mecânicos de tração, compressão, flexão e torção. Foi realizada avaliação microbiológica das placas anterior e imediatamente após a reidratação, com ou sem adição de enrofloxacina a 0,5%. Não se observou diferença significativa (PThe objective of this study was to evaluate the mechanical strength of bone plates yielded from bovine cortical bone, conserved in different solutions, and the efficiency of these solutions in the inhibition of microorganism's growth. A hundred and sixty eight plates yielded from bovine tibiae were conserved in 98% glycerin, 150% saline solution, 300% sugar solution, Dakin solution, frozen in N2L at - 196°C, or sterilized in ethylene oxide gas. After rehydration in NaCl 0.9% solution for six hours, plates were subjected to tensile, compression, bending and twisting testing. The microbiological evaluation of bone plates was s carried out before and immediately after rehydration, with or without enrofloxacin 0.5% addition. There was no significant difference (P<0.01% on resistance to the rupture point in plates conserved in different solutions, frozen-thawed or sterilized. Microorganisms were isolated from plates conserved in satured salt solution, sugar satured solution, Dakin solution or frozen in N2L, before and after rehydraion However, after the use of NaCl 0.9% solution added of enrofloxacin 0.5%, microorganisms were not

  11. Compressive forces achieved in simulated equine third metacarpal bone lateral condylar fractures of varying fragment thickness with Acutrak Plus screw and 4.5 mm AO cortical screws.

    Science.gov (United States)

    Lewis, Andrew J; Sod, Gary A; Burba, Daniel J; Mitchell, Colin F

    2010-01-01

    To compare compression pressure (CP) of 6.5 mm Acutrak Plus (AP) and 4.5 mm AO cortical screws (AO) when inserted in simulated lateral condylar fractures of equine 3rd metacarpal (MC3) bones. Paired in vitro biomechanical testing. Cadaveric equine MC3 bones (n=12 pair). Complete lateral condylar osteotomies were created parallel to the midsagittal ridge at 20, 12, and 8 mm axial to the epicondylar fossa on different specimens grouped accordingly. Interfragmentary compression was measured using a pressure sensor placed in the fracture plane before screw placement for fracture fixation. CP was acquired and mean values of CP for each fixation method were compared between the 6.5 mm (AP) and 4.5 mm (AO) for each group using a paired t-test within each fracture fragment thickness group with statistical significance set at Pfractures, especially complete fractures. Because interfragmentary compression plays a factor in the overall stability of a repair, it is recommended for use only in patients with thin lateral condyle fracture fragments, as the compression tends to decrease with an increase in thickness.

  12. Measuring autogenous strain of concrete with corrugated moulds

    DEFF Research Database (Denmark)

    Tian, Qian; Jensen, Ole Mejlhede

    2008-01-01

    A reliable technique to quantify autogenous strain is a prerequisite to numerical modeling in stress calculations for high performance concrete. The introducing of a special kind of corrugated tube mould helps to transforming volume strain measurement into liner strain measurement in horizontal...... direction for fluid concrete, which not only realizes the continuous monitoring of the autogenous shrinkage since casting, but also effectively eliminates the disturbance resulting from gravity, temperature variation and mould restraint on measuring results. Based on this measuring technique, this paper...

  13. Evaluation of the relationship of mandibular cortical index and panoramic mandibular index with bone mineral density using panoramic radiography in postmenopausal women: A short study

    Directory of Open Access Journals (Sweden)

    Gargi Saran

    2015-01-01

    Full Text Available Introduction: The problems associated with age-related skeletal osteopenia have received attention since the human skeleton undergoes a continuous physiologic decrease in bone mass with advancing age. Bone status at various sites can be assessed using dual-energy X-ray absorptiometry (DXA or quantitative computed tomography. It would be useful to answer whether radiographic changes in the mandible indicate skeletal osteopenia. Aims and Objectives: The aim and objective of the study was to examine the mandibular cortical index (MCI and panoramic mandibular index (PMI on panoramic radiograph and to establish a relationship between the two indices (MCI and PMI with the bone mineral density (BMD in postmenopausal women. Materials and Methods: The study consisted of 15 postmenopausal women within the age group of 45-75 years. BMD was performed by DXA and measured at the lumbar spine and femoral neck and values were recorded. Panoramic radiographs of the same women were obtained for measuring MCI and PMI. There were two groups taken as C1 and C2 for determination of MCI and PMI. Results: The Pearson correlation analysis revealed a significant correlation between age and T-score (r = −0.59, P < 0.05, i.e., as age increased the T-score decreased. Comparing the T-score of two MCI groups, t-test revealed MCI was 69.1% lower in C2 as compared to C1. The value of P < 0.001 and t-test revealed significantly different and lowered (32.4% inferior cortex level in C2 as compared to C1 (t = 4.76, P < 0.001. Conclusion: Results suggest that in this study panoramic radiography could be a reliable tool in screening for BMD.

  14. Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses?

    Science.gov (United States)

    Trope, G D; Ghasem-Zadeh, A; Anderson, G A; Mackie, E J; Whitton, R C

    2015-07-01

    High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Cross-sectional study using cadaver material. Thoroughbreds that died on racetracks were grouped as: 1) horses with third metacarpal (McIII) fractures with a condylar component (cases, n = 13); 2) horses with no limb fracture (controls, n = 8); 3) horses with fractures in other bones or suspensory apparatus disruption (other fatal injuries, n = 16). The palmar condyles of McIII and the midshaft were examined with high resolution peripheral quantitative computed tomography (HR-pQCT). Statistical analysis included logistic regression and Spearman's correlation. There were no significant differences in BV/TV of distal McIII and second moment of inertia of the midshaft between cases and controls. Epiphyseal bone BV/TV was greater in injured limbs of horses with any fatal limb injury (Groups 1 and 3 combined) compared with controls (odds ratio = 1.20, 95% confidence interval 1.01-1.42, P = 0.034). An epiphyseal BV/TV>0.742 resulted in a sensitivity of 82.8% and specificity of 62.5% in identifying horses with fatal limb injury. In horses without condylar fracture, increased subchondral bone thickness was associated with palmar osteochondral disease lesions in the adjacent condyle (rs = 0.65, Phorses at risk of any fatal breakdown injury but not metacarpal condylar fractures. Measurement of parasagittal groove subchondral bone thickness is complicated by adjacent palmar osteochondral disease lesions. Thus, high-resolution imaging of the distal metacarpus appears to have limited

  15. Anterior cruciate ligament reconstruction with double-looped semitendinosus and gracilis tendon graft directly fixed to cortical bone: 5-year results.

    Science.gov (United States)

    Giron, Francesco; Aglietti, Paolo; Cuomo, Pierluigi; Mondanelli, Nicola; Ciardullo, Antonio

    2005-03-01

    Forty-three patients who had undergone an anterior cruciate ligament (ACL) reconstruction using a doubled semitendinosus and gracilis graft were prospectively reviewed at 5-year follow-up. All had suffered subacute or chronic tears of the ligament. At surgery, the femoral tunnel was drilled first through the antero-medial portal. The correct position of the femoral and tibial guide wire was checked fluoroscopically. A cortical fixation to the bone was achieved in the femur with a Mitek anchor, directly passing the two tendons in the slot of the anchor, and in the tibia with an RCI screw, supplemented with a spiked washer and bicortical screw. Rehabilitation was aggressive, controlled and without braces. The International Knee Documentation Committee (IKDC) form, KT-1000 arthrometer, and Cybex dynamometer were employed for clinical evaluation. A radiographic study was also performed. At the 5-year follow-up all the patients had recovered full range of motion and 2% of them complained of pain during light sports activities. Four patients (9.5%) reported giving-way symptoms. The KT-1000 side-to-side difference was on average 2.1 mm at 30 lb, and 68% of the knees were within 2 mm. The final IKDC score showed 90% satisfactory results. There was no difference between the 2-year and 5-year evaluations in terms of stability. Extensor and flexor muscle strength recovery was almost complete (maximum deficit 5%). Radiographic study showed a tunnel widening in 32% of the femurs and 40% of the tibias. A correlation was found between the incidence of tibial tunnel widening and the distance of the RCI screw from the joint (the closer the screw to the joint, the lower the incidence of widening). In conclusion, we can state that, using a four-strand hamstring graft and a cortical fixation at both ends, we were able to achieve satisfactory 5-year results in 90% of the patients.

  16. Various autogenous fresh demineralized tooth forms for alveolar socket preservation in anterior tooth extraction sites: a series of 4 cases.

    Science.gov (United States)

    Kim, Eun-Suk; Lee, In-Kyung; Kang, Ji-Yeon; Lee, Eun-Young

    2015-12-01

    The aim of this study was to evaluate the clinical relevance of autogenous fresh demineralized tooth (Auto-FDT) prepared at chairside immediately after extraction for socket preservation. Teeth were processed to graft materials in block, chip, or powder types immediately after extraction. Extraction sockets were filled with these materials and dental implants were installed immediately or after a delay. A panoramic radiograph and a conebeam CT were taken. In two cases, tissue samples were taken for histologic examination. Vertical and horizontal maintenance of alveolar sockets showed some variance depending on the Auto-FDT and barrier membrane types used. Radiographs showed good bony healing. Histologic sections showed that it guided good new bone formation and resorption pattern of the Auto-FDT. This case series shows that Auto-FDT prepared at chairside could be a good material for the preservation of extraction sockets. This study will suggest the possibility of recycling autogenous tooth after immediate extraction.

  17. Functional adaptation to mechanical loading in both cortical and cancellous bone is controlled locally and is confined to the loaded bones

    OpenAIRE

    Sugiyama, Toshihiro; Price, Joanna S.; Lanyon, Lance E.

    2010-01-01

    In order to validate whether bones' functional adaptation to mechanical loading is a local phenomenon, we randomly assigned 21 female C57BL/6 mice at 19?weeks of age to one of three equal numbered groups. All groups were treated with isoflurane anesthesia three times a week for 2?weeks (approximately 7?min/day). During each anaesthetic period, the right tibiae/fibulae in the DYNAMIC?+?STATIC group were subjected to a peak dynamic load of 11.5?N (40 cycles with 10-s intervals between cycles) s...

  18. Posterior Lumbar Interbody Fusion with 3D-Navigation Guided Cortical Bone Trajectory Screws for L4/5 Degenerative Spondylolisthesis: 1-Year Clinical and Radiographic Outcomes.

    Science.gov (United States)

    Hussain, Ibrahim; Virk, Michael S; Link, Thomas W; Tsiouris, Apostolos J; Elowitz, Eric

    2018-02-01

    We describe our technique and evaluate clinical and radiographic outcomes for patients undergoing L4/5 posterior lumbar interbody fusion with 3D-navigation guided cortical bone trajectory screws (PLIF-CBT) for grade 1 or 2 degenerative spondylolisthesis with a minimum follow-up time of 12 months. A single-institution series of 18 patients was evaluated with data prospectively collected and retrospectively analyzed. Pain and disability scores were collected preoperatively and at a minimum of 12 months postoperatively, including back and bilateral leg pain visual analog scores (VAS) and Oswestry Disability Index (ODI) scores. Radiographic fusion was assessed as complete, partial, or none based on the presence of bridging bones across the disc space, posterior elements, or both. Patients demonstrated statistically significant reductions in back pain VAS (P = 0.0025), leg pain VAS (P fusion at an average of 14.9 months postoperatively was available for 16/18 patients, with 6 patients demonstrating fusion (4/6 with complete fusion; 2/6 with partial fusion). There were no instances of intraoperative complications or delayed complications requiring subsequent interventions. PLIF-CBT can be performed in a safe and reproducible fashion with excellent clinical outcomes at 1 year postoperatively. The outcomes did not correlate with fusion status, which was unexpectedly low at 37.5% without significant hardware abnormalities necessitating reoperations. PLIF-CBT offers several perioperative advantages compared with traditional open PLIF and requires longer-term studies to demonstrate its durability with regard to improvement in clinical pain and radiographic endpoints, including anterior and/or posterior element fusion. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. A biomechanical comparison of headless tapered variable pitch compression and ao cortical bone screws for fixation of a simulated midbody transverse fracture of the proximal sesamoid bone in horses.

    Science.gov (United States)

    Eddy, Alison L; Galuppo, Larry D; Stover, Susan M; Taylor, Kenneth T; Jensen, David G

    2004-01-01

    To compare mechanical properties and failure characteristics of 2 methods of fixation for repair of a transverse, midbody fracture of the proximal sesamoid bone (PSB): 4.5-mm AO cortical bone screw (AO) placed in lag fashion and 4/5-mm Acutrak (AT) self-compressing screw. An in vitro biomechanical evaluation of intact forelimb preparations and forelimb preparations with a simulated midbody PSB fracture stabilized by a bone screw. Sixteen paired and 8 unilateral cadaveric equine forelimbs. A midbody transverse osteotomy was created in the medial PSB of bilateral forelimbs of 8 equine cadavers. The osteotomized PSB in 1 forelimb from each cadaver was repaired with an AO screw. The osteotomized PSB in each contralateral limb was repaired with an AT screw. Eight unilateral intact control limbs were also studied. Mechanical properties were determined from axial compression, single cycle to failure, load-deformation curves. Failure characteristics were determined by evaluation of video images and radiographs. No statistically significant differences were found between repair groups. Both AO and AT groups had significantly lower mechanical properties than intact limbs except for stiffness. AO and AT constructs were mechanically comparable when used to stabilize a simulated midbody fracture of the medial PSB. Both constructs were mechanically inferior to intact limbs. Clinical Relevance- The AT screw should be considered for clinical use because of the potential for less soft tissue impingement and superior biocompatibility compared with the stainless-steel AO screw. However, postoperative external coaptation is necessary to augment initial fracture stability for either fixation method, and to maintain a standing metacarpophalangeal joint dorsiflexion angle between 150 degrees and 155 degrees.

  20. An in vitro biomechanical comparison of hydroxyapatite coated and uncoated ao cortical bone screws for a limited contact: dynamic compression plate fixation of osteotomized equine 3rd metacarpal bones.

    Science.gov (United States)

    Durham, Myra E; Sod, Gary A; Riggs, Laura M; Mitchell, Colin F

    2015-02-01

    To compare the monotonic biomechanical properties of a broad 4.5 mm limited contact-dynamic compression plate (LC-DCP) fixation secured with hydroxyapatite (HA) coated cortical bone screws (HA-LC-DCP) versus uncoated cortical bone screws (AO-LC-DCP) to repair osteotomized equine 3rd metacarpal (MC3) bones. Experimental. Adult equine cadaveric MC3 bones (n = 12 pair). Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for: (1) 4 point bending single cycle to failure testing; (2) 4 point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. For the HA-LC-DCP-MC3 construct, an 8-hole broad LC-DCP (Synthes Ltd, Paoli, PA) was secured on the dorsal surface of each randomly selected MC3 bone with a combination of four 5.5 mm and four 4.5 mm HA-coated cortical screws. For the AO-LC-DCP-MC3 construct, an 8-hole 4.5 mm broad LC-DCP was secured on the dorsal surface of the contralateral MC3 bone with a combination of four 5.5 mm and four 4.5 mm uncoated cortical screws. All MC3 bones had mid-diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t-test within each group. Significance was set at P < .05. Mean yield load, yield bending moment, composite rigidity, failure load, and failure bending moment, under 4 point bending, single cycle to failure, of the HA-LC-DCP fixation were significantly greater than those of the AO-LC-DCP fixation. Mean ± SD values for the HA-LC-DCP and the AO-LC-DCP fixation techniques, respectively, in single cycle to failure under 4 point bending were: yield load, 26.7 ± 2.15 and 16.3 ± 1.38 kN; yield bending moment, 527.4 ± 42.4 and 322.9 ± 27.2 N-m; composite rigidity, 5306 ± 399 and 3003 ± 300 N-m/rad; failure load, 40.6 ± 3.94 and 26.5 ± 2.52 kN; and failure bending moment, 801.9 ± 77.9 and 522.9 ± 52.2 N-m. Mean cycles to failure in 4 point bending of the HA

  1. Decibel attenuation of pulsed electromagnetic field (PEMF) in blood and cortical bone determined experimentally and from the theory of ohmic losses.

    Science.gov (United States)

    Zborowski, Maciej; Kligman, Boris; Midura, Ronald J; Wolfman, Alan; Patterson, Thomas E; Ibiwoye, Michael; Grabiner, Mark

    2006-06-01

    We studied the PEMF power attenuation in tissues representative of clinical applications (blood and cortical bone) to determine the amount of power available for PEMF purported biological effects. The experimental system consisted of a pair of nearly circular, parallel and coaxial coils separated by a distance of one coil diameter. The power attenuation was measured using a small search coil connected to a digital oscilloscope. The coils were powered by a voltage switch operating at two different frequencies (3.8 and 63 kHz) producing bursts of pulses (numbering 21 and 1619) and triggered at two different frequencies (1.5 and 15 Hz, respectively). The tissue samples were placed inside the coils so as to expose them to either transverse electric field (at the center of coils) or the transverse magnetic field (at the coil wire). The cylindrical coil geometry yielded closed-form expressions for power attenuation based on magnetic diffusion equation and ohmic losses due to bulk tissue magnetic permeability and electrical conductivity. The measured power attenuation at these PEMF frequencies of not more than one decibel (1 dB) was well explained by the theory for the 3.8 kHz but less so for the 63 kHz frequency PEMF. The results provide important insights regarding physical mechanism of weak PEMF power dissipation in tissues.

  2. [Clinical experience in communication in autogenous psychotherapy and hypnosis].

    Science.gov (United States)

    Eletti, P L; Peresson, L

    1983-12-30

    Questions relating to communication and metacommunication during two forms of directive psychotherapy (Schultz's autogenous training and hypnosis) are examined. The concept of rigidity and cognitive flexibility with regard to the physician-patient relationship is discussed: abstract-concrete dynamics, abstract generalisation of diagnosis, linguistic egocentricity, stereotypical adaptation to conventional language. Some attention is devoted to Heider's balance theory as the first approach to psychological understanding of the therapeutic relationship. The communicative and metacommunicative process described by the Palo Alto (California) school is discussed. Autogenous psychotherapy and hypnosis extend through the concepts of symmetrical relation and inferior complementarity. The criteria for reaching these objectives are stated, along with the pragmatic methods devised for decoding messages and gaining access to metacommunication. Three clinical cases treated through autogenous training and one with hypnosis are analysed with respect to communication and from the relational standpoint. The patient's messages are decoded, the ambiguity of the communication is detected, and the physician's possible answers are examined at both the technical and the emotive level. It is felt that the correct use of the communicational perspective greatly extends the possibilities of autogenous training and hypnosis. It is not a question of combining relational and autogenous management, but of using the Palo Alto discoveries in the more complete understanding of cases in which psychotherapy is employed.

  3. Modulation of microglial activation enhances neuroprotection and functional recovery derived from bone marrow mononuclear cell transplantation after cortical ischemia.

    Science.gov (United States)

    Franco, Edna C S; Cardoso, Marcelo M; Gouvêia, Amauri; Pereira, Antonio; Gomes-Leal, Walace

    2012-06-01

    Activated microglia may exacerbate damage in neural disorders; however, it is unknown how they affect stem cells transplanted after stroke. Focal ischemia was induced by microinjections of 40 pmol of endothelin-1 into the motor cortex of adult rats. Ischemic animals were treated with sterile saline (n = 5), bone marrow mononuclear cells (BMMCs, n = 8), minocycline (n = 5) or concomitantly with minocycline and BMMCs (n = 5). BMMC-treated animals received 5 × 10(6)BMMCs through the caudal vein 24h post-ischemia. Behavioral tests were performed to evaluate functional recovery. Morphometric and histological analyses were performed to assess infarct area, neuronal loss and microglia/macrophage activation up to 21 days post-ischemia. Treatments with minocycline, BMMCs or minocycline-BMMCs reduced infarct area, increased neuronal survival and decreased the number of caspase-3+ and ED-1+ cells, but these effects were more prominent in the minocycline-BMMC group. Behavioral analyses using the modified sticky-tape and open-field tests showed that ischemic rats concomitantly treated with BMMCs and minocycline showed better motor performance than rats treated with BMMCs or minocycline only. The results suggest that proper modulation of the inflammatory response through the blockage of microglia activation enhances neuroprotection and functional recovery induced by intravenous transplantation of BMMCs after motor cortex ischemia. Copyright © 2012 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  4. Estimulação da cicatrização óssea pelo plasma autógeno rico em plaquetas: estudo experimental em coelhos Bone healing stimulation by platelet-rich autogenous plasma: an experimental study in rabbits

    Directory of Open Access Journals (Sweden)

    Elisabete Mitiko Kobaiashi Wilson

    2006-01-01

    Full Text Available O plasma sangüíneo autógeno com alta concentração de plaquetas obtido por centrifugação (plasma rico em plaquetas, ou PRP tem sido utilizado na prática clínica para estimular a cicatrização óssea numa variedade de situações, sob alegação de que ele carrega uma elevada concentração de fatores de crescimento derivados da plaqueta e beta-transformadores, os quais sabidamente estimulam o crescimento e regeneração de diferentes tecidos. No presente estudo, o PRP foi utilizado para reparar uma falha óssea diafisária segmentar de meia espessura e 2 cm de comprimento produzida no radio de coelhos Nova Zelândia. O periósteo foi ressecado na circunferência do local da falha e a cavidade medular foi selada com cera óssea em todos os animais para bloquear a chegada de celular regeneradoras que não fossem do próprio osso, mas dos tecidos vizinhos. Três grupos de 15 animais cada foram planejados, de acordo com o procedimento realizado: 1 falha deixada vazia; 2 falha preenchida com o PRP; e 3 falha preenchida com um material inerte (Gelfoam®. Em cada grupo os animais foram distribuídos em três subgrupos de acordo com o período de observação pós-operatória, de 4, 8 e 12 semanas, respectivamente, depois do qual os animais foram mortos e o radio, ressecado para os estudos histológicos. Radiografias e cintilografias foram obtidas a intervalos de 4 semanas, começando na quarta semana pós-operatória. Cicatrização completa e remodelação foram observadas no grupo 2 já na 8ª semana, enquanto que nos grupos 1 e 3 esse processo era apenas parcial na 12ª. A captação do tecnécio estava aumentada em todos os grupos, assim permanecendo durante todo o período de observação nos grupos 1 e 3, mas diminuindo da 8ª para a 12ª semana no grupo 2, acompanhando o processo de remodelação, com diferenças significantes entre os grupos (pThe autogenous blood plasma with high platelet concentration obtained through centrifugation

  5. Comparison of Autogenous Vaccine and Autohaemotherapy Administrations in the Treatment of Bovine Papillomatosis

    OpenAIRE

    BİRİCİK, Halil Selçuk

    2014-01-01

    The objective of this study was to compare the efficacy of autogenous vaccine, autohaemotherapy and autogenous vaccine-autohaemotherapy combinations in the treatment of bovine papillomatosis. The study was performed on 27 cattle aged between 1 and 2.5 years. The animals were divided into three groups (nine in each group) as autogenous vaccine, autohaemotherapy and autogenous vaccine-autohaemotherapy combinations. Doses of 10 ml per animal were injected subcutaneously at weekly intervals, a t...

  6. Evaluation of autogenous tooth transplantation for replacement of the missing or unrestorable mandibular molar tooth

    Directory of Open Access Journals (Sweden)

    Wahiduj Jaman

    2017-06-01

    Full Text Available This study was undertaken to evaluate the functional and occlusal stability of autogenous tooth transplantation. A total of 30 patients were included. Among them, 21 participants received transplanted first molar and the remaining 9 received transplanted second molar. In all the cases, donor tooth were third molar. In each participant, extraction of un-restorable first or second molar tooth was performed which was then replaced by atrumatic extracted third molar tooth. Each third molar tooth was placed in the recipient extracted socket, followed by the evaluation of the occlusion and then stabilized with arch bar and ligature wire. Clinical follow-up evaluation was performed at 15 days, 3 and 12 months in respect to occlusal stability, tooth mobility and periodontal status. It was found that 23 transplanted tooth were successful and the remaining 7 tooth need long-term observation for the final outcome, which was statistically significant. It can be concluded that the autogenous tooth transplantation can replace missing tooth to ensure the preservation of function, aesthetic and to prevent bone resorption of the missing area of the jaw, which can lead to exceptional esthetic and functional outcome.

  7. Cracking in cement paste induced by autogenous shrinkage

    DEFF Research Database (Denmark)

    Lura, Pietro; Jensen, Ole Mejlhede; Weiss, Jason

    2009-01-01

    Detection and quantification of microcracks caused by restrained autogenous shrinkage in high-performance concrete is a difficult task. Available techniques either lack the required resolution or may produce additional cracks that are indistinguishable from the original ones. A recently developed...... technique allows identification of microcracks while avoiding artefacts induced by unwanted restraint, drying, or temperature variations during sample preparation. Small cylindrical samples of cement paste are cast with steel rods of different diameters in their centre. The rods restrain the autogenous...... shrinkage of the paste and may cause crack formation. The crack pattern is identified by impregnation with gallium and analyzed by optical and scanning electron microscopy. In this study, a non-linear numerical analysis of the samples was performed. Autogenous strain, elastic modulus, fracture energy...

  8. Evaluation of the efficacy of an autogenous Escherichia coli vaccine in broiler breeders

    DEFF Research Database (Denmark)

    Li, Lili; Thøfner, Ida; Christensen, Jens Peter

    2017-01-01

    In poultry production Escherichia coli autogenous vaccines are often used. However, the efficacy of autogenous E. coli vaccinations has not been evaluated experimentally in chickens after start of lay. The aim of the present study was to evaluate the protective effect of an autogenous E. coli vac...

  9. Evaluation of “Autogenous Bioengineered Injectable PRF – Tooth graft” combination (ABIT in reconstruction of maxillary alveolar ridge defects: CBCT volumetric analysis

    Directory of Open Access Journals (Sweden)

    Lydia Nabil Melek

    2017-01-01

    Full Text Available Background: Extracted human teeth were suggested as a source for autogenous bone grafts, especially that they have similar chemical composition to bone. In order to accelerate healing of bone graft over the bony defect, numerous techniques utilizing platelet and fibrinogen concentrations have been introduced in the literature. Objectives: To evaluate clinically and radiographically the use of autogenous tooth bone graft material in combination with injectable platelet-rich fibrin for reconstruction of resorbed maxillary alveolar ridge. Patients and methods: This study was conducted in ten patients indicated for extraction of maxillary anterior or premolar teeth and having maxillary ridge deficiency. Implants were placed after a period of 3 months of bone grafting. The patients were selected from those attending the Oral and Maxillofacial Surgery Department, Faculty of Dentistry, Alexandria University. Results: Clinically, all the patients showed uneventful healing. Radiographically, the results show 30% increase in mean bone density in the period of six months when compared to pre-operative readings. The grafted site showed an increase in the mean volume by 23.47% three months post-operative when compared to the base line measurements preoperatively. Radiographic evaluation of the alveolar ridge after 3 months of grafting showed a significant mean increase in the ridge width and height at the grafted site. Conclusion: Autogenous fresh demineralized tooth graft that is prepared at the chairside after extractions could be considered as the gold standard for socket preservation, bone augmentation in sinuses or filling bone defects, in patients having non restorable teeth indicated for extraction. The adjuvant use of injectable PRF with its high growth factor content may contribute to more favorable and predictable bone formation at the grafted site.

  10. Bone Marrow Concentrate and Bovine Bone Mineral for Sinus Floor Augmentation : A Controlled, Randomized, Single-Blinded Clinical and Histological Trial-Per-Protocol Analysis

    NARCIS (Netherlands)

    Sauerbier, Sebastian; Rickert, Daniela; Gutwald, Ralf; Nagursky, Heiner; Oshima, Toshiyuki; Xavier, Samuel P.; Christmann, Johannes; Kurz, Patrick; Menne, Dieter; Vissink, Arjan; Raghoebar, Gerry; Schmelzeisen, Rainer; Wagner, Wilfried; Koch, Felix P.

    Purpose: The purpose of this work was to evaluate the potential of substituting autogenous bone (AB) by bone marrow aspirate concentrate (BMAC). Both AB and BMAC were tested in combination with a bovine bone mineral (BBM) for their ability of new bone formation (NBF) in a multicentric, randomized,

  11. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs

    OpenAIRE

    McGee-Lawrence, Meghan E.; Wojda, Samantha J.; Barlow, Lindsay N.; Drummer, Thomas D.; Bunnell, Kevin; Auger, Janene; Black, Hal L.; Donahue, Seth W.

    2009-01-01

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechan...

  12. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05). CONCLUSIONS PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  13. [Cortical blindness].

    Science.gov (United States)

    Chokron, S

    2014-02-01

    Cortical blindness refers to a visual loss induced by a bilateral occipital lesion. The very strong cooperation between psychophysics, cognitive psychology, neurophysiology and neuropsychology these latter twenty years as well as recent progress in cerebral imagery have led to a better understanding of neurovisual deficits, such as cortical blindness. It thus becomes possible now to propose an earlier diagnosis of cortical blindness as well as new perspectives for rehabilitation in children as well as in adults. On the other hand, studying complex neurovisual deficits, such as cortical blindness is a way to infer normal functioning of the visual system. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  14. Thermodynamics of Autogenous Self-healing in Cementitious Materials

    NARCIS (Netherlands)

    Huang, H.

    2014-01-01

    Concrete is a brittle composite cementitious material that easily fractures under tensile loading. Microcracks can appear throughout the concrete prior to application of any load because of temperature-induced strain and autogenous and drying shrinkage. There is no doubt that these cracks provide

  15. Alveolar ridge preservation using autogenous tooth graft versus beta-tricalcium phosphate alloplast: A randomized, controlled, prospective, clinical pilot study.

    Science.gov (United States)

    Joshi, Chaitanya Pradeep; Dani, Nitin Hemchandra; Khedkar, Smita Uday

    2016-01-01

    A randomized, prospective clinical, radiographical, and histological study was conducted to evaluate healing after alveolar ridge preservation technique using two different graft materials, namely, a novel autogenous graft material i. e., autogenous tooth graft (ATG) and beta-tricalcium phosphate (β-TCP) alloplast. Fifteen patients undergoing extraction of at least three teeth were selected. Atraumatic extractions were performed. Of the three extraction sockets, one was grafted with ATG, other with β-TCP, and the third was left ungrafted. Cone-beam computed tomography scans were taken immediately after grafting and 4 months postoperatively to check the changes in alveolar crest height and width at all the sites. Three patients in whom implant placement was done after complete healing; bone samples were harvested using a 3 mm diameter trephine during osteotomy preparation from both the ridge preserved sites and studied histologically. There was a statistically significant difference when the changes in width and height of alveolar crest were compared within all the three groups ( P alveolar crest height and width. Histological analysis also showed the same trend with more new bone formation at ATG-grafted sites as compared to β-TCP-grafted sites. Postextraction, ridge preservation leads to more predictable maintenance of alveolar ridge height and width. ATG as compared to β-TCP provided superior results. Based on this, we conclude that ATG material can serve as a better alternative to conventional bone graft materials.

  16. Evaluation of the effect of platelet rich plasma (PRP) on enhancement of bone healing in diaphyseal bone defects by radiography and computed tomography

    International Nuclear Information System (INIS)

    Özak, Ahmet; Yardimci, Cenk; Nİsbet, Özlem H.; Bayrak, İlkay Koray; Nİsbet, Cevat

    2010-01-01

    The effect of platelet-rich plasma (PRP) with autogenous cancellous bone graft on enhancement of bone healing in diaphyseal bone defects was evaluated. A 4-mm defect was created in the middiaphysis of the tibias of 20 rabbits. Rabbits were divided into two groups of ten animals each: only autogenous cancellous graft, PRP and autogenous cancellous graft. In animals of group 1, only autogenous cancellous grafts, and to those in group 2, PRP and autogenous cancellous grafts, were applied to the defect. Radiographical and computed tomography (CT) views were taken and evaluated on postoperative days 0, 15, 30, 60, and 90. According to the bone formation, union, and remodeling scores, group 1 had better scores than group 2 on days 30, 60, and 90. The density was significantly increased on day 60 than on days 0, 15, and 30 in group 1. In conclusion, it was evaluated that PRP could not enhance the bone regeneration in diaphyseal defects when used with autogenous cancellous bone graft

  17. Effect of anti-inflammatory agents on the integration of autogenous bone graft and bovine bone devitalized matrix in rats Efeito de antiinflamatórios na integração de enxerto ósseo autógeno e de matriz óssea bovina desvitalizada em ratos

    Directory of Open Access Journals (Sweden)

    Roberto Antoniolli da Silva

    2008-04-01

    Full Text Available PURPOSE: To study the repair of bone defect filled with autograft or bovine bone devitalized matrix in rats under anti-inflammatory action. METHODS: Two hundred and forty Wistar rats were distributed to two groups of 120 animals each. A 2mm-diameter defect was created in the femoral diaphysis. Animals of Group I had the bone defect filled with autograft and those of Group II, with bovine bone devitalized matrix. Animals of each group were redistributed to four subgroups according to the intramuscular administration of anti-inflammatory drug or saline solution: A - diclofenac sodium; B - dexamethasone; C - meloxicam; D - saline solution. Evaluation periods were 7, 14 and 30 days. Histological evaluation consisted of quantifying the inflammatory process, the bone neoformation, the collagen formation and the presence of macrophages. RESULTS: Animals of Group I did not show significant difference considering inflammatory reaction. Significant and progressive increase of bone neoformation was observed in both groups. The animals that received meloxicam and autograft showed less collagen formation at 14 and 30 days. The number of macrophages was higher in Group II than in Group I. The animals treated with dexamethasone and saline solution did not show statistically significant difference. CONCLUSIONS: Diclofenac sodium and meloxicam delayed bone graft repair and dexamethasone did not interfere in it.OBJETIVO: Estudar o reparo do defeito ósseo preenchido com enxerto ósseo autógeno ou matriz óssea bovina desvitalizada sob ação de antiinflamatórios em ratos. MÉTODOS: 240 ratos Wistar, distribuídos em dois grupos de 120 animais. Confeccionou-se defeito de 2 mm de diâmetro na diáfise femoral. Os animais do Grupo I tiveram o defeito ósseo preenchido com enxerto ósseo autógeno e os do Grupo II com matriz óssea bovina desvitalizada. Cada grupo foi redistribuído em quatro subgrupos segundo a administração intramuscular de antiinflamatório ou

  18. Evaluation on Bending Properties of Biomaterial GUM Metal Meshed Plates for Bone Graft Applications

    Science.gov (United States)

    Suzuki, Hiromichi; He, Jianmei

    2017-11-01

    There are three bone graft methods for bone defects caused by diseases such as cancer and accident injuries: Autogenous bone grafts, Allografts and Artificial bone grafts. In this study, meshed GUM Metal plates with lower elasticity, high strength and high biocompatibility are introduced to solve the over stiffness & weight problems of ready-used metal implants. Basic mesh shapes are designed and applied to GUM Metal plates using 3D CAD modeling tools. Bending properties of prototype meshed GUM Metal plates are evaluated experimentally and analytically. Meshed plate specimens with 180°, 120° and 60° axis-symmetrical types were fabricated for 3-point bending tests. The pseudo bending elastic moduli of meshed plate specimens obtained from 3-point bending test are ranged from 4.22 GPa to 16.07 GPa, within the elasticity range of natural cortical bones from 2.0 GPa to 30.0 GPa. Analytical approach method is validated by comparison with experimental and analytical results for evaluation on bending property of meshed plates.

  19. Impact of bone graft harvesting techniques on bone formation and graft resorption

    DEFF Research Database (Denmark)

    Saulacic, Nikola; Bosshardt, Dieter D; Jensen, Simon S

    2015-01-01

    in the mandibles of 12 minipigs. The animals were sacrificed after 1, 2, 4 and 8 weeks of healing. Histology and histomorphometrical analyses were performed to assess bone formation and graft resorption. An explorative statistical analysis was performed. RESULTS: The amount of new bone increased, while the amount......: Transplantation of autogenous bone particles harvested with four techniques in the present model resulted in moderate differences in terms of bone formation and graft resorption....

  20. Cortical Maps.

    Science.gov (United States)

    Bednar, James A; Wilson, Stuart P

    2016-12-01

    In this article, we review functional organization in sensory cortical regions-how the cortex represents the world. We consider four interrelated aspects of cortical organization: (1) the set of receptive fields of individual cortical sensory neurons, (2) how lateral interaction between cortical neurons reflects the similarity of their receptive fields, (3) the spatial distribution of receptive-field properties across the horizontal extent of the cortical tissue, and (4) how the spatial distributions of different receptive-field properties interact with one another. We show how these data are generally well explained by the theory of input-driven self-organization, with a family of computational models of cortical maps offering a parsimonious account for a wide range of map-related phenomena. We then discuss important challenges to this explanation, with respect to the maps present at birth, maps present under activity blockade, the limits of adult plasticity, and the lack of some maps in rodents. Because there is not at present another credible general theory for cortical map development, we conclude by proposing key experiments to help uncover other mechanisms that might also be operating during map development. © The Author(s) 2015.

  1. Influence of estrogen deficiency and tibolone therapy on trabecular and cortical bone evaluated by computed radiography system in rats Influência da deficiência estrogênica e do tratamento com tibolona no osso trabecular e cortical avaliada pelo sistema de radiografia computadorizada em ratas

    Directory of Open Access Journals (Sweden)

    Ana Carolina Bergmann de Carvalho

    2012-03-01

    Full Text Available PURPOSE: To verify the effects of tibolone administration on trabecular and cortical bone of ovariectomized female rats by computed radiography system (CRS. METHODS: The experiment was performed on two groups of rats previously ovariectomized, one received tibolone (OVX+T while the other did not (OVX, those groups were compared to a control group (C not ovariectomized. Tibolone administration (1mg/day began thirty days after the ovariectomy and the treatment remained for five months. At last, the animals were euthanized and femurs and tibias collected. Computed radiographies of the bones were obtained and the digital images were used to determine the bone optical density and cortical thickness on every group. All results were statistically evaluated with significance set at POBJETIVO: Verificar o efeito da administração de tibolona no tecido ósseo cortical e trabecular de ratas castradas através de radiografia computadorizada. MÉTODOS: O experimento foi realizado em dois grupos de ratas previamente ooforectomizadas, onde um grupo recebeu tibolona (OVX+T e o outro não (OVX. Esses grupos foram comparados a um grupo controle (C não ooforectomizado. A administração de tibolona (1mg/dia começou trinta dias após a ooforectomia e o tratamento teve duração de cinco meses. No final, os animais foram mortos e fêmures e tibias coletados. As radiografias computadorizadas dos ossos foram obtidas e as imagens digitais usadas para determinar a densidade óssea e a espessura cortical em todos os grupos. Todos os resultados foram avaliados estatisticamente com significância estabelecida a 5%. RESULTADOS: A administração de tibolona mostrou ser benéfica apenas para análise densitométrica da cabeça do fêmur, apresentando maiores valores de densidade comparada ao grupo OVX. Nenhuma diferença significativa foi encontrada para espessura óssea cortical. CONCLUSÃO: A ooforectomia ocasionou perda óssea nas regiões analisadas e a tibolona

  2. Cortical bone trajectory screw fixation versus traditional pedicle screw fixation for 2-level posterior lumbar interbody fusion: comparison of surgical outcomes for 2-level degenerative lumbar spondylolisthesis.

    Science.gov (United States)

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2018-01-01

    OBJECTIVE The cortical bone trajectory (CBT) screw technique is a new nontraditional pedicle screw (PS) insertion method. However, the biomechanical behavior of multilevel CBT screw/rod fixation remains unclear, and surgical outcomes in patients after 2-level posterior lumbar interbody fusion (PLIF) using CBT screw fixation have not been reported. Thus, the purposes of this study were to examine the clinical and radiological outcomes after 2-level PLIF using CBT screw fixation for 2-level degenerative lumbar spondylolisthesis (DS) and to compare these outcomes with those after 2-level PLIF using traditional PS fixation. METHODS The study included 22 consecutively treated patients who underwent 2-level PLIF with CBT screw fixation for 2-level DS (CBT group, mean follow-up 39 months) and a historical control group of 20 consecutively treated patients who underwent 2-level PLIF using traditional PS fixation for 2-level DS (PS group, mean follow-up 35 months). Clinical symptoms were evaluated using the Japanese Orthopaedic Association (JOA) scoring system. Bony union was assessed by dynamic plain radiographs and CT images. Surgery-related complications, including symptomatic adjacent-segment disease (ASD), were examined. RESULTS The mean operative duration and intraoperative blood loss were 192 minutes and 495 ml in the CBT group and 218 minutes and 612 ml in the PS group, respectively (p 0.05, respectively). The mean JOA score improved significantly from 12.3 points before surgery to 21.1 points (mean recovery rate 54.4%) at the latest follow-up in the CBT group and from 12.8 points before surgery to 20.4 points (mean recovery rate 51.8%) at the latest follow-up in the PS group (p > 0.05). Solid bony union was achieved at 90.9% of segments in the CBT group and 95.0% of segments in the PS group (p > 0.05). Symptomatic ASD developed in 2 patients in the CBT group (9.1%) and 4 patients in the PS group (20.0%, p > 0.05). CONCLUSIONS Two-level PLIF with CBT screw fixation

  3. Marginal bone loss in implants placed in grafted maxillary sinus.

    Science.gov (United States)

    Galindo-Moreno, Pablo; Fernández-Jiménez, Andrés; O'Valle, Francisco; Silvestre, Francisco J; Sánchez-Fernández, Elena; Monje, Alberto; Catena, Andrés

    2015-04-01

    The purpose of this study is to evaluate the vertical and horizontal graft bone resorption (GR) in grafted maxillary sinuses and the marginal bone loss (MBL) around implants placed in the sinuses with different prosthetic connections and to determine the effect of other clinical factors on these tissue responses at 6 and 18 months postloading. A total of 254 implants were placed in 150 grafted maxillary sinuses of 101 patients (51.5% female) with mean age of 52.2 years (range, 32-82 years). GR and MBL measurements were made in implants placed with two different prosthetic connections (internal and external) at 6 and 18 months postloading. The complex samples general linear model was used to analyze the influence of patient age, gender, smoking habit, history of periodontal disease, implantation timing (simultaneous vs deferred), and prosthetic abutment length on radiographic GR and MBL values. At 18 months postloading, the MBL ranged from 0 mm to 5.89 mm; less than 1 mm was lost around 49.0% (mesial) and 44.3% (distal) of the implants, while no bone was lost around 32.9% (mesial) and 26.7% (distal). The GR was significantly affected by smoking, remnant alveolar bone height, graft length, graft height, gender, and age, and it significantly decreased over time. The MBL was influenced by the type of connection, implantation timing, and prosthetic abutment length. The MBL was greater with longer postloading interval and higher patient age and in smokers. Resorption of grafts that combine autogenous cortical bone with anorganic bovine bone is dependent on the anatomic features of the sinus and is not affected by the time elapsed after the first 6 months. The MBL in implants placed in these grafted areas is time dependent and mainly related to potentially modifiable clinical decisions and patient habits. © 2013 Wiley Periodicals, Inc.

  4. Orthogonal Double Plating and Autologous Bone Grafting of Postoperative Humeral Shaft Nonunion - A Rare Case Report and Review of Literature.

    Science.gov (United States)

    Metikala, Sreenivasulu; Bhogadi, Prabhudheer

    2015-01-01

    Nonunion following surgical stabilization of humeral shaft fractures, although infrequent, remains a challenge as limited surgical options are available. The difficulties in re-fixation are due to osteolysis produced by the loose implant components and disuse osteopenia of the entire bone segment. We share our experience in the management of a long standing diaphyseal nonunion of humerus following titanium LCP fixation. A 58 years old woman presented with 20 months old nonunion following titanium LCP fixation of her closed humeral shaft fracture, done elsewhere. The interesting intraoperative findings, noteworthy, are about the extensive metallosis and the gross cortical defect measuring 10cm x 1cm x 1cm, corresponding to the foot print of the previous plate with exposed medullary canal. It was managed by debridement, dual plate fixation using 9 holed and 12 holed stainless steel LCPs in an orthogonal fashion and autologous bone grafting. The nonunion healed in 5 months and she regained all the movements except for terminal 10° of elbow extension and 15° of shoulder abduction at her final follow up of 30 months. According to Stewart and Hundley classification the final result was found to be good. We recommend the judicious use of long and short plates in 90-90 orientation along with autogenous bone grafting in the management of a long standing humeral shaft nonunion having extensive cortical resorption following surgical stabilization by plating.

  5. Análise por tomografia computadorizada do enxerto autógeno na cirurgia de "sinus lift" Computed tomography evaluation of autogenous graft in sinus lift surgery

    Directory of Open Access Journals (Sweden)

    Sérgio Aron Ajzen

    2005-02-01

    Full Text Available OBJETIVO: Quantificar a formação óssea nos enxertos com e sem plasma rico em plaquetas, obtido pelos métodos de centrifugação e aférese, comparando os três tipos de enxertos realizados por meio de análise tomográfica. MATERIAIS E MÉTODOS: Este estudo prospectivo, duplo cego, utilizou uma amostra composta de 34 pacientes adultos, de ambos os sexos, com idade média de 48 anos e 8 meses, portadores de pneumatização unilateral ou bilateral dos seios maxilares, que necessitavam de enxertos ósseos, com a finalidade de melhorar as condições locais para a colocação dos implantes dentários. Todos os pacientes realizaram tomografia computadorizada antes da cirurgia. Foram operados 53 seios maxilares, divididos em três grupos: enxerto de plasma rico em plaquetas obtido pelos métodos de aférese, centrifugação e enxerto apenas de osso autógeno. Após seis meses do procedimento cirúrgico foram realizados novos exames de imagem. RESULTADOS: Pela avaliação tomográfica, houve crescimento em altura e em largura nos três grupos quando foram comparados os momentos inicial e final, entretanto, não houve diferença estatística para a altura e para a largura. CONCLUSÃO: Evidências clínicas demonstram a eficácia dos enxertos autógenos, principalmente os associados a fatores indutores de crescimento ósseo, como o plasma rico em plaquetas, recuperando o arcabouço maxilofacial, necessário para a reconstrução protética e funcional por meio de implantes dentários.OBJECTIVE: To quantify bone formation within autogenous bone grafts and autogenous bone grafts in combination with platelet-rich plasma obtained either from aphaeresis or centrifugation using computed tomography. MATERIALS AND METHODS: This prospective, double-blind study was conducted in 34 male and female adult patients (mean age of 28 years and 8 months, with either unilateral or bilateral pneumatization of the maxillary sinuses, requiring bone graft for dental

  6. Synthesis of Magnesium Nickel Boride Aggregates via Borohydride Autogenous Pressure.

    Science.gov (United States)

    Shahbazi, Mahboobeh; Cathey, Henrietta E; Mackinnon, Ian D R

    2018-03-23

    We demonstrate synthesis of the ternary intermetallic MgNi₃B₂ using autogenous pressure from the reaction of NaBH₄ with Mg and Ni metal powder. The decomposition of NaBH₄ to H₂ and B₂H₆ commences at low temperatures in the presence of Mg and/or Ni and promotes formation of Ni-borides and MgNi₃B₂ with the increase in temperature. MgNi₃B₂ aggregates with Ni-boride cores are formed when the reaction temperature is >670 °C and autogenous pressure is >1.7 MPa. Morphologies and microstructures suggest that solid-gas and liquid-gas reactions are dominant mechanisms and that Ni-borides form at a lower temperature than MgNi₃B₂. Magnetic measurements of the core-shell MgNi₃B₂ aggregates are consistent with ferromagnetic behaviour in contrast to stoichiometric MgNi₃B₂ which is diamagnetic at room temperature.

  7. Grau de desmineralização em osso trabecular e cortical por meio de tomografia computadorizada quantitativa em cães submetidos à terapia com prednisona Trabecular and cortical bone demineralization degree by quantitative computed tomography in dogs treated with prednisone

    Directory of Open Access Journals (Sweden)

    Lorena Adão Vescovi Séllos Costa

    2010-12-01

    Full Text Available Os glicocorticóides são fármacos amplamente utilizados na medicina veterinária, entretanto, além dos efeitos benéficos, o seu emprego pode desencadear uma série de efeitos indesejados. Foi realizado um ensaio clínico em oito cães hígidos com o intuito de avaliar possíveis alterações na densidade mineral óssea após a terapia com prednisona, utilizando a tomografia computadorizada helicoidal. Todos os animais receberam a prednisona via oral na dose diária de 2mg kg-1 de peso durante 30 dias. A densidade mineral óssea foi determinada a partir da obtenção de valores de radiodensidade da região de osso cortical e osso trabecular do corpo vertebral da segunda vértebra lombar, imediatamente antes e após o período de administração do medicamento. O protocolo experimental permitiu a caracterização de significativa (PGlucocorticoids are widely used in veterinary medicine. However, beyond the beneficial effects, their use can trigger a series of unwanted effects. A clinical trial was conducted in eight healthy dogs in order to assess possible changes in bone mineral density after therapy with prednisone using helical computed tomography. All animals received oral prednisone at a daily dose of 2mg kg-1 of body weight for 30 days. Bone mineral density was determined by the obtaining of radiodensity values from the cortical region and the trabecular region of the second lumbar vertebra immediately before and after the period of drug administration. The experimental protocol allowed the characterization of a significant (P<0.01 decrease of trabecular bone radiodensity on the second lumbar vertebra, but no significant demineralization was found in the cortical region. None of the dogs used in this experiment had pathological fracture at the end of the experimental protocol. This study showed that in dogs subjected to therapy with prednisone at a dose of 2mg kg-1 changes in bone metabolism occur early in trabecular bone, being

  8. Autogenous tooth transplantation for replacing a lost tooth: case reports

    Directory of Open Access Journals (Sweden)

    Ji-Youn Kang

    2013-02-01

    Full Text Available The autogenous tooth transplantation is an alternative treatment replacing a missing tooth when a suitable donor tooth is available. It is also a successful treatment option to save significant amount of time and cost comparing implants or conventional prosthetics. These cases, which required single tooth extraction due to deep caries and severe periodontal disease, could have good results by transplanting non-functional but sound donor tooth to the extraction site.

  9. Immediate autogenous cartilage grafts in rhinoplasty after alloplastic implant rejection.

    Science.gov (United States)

    Raghavan, Ullas; Jones, Nick S; Romo, Thomas

    2004-01-01

    It is accepted in rhinoplasty that complications are more common with alloplastic implants than with autografts. There is little guidance in the literature on how to deal with the cosmetic and/or functional problems that follow alloplastic implant rejection. The conventional advice has been to remove the allograft and not place any graft at the same time. The present article presents our experience treating allograft rejection and immediately repairing any structural defect with autografts. To demonstrate that immediate nasal reconstruction using autogenous cartilage is a good technique when an alloplastic material has to be removed because of rejection, inflammation, or infection. A retrospective analysis of outcome for a case series. A retrospective review of the management of 8 patients who presented to 2 tertiary referral centers with alloplastic implant rejection following rhinoplasty. In 7 cases, the alloplastic implant had to be removed because it had migrated and caused a foreign body reaction; in 1 case, the implant had caused a bacterial infection. In all 8 cases, the nasal deformity that followed the removal of the allograft was so marked that the nose was immediately reconstructed with autogenous cartilage. The patients all made a good recovery after immediate reconstruction, although skin changes associated with the alloplastic implant remained after a mean follow-up of 3 years 3 months. The use of autogenous cartilage is a good option for nasal augmentation immediately after the removal of an alloplastic implant.

  10. Guided bone regeneration with local zoledronic acid and titanium barrier: An experimental study.

    Science.gov (United States)

    Dundar, Serkan; Ozgur, Cem; Yaman, Ferhan; Cakmak, Omer; Saybak, Arif; Ozercan, Ibrahim Hanifi; Alan, Hilal; Artas, Gokhan; Nacakgedigi, Onur

    2016-10-01

    The aim of this study was to evaluate the effects on new bone formation of autogenous blood alone or in combination with zoledronic acid (ZA), a β-tricalcium phosphate (β-TCP) graft or ZA plus a β-TCP graft placed under titanium barriers. For this purpose, eight adult male New Zealand white rabbits were used in the study, each with four titanium barriers fixed around four sets of nine holes drilled in the calvarial bones. The study included four groups, each containing 2 rabbits. In the autogenous blood (AB group), only autogeneous blood was placed under the titanium barriers. The three experimental groups were the AB+ZA group, with autogenous blood plus ZA, the AB+β-TCP group, with autogeneous blood plus a β-TCP graft, and the AB+β-TCP+ZA group, with autogeneous blood plus a β-TCP graft and ZA mixture under the titanium barriers. The animals were sacrificed after 3 months. The amounts of new bone formation identified histomorphometrically were found to be higher after 3 months than at the time of surgery in all groups. The differences between the groups were examined with histomorphometric analysis, and statistically significant differences were identified at the end of the 3 months. The bone formation rate in the AB+β-TCP+ZA group was determined to be significantly higher than that in the other groups (Pbone formation rate was determined to be significantly higher than that in the AB group (Pbone formation rate was observed between the AB+β-TCP and AB+ZA groups. Local ZA used with autogeneous blood and/or graft material appears to be a more effective method than the use of autogeneous blood or graft alone in bone augmentation executed with a titanium barrier.

  11. Orthogonal Double Plating and Autologous Bone Grafting of Postoperative Humeral Shaft Nonunion – A Rare Case Report and Review of Literature

    Science.gov (United States)

    Metikala, Sreenivasulu; Bhogadi, Prabhudheer

    2015-01-01

    Introduction: Nonunion following surgical stabilization of humeral shaft fractures, although infrequent, remains a challenge as limited surgical options are available. The difficulties in re-fixation are due to osteolysis produced by the loose implant components and disuse osteopenia of the entire bone segment. We share our experience in the management of a long standing diaphyseal nonunion of humerus following titanium LCP fixation. Case Report: A 58 years old woman presented with 20 months old nonunion following titanium LCP fixation of her closed humeral shaft fracture, done elsewhere. The interesting intraoperative findings, noteworthy, are about the extensive metallosis and the gross cortical defect measuring 10cm x 1cm x 1cm, corresponding to the foot print of the previous plate with exposed medullary canal. It was managed by debridement, dual plate fixation using 9 holed and 12 holed stainless steel LCPs in an orthogonal fashion and autologous bone grafting. The nonunion healed in 5 months and she regained all the movements except for terminal 10° of elbow extension and 15° of shoulder abduction at her final follow up of 30 months. According to Stewart and Hundley classification the final result was found to be good. Conclusion: We recommend the judicious use of long and short plates in 90-90 orientation along with autogenous bone grafting in the management of a long standing humeral shaft nonunion having extensive cortical resorption following surgical stabilization by plating. PMID:27299099

  12. Influence of temperature on autogenous deformation and relative humidity change in hardening cement paste

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben

    1999-01-01

    This paper deals with autogenous deformation and autogenous relative humidity change (RH change) in hardening cement paste. Theoretical considerations and experimental data are presented, which elucidate the influence of temperature on these properties. This is an important subject in the control...

  13. Adjuvant auricular electroacupuncture and autogenic training in rheumatoid arthritis: a randomized controlled trial. Auricular acupuncture and autogenic training in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Bernateck, M; Becker, M; Schwake, C

    2008-01-01

    BACKGROUND: In contrast to psychological interventions the usefulness of acupuncture as an adjuvant therapy in rheumatoid