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Sample records for biodegradable bone fixation

  1. Effect of hydroxyapatite concentration on high-modulus composite for biodegradable bone-fixation devices.

    Science.gov (United States)

    Heimbach, Bryant; Grassie, Kevin; Shaw, Montgomery T; Olson, James R; Wei, Mei

    2016-06-14

    There are over 3 million bone fractures in the United States annually; over 30% of which require internal mechanical fixation devices to aid in the healing process. The current standard material used is a metal plate that is implanted onto the bone. However, metal fixation devices have many disadvantages, namely stress shielding and metal ion leaching. This study aims to fix these problems of metal implants by making a completely biodegradable material that will have a high modulus and exhibit great toughness. To accomplish this, long-fiber poly-l-lactic acid (PLLA) was utilized in combination with a matrix composed of polycaprolactone (PCL) and hydroxyapatite (HA) nano-rods. Through single fibril tensile tests, it was found that the PLLA fibers have a Young's modulus of 8.09 GPa. Synthesized HA nanorods have dimensions in the nanometer range with an aspect ratio over 6. By dip coating PLLA fibers in a suspension of PCL and HA and hot pressing the resulting coated fibers, dense fiber-reinforced samples were made having a flexural modulus up to 9.2 GPa and a flexural strength up to 187 MPa. The flexural modulus of cortical bone ranges from 7 to 25 GPa, so the modulus of the composite material falls into the range of bone. The typical flextural strength of bone is 130 MPa, and the samples here greatly exceed that with a strength of 187 MPa. After mechanical testing to failure the samples retained their shape, showing toughness with no catastrophic failure, indicating the possibility for use as a fixation material. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  2. Self-dissolution assisted coating on magnesium metal for biodegradable bone fixation devices

    Science.gov (United States)

    Khakbaz, Hadis; Walter, Rhys; Gordon, Timothy; Bobby Kannan, M.

    2014-12-01

    An attempt was made to develop a self-dissolution assisted coating on a pure magnesium metal for potential bone fixation implants. Magnesium phosphate cement (MPC) was coated successfully on the magnesium metal in ammonium dihydrogen phosphate solution. The in vitro degradation behaviour of the MPC coated metal was evaluated using electrochemical techniques. The MPC coating increased the polarisation resistance (RP) of the metal by ˜150% after 2 h immersion in simulated body fluid (SBF) and reduced the corrosion current density (icorr) by ˜80%. The RP of the MPC coated metal remained relatively high even after 8 h immersion period. However, post-degradation analysis of the MPC coated metal revealed localized attack. Hence, the study suggests that MPC coating alone may not be beneficial, but this novel coating could provide additional protection if used as a precursor for other potential coatings such as biodegradable polymers or calcium phosphates.

  3. Biodegradable synthetic bone composites

    Science.gov (United States)

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  4. Preliminary experience with biodegradable implants for fracture fixation

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    Dhillon Mandeep

    2008-01-01

    Full Text Available Background: Biodegradable implants were designed to overcome the disadvantages of metal-based internal fixation devices. Although they have been in use for four decades internationally, many surgeons in India continue to be skeptical about the mechanical strength of biodegradable implants, hence this study. Materials and Methods: A prospective study was done to assess the feasibility and surgeon confidence level with biodegradable implants over a 12-month period in an Indian hospital. Fifteen fractures (intra-articular, metaphyseal or small bone fractures were fixed with biodegradable implants. The surgeries were randomly scheduled so that different surgeons with different levels of experience could use the implants for fixation. Results: Three fractures (one humeral condyle, two capitulum, were supplemented by additional K-wires fixation. Trans-articular fixator was applied in two distal radius and two pilon fractures where bio-pins alone were used. All fractures united, but in two cases the fracture displaced partially during the healing phase; one fibula due to early walking, and one radius was deemed unstable even after bio-pin and external fixator. Conclusions: Biodegradable -implants are excellent for carefully selected cases of intra-articular fractures and some small bone fractures. However, limitations for use in long bone fractures persist and no great advantage is gained if a "hybrid" composite is employed. The mechanical properties of biopins and screws in isolation are perceived to be inferior to those of conventional metal implants, leading to low confidence levels regarding the stability of reduced fractures; these implants should be used predominantly in fracture patterns in which internal fixation is subjected to minimal stress.

  5. Clinical and radiographic evaluation of biodegradable bone plates in the treatment of mandibular body fractures

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    Sherin Kamal Elhalawany

    2015-01-01

    Full Text Available Background: Many different systems are available for the treatment of fractures ranging from the heavy compression plates for mandibular reconstruction to low profile plates for mid-facial fixation, and are made either from stainless steel, titanium or vitallium. Recently, biodegradable, self-reinforced polylactide plates and screws have been used for the internal fixation of fractures of the mandible with good results. Aim of this study: This study evaluated clinically the biodegradable bone plates for treatment of mandibular body fracture and to evaluate bone healing during the follow-up period using digital radiography. Materials and Methods : Eight patients had been suffered from mandibular body fractures were treated using Inion CPS TM bioresorbable fixation system and the healing process were followed up using digitised panoramic radiography at first week and after 1, 3 and 6 months. Results: Clinical examination of fractured segments revealed stable fixation across the fracture sites while visual and quantitative assessment of radiograph showed healing process was comparable with results previously reported by titanium bone plates. Conclusion: Open reduction and internal fixation of mandibular fractures using bioresorbable fixation system with a brief period of inter-maxillary fixation have evolved to the point where the physical properties are sufficient to withstand the post-operative loads required for fracture repair of mandibular body fractures. The foreign body reaction is a major material-related problem which requires further studies.

  6. Biodegradable Materials for Bone Repairs: A Review

    Institute of Scientific and Technical Information of China (English)

    Lili Tan; Xiaoming Yu; Peng Wan; Ke Yang

    2013-01-01

    With attractive research and development of biomaterials,more and more opportunities have been brought to the treatments of human tissue repairs.The implant is usually no need to exist in the body accompanied with the recovery or regeneration of the tissue lesions,and the long-term effect of exotic substance to human body should be reduced as lower as possible.For this purpose,biodegradable materials,including polymers,magnesium alloys and ceramics,have attracted much attention for medical applications due to their biodegradable characters in body environment.This paper in turn introduces these three different types of widely studied biodegradable materials as well as their advantages as implants in applications for bone repairs.Relevant history and research progresses are summarized.

  7. Fixation Release and the Bone Bandaid: A New Bone Fixation Device Paradigm

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    Narges Shayesteh Moghaddam

    2017-01-01

    Full Text Available The current gold standard of care for mandibular segmental defeat reconstruction is the use of Ti-6Al-4V immobilization hardware and fibular double barrel graft. This method is often successful immediately at restoring mandible function, however the highly stiff fixation hardware causes stress shielding of the grafted bone and stress concentration in the fixation device over time which can lead to fixation device failure and revision surgery. The purpose of reconstructive surgery could be to create normal stress trajectories in the mandible following engraftment. We investigate the use of a two stage mechanism which separates the immobilization/healing and regenerative phases of mandibular segmental defect treatment. The device includes the use of a very stiff, Ti-6Al-4V, releasable mechanism which assures bone healing. Therefore it could be released once the reconstructed boney tissue and any of its ligamentous attachments have completely healed. Underneath the released Ti-6Al-4V plate would be a pre-loaded nitinol (NiTi wire-frame apparatus that facilitates the normal stress-strain trajectory through the engrafted bone after the graft is healed in place and the Ti-6Al-4V fixation device has been released. Due to the use of NiTi wires forming a netting that connects vascularized bone and possibly bone chips, bone grafts are also more likely to be incorporate rather than to resorb. We first evaluated a healthy adult mandible during normal mastication to obtain the normal stress-strain distribution. Then, we developed the finite element (FE model of the mandibular reconstruction (in the M1-3 region with the proposed fixation device during the healing (locked state and post-healing (released state periods. To recreate normal stress trajectory in the reconstructed mandible, we applied the Response Surface Methodology (RMS to optimize the Bone Bandaid geometry (i.e., wire diameters and location. The results demonstrate that the proposed mechanism

  8. Analysis of Bone Fixation Methods in Digital Replantation

    Science.gov (United States)

    Lee, Seung Woo; Kim, Jin Soo; Roh, Si Young; Lee, Kyung Jin

    2017-01-01

    Background Adequate fixation of replanted digits is essential not only for short-term healing but for long-term function. Various bony fixation methods using Kirschner (K-) and intraosseous wire are available in replantation. We examined clinical and radiographic outcomes of fixation methods on bone union after digital replantation. Methods A single institutional retrospective review identified 992 patients who had undergone 1,247 successful replantations between July 2009 and September 2015. Exclusion criteria included amputations of the distal phalanx, comminuted fractures, and intra-articular fractures. Patients were classified according to 5 categories of fixation methods: single K-wire, double longitudinal K-wires, cross K-wires, wire with, and wire without K-wire support. Bone union was evaluated by 5-month postoperative X-ray and fixation outcomes were compared across the 5 groups. Results The exclusion criteria were applied, and 88 patients with 103 replanted digits remained for analysis. Single K-wire fixation was used in 40 digits, double longitudinal K-wires in 30, and cross fixation in 14. Wire with and without K-wire support was required in 15 and 4 digits. Nonunion was observed in 32 digits (31.1%), of which 13 required additional operations such as bone graft or corrective osteotomy. The highest percent of nonunion was observed after cross fixation (35.7%) and the lowest after wire alone (25.0%). Conclusions In this study, contrary to general knowledge, we found that single K-wire fixation was not associated with poorer outcomes. Successful bone union outcomes may be achieved by careful selection of bone fixation methods. This study provides useful information for planning bone fixation in digital replantation. PMID:28194348

  9. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking...... bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA...

  10. Fixation of tibial plateau fractures with synthetic bone graft versus natural bone graft: a comparison study.

    LENUS (Irish Health Repository)

    Ong, J C Y

    2012-06-01

    The goal of this study was to determine differences in fracture stability and functional outcome between synthetic bone graft and natural bone graft with internal fixation of tibia plateau metaphyseal defects.

  11. Injectable calcium phosphate cement for bone repair and implant fixation.

    NARCIS (Netherlands)

    Jansen, J.; Ooms, E.M.; Verdonschot, N.J.J.; Wolke, J.G.C.

    2005-01-01

    The studies as described are aimed at determining the efficacy of newly developed calcium phosphate cement when this material is used as a bone defect filler or gap filler around metal implants. An overview is provided about bone graft substitutes and methods of metal implant fixation.

  12. Bone graft materials in fixation of orthopaedic implants in sheep.

    Science.gov (United States)

    Babiker, Hassan

    2013-07-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking skeletal bones. The osteoconductive properties of the composite might be improved by adding bone marrow aspirate (BMA), which can be harvested during surgery. Other alternatives to bone graft are demineralised bone matrix (DBM) and human cancellous bone (CB). DBM is prepared by acid extraction of human bone and includes bone collagen, morphogenetic proteins and growth factors. The combination of DBM with CB and with allograft might improve the healing potential of these grafts around non-cemented orthopaedic implants and thereby the implant fixation. Study I investigates the effect of HA/Collagen composite alone and in combination with BMA on the early fixation of porous coated titanium implants. In addition, the study compares also the effect of autograft with the gold standard allograft. By using a sheep model, the implants were inserted in the trabecular bone of femoral condyles. The test biomaterials were placed in a well defined peri-implant gap. After the observation period, the bone-implant specimens were harvested and evaluated mechanically by a destructive push

  13. Joint prosthesis and method of bone fixation

    NARCIS (Netherlands)

    Oosterom, R.; Van der Pijl, A.J; Bersee, H.E.N.; Van der Helm, F.C.; Herder, J.L

    2006-01-01

    The invention relates to a joint prosthesis (10), for example, a knee joint or shoulder joint prosthesis comprising a first, socket-holding prosthesis part (11) for attachment to a first bone (12) and a second, ball-holding prosthesis part (13) for attachment to a second bone (14) that intermates wi

  14. Mechanical design optimization of bioabsorbable fixation devices for bone fractures.

    Science.gov (United States)

    Lovald, Scott T; Khraishi, Tariq; Wagner, Jon; Baack, Bret

    2009-03-01

    Bioabsorbable bone plates can eliminate the necessity for a permanent implant when used to fixate fractures of the human mandible. They are currently not in widespread use because of the low strength of the materials and the requisite large volume of the resulting bone plate. The aim of the current study was to discover a minimally invasive bioabsorbable bone plate design that can provide the same mechanical stability as a standard titanium bone plate. A finite element model of a mandible with a fracture in the body region is subjected to bite loads that are common to patients postsurgery. The model is used first to determine benchmark stress and strain values for a titanium plate. These values are then set as the limits within which the bioabsorbable bone plate must comply. The model is then modified to consider a bone plate made of the polymer poly-L/DL-lactide 70/30. An optimization routine is run to determine the smallest volume of bioabsorbable bone plate that can perform and a titanium bone plate when fixating fractures of this considered type. Two design parameters are varied for the bone plate design during the optimization analysis. The analysis determined that a strut style poly-L-lactide-co-DL-lactide plate of 690 mm2 can provide as much mechanical stability as a similar titanium design structure of 172 mm2. The model has determined a bioabsorbable bone plate design that is as strong as a titanium plate when fixating fractures of the load-bearing mandible. This is an intriguing outcome, considering that the polymer material has only 6% of the stiffness of titanium.

  15. Bioreactor activated graft material for early implant fixation in bone

    DEFF Research Database (Denmark)

    Snoek Henriksen, Susan; Ding, Ming; Overgaard, Søren

    2011-01-01

    Introduction The combined incubation of a composite scaffold with bone marrow stromal cells in a perfusion bioreactor could make up a novel hybrid graft material with optimal properties for early fixation of implant to bone. The aim of this study was to create a bioreactor activated graft (BAG......) material, which could induce early implant fixation similar to that of allograft. Two porous scaffold materials incubated with cells in a perfusion bioreactor were tested in this study. Methods and Materials Two groups of 8 skeletally mature female sheep were anaesthetized before aspiration of bone marrow...... Technological Institute, Denmark). The granules were coated with poly-lactic acid (PLA) 12%, in order to increase the mechanical strength of the material (Phusis, France). Scaffold granules (Ø~900-1400 µm, 80% porosity) in group 2 consisted of pure HA/β-TCP (FinCeramica, Italy). For both groups, cells were...

  16. Biodegradable Polymers in Bone Tissue Engineering

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    Leon E. Govaert

    2009-07-01

    Full Text Available The use ofdegradable polymers in medicine largely started around the mid 20th century with their initial use as in vivo resorbing sutures. Thorough knowledge on this topic as been gained since then and the potential applications for these polymers were, and still are, rapidly expanding. After improving the properties of lactic acid-based polymers, these were no longer studied only from a scientific point of view, but also for their use in bone surgery in the 1990s. Unfortunately, after implanting these polymers, different foreign body reactions ranging from the presence of white blood cells to sterile sinuses with resorption of the original tissue were observed. This led to the misconception that degradable polymers would, in all cases, lead to inflammation and/or osteolysis at the implantation site. Nowadays, we have accumulated substantial knowledge on the issue of biocompatibility of biodegradable polymers and are able to tailor these polymers for specific applications and thereby strongly reduce the occurrence of adverse tissue reactions. However, the major issue of biofunctionality, when mechanical adaptation is taken into account, has hitherto been largely unrecognized. A thorough understanding of how to improve the biofunctionality, comprising biomechanical stability, but also visualization and sterilization of the material, together with the avoidance of fibrotic tissue formation and foreign body reactions, may greatly enhance the applicability and safety of degradable polymers in a wide area of tissue engineering applications. This review will address our current understanding of these biofunctionality factors, and will subsequently discuss the pitfalls remaining and potential solutions to solve these problems.

  17. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss.

    Science.gov (United States)

    Tomaszewski, P K; van Diest, M; Bulstra, S K; Verdonschot, N; Verkerke, G J

    2012-07-26

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system, Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanical issues such as considerable bone loss around the stem and peri-prosthetic bone fractures are present. To overcome these limiting issues a new concept of the direct intramedullary fixation was developed. We hypothesize that the new design will reduce the peri-prosthetic bone failure risk and adverse bone remodeling by restoring the natural load transfer in the femur. Generic CT-based finite element models of an intact femur and amputated bones implanted with 3 analyzed implants were created and loaded with a normal walking and a forward fall load. The strain adaptive bone remodeling theory was used to predict long-term bone changes around the implants and the periprosthetic bone failure risk was evaluated by the von Mises stress criterion. The results show that the new design provides close to physiological distribution of stresses in the bone and lower bone failure risk for the normal walking as compared to the OPRA and the ISP implants. The bone remodeling simulations did not reveal any overall bone loss around the new design, as opposed to the OPRA and the ISP implants, which induce considerable bone loss in the distal end of the femur. This positive outcome shows that the presented concept has a potential to considerably improve safety of the rehabilitation with the direct fixation implants.

  18. APPLICATION OF A BIODEGRADABLE MATERIAL FOR BONE REPLACEMENT IN TRAUMATOLOGY

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    T. V. Druzhinina

    2014-01-01

    Full Text Available 20 men (medium age (31.5 ± 13.5 years were studied. All patients underwent arthroscopic auditing plastic anterior cruciate ligament of the knee. Osteoregeneration dynamics were determined by biochemical testing of blood serum and X-ray computed tomography (CT of the fracture in 1–4 months after surgery. As a result, an estimation of the bone tissue reparative regeneration according to CT data in 10 patients with a defect of the patella, treated with the material is provided. The obtained results of the clinical study indicate the reparative effect of the biodegradable material for bone replacing on bone regeneration

  19. Autologous bone graft versus demineralized bone matrix in internal fixation of ununited long bones

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    Rubenbauer Bianka

    2009-12-01

    Full Text Available Abstract Background Non-unions are severe complications in orthopaedic trauma care and occur in 10% of all fractures. The golden standard for the treatment of ununited fractures includes open reduction and internal fixation (ORIF as well as augmentation with autologous-bone-grafting. However, there is morbidity associated with the bone-graft donor site and some patients offer limited quantity or quality of autologous-bone graft material. Since allogene bone-grafts are introduced on the market, this comparative study aims to evaluate healing characteristics of ununited bones treated with ORIF combined with either iliac-crest-autologous-bone-grafting (ICABG or demineralized-bone-matrix (DBM. Methods and results From 2000 to 2006 out of sixty-two consecutive patients with non-unions presenting at our Level I Trauma Center, twenty patients had ununited diaphyseal fractures of long bones and were treated by ORIF combined either by ICABG- (n = 10 or DBM-augmentation (n = 10. At the time of index-operation, patients of the DBM-group had a higher level of comorbidity (ASA-value: p = 0.014. Mean duration of follow-up was 56.6 months (ICABG-group and 41.2 months (DBM-group. All patients were clinically and radiographically assessed and adverse effects related to bone grafting were documented. The results showed that two non-unions augmented with ICABG failed osseous healing (20% whereas all non-unions grafted by DBM showed successful consolidation during the first year after the index operation (p = 0.146. No early complications were documented in both groups but two patients of the ICABG-group suffered long-term problems at the donor site (20% (p = 0.146. Pain intensity were comparable in both groups (p = 0.326. However, patients treated with DBM were more satisfied with the surgical procedure (p = 0.031. Conclusion With the use of DBM, the costs for augmentation of the non-union-site are more expensive compared to ICABG (calculated difference: 160

  20. Poly(L-lactide) bone plates and screws for internal fixation of mandibular swing osteotomies

    NARCIS (Netherlands)

    Tams, J; Rozema, FR; Bos, RRM; Roodenburg, JLN; Nikkels, PGJ; Vermey, A

    1996-01-01

    This study evaluated bone healing after mandibular swing osteotomies fixed with biodegradable poly(L-lactide) (PLLA) bone plates in four patients. A step osteotomy treated with two PLLA bone plates (n=3), and a straight osteotomy treated with one PLLA bone plate (n=1) were performed. Bone healing wa

  1. Development of a Three-Dimensional (3D Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft

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    Ying-Chao Chou

    2016-04-01

    Full Text Available This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

  2. Development of a Three-Dimensional (3D) Printed Biodegradable Cage to Convert Morselized Corticocancellous Bone Chips into a Structured Cortical Bone Graft.

    Science.gov (United States)

    Chou, Ying-Chao; Lee, Demei; Chang, Tzu-Min; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung; Ueng, Steve Wen-Neng

    2016-04-20

    This study aimed to develop a new biodegradable polymeric cage to convert corticocancellous bone chips into a structured strut graft for treating segmental bone defects. A total of 24 adult New Zealand white rabbits underwent a left femoral segmental bone defect creation. Twelve rabbits in group A underwent three-dimensional (3D) printed cage insertion, corticocancellous chips implantation, and Kirschner-wire (K-wire) fixation, while the other 12 rabbits in group B received bone chips implantation and K-wire fixation only. All rabbits received a one-week activity assessment and the initial image study at postoperative 1 week. The final image study was repeated at postoperative 12 or 24 weeks before the rabbit scarification procedure on schedule. After the animals were sacrificed, both femurs of all the rabbits were prepared for leg length ratios and 3-point bending tests. The rabbits in group A showed an increase of activities during the first week postoperatively and decreased anterior cortical disruptions in the postoperative image assessments. Additionally, higher leg length ratios and 3-point bending strengths demonstrated improved final bony ingrowths within the bone defects for rabbits in group A. In conclusion, through this bone graft converting technique, orthopedic surgeons can treat segmental bone defects by using bone chips but with imitate characters of structured cortical bone graft.

  3. Novel intramedullary-fixation technique for long bone fragility fractures using bioresorbable materials.

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    Takanobu Nishizuka

    Full Text Available Almost all of the currently available fracture fixation devices for metaphyseal fragility fractures are made of hard metals, which carry a high risk of implant-related complications such as implant cutout in severely osteoporotic patients. We developed a novel fracture fixation technique (intramedullary-fixation with biodegradable materials; IM-BM for severely weakened long bones using three different non-metallic biomaterials, a poly(l-lactide (PLLA woven tube, a nonwoven polyhydroxyalkanoates (PHA fiber mat, and an injectable calcium phosphate cement (CPC. The purpose of this work was to evaluate the feasibility of IM-BM with mechanical testing as well as with an animal experiment. To perform mechanical testing, we fixed two longitudinal acrylic pipes with four different methods, and used them for a three-point bending test (N = 5. The three-point bending test revealed that the average fracture energy for the IM-BM group (PLLA + CPC + PHA was 3 times greater than that of PLLA + CPC group, and 60 to 200 times greater than that of CPC + PHA group and CPC group. Using an osteoporotic rabbit distal femur incomplete fracture model, sixteen rabbits were randomly allocated into four experimental groups (IM-BM group, PLLA + CPC group, CPC group, Kirschner wire (K-wire group. No rabbit in the IM-BM group suffered fracture displacement even under full weight bearing. In contrast, two rabbits in the PLLA + CPC group, three rabbits in the CPC group, and three rabbits in the K-wire group suffered fracture displacement within the first postoperative week. The present work demonstrated that IM-BM was strong enough to reinforce and stabilize incomplete fractures with both mechanical testing and an animal experiment even in the distal thigh, where bone is exposed to the highest bending and torsional stresses in the body. IM-BM can be one treatment option for those with severe osteoporosis.

  4. Press-fit Femoral Fixation in ACL Reconstruction using Bone-Patellar Tendon-Bone Graft

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    Kaseb Mohammad Hasan

    2009-05-01

    Full Text Available Bone-patellar tendon auto graft is probably the most widely used graft for ACL reconstruction. Several methods for graft fixation have been described. To avoid intra-articular hardware we adopt biological fixation with a femoral trapezoidal press-fit fixation. A prospective study was performed on 30 consecutive active people who underwent ACL reconstruction with this technique by two surgeons between september2004 and march2007 (mean follow-up 15.2 months. Results were evaluated by an independent examiner using radiography, subjective and objective evaluation. Assessment using the IKDC knee scoring revealed 92% of the patients with a normal or nearly normal knee joint. Lysholm's score was 63.6(40- 86 preoperatively and 91.88(73-100 at the latest follow up (P < 0.005. No patient complained of instability at latest follow up. The quadriceps muscle showed mild atrophy at 3 and 6 months and at final follow-up. Five Patients complained of anterior knee pain and had a positive kneeling test. We found no graft displacement on follow up radiographs. All cases showed radiological evidence of graft osteointegration at last follow up. Our results show that press-fit fixation of trapezoidal bone graft in femoral tunnel is a simple, reliable, and cost-effective alternative for ACL recon-struction using bone-patellar tendon-bone graft.

  5. Treatment of tibial defect and bone nonunion with limb shortening with external fixator and reconstituted bone xenograft

    Institute of Scientific and Technical Information of China (English)

    王志刚; 刘建; 胡蕴玉; 孟国林; 金格勒; 袁志; 王海强; 戴先文

    2003-01-01

    Objective: To explore the effect of external fixator and reconstituted bone xenograft (RBX) in the treatment of tibial bone defect, tibial bone nonunion and congenital pseudarthrosis of the tibia with limb shortening. Methods: Twenty patients ( 13 males and 7 females) with tibial bone defect, tibial bone nonunion or congenital pseudarthrosis of the tibia with limb shortening were treated with external fixation. Two kinds of external fixators were used: a half ring sulcated external fixator used in 13 patients and a combined external fixator in 7 patients. Foot-drop was corrected at the same time with external fixation in 4 patients. The shortened length of the tibia was in the range of 2-9 cm, with an average of 4.8 cm. For bone grafting, RBX was used in 12 patients, autogenous ilium was used in 3 patients and autogenous fibula was implanted as a bone plug into the medullary canal in 1 case, and no bone graft was used in 4 patients. Results: All the 20 patients were followed-up for 8 months to 7 years, averaging 51 months. Satisfactory function of the affected extremities was obtained. All the shortened extremities were lengthened to the expected length. For all the lengthening area and the fracture sites, bone union was obtained at the last. The average healing time of 12 patients treated with RBX was 4.8 months. Conclusions: Both the half ring sulcated external fixator and the combined external fixator have the advantages of small trauma, simple operation, elastic fixation without stress shielding and non-limitation from local soft tissue conditions, and there is satisfactory functional recovery of affected extremities in the treatment of tibial bone defects, tibial bone nonunion and congenital pseudarthrosis of the tibia combined with limb shortening. RBX has good biocompatibility and does not cause immunological rejections. It can also be safely used in treatment of bone nonunion and has reliable effect to promote bone healing.

  6. Surgical treatment of zygomatic bone fracture using two points fixation versus three point fixation-a randomised prospective clinical trial

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    Rana Majeed

    2012-04-01

    Full Text Available Abstract Background The zygoma plays an important role in the facial contour for both cosmetic and functional reasons; therefore zygomatic bone injuries should be properly diagnosed and adequately treated. Comparison of various surgical approaches and their complications can only be done objectively using outcome measurements which in turn require protocol management and long-term follow up. The preference for open reduction and internal fixation of zygomatic fractures at three points has continued to grow in response to observations of inadequate results from two point and one point fixation techniques. The objectives of this study were to compare the efficacy of zygomatic bone after treatment with ORIF using 2 point fixation and ORIF using 3 point fixation and compare the outcome of two procedures. Methods 100 patients were randomly divided equally into two groups. In group A, 50 patients were treated by ORIF using two point fixation by miniplates and in group B, 50 patients were treated by ORIF using three point fixation by miniplates. They were evaluated for their complications during and after surgery with their advantages and disadvantages and the difference between the two groups was observed. Results A total of 100 fractures were sustained. We found that postoperative complication like decreased malar height and vertical dystopia was more common in those patients who were treated by two point fixation than those who were treated with three point fixation. Conclusions Based on this study open reduction and internal fixation using three point fixation by miniplates is the best available method for the treatment zygomatic bone fractures.

  7. Biodegradable Polymer-Based Scaffolds for Bone Tissue Engineering

    CERN Document Server

    Sultana, Naznin

    2013-01-01

    This book addresses the principles, methods and applications of biodegradable polymer based scaffolds for bone tissue engineering. The general principle of bone tissue engineering is reviewed and the traditional and novel scaffolding materials, their properties and scaffold fabrication techniques are explored. By acting as temporary synthetic extracellular matrices for cell accommodation, proliferation, and differentiation, scaffolds play a pivotal role in tissue engineering. This book does not only provide the comprehensive summary of the current trends in scaffolding design but also presents the new trends and directions for scaffold development for the ever expanding tissue engineering applications.

  8. Assessment of activated porous granules on implant fixation and early bone formation in sheep

    Directory of Open Access Journals (Sweden)

    Ming Ding

    2016-04-01

    Conclusion: In conclusion, despite nice bone formation and implant fixation in all groups, bioreactor activated graft material did not convincingly induce early implant fixation similar to allograft, and neither bioreactor nor by adding BMA credited additional benefit for bone formation in this model.

  9. Outcome of rail fixator system in reconstructing bone gap

    Directory of Open Access Journals (Sweden)

    Amit Lakhani

    2014-01-01

    Conclusion: All patients well tolerated rail fixator with good functional results and gap reconstruction. Easy application of rail fixator and comfortable distraction procedure suggest rail fixator a good alternative for gap reconstruction of limbs.

  10. The effects of bone marrow aspirate, bone graft, and collagen composites on fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Sandri, Monica

    2012-01-01

    contamination, and non union as well as the potential risk of disease transmission. Hydroxyapatite and collagen composites (HA/Collagen) have the potential in mimicking and replacing skeletal bones. This study attempted to determine the effects of newly developed HA/Collagen-composites with and without bone...... marrow aspirate (BMA) on enhancement of bone implant fixation. Method: Titanium alloy implants were inserted into bilateral femoral condyles of eight skeletally mature sheep, four implants per sheep. The implant had a circumferential gap of 2 mm. The gap was filled with: HA/Collagen; HA/Collagen...... and histomorphometry between autograft and allograft groups. The implants in both the HA/Collagen and HA/Collagen-BMA groups were mostly surrounded by fibrous tissue. Thus, mechanical testing of these samples was impossible. The histomorphometry results showed significantly more new bone and bone ongrowth...

  11. An in vivo evaluation of PLLA/PLLA-gHA nano-composite for internal fixation of mandibular bone fractures.

    Science.gov (United States)

    Peng, Weihai; Zheng, Wei; Shi, Kai; Wang, Wangshu; Shao, Ying; Zhang, Duo

    2015-11-09

    Internal fixation of bone fractures using biodegradable poly(L-lactic-acid) (PLLA)-based materials has attracted the attention of many researchers. In the present study, 36 male beagle dogs were randomly assigned to two groups: PLLA/PLLA-gHA (PLLA-grafted hydroxyapatite) group and PLLA group. PLLA/PLLA-gHA and PLLA plates were embedded in the muscular bags of the erector spinae and also implanted to fix mandibular bone fractures in respective groups. At 1, 2, 3, 6, 9, and 12 months postoperatively, the PLLA/PLLA-gHA and PLLA plates were evaluated by adsorption and degradation tests, and the mandibles were examined through radiographic analysis, biomechanical testing, and histological analysis. The PLLA/PLLA-gHA plates were non-transparent and showed a creamy white color, and the PLLA plates were transparent and faint yellow in color. At all time points following surgery, adsorption and degradation of the PLLA/PLLA-gHA plates were significantly less than those of the PLLA plates, and the lateral and longitudinal bending strengths of the surgically treated mandibles of the beagle dogs in the PLLA/PLLA-gHA group were significantly greater than those of the PLLA group and reached almost the value of intact mandibles at 12 months postoperatively. Additionally, relatively rapid bone healing was observed in the PLLA/PLLA-gHA group with the formation of new lamellar bone tissues at 12 months after the surgery. The PLLA/PLLA-gHA nano-composite can be employed as a biodegradable material for internal fixation of mandibular bone fractures.

  12. Calcium phosphate cement augmentation of cancellous bone screws can compensate for the absence of cortical fixation.

    Science.gov (United States)

    Stadelmann, Vincent A; Bretton, Elise; Terrier, Alexandre; Procter, Philip; Pioletti, Dominique P

    2010-11-16

    An obvious means to improve the fixation of a cancellous bone screw is to augment the surrounding bone with cement. Previous studies have shown that bone augmentation with Calcium Phosphate (CaP) cement significantly improves screw fixation. Nevertheless, quantitative data about the optimal distribution of CaP cement is not available. The present study aims to show the effect of cement distribution on the screw fixation strength for various cortical thicknesses and to determine the conditions at which cement augmentation can compensate for the absence of cortical fixation in osteoporotic bone. In this study, artificial bone materials were used to mimic osteoporotic cancellous bone and cortical bone of varying thickness. These bone constructs were used to test the fixation strength of cancellous bone screws in different cortical thicknesses and different cement augmentation depths. The cement distribution was measured with microCT. The maximum pullout force was measured experimentally. The microCT analysis revealed a pseudo-conic shape distribution of the cement around the screws. While the maximum pullout strength of the screws in the artificial bone only was 30±7N, it could increase up to approximately 1000N under optimal conditions. Cement augmentation significantly increased pullout force in all cases. The effect of cortical thickness on pullout force was reduced with increased cement augmentation depth. Indeed, cement augmentation without cortical fixation increased pullout forces over that of screws without cement augmentation but with cortical fixation. Since cement augmentation significantly increased pullout force in all cases, we conclude that the loss of cortical fixation can be compensated by cement augmentation.

  13. Periosteal augmentation of allograft bone and its effect on implant fixation - an experimental study on 12 dogs()

    DEFF Research Database (Denmark)

    Barckman, Jeppe; Baas, Jorgen; Sørensen, Mette;

    2013-01-01

    Periosteum provides essential cellular and biological components necessary for fracture healing and bone repair. We hypothesized that augmenting allograft bone by adding fragmented autologous periosteum would improve fixation of grafted implants.......Periosteum provides essential cellular and biological components necessary for fracture healing and bone repair. We hypothesized that augmenting allograft bone by adding fragmented autologous periosteum would improve fixation of grafted implants....

  14. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Directory of Open Access Journals (Sweden)

    Yun-Gang Luo

    2015-01-01

    Full Text Available Background: We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae. Methods: Twenty-four goats aged 2-3 years had Cosmic ® pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group. Results: In the static control group, new bone was formed around the pedicle screw and on the screw surface. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest (ROI in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05, but were lower in the fixed groups than the static control group (P 0.05; however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01. Conclusions: Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.

  15. The effect of bone marrow aspirate, bone graft and collagen composites on fixation of bone implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2007-01-01

    to be sought. Hydroxyapatite and collagen composites have the potential in mimicking and replacing skeletal bones. Aim: This study attempted to determine the effect of hydroxyapatite/collagen composites in the fixation of bone implants. The composites used in this study is produced by Institute of Science...... of the Biomedical Laboratories, University of Southern Denmark, Odense. The observation period was 5 weeks. The sheeps were euthanized and both of femurs were harvested and sectioned in two parts by using a water-cooled diamond band saw. Specimens for mechanical testing were always taken from the most superficial...

  16. Surgical treatment of zygomatic bone fracture using two points fixation versus three point fixation-a randomised prospective clinical trial

    OpenAIRE

    2012-01-01

    Abstract Background The zygoma plays an important role in the facial contour for both cosmetic and functional reasons; therefore zygomatic bone injuries should be properly diagnosed and adequately treated. Comparison of various surgical approaches and their complications can only be done objectively using outcome measurements which in turn require protocol management and long-term follow up. The preference for open reduction and internal fixation of zygomatic fractures at three points has con...

  17. Biodegradable versus tutanium plates and screws in maxillofacial surgery

    NARCIS (Netherlands)

    van Bakelen, Nicolaas

    2014-01-01

    Nowadays, titanium is regarded as the ‘golden standard’ for fixation of bone segments. It appears to be necessary that titanium is removed following bone healing in a second operation in 5-40% of the cases. Biodegradable fixation systems have been developed to dissolve gradually in the human body in

  18. Decision-making considerations in application of biodegradable fixation systems in maxillofacial surgery--a retrospective cohort study.

    Science.gov (United States)

    van Bakelen, N B; Buijs, G J; Jansma, J; de Visscher, J G A M; Hoppenreijs, Th J M; Bergsma, J E; Stegenga, B; Bos, R R M

    2014-07-01

    In a recent RCT comparing biodegradable (Inion CPS) with titanium (KLS Martin) plates and screws for fixation of osteotomies or fractures, we found that in 21% of the cases the surgeon decided intra-operatively to switch from biodegradable to titanium. The aim of the current retrospective cohort study was to analyse the reasons for these switches in order to find predictor variables that may be helpful in the decision to use biodegradable devices or not. The surgeons' opinion about the biodegradable system, and if there was a learning curve in the application of the biodegradable system were also investigated. All variables were assessed during the original RCT by using a questionnaire that was completed by the OMF surgeon directly post-operatively. For the outcome variable "surgeons' opinion" a separate questionnaire was used. Regarding the predictor variables a mandibular fracture had a higher risk of switching compared to a BSSO. However, looking at the reasons for these switches no firm conclusions can be drawn. There was a subjective learning curve to acquire the application-skills for the biodegradable system. There were no changes in isolated Le-Fort-I osteotomies despite the fact that the biodegradable system seems more difficult to apply in the midface. Inadequate stability was the main reason for switching. This can be material-related, or related to inexperience with or lack of confidence in the system, or impatience of the surgeon. A learning curve and personal preferences probably play an important role in the decision to switch. We think that with more patience and more experience it should be possible to increase both user comfort and confidence in the biodegradable system of Inion CPS, which likely will decrease the number of intra-operative switches.

  19. Study of Bone-screw Surface Fixation in Lumbar Dynamic Stabilization

    Institute of Scientific and Technical Information of China (English)

    Yun-Gang Luo; Tao Yu; Guo-Min Liu; Nan Yang

    2015-01-01

    Background:We aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone,and determine whether pedicle screws achieve good mechanical stability in the vertebrae.Methods:Twenty-four goats aged 2-3 years had Cosmic(R) pedicle screws implanted into both sides of the L2-L5 pedicles.Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5.Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine.The side that was not implanted with fixation rods was used as a static control group.Results:In the static control group,new bone was formed around the pedicle screw and on the screw surface.In the unilateral and bilateral dynamic fixation groups,large amounts of connective tissue formed between and around the screw threads,with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed.The bone mineral density and morphological parameters of the region of interest (ROI) in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05),but were lower in the fixed groups than the static control group (P < 0.05).This showed the description bone of the ROI in the static control group was greater than in the fixation groups.Under loading conditions,the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups (P > 0.05); however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01).Conclusions:Fibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation,and the pedicle screws lost mechanical stability in the vertebrae.

  20. Engineered polycaprolactone-magnesium hybrid biodegradable porous scaffold for bone tissue engineering

    Institute of Scientific and Technical Information of China (English)

    Hoi Man Wong; Paul K. Chu; Frankie K.L. Leung; Kenneth M.C. Cheung; Keith D.K. Luk; Kelvin W.K. Yeung

    2014-01-01

    In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone (PCL) and magnesium (Mg) micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150%by incorporating 29%Mg particles with the porosity of 74%using Micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236%when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and Mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

  1. Engineered polycaprolactone–magnesium hybrid biodegradable porous scaffold for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Hoi Man Wong

    2014-10-01

    Full Text Available In this paper, we describe the fabrication of a new biodegradable porous scaffold composed of polycaprolactone (PCL and magnesium (Mg micro-particles. The compressive modulus of PCL porous scaffold was increased to at least 150% by incorporating 29% Mg particles with the porosity of 74% using Micro-CT analysis. Surprisingly, the compressive modulus of this scaffold was further increased to at least 236% when the silane-coupled Mg particles were added. In terms of cell viability, the scaffold modified with Mg particles significantly convinced the attachment and growth of osteoblasts as compared with the pure PCL scaffold. In addition, the hybrid scaffold was able to attract the formation of apatite layer over its surface after 7 days of immersion in normal culture medium, whereas it was not observed on the pure PCL scaffold. This in vitro result indicated the enhanced bioactivity of the modified scaffold. Moreover, enhanced bone forming ability was also observed in the rat model after 3 months of implantation. Though bony in-growth was found in all the implanted scaffolds. High volume of new bone formation could be found in the Mg/PCL hybrid scaffolds when compared to the pure PCL scaffold. Both pure PCL and Mg/PCL hybrid scaffolds were degraded after 3 months. However, no tissue inflammation was observed. In conclusion, these promising results suggested that the incorporation of Mg micro-particles into PCL porous scaffold could significantly enhance its mechanical and biological properties. This modified porous bio-scaffold may potentially apply in the surgical management of large bone defect fixation.

  2. Modulation of fixation stiffness from flexible to stiff in a rat model of bone healing.

    Science.gov (United States)

    Bartnikowski, Nicole; Claes, Lutz E; Koval, Lidia; Glatt, Vaida; Bindl, Ronny; Steck, Roland; Ignatius, Anita; Schuetz, Michael A; Epari, Devakara R

    2016-11-14

    Background and purpose - Constant fixator stiffness for the duration of healing may not provide suitable mechanical conditions for all stages of bone repair. We therefore investigated the influence of stiffening fixation on callus stiffness and morphology in a rat diaphyseal osteotomy model to determine whether healing time was shortened and callus stiffness increased through modulation of fixation from flexible to stiff. Material and methods - An external unilateral fixator was applied to the osteotomized femur and stiffened by decreasing the offset of the inner fixator bar at 3, 7, 14, and 21 days after operation. After 5 weeks, the rats were killed and healing was evaluated with mechanical, histological, and microcomputed tomography methods. Constant fixation stiffness control groups with either stiff or flexible fixation were included for comparison. Results - The callus stiffness of the stiff group and all 4 experimental groups was greater than in the flexible group. The callus of the flexible group was larger but contained a higher proportion of unmineralized tissue and cartilage. The stiff and modulated groups (3, 7, 14, and 21 days) all showed bony bridging at 5 weeks, as well as signs of callus remodeling. Stiffening fixation at 7 and 14 days after osteotomy produced the highest degree of callus bridging. Bone mineral density in the fracture gap was highest in animals in which the fixation was stiffened after 14 days. Interpretation - The predicted benefit of a large robust callus formed through early flexible fixation could not be shown, but the benefits of stabilizing a flexible construct to achieve timely healing were demonstrated at all time points.

  3. MODELING OF BONE FRAGMENTS FIXATION WITH AN EXTERNAL FIXATION DEVICE FOR BILATERAL ROTATION UNSTABLE PELVIC INJURIES B TYPE ACCORDING TO AO/ASIF CLASSIFICATION

    Directory of Open Access Journals (Sweden)

    V. G. Vinogradov

    2014-01-01

    Full Text Available Objective: to determine the stability of bone fragments fixation with an external fixation device in the simulation of bilateral partly unstable pelvic injuries of B type according to AO/ASIF classification and to identify the role of different fixation elements in the stability of fixation. Material and methods: the study was performed on the finite element model of a system “an external fixation device - pelvis” developed for a software package MSCNastran. Formation of a fracture of pubic and ischial pelvic bones was accomplished by means of rupture in the finite element network and decrease of elasticity modulus in the ilio-sacral joint on both sides up to 35 mm at the site of a fracture. Loads were carried on top of the body of the first sacral vertebra with a force of 500H.The second area of application of the load was from the bottom-up on the acetabular roof with a force of 250H. In this study the effect of different elements of an external fixation device on the stiffness of bone fragments fixation was evaluated. Symmetrical elements were removed both separately and together. As a result, the stiffness of a system decreased and the displacement at the fracture site increased. Conclusion: in a model of partly stable pelvic injuries accompanied by general rotation instability in the horizontal and sagittal planes to 35 mm, an external fixation device provided high stability of bone fragments (to 3 mm due to introduction of bone rods in the iliac wings with the obligatory introduction of the rod in the vertical branches of pubic bones and strengthening the anterior lower bar between the subsystems. What is more, installing the anterior upper bar or introduction of bone rods in the bodies of iliac bone are not necessary.

  4. Demineralized bone matrix and human cancellous bone enhance fixation of porous-coated titanium implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    2016-01-01

    Allogenic bone graft has been considered the gold standard in connection with bone graft material in revision joint arthroplasty. However, the lack of osteogenic potential and the risk of disease transmission are clinical challenges. The use of osteoinductive materials, such as demineralized bone...... of DBM alone, DBM with CB, or allograft on the fixation of porous-coated titanium implants. DBM100 and CB produced from human tissue were included. Both materials are commercially available. DBM granules are placed in pure DBM and do not contain any other carrier. Titanium alloy implants, 10 mm long × 10...... (gold standard), respectively. A standardized surgical procedure was used. At sacrifice 6 weeks after implantation, both distal femurs were harvested. The implant fixation was evaluated by mechanical push-out testing to test shear mechanical properties between implant and the host bone...

  5. Timing of long bone fracture fixation in severe traumatic brain injury.

    Science.gov (United States)

    Jamjoom, Bakur A; Jamjoom, Abdulhakim B

    2012-04-01

    We present a review of the published evidence on the optimal timing for long bone fracture fixation in severe traumatic brain injury (TBI); a matter that remains under debate. Fifteen retrospective articles (level II-3 evidence) were considered suitable for the review. We conclude that the published evidence does not provide a definitive answer to the optimal timing of long bone fracture surgery in severe TBI, and a randomized controlled trial is required. We recommend a safe strategy that combines damage control surgery with a period of monitoring of intracranial pressure, cerebral perfusion pressure, and if available brain tissue oxygen until the patient is considered fit for the fracture fixation.

  6. Bone compaction enhances fixation of weightbearing titanium implants

    DEFF Research Database (Denmark)

    Kold, Søren Vedding; Rahbek, Ole; Vestermark, Marianne Toft;

    2005-01-01

    Implant stability is crucial for implant survival. A new surgical technique, compaction, has increased in vitro implant stability and in vivo fixation of nonweightbearing implants. However, the in vivo effects of compaction on weightbearing implants are unknown. As implants inserted clinically...... are weightbearing, the effects of compaction on weightbearing implants were examined. The hypothesis was that compaction would increase implant fixation compared with conventional drilling. Porous-coated titanium implants were inserted bilaterally into the weightbearing portion of the femoral condyles of dogs....... In each dog, one knee had the implant cavity prepared with drilling, and the other knee was prepared with compaction. Eight dogs were euthanized after 2 weeks, and eight dogs were euthanized after 4 weeks. Femoral condyles from an additional eight dogs represented Time 0. Compacted specimens had higher...

  7. Is there enough evidence to regularly apply bone screws for intermaxillary fixation in mandibular fractures?

    NARCIS (Netherlands)

    A. Bins; M.A.E. Oomens; P. Boffano; T. Forouzanfar

    2015-01-01

    Purpose Intermaxillary fixation (IMF) is traditionally achieved with arch bars; however, this method has several well-known disadvantages and other techniques, such as bone screws, are available. This study evaluated current evidence regarding these IMF screws (IMFSs) for mandibular trauma and to as

  8. FIBULA AND ILIAC BONE GRAFTING WITH INTERNAL FIXATION FOR GAINT CELL TUMOUR OF PROXIMAL TIBIA

    Directory of Open Access Journals (Sweden)

    Nishant Gaonkar

    2015-02-01

    Full Text Available Middle aged old female with swelling in left knee suggestive of giant cell tumour was treated with excisional biopsy with curettage, phenol cauterisation , bone graft and proximal tibia locking plate fixation. Sample sent for histopathology was consistent with diagnosis of giant cell tumour. No recurrence has been seen after 1 year of follow up.

  9. Bioabsorbable bone fixation plates for X-ray imaging diagnosis by a radiopaque layer of barium sulfate and poly(lactic-co-glycolic acid).

    Science.gov (United States)

    Choi, Sung Yoon; Hur, Woojune; Kim, Byeung Kyu; Shasteen, Catherine; Kim, Myung Hun; Choi, La Mee; Lee, Seung Ho; Park, Chun Gwon; Park, Min; Min, Hye Sook; Kim, Sukwha; Choi, Tae Hyun; Choy, Young Bin

    2015-04-01

    Bone fixation systems made of biodegradable polymers are radiolucent, making post-operative diagnosis with X-ray imaging a challenge. In this study, to allow X-ray visibility, we separately prepared a radiopaque layer and attached it to a bioabsorbable bone plate approved for clinical use (Inion, Finland). We employed barium sulfate as a radiopaque material due to the high X-ray attenuation coefficient of barium (2.196 cm(2) /g). The radiopaque layer was composed of a fine powder of barium sulfate bound to a biodegradable material, poly(lactic-co-glycolic acid) (PLGA), to allow layer degradation similar to the original Inion bone plate. In this study, we varied the mass ratio of barium sulfate and PLGA in the layer between 3:1 w/w and 10:1 w/w to modulate the degree and longevity of X-ray visibility. All radiopaque plates herein were visible via X-ray, both in vitro and in vivo, for up to 40 days. For all layer types, the radio-opacity decreased with time due to the swelling and degradation of PLGA, and the change in the layer shape was more apparent for layers with a higher PLGA content. The radiopaque plates released, at most, 0.5 mg of barium sulfate every 2 days in a simulated in vitro environment, which did not appear to affect the cytotoxicity. The radiopaque plates also exhibited good biocompatibility, similar to that of the Inion plate. Therefore, we concluded that the barium sulfate-based, biodegradable plate prepared in this work has the potential to be used as a fixation device with both X-ray visibility and biocompatibility.

  10. Guided bone regeneration with a synthetic biodegradable membrane: a comparative study in dogs

    OpenAIRE

    Jung, R E; Kokovic, V; Jurisic, M; Yaman, D; K. Subramani; Weber, F. E.

    2011-01-01

    Objectives: The aim of the present study was to compare a newly developed biodegradable polylactide/polyglycolide/N-methyl-2-pyrrolidone (PLGA/NMP) membrane with a standard resorbable collagen membrane (RCM) in combination with and without the use of a bone substitute material (deproteinized bovine bone mineral [DBBM]) looking at the proposed tenting effect and bone regeneration. Materials and methods: In five adult German sheepdogs, the mandibular premolars P2, P3, P4, and the molar M1 were ...

  11. Ergotropic effect of bone cement on pedicle screw fixation in treatment of osteoporotic thoracolumbar fracture

    Directory of Open Access Journals (Sweden)

    Da LIU

    2017-02-01

    Full Text Available Objective To evaluate the ergotropic effect of bone cement on pedicle screw fixation in treatment of osteopo¬rotic thoracolumbar fracture. Methods Fifty-three patients with osteoporotic thoracolumbar fracture, admitted from Jun. 2013 to Dec. 2014, were included for treatment by augmentation of pedicle screw fixation with bone cement. All patients underwent pre-operative examination of bone mineral density with T-score ≤-2.5 and augmentation of pedicle screw fixation with injection of 1.5 ml bone cement in adjacent to fractured vertebra. All patients were treated with anti-osteoporosis therapy pre- and post-operation, ob¬served and recorded with basic conditions and complications. At pre-operation, one-week post-operation and last follow-up, pain vi¬sual analogue scale (VAS and neurological function score (ASIA of all patients were recorded, and the compression rats of anterior and posterior edge of fractured vertebra, and compression rats of spinal canal and Cobb angel of all patients were measured. Results All the 53 patients were successfully undergone operation in about 90-140 min with blood loss of about 150-350 ml. No spinal cord or nerve injury, dural tear and obvious leakage of bone cement and screw loosening occurred during operation. All patients were followed up for 12 to 36 months and the neurological function obviously recovered contrasted with pre-operation. X-ray and CT examination at last follow-up showed good fractures healing, good position and non-loosening of internal fixation device and non-leakage of bone cement. At one week post-operation and last follow-up, VAS, compression rats of anterior edge and posterior edge of fractured vertebra, compression rats of spinal canal and Cobb angel were significantly lower than those at pre-operation (P0.05. Conclusions Augmentation of pedicle screw fixation with bone cement can effectively strengthen the initial stability of pedicle screw in osteo¬porosis, restore the

  12. Bone compaction enhances implant fixation in a canine gap model

    DEFF Research Database (Denmark)

    Kold, Søren; Rahbek, Ole; Toft, Marianne;

    2005-01-01

    implants and bone. However, it is unknown whether the compression and breakage of trabeculae during the compaction procedure results in impaired gap-healing of compacted bone. Therefore, we compared compaction with conventional drilling in a canine gap model. Grit-blasted titanium implants (diameter 6 mm......) were bilaterally inserted into cavities initially expanded to 8 mm diameters in the proximal humeri. Each dog served as its own control; thus, one humerus had the implant cavity prepared with compaction, the other with drilling. Eight dogs were euthanized after 2 weeks, and 7 dogs after 4 weeks. Humeri...... from additional 7 dogs represented time 0. At time 0 a spring-back effect of compacted bone was demonstrated as cavities, initially expanded to 8 mm by compaction, were reduced to a median cavity diameter of 6.6 mm. In contrast, cavities initially expanded to 8 mm by drilling, had a median cavity...

  13. Observations concerning different patterns of bone healing using the Point Contact Fixator (PC-Fix) as a new technique for fracture fixation.

    Science.gov (United States)

    Hofer, H P; Wildburger, R; Szyszkowitz, R

    2001-09-01

    The recent trend in all surgical disciplines has been the development of techniques in minimally invasive surgery and the optimal maintenance of the blood supply to the bone fragments during osteosynthesis. Currently, the Point Contact Fixator (PC-Fix) has been introduced as a new implant for the stabilization of forearm bones. This plate-like splint and screw fixation system, which actually acts as an internal fixator, is characterized by minimized isolated contacts to the bone and proven angular stability of the monocortically locked screws. By using the PC-Fix, a further reduction of damage to the blood supply to the bone is achieved. Since 1994, 38 patients have been treated with this new device; we have reviewed the radiographs of 52 consolidated forearm fractures/osteotomies in accordance with the patterns of bone healing associated with the different methods of implant application according to the fracture type. In the groups in which traditionally precise reduction, interfragmentary compression and stable fixation was achieved (N=31), we found in 71% an absence of periosteal callus (direct bone healing). In the groups in which compression and adaptation were combined, or even main fragments adapted without compression, with wedges remaining unreduced in soft tissue connection (N=21), we found a visible external callus in 81% (indirect healing) (P = 0.002). Indirect healing after internal fixation is no longer regarded as a disturbance to healing, but is a goal in itself. The appearance of callus is a welcome sign indicating a prompt and positive reaction in the course of bone union which will lead to progressive fracture immobilization. When using the PC-Fix in a "biological way", callus formation and solid union take place earlier than in conventional plating. The new internal fixator offers substantial technical and mechanical advantages in fracture treatment. Therefore, it is an ideal implant to satisfy the requirements of modern biological

  14. External fixation of femoral defects in athymic rats: Applications for human stem cell implantation and bone regeneration

    Directory of Open Access Journals (Sweden)

    Terasa Foo

    2013-01-01

    Full Text Available An appropriate animal model is critical for the research of stem/progenitor cell therapy and tissue engineering for bone regeneration in vivo. This study reports the design of an external fixator and its application to critical-sized femoral defects in athymic rats. The external fixator consists of clamps and screws that are readily available from hardware stores as well as Kirschner wires. A total of 35 rats underwent application of the external fixator with creation of a 6-mm bone defect in one femur of each animal. This model had been used in several separate studies, including implantation of collagen gel, umbilical cord blood mesenchymal stem cells, endothelial progenitor cells, or bone morphogenetic protein-2. One rat developed fracture at the proximal pin site and two rats developed deep tissue infection. Pin loosening was found in nine rats, but it only led to the failure of external fixation in two animals. In 8 to 10 weeks, various degrees of bone growth in the femoral defects were observed in different study groups, from full repair of the bone defect with bone morphogenetic protein-2 implantation to fibrous nonunion with collagen gel implantation. The external fixator used in these studies provided sufficient mechanical stability to the bone defects and had a comparable complication rate in athymic rats as in immunocompetent rats. The external fixator does not interfere with the natural environment of a bone defect. This model is particularly valuable for investigation of osteogenesis of human stem/progenitor cells in vivo.

  15. Modeling and simulation of physical performance of a external unilateral mechatronic orthopaedic fixator - bone system.

    Science.gov (United States)

    Lesniewska, A; Choromanski, W; Deszczynski, J; Dobrzynski, G

    2006-01-01

    Restricted element study of the fracture healing by external fixation device was investigated. The analyses were performed under an axial and variable loaded boundary conditions. The effect of different fracture size and different distance between bone and the external fixator device on the stress distribution was investigated. The results show that stresses in the external fixator device are highest at the beginning of the fracture healing process, and are gradually decreasing with the time of the treatment. The analyses were carried out using the commercial package CATIA P3 V5R11. This allowed to build a three-dimensional model more similar to the geometrical architecture of the long bone as well as of the external fixator. Three-dimensional restricted element model also allowed a collection of more realistic results. However, the accuracy of the results depends not only on the quality of the model geometry but also on the material properties assigned to the model components. It also depends on the accuracy in the simulation of the finite element model and the optimized mesh generation.

  16. Histomorphometric evaluation of bone healing in rabbit fibular osteotomy model without fixation

    Directory of Open Access Journals (Sweden)

    Paixão Fabio B

    2008-01-01

    Full Text Available Abstract Background Animal models of fracture consolidation are fundamental for the understanding of the biological process of bone repair in humans, but histological studies are rare and provide only qualitative results. The objective of this article is to present the histomorphometric study of the bone healing process using an experimental model of osteotomy in rabbit fibula without interference of synthesis material. Methods Fifteen rabbits were submitted to fibular osteotomy without any fixation device. Groups of five animals were submitted to pharmacological euthanasia during a period of one (group A, two (group B and four weeks (group C after osteotomy. Histomorphometric evaluation was performed in the histological sections. Results During week one there was intense cellularity (67/field, a large amount of woven bone (75.7% and a small amount of lamellar bone (7.65%. At two weeks there was a decrease in woven bone (41.59% and an increase in lamellar bone (15.16%. At four weeks there was a decrease of cellularity (19.17/field and lamellar bone (55.56% exceeded the quantity of woven bone (31.68%. Conclusion Histomorphometric (quantitative evaluation of the present study was shown to be compatible with bone healing achieved in qualitative experimental models that have been commended in the literature.

  17. Simulated bone remodeling around two types of osseointegrated implants for direct fixation of upper-leg prostheses

    NARCIS (Netherlands)

    Tomaszewski, P.K.; Verdonschot, N.; Bulstra, S.K.; Rietman, J.S.; Verkerke, G.J.

    2012-01-01

    Direct attachment of an upper leg prosthesis to the skeletal system by a percutaneous implant is an alternative solution to the traditional socket fixation. In this study, we investigated long-term periprosthetic bone changes around two types of fixation implants using two different initial conditio

  18. Bone compaction enhances fixation of weight-bearing hydroxyapatite-coated implants

    DEFF Research Database (Denmark)

    Kold, Søren; Rahbek, Ole; Vestermark, Marianne;

    2006-01-01

    The effect of bone compaction vs conventional drilling on the fixation of hydroxyapatite-coated implants was examined in a weight-bearing canine model. In each dog, one knee joint had the implant cavity prepared with drilling, the other with compaction. Eight dogs were euthanized after 2 weeks...... and 8 dogs after 4 weeks. Femoral condyles from additional 7 dogs represented time 0. Compacted specimens had significantly higher bone implant contact and energy absorption at time 0. Compaction significantly increased ultimate shear strength at 0 and 2 weeks. There was no significant difference...... in implant fixation after 4 weeks. The results of this study suggest that compaction may be beneficial in optimizing the crucial initial implant stability, even when hydroxyapatite-coated implants with osteoconductive properties are inserted in vivo....

  19. Internal fixation and bone grafting for intraarticular nonunion of tibial plateau: a report of four cases

    Institute of Scientific and Technical Information of China (English)

    Ramesh K Sen; Ashwani Soni; Uttam Chand Saini; Daljit Singh

    2011-01-01

    Intraarticular nonunion of tibial plateau is rare.In the literature,only 9 patients were found to be treated for intraarticular tibial plateau nonunion and they got varying results.Internal fixation along with bone grafting was done as a standard treatment in all cases.We treated 4 different profile cases of intraarticular tibial plateau nonunion in our institution by 4 different methods.We treated these cases with plaster of paris cast,internal fixation along with bone graft,arthrodesis with K-nail and total knee replacement.Case 1 was treated with plaster of paris (POP)cast as the patient refused surgery.The fracture was united and the patient was fully satisfied with full range of motion despite valgus malalignment.Case 2 was managed with open reduction internal fixation along with bone grafting.The patient had a good union and got full range of motion at the knee joint.Case 3 was treated with total knee arthroplasty due to her old age and got satisfactory result.Case 4 was an infected nonunion.Arthrodesis was done and the patient could walk with full weight bearing independently.We conclude that internal fixation along with bone grafting may not be suitable in all cases of intraarticular nonunion of tibial plateau.Causes of nonunion,present condition and range of motion of the knee joint,as well as the age of patient should be all considered and the treatment should be individualised according to each patient's situation.

  20. Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone

    OpenAIRE

    Mick E.; Steinke H.; Wolfskämpf T.; Wieding J.; Hammer N.; Schulze M.; Souffrant R.; Bader R.

    2015-01-01

    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 ethano...

  1. A computer study of biodegradable plates for internal fixation of mandibular angle fractures

    NARCIS (Netherlands)

    Tams, J; Van Loon, JP; Otten, B; Bos, RRM

    2001-01-01

    Purpose: This computer-based study was performed to determine the suitability of small biodegradable plate systems for mandibular angle fractures. Materials and Methods: In a 3-dimensional computer model of the mandible, fracture mobility and plate strain were calculated for bite forces applied on 1

  2. Augmentation of screw fixation with injectable calcium sulfate bone cement in ovariectomized rats.

    Science.gov (United States)

    Yu, Xiao-Wei; Xie, Xin-Hui; Yu, Zhi-Feng; Tang, Ting-Ting

    2009-04-01

    The objective of this study was to determine the effect of augmenting screw fixation with an injectable calcium sulfate cement (CSC) in the osteoporotic bone of ovariectomized rats. The influence of the calcium sulfate (CS) on bone remodeling and screw anchorage in osteoporotic cancellous bone was systematically investigated using histomorphometric and biomechanical analyses. The femoral condyles of 55 Sprague-Dawley ovariectomized rats were implanted with screw augmented with CS, while the contralateral limb received a nonaugmented screw. At time intervals of 2, 4, 8, 12, and 16 weeks, 11 rats were euthanized. Six pair-matched samples were used for histological analysis, while five pair-matched samples were preserved for biomechanical testing. Histomorphometric data showed that CS augmented screws activated cancellous bone formation, evidenced by a statistically higher (p < 0.05) percentage of osteoid surface at 2, 4, and 8 weeks and a higher rate of bone mineral apposition at 12 weeks compared with nonaugmented screws. The amount of the bone-screw contact at 2, 8, and 12 weeks and of bone ingrowth on the threads at 4 and 8 weeks was greater in the CS group than in the nonaugmented group (p < 0.05), although these parameters increased concomitantly with time for both groups. The CS was resorbed completely at 8 weeks without stimulating fibrous encapsulation on the screw surface. Also, the cement significantly increased the screw pull-out force and the energy to failure at 2, 4, 8, and 12 weeks after implantation, when compared with the control group (p < 0.05). These results imply that augmentation of screw fixation with CS may have the potential to decrease the risk of implant failure in osteoporotic bone.

  3. A numerical simulation of the effect of using porous superelastic Nitinol and stiff Titanium fixation hardware on the bone remodeling

    Science.gov (United States)

    Raad, Bahram; Shayesteh Moghaddam, Narges; Elahinia, Mohammad

    2016-04-01

    The aim of this article is to investigate the effect of two different fixation hardware materials on bone remodeling after a mandibular reconstruction surgery and to restore the mandible's function, healthy appearance, mastication, swallowing, breathing, and speech. The hypothesis is that using fixation hardware with stiffness close to that of the surrounding bone will result in a more successful healing process in the mandible bone. The finite element model includes the material properties and forces of the cancellous bone, cortical bone, ligaments, muscles, and teeth. The reconstruction surgery is modeled by including the fixation hardware and the grafted bone. In the sectioned mandible, to best mimic the geometry of the mandible, two single barrel grafts are placed at the top of each other to form a double barrel graft set. Two different materials were used as the mandibular fixation parts, stiff Ti-6Al-4V, and porous superelastic Nickel-Titanium (NiTi) alloys. A comparison of these two alloys demonstrates that using porous NiTi alloy as the fixation part results in a faster healing pace. Furthermore, the density distribution in the mandibular bone after the healing process is more similar to the normal mandible density distribution. The simulations results indicate that the porous superelastic NiTi fixation hardware transfers and distributes the existing forces on the mandible bone more favorably. The probability of stress shielding and/or stress concentration decrease. This type of fixation hardware, therefore, is more appropriate for mandible bone reconstruction surgery. These predictions are in agreement with the clinical observations.

  4. In vitro study of a new biodegradable nanocomposite based on poly propylene fumarate as bone glue.

    Science.gov (United States)

    Shahbazi, S; Moztarzadeh, F; Sadeghi, G Mir Mohamad; Jafari, Y

    2016-12-01

    A novel poly propylene fumarate (PPF)-based glue which is reinforced by nanobioactive glass (NBG) particles and promoted by hydroxyethyl methacrylate (HEMA) as crosslinker agent, was developed and investigated for bone-to-bone bonding applications. In-vitro bioactivity, biodegradability, biocompatibility, and bone adhesion were tested and the results have verified that it can be used as bone glue. In an in-vitro condition, the prepared nanocomposite (PPF/HEMA/NBG) showed improved adhesion to wet bone surfaces. The combined tension and shear resistance between two wet bone surfaces was measured, and its maximum value was 9±59MPa. To investigate the bioactivity and biodegradability of the nanocomposite, it has been immersed in simulated body fluid (SBF). After 14days exposure to SBF, a hydroxyapatite (HA) layer formed on the surface of the composite confirms the bioactivity of this material. In the XRD pattern of the nanocomposite surface, the HA characteristic diffraction peak at θ=26 and 31.8 were observed. Also, by monitoring the weight change after 8weeks immersion in SBF, the mass loss was about 16.46wt%. It has been confirmed that this nanocomposite is a biodegradable material. Also, bioactivity and biodegradability of nanocomposite have been proved by SEM images. It has been showed that by using NBG particles and HEMA precursor, mechanical properties increased significantly. The ultimate tensile strength (UTS) of nanocomposite which contains 20% NBG and the ratio of 70/30wt% PPF/HEMA (PHB.732) was approximately 62MPa, while the UTS in the pure PPF/HEMA was about 32MPa. High cell viability in this nanocomposite (MTT assays, 85-95%) can be attributed to the NBG nature which contains calcium phosphate and is similar to physiological environment. Furthermore, it possesses biomineralization and biodegradation which significantly affected by impregnation of hydrophilic HEMA in the PPF-based polymeric matrix. The results indicated that the new synthesized

  5. Bone radiofrequency ablation combined with prophylactic internal fixation for metastatic bone tumor of the femur from hepatocellular carcinoma.

    Science.gov (United States)

    Ogura, Koichi; Miyake, Ryoko; Shiina, Shuichiro; Shinoda, Yusuke; Okuma, Tomotake; Kobayashi, Hiroshi; Goto, Takahiro; Nakamura, Kozo; Kawano, Hirotaka

    2012-08-01

    A 64-year-old man with 6-year history of hepatocellular carcinoma (HCC) was referred to us regarding bone metastasis to the right proximal femur. Although he underwent radiotherapy for pain palliation and local tumor control, the pain persisted and the tumor relapsed 3 months after the radiotherapy and he was thought to be at high risk of pathologic fracture. Given hypervascularity and large tumor size, a prophylactic internal fixation combined with adjuvant radiofrequency ablation (RFA) was proposed to reduce blood loss and prevent viable tumor cells being disseminated. His postoperative course was uneventful without requiring blood transfusion and preoperative symptoms immediately disappeared after surgery. He became capable of weight-bearing walk with a single cane and was almost asymptomatic without local progression on the plain radiographs when he died 14 months after surgery. Combination therapy of RFA and internal fixation using intramedullary nailing for metastases of the long bones from HCC seems to be a very promising technique both for sufficient pain relief and for local control of the tumor. Adjuvant RFA may become a potential option for patients with metastases of the long bones for the purpose of prevention of tumor dissemination and reduction of intraoperative blood loss.

  6. The effects of laparoscopic mesh fixation device on bone, costo-chondral junction and tendon site.

    Science.gov (United States)

    Ekçi, Baki; Altinli, Ediz; Dervisoglu, Sergülen; Demir, Mustafa; Tasci, Ihsan

    2011-01-01

    Osteitis pubis is one of the important complications of inguinal hernia repair surgery occurring with the placement of sutures through the periosteum. The aim of this study is to evaluate scintigraphic and histopathological alterations associated with the use of mesh fixation device on pelvic bone, cartilage and tendons in an experimental animal model. Twenty New-Zealand young male rabbits were used. A mesh fixation device was inserted at each animal's costa-chondral junction, superior anterior iliac crest, and achiles tendon. One week prior to the surgery and 16 weeks after the operation, scintigraphic evaluation was performed. Histopathological evaluation was performed at the end of study. No nuclear activity or pathological change was found at bone site (p > 0.05). Foreign body reaction was evident at the tendon and costa-chondral site (p = 0.001). In conclusion; the mesh fixation device leads to foreign body reaction in costa-chondral junction and tendon. It does not cause any nuclear activity increase.

  7. Internal fixation and muscle pedicle bone grafting in femoral neck fractures

    Directory of Open Access Journals (Sweden)

    Gupta A

    2008-01-01

    Full Text Available Background: The treatment of displaced intracapsular femoral neck fracture is still an unsolved problem. Non-union and avascular necrosis are the two main complications of this fracture, especially if patient presents late. Muscle pedicle bone grafting has been advocated to provide additional blood supply. We present analysis of our 32 cases of displaced femoral neck fracture treated by internal fixation and quadratus femoris based muscle pedicle bone grafting. Materials and Methods: Open reduction and internal fixation with muscle pedicle grafting was done in 32 patients. The age of patients varied from 14-62 years (average age 45 years with male to female ratio of 13:3. Twenty-nine fractures were more than three weeks old. All the cases were treated by Meyers′ procedure. The fracture was internally fixed after open reduction and then a muscle pedicle graft was applied. It was supplemented by cancellous bone graft in seven cases. Fixation was done by parallel cancellous lag screws ( n = 19, crossed Garden′s screws ( n = 7, parallel Asnis screws ( n = 5 and Moore′s pin ( n = 1.Quadratus femoris muscle pedicle graft was used in 32 cases. In the initial 12 cases the graft was fixed with circumferential proline sutures, but later, to provide a secure fixation, the graft was fixed with a cancellous screw ( n = 20. Postoperative full weight bearing was deferred to an average of 10 weeks. Results: Union was achieved in 26/29 (89.65% cases which could be followed for an average period of 3.4 years, (2-8.5 years with good functional results and had the ability to squat and sit cross-legged. Results were based on hip rating system given by Salvatti and Wilson. The results were excellent in 15 cases, good in four cases, fair in four cases and poor in six cases. Complications were avascular necrosis ( n = 2, transient foot drop ( n = 2, coxa-vara ( n = 1 and temporary loss of scrotal sensation ( n = 1. Conclusion: Muscle pedicle bone grafting with

  8. Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep

    DEFF Research Database (Denmark)

    Ding, Ming; Andreasen, Christina Møller; Dencker, Mads L.;

    2015-01-01

    hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could...... implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone...

  9. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss

    NARCIS (Netherlands)

    Tomaszewski, P. M.; van Diest, M.; Bulstra, S. K.; Verdonschot, N.; Verkerke, G. J.

    2012-01-01

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system. Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanic

  10. Numerical analysis of an osseointegrated prosthesis fixation with reduced bone failure risk and periprosthetic bone loss.

    NARCIS (Netherlands)

    Tomaszewski, P.K.; Diest, M. van; Bulstra, S.K.; Verdonschot, N.J.; Verkerke, G.J.

    2012-01-01

    Currently available implants for direct attachment of prosthesis to the skeletal system after transfemoral amputation (OPRA system, Integrum AB, Sweden and ISP Endo/Exo prosthesis, ESKA Implants AG, Germany) show many advantages over the conventional socket fixation. However, restraining biomechanic

  11. Biodegradable hybrid tissue engineering scaffolds for reconstruction of large bone defects

    Science.gov (United States)

    Barati, Danial

    Complex skeletal injuries and large bone fractures are still a significant clinical problem in US. Approximately 1.5 million Americans (veterans, their families, and civilians) every year suffer from bone loss due to traumatic skeletal injuries, infection, and resection of primary tumors that require extensive grafting to bridge the gap. The US bone graft market is over $2.2 billion a year. Due to insufficient mechanical stability, lack of vascularity, and inadequate resorption of the graft, patients with traumatic large skeletal injuries undergo multiple costly operations followed by extensive recovery steps to maintain proper bone alignment and length. Current strategies for repairing damaged or diseased bones include autologous or allograft bone transplantations. However, limited availability of autografts and risk of disease transmission associated with allografts have necessitated the search for the development of new bone graft options and strategies. The overall goal of this project is to develop a much-needed bone-mimetic engineered graft as a substitute for current strategies providing required bone grafts for reconstruction of large bone defects. This project will use the structure of natural cortical bone as a guide to produce an engineered bone graft with balanced strength, osteogenesis, vascularization, and resorption. The outcome of this project will be a biodegradable hybrid scaffold system (similar to natural cortical bone) including a mechanically strong scaffold allowing for mechanical stability of the load-bearing defect site and a soft and highly porous structure such as a hydrogel phase which will allow for efficient cell and growth factor delivery into the defect implantation site, cell niche establishment and promotion of mineralization. Successful completion of this project will transform bone graft technology for regeneration of complex bone defects from a frozen or freeze-dried allograft to a safe, infection-free, mechanically

  12. A novel technique of lumbar hernia repair using bone anchor fixation.

    Science.gov (United States)

    Carbonell, A M; Kercher, K W; Sigmon, L; Matthews, B D; Sing, R F; Kneisl, J S; Heniford, B T

    2005-03-01

    Lumbar hernias are difficult to repair due to their proximity to bone and inadequate surrounding tissue to buttress the repair. We analyzed the outcome of patients undergoing a novel retromuscular lumbar hernia repair technique. The repair was performed in ten patients using a polypropylene or polytetrafluoroethylene mesh placed in an extraperitoneal, retromuscular position with at least 5 cm overlap of the hernia defect. The mesh was fixed with circumferential, transfascial, permanent sutures and inferiorly fixed to the iliac crest by suture bone anchors. Five hernias were recurrent, and five were incarcerated; seven were incisional hernias, and three were posttraumatic. Back and abdominal pain was the most common presenting symptom. Mean hernia size was 227 cm(2) (60-504) with a mesh size of 620 cm(2) (224-936). Mean operative time was 181 min (120-269), with a mean blood loss of 128 ml (50-200). Mean length of stay was 5.2 days (2-10), and morphine equivalent requirement was 200 mg (47-460). There were no postoperative complications or deaths. After a mean follow-up of 40 months (3-99) there have been no recurrences. Our sublay repair of lumbar hernias with permanent suture fixation is safe and to date has resulted in no recurrences. Suture bone anchors ensure secure fixation of the mesh to the iliac crest and may eliminate a common area of recurrence.

  13. Nanocomposites of Polyacrylic Acid Nanogels and Biodegradable Polyhydroxybutyrate for Bone Regeneration and Drug Delivery

    Directory of Open Access Journals (Sweden)

    Mikael Larsson

    2014-01-01

    Full Text Available Biodegradable cell scaffolds and local drug delivery to stimulate cell response are currently receiving much scientific attention. Here we present a nanocomposite that combines biodegradation with controlled release of lithium, which is known to enhance bone growth. Nanogels of lithium neutralized polyacrylic acid were synthesized by microemulsion-templated polymerization and were incorporated into a biodegradable polyhydroxybutyrate (PHB matrix. Nanogel size was characterized using dynamic light scattering, and the nanocomposites were characterized with regard to structure using scanning electron microscopy, mechanical properties using tensile testing, permeability using tritiated water, and lithium release in PBS using a lithium specific electrode. The nanogels were well dispersed in the composites and the mechanical properties were good, with a decrease in elastic modulus being compensated by increased tolerance to strain in the wet state. Approximately half of the lithium was released over about three hours, with the remaining fraction being trapped in the PHB for subsequent slow release during biodegradation. The prepared nanocomposites seem promising for use as dual functional scaffolds for bone regeneration. Here lithium ions were chosen as model drug, but the nanogels could potentially act as carriers for larger and more complex drugs, possibly while still carrying lithium.

  14. Poly(dopamine) coating to biodegradable polymers for bone tissue engineering.

    Science.gov (United States)

    Tsai, Wei-Bor; Chen, Wen-Tung; Chien, Hsiu-Wen; Kuo, Wei-Hsuan; Wang, Meng-Jiy

    2014-02-01

    In this study, a technique based on poly(dopamine) deposition to promote cell adhesion was investigated for the application in bone tissue engineering. The adhesion and proliferation of rat osteoblasts were evaluated on poly(dopamine)-coated biodegradable polymer films, such as polycaprolactone, poly(l-lactide) and poly(lactic-co-glycolic acid), which are commonly used biodegradable polymers in tissue engineering. Cell adhesion was significantly increased to a plateau by merely 15 s of dopamine incubation, 2.2-4.0-folds of increase compared to the corresponding untreated substrates. Cell proliferation was also greatly enhanced by poly(dopamine) deposition, indicated by shortened cell doubling time. Mineralization was also increased on the poly(dopamine)-deposited surfaces. The potential of poly(dopamine) deposition in bone tissue engineering is demonstrated in this study.

  15. Biodegradable effect of PLGA membrane in alveolar bone regeneration on beagle dog.

    Science.gov (United States)

    Hua, Nan; Ti, Vivian Lao; Xu, Yuanzhi

    2014-11-01

    Guided bone regeneration (GBR) is a principle adopted from guided tissue regeneration (GTR). Wherein, GBR is used for the healing of peri-implant bony dehiscences, for the immediate placement of implants into extraction sockets and for the augmentation of atrophic alveolar ridges. This procedure is done by the placement of a resorbable or non-resorbable membrane that will exclude undesirable types of tissue growth between the extraction socket and the soft tissue to allow only bone cells to regenerate in the surgically treated lesion. Here, we investigated the biodegradable effect of polylactic-co-glycolic acid (PLGA) membrane in the alveolar bone on Beagle dogs. Results show that both collagen and PLGA membrane had been fully resorbed, biodegraded, at four weeks post-operative reentry into the alveolar bone. Histological results under light microscopy revealed formation of new bone trabeculae in the extraction sites on both collagen and PLGA membrane. In conclusion, PLGA membrane could be a potential biomaterials for use on GBR and GTR. Nevertheless, further studies will be necessary to elucidate the efficiency and cost effectiveness of PLGA as GBR membrane in clinical.

  16. A STUDY ON FUNCTIONAL OUTCOME OF ILIZAROV FIXATION IN THE MANAGEMENT OF INFECTED NONUNION OF LONG BONES

    Directory of Open Access Journals (Sweden)

    Vellanki

    2016-01-01

    Full Text Available Healing of non-union infected fracture bones like tibia is a challenging one. Ilizarov external ring fixation is the appropriate method. The aim of our study is to evaluate the efficacy of Ilizarov external ring fixator in infected nonunion of bones and functional results in 20 patients and to conduct the study of complications. The age group included in our study were between 30 to 40 years of the 20 cases 17 were males and 3 were females. Of the 20 cases in our study, 14 cases had excellent results, 4 cases had good outcome, 1 patient had fair outcome, 1 cases had poor outcome. The study shows that Ilizarov ring external fixator system is ideal for limb salvage in infected nonunion of long bones.

  17. Long-term implant-bone fixation of the femoral component in total knee replacement.

    Science.gov (United States)

    Cristofolini, L; Affatato, S; Erani, P; Leardini, W; Tigani, D; Viceconti, M

    2008-04-01

    Success of total knee replacement (TKR) depends on the prosthetic design. Aseptic loosening of the femoral component is a significant failure mode that has received little attention. Despite the clinical relevance of failures, no protocol is available to test long-term implant-bone fixation of TKR in vitro. The scope of this work was to develop and validate a protocol to assess pre-clinically the fixation of TKR femoral components. An in vitro protocol was designed to apply a simplified but relevant loading profile using a 6-degrees-of-freedom knee simulator for 1,000000 cycles. Implant-bone inducible micromotions and permanent migrations were measured at three locations throughout the test. After test completion, fatigue damage in the cement was quantified. The developed protocol was successfully applied to a commercial TKR. Additional tests were performed to exclude artefacts due to swelling or creep of the composite femur models. The components migrated distally; they tilted towards valgus in the frontal plane and in extension in the sagittal plane. The migration patterns were consistent with clinical roentgen-stereophotogrammetric recordings with TKR. Additional indicators were proposed that could quantify the tendency to loosen/stabilize. The type and amount of damage found in the cement, as well as the migration patterns, were consistent with clinical experience with the specific TKR investigated. The proposed pre-clinical test yielded repeatable results, which were consistent with the clinical literature. Therefore, its relevance and reliability was proved.

  18. Antimicrobial activity of nanocomposite zirconium nitride/silver coatings to combat external bone fixation pin infections.

    Science.gov (United States)

    Wickens, David J; West, Glen; Kelly, Peter J; Verran, Joanna; Lynch, Stephen; Whitehead, Kathryn A

    2012-10-01

    During external fixation, temporary implants are used to penetrate the skin, muscle and bone to support severely fractured bones. This creates a biologically critical interface at the site of entry, which potentially allows a risk of infection. The aim of this study, therefore, was to investigate potential antimicrobial nanocomposites to combat infection. Magnetron sputtering was used to produce zirconium nitride/silver nanocomposite coatings, which were prepared at two different silver concentrations of 15.5 at.% and 29.8 at.%. These coatings were characterized for morphology, chemical composition, and antimicrobial activity in comparison to pure zirconium nitride and stainless steel. Staphylococcus aureus and Staphylococcus epidermidis were used as in vitro test organisms in a range of antimicrobial assays; retention of the bacteria on the surfaces and their survival using LiveDead™ staining; the use of a metabolic redox dye to indicate a contact kill and zone of inhibition assays to indicate leaching of inhibitory silver ions. Antimicrobial tests demonstrated a significant kill when the bacterial cells came in contact with the coatings containing silver at both 15.5 at.% and 29.8 at.%. No inhibitory leaching from the surfaces occurred. These surfaces demonstrate potential for use as antimicrobial fixation pin coatings.

  19. A biomechanical study on fixation stability with twin hook or lag screw in artificial cancellous bone.

    Science.gov (United States)

    Olsson, O; Tanner, K E; Ceder, L; Ryd, L

    2002-01-01

    The twin hook has been developed as an alternative to the conventional lag screw to be combined with a barrelled side-plate in the treatment of trochanteric hip fractures. With two oppositely directed apical hooks introduced into the subchondral bone of the femoral head, the twin hook provides different stabilising properties to the lag screw. The femoral head purchase of the twin hook and the lag screw were compared in a biomechanical study using artificial cancellous bone, and responses to axial and torsional loading was determined. A distinct yield point in load and torque was noted for the lag screw, representing failure of the laminas supporting the threads. For the twin hook, gradual increase of load and torque occurred during impaction of the bone supporting the hooks. The peak loads and torques were higher for the lag screw, but were similar for both devices after 8 mm deformation. The stiffness was higher for the lag screw, but in counter-clockwise rotation the stiffness for the lag screw was negligible. The twin hook appeared to provide fixation stability comparable to that offered by the lag screw, but with conceivable advantages in terms of a deformation response involving bone impaction and gradually increasing stability.

  20. 3D perfusion bioreactor-activated porous granules on implant fixation and early bone formation in sheep

    DEFF Research Database (Denmark)

    Ding, Ming; Snoek Henriksen, Susan; Martinetti, Roberta

    2017-01-01

    Early fixation of total joint arthroplasties is crucial for ensuring implant survival. An alternative bone graft material in revision surgery is needed to replace the current gold standard, allograft, seeing that the latter is associated with several disadvantages. The incubation of such a constr......, bone formation was observed in all groups, while the bioreactor-activated graft material did not reveal additional effects on early implant fixation comparable to allograft in this model. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016....

  1. Radiation-Associated Fracture Nonunion of the Clavicle Treated with Locking Plate Fixation and Autologous Bone Grafting

    Directory of Open Access Journals (Sweden)

    Takahiro Niikura

    2012-01-01

    Full Text Available We describe a case of radiation-associated fracture nonunion of the clavicle, which was treated by locking plate fixation and autologous bone grafting. The patient was a 67-year old man who received 70 Gy radiation therapy to treat nasopharyngeal carcinoma. Eight years later, he suffered a pathological fracture of the right clavicle. One year after the fracture, surgical treatment was performed due to persistent pain and weakness. Radiographs demonstrated atrophic nonunion. Bone scan demonstrated hot uptake at both ends of the fractured bone. MRI demonstrated a formation of pseudoarthrosis with fluid collection and suggested bone marrow edema at both ends of the fracture fragments. In surgery, fibrous pseudoarthrosis tissue was excised and both ends of the fracture fragments were refreshed to identify bleeding. Open reduction and internal fixation using a 7-hole locking plate and autologous bone grafting were performed. Successful bony union was obtained 1 year postoperatively, and no adverse events were observed up to 52 months after the operation. Our case suggests that a locking plate provides sufficient fixation and autologous bone grafting is effective in enhancing bone healing in a radiation-associated fracture nonunion of the clavicle in which it is difficult to achieve bony union.

  2. Bone cement enhanced pedicle screw fixation combined with vertebroplasty for elderly patients with malignant spinal tumors

    Institute of Scientific and Technical Information of China (English)

    TAN Jiang-wei; SHEN Bing-hua; DU Wei; LIU Jiang-qing; LU Shi-qiao

    2013-01-01

    Background Older patients with malignant spinal tumors are difficult to treat because they have many co-morbidities including osteoporosis.The purpose of this research is to discuss the technique and clinical outcome of bone cement enhanced pedicle screw fixation combined with vertebroplasty (the Sandwich Procedure) for elderly patients with severe osteoporosis and malignant spinal tumors.Methods This study includes 28 consecutive elderly patients with malignant thoracic or lumbar spinal tumors.There were nine patients with myelomas,and 19 patients with metastatic bone tumors.The Sandwich Procedure began with curettage of the tumor and a vertebroplasty with bone cement (polymethyl methacrylate,PMMA),followed by PMMA enhanced pedicle screw fixation.Patients were evaluated with the visual analogue scale (VAS),oswestry disability index (ODI),American Spinal Cord Injury Association (ASIA) neurological function classification,and the radiographic degree of kyphosis (Cobb angle).Data were analyzed using paired t-test to compare the pre-and post-operative values.The complications,local recurrences,and the survival status were also recorded.Results There was no operative mortality,and the mean operative time was 210 minutes (range 150-250 minutes).The average blood loss was 1550 ml (range 650-3300 ml).The average amount of cement for vertebroplasty was 3.6 ml (range 3-5 ml).The VAS,ODI,and ASIA scores were significantly improved after surgery (P <0.05).However,we found no differences between the pre and post-operative Cobb angles.The shortest survival time was 3 months,and we found no evidence of local recurrence in this group of patients.Conclusion The Sandwich Procedure is a safe operation and provides symptomatic relief in these difficult patients,permitting further treatment with chemotherapy or radiotherapy.

  3. Hydroxyapatite nanorod-reinforced biodegradable poly(L-lactic acid) composites for bone plate applications.

    Science.gov (United States)

    Aydin, Erkin; Planell, Josep A; Hasirci, Vasif

    2011-11-01

    Novel PLLA composite fibers containing hydroxyapatite (HAp) nanorods with or without surface lactic acid grafting were produced by extrusion for use as reinforcements in PLLA-based bone plates. Fibers containing 0-50% (w/w) HAp nanorods, aligned parallel to fiber axis, were extruded. Lactic acid surface grafting of HAp nanorods (lacHAp) improved the tensile properties of composites fibers better than the non-grafted ones (nHAp). Best tensile modulus values of 2.59, 2.49, and 4.12 GPa were obtained for loadings (w/w) with 30% lacHAp, 10% nHAp, and 50% amorphous HAp nanoparticles, respectively. Bone plates reinforced with parallel rows of these composite fibers were molded by melt pressing. The best compressive properties for plates were obtained with nHAp reinforcement (1.31 GPa Young's Modulus, 110.3 MPa compressive strength). In vitro testing with osteoblasts showed good cellular attachment and spreading on composite fibers. In situ degradation tests revealed faster degradation rates with increasing HAp content. To our knowledge, this is the first study containing calcium phosphate-polymer nanocomposite fibers for reinforcement of a biodegradable bone plate or other such implants and this biomimetic design was concluded to have potential for production of polymer-based biodegradable bone plates even for load bearing applications.

  4. 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

  5. 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 fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, 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 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.

  6. Biodegradable Magnesium Screws Accelerate Fibrous Tissue Mineralization at the Tendon-Bone Insertion in Anterior Cruciate Ligament Reconstruction Model of Rabbit

    Science.gov (United States)

    Wang, Jiali; Xu, Jiankun; Fu, Weimin; Cheng, Wenxiang; Chan, Kaiming; Yung, Patrick Shu-hang; Qin, Ling

    2017-01-01

    The incorporation of tendon graft into bone tunnel is one of the most challenging clinical issues in anterior cruciate ligament (ACL) reconstruction. As a biodegradable metal, Mg has appropriate mechanical strength and osteoinductive effects, thus may be a promising alternative to commercialized products used for graft fixation. Therefore, it was hypothesized that Mg based interference screws would promote tendon graft-bone junction healing when compared to Ti screws. Herein, we compared the effects of Mg and Ti screws on tendon graft healing in rabbits with ACL reconstruction via histological, HR-pQCT and mechanical analysis. The histological results indicated that Mg screws significantly improved the graft healing quality via promoting mineralization at the tendon graft enthesis. Besides, Mg screws significantly promoted bone formation in the peri-screw region at the early healing stage. Importantly, Mg screws exhibited excellent corrosion resistance and the degradation of Mg screws did not induce bone tunnel widening. In tensile testing, there were no significant differences in the load to failure, stress, stiffness and absorption energy between Mg and Ti groups due to the failure mode at the midsubstance. Our findings demonstrate that Mg screws can promote tendon graft healing after ACL reconstruction, implying a potential alternative to Ti screws for clinical applications. PMID:28071744

  7. Efficacy of a small cell-binding peptide coated hydroxyapatite substitute on bone formation and implant fixation in sheep.

    Science.gov (United States)

    Ding, Ming; Andreasen, Christina M; Dencker, Mads L; Jensen, Anders E; Theilgaard, Naseem; Overgaard, Søren

    2015-04-01

    Cylindrical critical size defects were created at the distal femoral condyles bilaterally of eight female adult sheep. Titanium implants with 2-mm concentric gaps were inserted and the gaps were filled with one of the four materials: allograft; a synthetic 15-amino acid cell-binding peptide coated hydroxyapatite (ABM/P-15); hydroxyapatite + βtricalciumphosphate+ Poly-Lactic-Acid (HA/βTCP-PDLLA); or ABM/P-15+HA/βTCP-PDLLA. After nine weeks, bone-implant blocks were harvested and sectioned for micro-CT scanning, push-out test, and histomorphometry. Significant bone formation and implant fixation could be observed in all four groups. Interestingly, the microarchitecture of the ABM/P-15 group was significantly different from the control group. Tissue volume fraction and thickness were significantly greater in the ABM/P-15 group than in the allograft group. Bone formation and bone ingrowth to porous titanium implant were not significantly different among the four groups. The ABM/P-15 group had similar shear mechanical properties on implant fixation as the allograft group. Adding HA/βTCP-PDLLA to ABM/P-15 did not significantly change these parameters. This study revealed that ABM/P-15 had significantly bone formation in concentric gap, and its enhancements on bone formation and implant fixation were at least as good as allograft. It is suggested that ABM/P-15 might be a good alternative biomaterial for bone implant fixation in this well-validated critical-size defect gap model in sheep. Nevertheless, future clinical researches should focus on prospective, randomized, controlled trials in order to fully elucidate whether ABM/P-15 could be a feasible candidate for bone substitute material in orthopedic practices.

  8. Outcome after open reduction and internal fixation of intraarticular fractures of the calcaneum without the use of bone grafts

    Directory of Open Access Journals (Sweden)

    Pendse Aniruddha

    2006-01-01

    Full Text Available Background: Intraarticular fractures of calcaneum are commenest type of calcaneal fractures. Lots of controversies exist about the ideal management for them. The focus is now shifting on operative management by open reduction and internal fixation for these fractures with or without the use of bone grafts. Method: Thirty intraarticular fractures classified by Essex Lopresti radiological classification, were treated by open reduction and fixation. The patients were followed over a mean period of 30 months (25-40 months. Results: All the fractures united at a mean duration of 14 weeks. 86% patients had excellent functional outcome with one patient having fair and one having poor functional outcome. Conclusion: Open reduction and internal fixation with plate is a good method for treatment of intraarticular fractures of calcaneum to achieve anatomical restoration of articular surface under vision, stable fixation, early mobilization and an option for primary subtalar arthrodesis if deemed necessary.

  9. Demineralized bone matrix and human cancellous bone enhance fixation of titanium implants

    DEFF Research Database (Denmark)

    Babiker, Hassan; Ding, Ming; Overgaard, Søren

    Denmark, DenmarkAbstractReplacement of extensive local bone loss especially in revision joint arthroplasty and spine fusion is a significant clinical challenge. Allograft and autograft have been considered as gold standard for bone replacement. However, there are several disadvantages such as donor site...... from human tissue were included (IsoTis OrthoBiologics, Inc. USA). Both materials are commercially available. Titanium alloy implants (Biomet Inc.) of 10 mm in length and 10 mm in diameter were inserted bilaterally into the femoral condyles of 8 skeletally mature sheep. Thus four implants...... with a concentric gap of 2 mm were implanted in each sheep. The gap was filled with: DBM; DBM/CB with ratio of 1/3; DBM/allograft with ratio of 1/3; or allograft (Gold standard), respectively. Standardised surgical procedure was used1. At sacrifice, 6 weeks after surgery, both distal femurs were harvested...

  10. Thoracolumbar spinal fractures : radiological results of transpedicular fixation combined with transpedicular cancellous bone graft and posterior fusion in 183 patients

    NARCIS (Netherlands)

    Leferink, VJM; Zimmerman, KW; Veldhuis, EFM; ten Vergert, EM; ten Duis, HJ

    2001-01-01

    In internal posterior fixation of thoracolumbar fractures combined with transpedicular cancellous bone graft and posterior fusion of the intervertebral facet joints at the level of the destroyed end plate it is still uncertain as to whether significant vertebral body collapse and loss of correction

  11. A modified cementing technique using BoneSource to augment fixation of the acetabulum in a sheep model.

    NARCIS (Netherlands)

    Timperley, A.J.; Nusem, I.; Wilson, K.; Whitehouse, S.L.; Buma, P.; Crawford, R.W.

    2010-01-01

    BACKGROUND AND PURPOSE: Our aim was to assess in an animal model whether the use of HA paste at the cement-bone interface in the acetabulum improves fixation. We examined, in sheep, the effect of interposing a layer of hydroxyapatite cement around the periphery of a polyethylene socket prior to fixi

  12. HYBRID EXTERNAL FIXATOR FOR THE TREATMENT OF UNICAMERAL BONE CYSTS WITH PATHOLOGICAL FRACTURE IN THE PROXIMAL HUMERUS

    Institute of Scientific and Technical Information of China (English)

    郭征; 王臻; 赵黎

    2004-01-01

    Objective: Unicameral bone cyst is a nonneoplastic bone lesion characterized by its tenacity and risk of recurrence. Pathological fracture is common and is often the presenting symptom. The objective of the present study was to evaluate the results of hybrid external fixator for the treatment of a unicameral bone cyst with a pathological fracture. Methods: Hybrid external fixator for the treatment of a unicameral bone cyst was performed in twelve patients. These patients presented with a pathological fracture and were managed immediately with hybrid external fixator, of whom four had been managed conservatively at other clinics before they were referred to our department. The cyst was located in the proximal humerus in all patients. The mean age of the patients at the time of surgery was 8.7 years, and the mean duration of follow-up was 32.6 months. Radiographic evaluation was performed according to the criteria of Capanna et al., and the cyst was classified as completely healed, healed with residual radiolucency (osteolysis), recurred, or having no response. Results: The healing period ranged from three to eight months. Eight cysts healed completely, and three healed with residual radiolucent areas visible on radiographs. There was recurrence of one cyst that had healed with residual radiolucency. All of the cysts in the present study responded to treatment. A modulation of hybrid external fixator was necessary in three patients, as the bars had become too short after bone growth or the pins had been loose. No major complications were observed.Conclusion: Hybrid external fixator provides early stability, which allows early mobilization and thus obviates the need for a plaster cast. This method of treatment also allows for an early return to normal activity.

  13. Biodegradable nanofibers-reinforced microfibrous composite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Martins, Albino; Pinho, Elisabete D; Correlo, Vítor M; Faria, Susana; Marques, Alexandra P; Reis, Rui L; Neves, Nuno M

    2010-12-01

    Native bone extracellular matrix (ECM) is a complex hierarchical fibrous composite structure, resulting from the assembling of collagen fibrils at several length scales, ranging from the macro to the nanoscale. The combination of nanofibers within microfibers after conventional reinforcement methodologies seems to be a feasible solution to the rational design of highly functional synthetic ECM substitutes. The present work aims at the development of bone ECM inspired structures, conjugating electrospun chitosan (Cht) nanofibers within biodegradable polymeric microfibers [poly(butylene succinate)-PBS and PBS/Cht], assembled in a fiber mesh structure. The nanofibers-reinforced composite fiber mesh scaffolds were seeded with human bone marrow mesenchymal stem cells (hBMSCs) and cultured under osteogenic differentiation conditions. These nanofibers-reinforced composite scaffolds sustained ECM deposition and mineralization, mainly in the PBS/Cht-based fiber meshes, as depicted by the increased amount of calcium phosphates produced by the osteogenic differentiated hBMSCs. The osteogenic genotype of the cultured hBMSCs was confirmed by the expression of osteoblastic genes, namely Alkaline Phosphatase, Osteopontin, Bone Sialoprotein and Osteocalcin, and the transcription factors Runx2 and Osterix, all involved in different stages of the osteogenesis. These data represent the first report on the biological functionality of nanofibers-reinforced composite scaffolds, envisaging the applicability of the developed structures for bone tissue engineering.

  14. A novel combined method of osteosynthesis in treatment of tibial fractures: a comparative study on sheep with application of rod-through-plate fixator and bone plating.

    Science.gov (United States)

    Tralman, G; Andrianov, V; Arend, A; Männik, P; Kibur, R T; Nõupuu, K; Uksov, D; Aunapuu, M

    2013-04-01

    The study compares the efficiency of a new bone fixator combining periostal and intramedullary osteosynthesis to bone plating in treatment of tibial fractures in sheep. Experimental osteotomies were performed in the middle third of the left tibia. Animals were divided into two groups: in one group (four animals) combined osteosynthesis (rod-through-plate fixator, RTP fixator) was applied, and in the other group (three animals) bone plating was used. The experiments lasted for 10 weeks during which fracture union was followed by radiography, and the healing process was studied by blood serum markers reflecting bone turnover and by histological and immunohistochemical investigations. In the RTP fixator group, animals started to load body weight on the operated limbs the next day after the surgery, while in the bone plating group, this happened only on the seventh day. In the RTP fixator group, consolidation of fractures was also faster, as demonstrated by radiographical, histological, and immunohistochemical investigations and in part by blood serum markers for bone formation. It can be concluded that application of RTP fixation is more efficient than plate fixation in the treatment of experimental osteotomies of long bones in sheep.

  15. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Science.gov (United States)

    Chou, Ying-Chao; Yeh, Wen-Lin; Chao, Chien-Lin; Hsu, Yung-Heng; Yu, Yi-Hsun; Chen, Jan-Kan; Liu, Shih-Jung

    2016-01-01

    A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA) bolt as the bone anchor and a poly(D,L-lactide-co-glycolide) (PLGA) nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. PMID:27601901

  16. Fixation of trapezial implants in a trapeziometacarpal total joint prosthesis tested in a model of porcine bone.

    Science.gov (United States)

    Hansen, Torben Bæk; Hengst, David; Mortensen, Jesper; Amstrup, Anders Læssøe

    2011-12-01

    High aseptic loosening rates have been reported in total joint prostheses of the carpometacarpal joint of the thumb, particularly in the trapezial component. The primary fixation of new implants may be tested in cadaver bones, but the anatomy of the pig is in many ways similar to that of the human, so we compared the central carpal bone from the forefoot of 6-month-old pigs, which has a saddle joint surface similar to the trapezium, to the trapezium in patients with carpometacarpal osteoarthritis. The mean (SD) bone mineral density of the 13 pig forefoot bones was 0.88 (0.12) g/cm(2) compared with 0.63 (0.16) g/cm(2) in the 31 human trapeziums. The measured size of the porcine bones was slightly larger than that of the human trapeziums. The similarity in form, size, and bone mineral density means that the central bone of the forefoot of 6-month-old pigs may be used for fixation tests in trapezial implants.

  17. Osteogenic protein-1 increases the fixation of implants grafted with morcellised bone allograft and ProOsteon bone substitute: an experimental study in dogs

    DEFF Research Database (Denmark)

    Baad-Hansen, Thomas Einer; Overgaard, S; Lind, M;

    2007-01-01

    (ProOsteon) would improve the incorporation of bone and implant fixation. We also compared the response to using ProOsteon alone against bone allograft used in isolation. We implanted two non-weight-bearing hydroxyapatite-coated implants into each proximal humerus of six dogs, with each implant...... surrounded by a concentric 3 mm gap. These gaps were randomly allocated to four different procedures in each dog: 1) bone allograft used on its own; 2) ProOsteon used on its own; 3) allograft and ProOsteon used together; or 4) allograft and ProOsteon with the addition of osteogenic protein-1. After three...

  18. Review of techniques for monitoring the healing fracture of bones for implementation in an internally fixated pelvis.

    Science.gov (United States)

    Wong, Lydia Chwang Yuh; Chiu, Wing Kong; Russ, Matthias; Liew, Susan

    2012-03-01

    Sacral fractures from high-impact trauma often cause instability in the pelvic ring structure. Treatment is by internal fixation which clamps the fractured edges together to promote healing. Healing could take up to 12 weeks whereby patients are bedridden to avoid hindrances to the fracture from movement or weight bearing activities. Immobility can lead to muscle degradation and longer periods of rehabilitation. The ability to determine the time at which the fracture is stable enough to allow partial weight-bearing is important to reduce hospitalisation time. This review looks into different techniques used for monitoring the fracture healing of bones which could lead to possible methods for in situ and non-invasive assessment of healing fracture in a fixated pelvis. Traditional techniques being used include radiology and CT scans but were found to be unreliable at times and very subjective in addition to being non in situ. Strain gauges have proven to be very effective for accurate assessment of fracture healing as well as stability for long bones with external fixators but may not be suitable for an internally fixated pelvis. Ultrasound provides in situ monitoring of stiffness recovery but only assesses local fracture sites close to the skin surface and has only been tested on long bones. Vibration analysis can detect non-uniform healing due to its assessment of the overall structure but may suffer from low signal-to-noise ratio due to damping. Impedance techniques have been used to assess properties of non-long bones but recent studies have only been conducted on non-biological materials and more research needs to be done before it can be applicable for monitoring healing in the fixated pelvis.

  19. Efficacy and safety of biodegradable osteofixation devices in oral and maxillofacial surgery : a systematic review

    NARCIS (Netherlands)

    Buijs, G. J.; Stegenga, B.; Bos, R. R. M.

    2006-01-01

    The use of osteofixation devices should be evidence-based if uncomplicated bone healing is to be achieved. Numerous studies describe and claim the advantages of biodegradable over titanium devices as a bone fixation method. Here, we systematically review the available literature to determine the cli

  20. Magnetic biodegradable Fe3O4/CS/PVA nanofibrous membranes for bone regeneration.

    Science.gov (United States)

    Wei, Yan; Zhang, Xuehui; Song, Yu; Han, Bing; Hu, Xiaoyang; Wang, Xinzhi; Lin, Yuanhua; Deng, Xuliang

    2011-10-01

    In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. The aim of this study is to develop magnetic biodegradable fibrous materials with potential use in bone regeneration. Magnetic biodegradable Fe(3)O(4)/chitosan (CS)/poly vinyl alcohol (PVA) nanofibrous membranes were achieved by electrospinning with average fiber diameters ranging from 230 to 380 nm and porosity of 83.9-85.1%. The influences of polymer concentration, applied voltage and Fe(3)O(4) nanoparticles loading on the fabrication of nanofibers were investigated. The polymer concentration of 4.5 wt%, applied voltage of 20 kV and Fe(3)O(4) nanoparticles loading of lower than 5 wt% could produce homogeneous, smooth and continuous Fe(3)O(4)/CS/PVA nanofibrous membranes. X-ray diffraction (XRD) data confirmed that the crystalline structure of the Fe(3)O(4), CS and PVA were maintained during electrospinning process. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the Fe(3)O(4) loading up to 5 wt% did not change the functional groups of CS/PVA greatly. Transmission electron microscopy (TEM) showed islets of Fe(3)O(4) nanoparticles evenly distributed in the fibers. Weak ferrimagnetic behaviors of membranes were revealed by vibrating sample magnetometer (VSM) test. Tensile test exhibited Young's modulus of membranes that were gradually enhanced with the increase of Fe(3)O(4) nanoparticles loading, while ultimate tensile stress and ultimate strain were slightly reduced by Fe(3)O(4) nanoparticles loading of 5%. Additionally, MG63 human osteoblast-like cells were seeded on the magnetic nanofibrous membranes to evaluate their bone biocompatibility. Cell growth dynamics according to MTT assay and scanning electron microscopy (SEM) observation exhibited good cell adhesion and proliferation, suggesting that this magnetic biodegradable Fe(3)O(4)/CS/PVA nanofibrous membranes can be one of promising biomaterials for facilitation of osteogenesis.

  1. Comparison of Biodegradable and Titanium Fixation Systems in Maxillofacial Surgery : A Two-year Multi-center Randomized Controlled Trial

    NARCIS (Netherlands)

    van Bakelen, N. B.; Buijs, G. J.; Jansma, J.; de Visscher, J. G. A. M.; Hoppenreijs, Th. J. M.; Bergsma, J. E.; Stegenga, B.; Bos, R. R. M.

    2013-01-01

    Biodegradable osteosynthesis could reduce/delete the problems associated with titanium plate removal. The aim of the present study was to compare the clinical performance in the first 2 post-operative years between a biodegradable and a titanium system in oral and maxillofacial surgery. The multicen

  2. Biodegradation, biocompatibility, and osteoconduction evaluation of collagen-nanohydroxyapatite cryogels for bone tissue regeneration.

    Science.gov (United States)

    Salgado, Christiane Laranjo; Grenho, Liliana; Fernandes, Maria Helena; Colaço, Bruno Jorge; Monteiro, Fernando Jorge

    2016-01-01

    Designing biomimetic biomaterials inspired by the natural complex structure of bone and other hard tissues is still a challenge nowadays. The control of the biomineralization process onto biomaterials should be evaluated before clinical application. Aiming at bone regeneration applications, this work evaluated the in vitro biodegradation and interaction between human bone marrow stromal cells (HBMSC) cultured on different collagen/nanohydroxyapatite cryogels. Cell proliferation, differentiation, morphology, and metabolic activity were assessed through different protocols. All the biocomposite materials allowed physiologic apatite deposition after incubation in simulated body fluid and the cryogel with the highest nanoHA content showed to have the highest mechanical strength (DMA). The study clearly showed that the highest concentration of nanoHA granules on the cryogels were able to support cell type's survival, proliferation, and individual functionality in a monoculture system, for 21 days. In fact, the biocomposites were also able to differentiate HBMSCs into osteoblastic phenotype. The composites behavior was also assessed in vivo through subcutaneous and bone implantation in rats to evaluate its tissue-forming ability and degradation rate. The cryogels Coll/nanoHA (30 : 70) promoted tissue regeneration and adverse reactions were not observed on subcutaneous and bone implants. The results achieved suggest that scaffolds of Coll/nanoHA (30 : 70) should be considered promising implants for bone defects that present a grotto like appearance with a relatively small access but a wider hollow inside. This material could adjust to small dimensions and when entering into the defect, it could expand inside and remain in close contact with the defect walls, thus ensuring adequate osteoconductivity.

  3. Locking plate fixation combined with iliac crest bone autologous graft for proximal humerus comminuted fracture

    Institute of Scientific and Technical Information of China (English)

    Zhu Lian; Liu Yueju; Yang Zongyou; Li Han; Wang Juan; Zhao Changping; Chen Xiao

    2014-01-01

    Background Although the use of an intramedullary fibular allograft together with locking plate fixation can provide additional medial support and prevent varus malalignment in displaced proximal humeral fractures with promising results,the fibular autograft donor site often sustains significant trauma and cannot restore the articular surface of comminuted fractures.The aim of this study was to evaluate the clinical and radiographic outcomes of a locking plate and crest bone autologous graft for treating proximal humerus comminuted fractures.Methods We assessed the functional outcomes and complication rates in 40 patients with proximal humerus comminuted fractures.Eighteen patients were treated with a locking plate and an autologous crest bone graft (experimental group),and 22 were treated with only the locking plate and no bone graft (control group).Postoperative assessments included radiographic imaging,range of motion analysis,pain level based on the visual analogue scale (VAS),and the SF-36 (Short Form (36) Health Survey),as well as whether patients could retum to their previous occupation.Results All fractures healed both clinically and radiologically in the experimental group.There was no more than 2 mm collapse of the humeral head,and no osteonecrosis or screw penetration of the articular surface.In contrast,two patients had a nonunion in the control group,and they eventually accepted total shoulder replacements.The average time from surgery to radiographic union was significantly shorter in the experimental group ((4.66±1.63) months) compared with the control group ((5.98±1.57) months) (P <0.05).For the experimental versus controls groups,the mean shoulder active flexion (148.00±18.59 vs.121.73±17.20) degrees,extension (49.00±2.22 vs.42.06±2.06) degrees,internal rotation (45.00±5.61 vs.35.00±3.55)degrees,external rotation (64.00±9.17 vs.52.14±5.73)degrees,and abduction (138.00±28.78 vs.105.95±15.66) degrees were all significantly higher (all P

  4. Osteogenic induction of bone marrow-derived stromal cells on simvastatin-releasing, biodegradable, nano- to microscale fiber scaffolds.

    Science.gov (United States)

    Wadagaki, Ryu; Mizuno, Daiki; Yamawaki-Ogata, Aika; Satake, Makoto; Kaneko, Hiroaki; Hagiwara, Sumitaka; Yamamoto, Noriyuki; Narita, Yuji; Hibi, Hideharu; Ueda, Minoru

    2011-07-01

    Tissue engineering is an effective approach for the treatment of bone defects. Statins have been demonstrated to promote osteoblastic differentiation of bone marrow-derived stromal cells (BMSCs). Electrospun biodegradable fibers have also shown applicability to drug delivery in the form of bone tissue engineered scaffolds with nano- to microscale topography and high porosity similar to the natural extracellular matrix (ECM). The aim of this study was to investigate the feasibility of a simvastatin-releasing, biodegradable, nano- to microscale fiber scaffold (SRBFS) for bone tissue engineering with BMSCs. Simvastatin was released from SRBFS slowly. BMSCs were observed to spread actively and rigidly adhere to SRBFS. BMSCs on SRBFS showed an increase in alkaline phosphatase activity 2 weeks after cell culture. Furthermore, osteoclastogenesis was suppressed by SRBFS in vitro. The new bone formation and mineralization in the SRBFS group were significantly better than in the biodegradable fiber scaffold (BFS) without simvastatin 12 weeks after implantation of the cell-scaffold construct into an ectopic site on the murine back. These results suggest that SRBFS promoted osteoblastic differentiation of BMSCs in vitro and in vivo, and demonstrate feasibility as a bone engineering scaffold.

  5. Ectopic osteogenesis and scaffold biodegradation of tissue engineering bone composed of chitosan and osteo-induced bone marrow mesenchymal stem cells in vivo

    Institute of Scientific and Technical Information of China (English)

    He Yiqun; Dong Youhai; Chen Xujun; Lin Rongqiang

    2014-01-01

    Background Chitosan (CS) scaffolds combined with osteogenically induced bone marrow mesenchymal stem cells (BMSCs) have been proved to be promising substitutes for repairing bone defects.Nevertheless,the bone-forming and scaffold-biodegrading processes are seldom studied.This study aimed to determine the osteogenic ability of CS/osteoinduced BMSC composites by observing the bone-forming process and explore the relationship between bone formation and scaffold biodegradation.Methods The CS/osteo-induced BMSC composites (CS+cells group) and the CS scaffolds (CS group) were,respectively,implanted into SD rat thigh muscles.At 2,4,6,8,and 12 weeks postoperatively,the rat femurs were scanned by CT,and the CT values of the implants were measured and comparatively analyzed.Subsequently,the implants were harvested and stained with hematoxylin and eosin and Masson trichrome,and the percentages of bone area,scaffold area,and collagen area were calculated and compared between the two groups.Results The imaging results showed that the densities of implants of the two groups gradually increased along with time,but the CT values of implants in the CS+cells group were much higher than in the CS group at the same time point (P <0.05).The histological results showed that the de novo bone and collagen formed in the pores of the scaffolds and gradually increased since 2 weeks postoperation in both groups,and the scaffold gradually degraded along with the boneforming process.However,the comparative analysis results showed that the CS+cells group gained more de novo bone and collagen formation and had less scaffold than the CS group at the same time point (P <0.05).Conclusion The CS/osteo-induced BMSC composites are excellent bone tissue engineering substitutes,and the scaffold biodegradation is accordant with the bone formation.

  6. Mechanical performance of external fixators with wires for the treatment of bone fractures--Part I: Load-displacement behavior.

    Science.gov (United States)

    Delprete, C; Gola, M M

    1993-02-01

    Using matrix algebra, a mathematical model is formulated for a particular type of external fixator with wires (system developed by Ilizarov) for the treatment of bone fractures. The mathematical model is used to give a linear estimate of the stiffness under lateral and axial loads in a representative number of practical conditions. Relative displacements of the bone ends at the fracture site are calculated not only in the common case of a gap, but also for various angles of inclined sliding contact; in this case, a realistic load is applied and nonlinear stiffening of the wires under transversal loads is iteratively taken into account.

  7. Experimental and Numerical Analyses of the Pull-out Response of a Steel Post/Bovine Bone Cementless Fixation

    Institute of Scientific and Technical Information of China (English)

    Khaled Gammoudi; Mohamed Kharrat; Maher Dammak

    2012-01-01

    Effect of initial interference fit on pull-out strength in cementless fixation between bovine tibia and smooth stainless steel post was investigated in this study.Compressive behavior of bovine spongious bone was studied using mechanical testing in order to evaluate the elastic-plastic properties in different regions of the proximal tibia.Friction tests were carried out in the aim to evaluate the friction behavior of the contact between bovine spongious bone and stainless steel.A cylindrical stainless steel post inserted in a pre-drilled bovine tibia with an initial interference fit was taken as an in vitro model to assess the contribution of post fixation to the initial stability of the Total Knee Arthroplasty (TKA) tibial component.Pull-out experiments were carried out for different initial interference fits.Finite Element Models (FEM) using local elastic-plastic properties of the bovine bone were developed for the analysis of the experimental ultimate pull-out force results.At the post/bone interface,Coulomb friction was considered in the FEM calculations with pressure-dependent friction coefficient.It was found that the FEM results of the ultimate force are in good agreement with the experimental results.The analysis of the FEM interfacial stresses indicates that the micro-slip initiation depends on the local bone properties.

  8. Biodegradable poly(epsilon-caprolactone) nanowires for bone tissue engineering applications.

    Science.gov (United States)

    Porter, Joshua R; Henson, Andrew; Popat, Ketul C

    2009-02-01

    Critical-sized defects in bone, whether caused by cancer tumor resection, trauma, or selective surgery have in many cases presented insurmountable challenges to the current gold-standard treatment for bone repair. The primary purpose of a tissue-engineered scaffold is to incite and promote the natural healing process of bone, which does not occur in critical-sized defects. In this work, a solvent-free template synthesis technique was utilized to fabricate uniform arrays of substrate-bound poly(epsilon-caprolactone) (PCL) nanowires. Biodegradation of PCL nanowire surfaces was characterized using scanning electron microscopy (SEM) and matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. Rat bone marrow-derived mesenchymal stem cells (MSCs) were employed to assess short-term biocompatibility and long-term bioactivity of nanowire surfaces. Short-term cell studies indicated that PCL nanowire surfaces supported enhanced cell adhesion and viability compared with control surfaces. MSCs seeded on nanowire surfaces also displayed increased levels of alkaline phosphatase (ALP) after 1, 2, and 3 weeks in culture. Calcium-phosphate mineralization was substantially accelerated on nanowire surfaces compared to control surfaces as indicated through calcium staining, von Kossa staining, SEM, and electron dispersive spectroscopy (EDS). Increased levels of inter- and extracellular levels of osteocalcin and osteopontin were observed on nanowire surfaces using immunofluorescence techniques after 3 weeks of culture. Considering the simplicity of the presented fabrication technique, capacity for solvent-free encapsulation of bioactive molecules or particles, and enhanced MSC performance on nanowire surfaces, this work presents an excellent foundation for the development of 3-D scaffolds for bone tissue regeneration.

  9. Enhancement of tendon–bone healing via the combination of biodegradable collagen-loaded nanofibrous membranes and a three-dimensional printed bone-anchoring bolt

    Directory of Open Access Journals (Sweden)

    Chou YC

    2016-08-01

    Full Text Available Ying-Chao Chou,1,2 Wen-Lin Yeh,2 Chien-Lin Chao,1 Yung-Heng Hsu,1,2 Yi-Hsun Yu,1,2 Jan-Kan Chen,3 Shih-Jung Liu1,2 1Department of Mechanical Engineering, Chang Gung University, 2Department of Orthopedic Surgery, Chang Gung Memorial Hospital, 3Department of Physiology and Pharmacology, Chang Gung University, Taoyuan, Taiwan Abstract: A composite biodegradable polymeric model was developed to enhance tendon graft healing. This model included a biodegradable polylactide (PLA bolt as the bone anchor and a poly(D,L-lactide-co-glycolide (PLGA nanofibrous membrane embedded with collagen as a biomimic patch to promote tendon–bone interface integration. Degradation rate and compressive strength of the PLA bolt were measured after immersion in a buffer solution for 3 months. In vitro biochemical characteristics and the nanofibrous matrix were assessed using a water contact angle analyzer, pH meter, and tetrazolium reduction assay. In vivo efficacies of PLGA/collagen nanofibers and PLA bolts for tendon–bone healing were investigated on a rabbit bone tunnel model with histological and tendon pullout tests. The PLGA/collagen-blended nanofibrous membrane was a hydrophilic, stable, and biocompatible scaffold. The PLA bolt was durable for tendon–bone anchoring. Histology showed adequate biocompatibility of the PLA bolt on a medial cortex with progressive bone ingrowth and without tissue overreaction. PLGA nanofibers within the bone tunnel also decreased the tunnel enlargement phenomenon and enhanced tendon–bone integration. Composite polymers of the PLA bolt and PLGA/collagen nanofibrous membrane can effectively promote outcomes of tendon reconstruction in a rabbit model. The composite biodegradable polymeric system may be useful in humans for tendon reconstruction. Keywords: polylactide–polyglycolide nanofibers, PLGA, collagen, 3D printing, polylactide, PLA, bone-anchoring bolts, tendon healing

  10. Investigation of the mechanical properties and failure modes of hybrid natural fiber composites for potential bone fracture fixation plates.

    Science.gov (United States)

    Manteghi, Saeed; Mahboob, Zia; Fawaz, Zouheir; Bougherara, Habiba

    2017-01-01

    The purpose of this study is to investigate the mechanical feasibility of a hybrid Glass/Flax/Epoxy composite material for bone fracture fixation such as fracture plates. These hybrid composite plates have a sandwich structure in which the outer layers are made of Glass/Epoxy and the core from Flax/Epoxy. This configuration resulted in a unique structure compared to prior composites proposed for similar clinical applications. In order to evaluate the mechanical properties of this hybrid composite, uniaxial tension, compression, three-point bending and Rockwell Hardness tests were conducted. In addition, water absorption tests were performed to investigate the rate of water absorption for the specimens. This study confirms that the proposed hybrid composite plates are significantly more flexible axially compared to conventional metallic plates. Furthermore, they have considerably higher ultimate strength in tension, compression and flexion. Such high strength will ensure good stability of bone-implant construct at the fracture site, immobilize adjacent bone fragments and carry clinical-type forces experienced during daily normal activities. Moreover, this sandwich structure with stronger and stiffer face sheets and more flexible core can result in a higher stiffness and strength in bending compared to tension and compression. These qualities make the proposed hybrid composite an ideal candidate for the design of an optimized fracture fixation system with much closer mechanical properties to human cortical bone.

  11. The effects of hydroxyapatite coating and bone allograft on fixation of loaded experimental primary and revision implants

    DEFF Research Database (Denmark)

    Søballe, Kjeld; Mouzin, Olivier R G; Kidder, Louis A;

    2003-01-01

    We used our established experimental model of revision joint replacement to examine the roles of hydroxyapatite coating and bone graft in improving the fixation of revision implants. The revision protocol uses the Søballe micromotion device in a preliminary 8-week period of implant instability...... for the presence of particulate polyethylene. During this procedure, a sclerotic endosteal bone rim forms, and a dense fibrous membrane is engendered, having macrophages with ingested polyethylene and high levels of inflammatory cytokines. At the time of revision after 8 weeks, the cavity is revised with either...... in each of the 8 treatment groups (total 64 implants in 32 dogs). The observation period was 4 weeks after revision. Outcome measures are based on histomorphometry and mechanical pushout properties. The revision setting was always inferior to its primary counterpart. Bone graft improved the revision...

  12. Incorporation of biodegradable electrospun fibers into calcium phosphate cement for bone regeneration.

    Science.gov (United States)

    Zuo, Yi; Yang, Fang; Wolke, Joop G C; Li, Yubao; Jansen, John A

    2010-04-01

    Inherent brittleness and slow degradation are the major drawbacks for the use of calcium phosphate cements (CPCs). To address these issues, biodegradable ultrafine fibers were incorporated into the CPC in this study. Four types of fibers made of poly(epsilon-caprolactone) (PCL) (PCL12: 1.1 microm, PCL15: 1.4 microm, PCL18: 1.9 microm) and poly(l-lactic acid) (PLLA4: 1.4 microm) were prepared by electrospinning using a special water pool technique, then mixed with the CPC at fiber weight fractions of 1%, 3%, 5% and 7%. After incubation of the composites in simulated body fluid for 7 days, they were characterized by a gravimetric measurement for porosity evaluation, a three-point bending test for mechanical properties, microcomputer topography and scanning electron microscopy for morphological observation. The results indicated that the incorporation of ultrafine fibers increases the fracture resistance and porosity of CPCs. The toughness of the composites increased with the fiber fraction but was not affected by the fiber diameter. It was found that the incorporated fibers formed a channel-like porous structure in the CPCs. After degradation of the fibers, the created space and high porosity of the composite cement provides inter-connective channels for bone tissue in growth and facilitates cement resorption. Therefore, we concluded that this electrospun fiber-CPC composite may be beneficial to be used as bone fillers.

  13. Microstructure, cytotoxicity and corrosion of powder-metallurgical iron alloys for biodegradable bone replacement materials

    Energy Technology Data Exchange (ETDEWEB)

    Wegener, Bernd; Sievers, Birte; Utzschneider, Sandra; Mueller, Peter; Jansson, Volkmar [Department of Orthopedic Surgery, Ludwig-Maximilians-University of Munich, Marchioninistrasse 15, 81377 Muenchen (Germany); Roessler, Sophie; Nies, Berthold [InnoTERE GmbH, Tatzberg 47, 01307 Dresden (Germany); Stephani, Guenter; Kieback, Bernd [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany); Quadbeck, Peter, E-mail: peter.quadbeck@ifam-dd.fraunhofer.de [Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM), Dresden Branch Lab, Winterbergstrasse 28, 01277 Dresden (Germany)

    2011-12-15

    Up to now biodegradable bone implants with the ability of bearing high loads for the temporary replacement of bones or as osteosynthesis material are not available. Iron and iron based alloys have been identified as appropriate materials, since they combine high strength at medium corrosion rates. Thus, the aim of the present study is the development of a degradable iron based alloy with the perspective of using them as matrix material of cellular structures with biomechanical tailored properties. A powder metallurgical approach has been used to manufacture Fe-C, Fe-0.6P, Fe-1.6P, Fe-B and Fe-Ag samples, which have been tested with respect to their microstructure, their cytotoxicity, and their degradation rate. In order to determine the cytotoxicity of the material a monolayer culture of fibroblast and a perfusion chamber system has been chosen, which was recommended by the ISO 10993-5:1999 for biological testing of medical devices. It has been found, that in particular phosphorus features beneficial properties, since density and thus the strength of the material are increased. No corrosion inhibiting effects of phosphorus on the degradation rate have been found.

  14. Are two retrograde 3.5 mm screws superior to one 7.3 mm screw for anterior pelvic ring fixation in bones with low bone mineral density?

    Science.gov (United States)

    Zderic, I.; Grechenig, S.; Richards, R. G.; Schmitz, P.; Gueorguiev, B.

    2017-01-01

    Objectives Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible. The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using either one large- or two small-diameter screws. Materials and Methods A total of 12 human cadaveric hemipelvises were analysed in a matched pair study design. Bone mineral density of the specimens was 68 mgHA/cm3 (standard deviation (sd) 52). The anterior pelvic ring fracture was fixed with either one 7.3 mm cannulated screw (Group 1) or two 3.5 mm pelvic cortex screws (Group 2). Progressively increasing cyclic axial loading was applied through the acetabulum. Relative movements in terms of interfragmentary displacement and gap angle at the fracture site were evaluated by means of optical movement tracking. The Wilcoxon signed-rank test was applied to identify significant differences between the groups Results Initial axial construct stiffness was not significantly different between the groups (p = 0.463). Interfragmentary displacement and gap angle at the fracture site were also not statistically significantly different between the groups throughout the evaluated cycles (p ⩾ 0.249). Similarly, cycles to failure were not statistically different between Group 1 (8438, sd 6968) and Group 2 (10 213, sd 10 334), p = 0.379. Failure mode in both groups was characterised by screw cutting through the cancellous bone. Conclusion From a biomechanical point of view, pubic ramus stabilisation with either one large or two small fragment screw osteosynthesis is comparable in osteoporotic bone. However, the two-screw fixation technique is less demanding as the smaller screws deflect at the cortical margins. Cite this article: Y. P. Acklin, I. Zderic, S. Grechenig, R. G. Richards, P

  15. Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour

    Directory of Open Access Journals (Sweden)

    Ewa Oledzka

    2015-09-01

    Full Text Available The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched, and contained an active substance—bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA or hyperbranched 2,2-bis(hydroxymethylpropionic acid polyester-16-hydroxyl (bis-MPA initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol. The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

  16. Selenium-Substituted Hydroxyapatite/Biodegradable Polymer/Pamidronate Combined Scaffold for the Therapy of Bone Tumour.

    Science.gov (United States)

    Oledzka, Ewa; Sobczak, Marcin; Kolmas, Joanna; Nalecz-Jawecki, Grzegorz

    2015-09-14

    The present study evaluated a new concept of combined scaffolds as a promising bone replacement material for patients with a bone tumour or bone metastasis. The scaffolds were composed of hydroxyapatite doped with selenium ions and a biodegradable polymer (linear or branched), and contained an active substance-bisphosphonate. For this purpose, a series of biodegradable polyesters were synthesized through a ring-opening polymerization of ε-caprolactone or d,l-lactide in the presence of 2-hydroxyethyl methacrylate (HEMA) or hyperbranched 2,2-bis(hydroxymethyl)propionic acid polyester-16-hydroxyl (bis-MPA) initiators, substances often used in the synthesis of medical materials. The polymers were obtained with a high yield and a number-average molecular weight up to 45,300 (g/mol). The combined scaffolds were then manufactured by a direct compression of pre-synthesized hydroxyapatite doped with selenite or selenate ions, obtained polymer and pamidronate as a model drug. It was found that the kinetic release of the drug from the scaffolds tested in vitro under physiological conditions is strongly dependent on the physicochemical properties and average molecular weight of the polymers. Furthermore, there was good correlation with the hydrolytic biodegradation results of the scaffolds fabricated without drug. The preliminary findings suggest that the fabricated combined scaffolds could be effectively used for the sustained delivery of bioactive molecules at bone defect sites.

  17. The efficacy of poly-d,l-lactic acid- and hyaluronic acid-coated bone substitutes on implant fixation in sheep

    Directory of Open Access Journals (Sweden)

    Christina M. Andreasen

    2017-01-01

    Conclusion: This study demonstrates that HA/βTCP granules coated with PDLLA and HyA have similar bone ingrowth and implant fixation as those with allograft, and with mechanical properties resembling those of allograft in advance, they may be considered as alternative substitute materials for bone formation in sheep.

  18. Should in the treatment of osteochondritis dissecans biodegradable or metallic fixation devices be used? A comparative study in goat knees

    NARCIS (Netherlands)

    Wouters, Diederick B.; Bos, Rudolf R. M.; van Horn, Jim R.; van Luyn, Marja J. A.

    2008-01-01

    Most of the metallic devices have to be removed, treating osteochondritis dissecans lesions. This animal study describes the biological and mechanical behavior of screws and pins, made of commercially available PGA/PLA and PLA96 and metallic screws and pins, used for fragment fixation. A sham operat

  19. Coracoid bone graft osteolysis after Latarjet procedure: A comparison study between two screws standard technique vs mini-plate fixation

    Directory of Open Access Journals (Sweden)

    Giovanni Di Giacomo

    2013-01-01

    Full Text Available Aims: One of the reason for Latarjet procedure failure may be coracoid graft osteolysis. In this study, we aimed to understand if a better compression between the coracoid process and the glenoid, using a mini-plate fixation during the Latarjet procedure, could reduce the amount of coracoid graft osteolysis. Materials and Methods: A computed tomography scan analysis of 26 prospectively followed-up patients was conducted after modified Latarjet procedure using mini-plate fixation technique to determine both the location and the amount of coracoid graft osteolysis in them. We then compared our current results with results from that of our previous study without using mini-plate fixation to determine if there is any statistical significant difference in terms of corcacoid bone graft osteolysis between the two surgical techniques. Results: The most relevant osteolysis was represented by the superficial part of the proximal coracoid, whereas the deep part of the proximal coracoid graft is least involved in osteolysis and has best bone healing. The current study showed a significant difference only for the deep part of the distal coracoid with our previous study (P < 0.01. Discussion: To our knowledge, there are no studies in literature that show the causes of coracoid bone graft osteolysis after Latarjet procedure. Conclusion: Our study suggests that there is a significant difference only for the deep part of the distal coracoid in terms of osteolysis. At clinical examination, this difference did not correspond with any clinical findings. Level of Evidence: Level 4. Clinical Relevance: Prospective case series, Treatment study.

  20. Coralline hydroxyapatite granules inferior to morselized allograft around uncemented porous Ti implants: unchanged fixation by addition of concentrated autologous bone marrow aspirate.

    Science.gov (United States)

    Baas, Jorgen; Svaneby, Dea; Jensen, Thomas Bo; Elmengaard, Brian; Bechtold, Joan; Soballe, Kjeld

    2011-10-01

    We compared early fixation of titanium implants grafted with impacted allograft bone or coralline hydroxyapatite (HA) granules (Pro Osteon 200) with and without the addition of concentrated bone marrow cells (BMC). Autologous bone marrow aspirate was centrifuged to increase the BMC concentration. Four nonloaded cylindrical, porous coated titanium implants with a circumferential gap of 2.3 mm were inserted in the proximal humeri of eight dogs. Coralline HA granules +/- BMC were impacted around the two implants on one side, and allograft +/- BMC was impacted around the contra lateral implants. Observation time was 4 weeks. The implants surrounded by allograft bone had a three-fold better fixation than the HA-grafted implants. The concentration of BMC after centrifugation was increased with a factor 2.1. The addition of BMC to either of the bone graft materials had no statistically significant effects on implant fixation. The allografted implants were well osseointegrated, whereas the HA-grafted implants were largely encapsulated in fibrous tissue. The addition of concentrated autologous BMCs to the graft material had no effect on implant fixation. The HA-grafted implants were poorly anchored compared with allografted implants, suggesting that coralline HA granules should be considered a bone graft extender rather than a bone graft substitute.

  1. Enhancement of osteogenesis and biodegradation control by brushite coating on Mg-Nd-Zn-Zr alloy for mandibular bone repair.

    Science.gov (United States)

    Guan, Xingmin; Xiong, Meiping; Zeng, Feiyue; Xu, Bin; Yang, Lingdi; Guo, Han; Niu, Jialin; Zhang, Jian; Chen, Chenxin; Pei, Jia; Huang, Hua; Yuan, Guangyin

    2014-12-10

    To diminish incongruity between bone regeneration and biodegradation of implant magnesium alloy applied for mandibular bone repair, a brushite coating was deposited on a matrix of a Mg-Nd-Zn-Zr (hereafter, denoted as JDBM) alloy to control the degradation rate of the implant and enhance osteogenesis of the mandible bone. Both in vitro and in vivo evaluations were carried out in the present work. Viability and adhesion assays of rabbit bone marrow mesenchyal stem cells (rBM-MSCs) were applied to determine the biocompatibility of a brushite-coated JDBM alloy. Osteogenic gene expression was characterized by quantitative real-time polymerase chain reaction (RT-PCR). Brushite-coated JDBM screws were implanted into mandible bones of rabbits for 1, 4, and 7 months, respectively, using 316L stainless steel screws as a control group. In vivo biodegradation rate was determined by synchrotron radiation X-ray microtomography, and osteogenesis was observed and evaluated using Van Gieson's picric acid-fuchsin. Both the naked JDBM and brushite-coated JDBM samples revealed adequate biosafety and biocompatibility as bone repair substitutes. In vitro results showed that brushite-coated JDBM considerably induced osteogenic differentiation of rBM-MSCs. And in vivo experiments indicated that brushite-coated JDBM screws presented advantages in osteoconductivity and osteogenesis of mandible bone of rabbits. Degradation rate was suppressed at a lower level at the initial stage of implantation when new bone tissue formed. Brushite, which can enhance oeteogenesis and partly control the degradation rate of an implant, is an appropriate coating for JDBM alloys used for mandibular repair. The Mg-Nd-Zn-Zr alloy with brushite coating possesses great potential for clinical applications for mandibular repair.

  2. Bone formation by three-dimensional stromal osteoblast culture in biodegradable polymer scaffolds

    Science.gov (United States)

    Ishaug, S. L.; Crane, G. M.; Miller, M. J.; Yasko, A. W.; Yaszemski, M. J.; Mikos, A. G.; McIntire, L. V. (Principal Investigator)

    1997-01-01

    Bone formation was investigated in vitro by culturing stromal osteoblasts in three-dimensional (3-D), biodegradable poly(DL-lactic-co-glycolic acid) foams. Three polymer foam pore sizes, ranging from 150-300, 300-500, and 500-710 microns, and two different cell seeding densities, 6.83 x 10(5) cells/cm2 and 22.1 x 10(5) cells/cm2, were examined over a 56-day culture period. The polymer foams supported the proliferation of seeded osteoblasts as well as their differentiated function, as demonstrated by high alkaline phosphatase activity and deposition of a mineralized matrix by the cells. Cell number, alkaline phosphatase activity, and mineral deposition increased significantly over time for all the polymer foams. Osteoblast foam constructs created by seeding 6.83 x 10(5) cells/cm2 on foams with 300-500 microns pores resulted in a cell density of 4.63 x 10(5) cells/cm2 after 1 day in culture; they had alkaline phosphatase activities of 4.28 x 10(-7) and 2.91 x 10(-6) mumol/cell/min on Days 7 and 28, respectively; and they had a cell density that increased to 18.7 x 10(5) cells/cm2 by Day 56. For the same constructs, the mineralized matrix reached a maximum penetration depth of 240 microns from the top surface of the foam and a value of 0.083 mm for mineralized tissue volume per unit of cross sectional area. Seeding density was an important parameter for the constructs, but pore size over the range tested did not affect cell proliferation or function. This study suggests the feasibility of using poly(alpha-hydroxy ester) foams as scaffolding materials for the transplantation of autogenous osteoblasts to regenerate bone tissue.

  3. Aluminum-free glass-ionomer bone cements with enhanced bioactivity and biodegradability

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Filipa O.; Pires, Ricardo A., E-mail: rpires@dep.uminho.pt; Reis, Rui L.

    2013-04-01

    Al-free glasses of general composition 0.340SiO{sub 2}:0.300ZnO:(0.250-a-b)CaO:aSrO:bMgO:0.050Na{sub 2}O:0.060P{sub 2}O{sub 5} (a, b = 0.000 or 0.125) were synthesized by melt quenching and their ability to form glass-ionomer cements was evaluated using poly(acrylic acid) and water. We evaluated the influence of the poly(acrylic acid) molecular weight and glass particle size in the cement mechanical performance. Higher compressive strength (25 ± 5 MPa) and higher compressive elastic modulus (492 ± 17 MPa) were achieved with a poly(acrylic acid) of 50 kDa and glass particle sizes between 63 and 125 μm. Cements prepared with glass formulation a = 0.125 and b = 0.000 were analyzed after immersion in simulated body fluid; they presented a surface morphology consistent with a calcium phosphate coating and a Ca/P ratio of 1.55 (similar to calcium-deficient hydroxyapatite). Addition of starch to the cement formulation induced partial degradability after 8 weeks of immersion in phosphate buffer saline containing α-amylase. Micro-computed tomography analysis revealed that the inclusion of starch increased the cement porosity from 35% to 42%. We were able to produce partially degradable Al-free glass-ionomer bone cements with mechanical performance, bioactivity and biodegradability suitable to be applied on non-load bearing sites and with the appropriate physical characteristics for osteointegration upon partial degradation. Zn release studies (concentrations between 413 μM and 887 μM) evidenced the necessity to tune the cement formulations to reduce the Zn concentration in the surrounding environment. Highlights: ► We developed partially degradable, bioactive, Al-free glass-ionomer cements (GICs). ► Enhanced mechanical behavior was achieved using 63–125 μm glass particle size range. ► The highest mechanical resistance was obtained using poly(acrylic acid) of 50 kDa. ► Biodegradation was successfully tuned to start 8 weeks after GIC preparation. ► Zn

  4. Osteogenic potential of porous {beta}-tricalcium phosphate ({beta}-TCP) combined with cultured bone. Tissue engineered bone using a biodegradable material as a scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Fu, S.; Yamada, Y.; Honda, M.; Ueda, M. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Yoshikawa, T. [Nara Medical Univ. (Japan). First Dept. of Pathology; Hibino, Y.; Hata, K. [Nagoya Univ. (Japan). Dept. of Tissue Engineering; Niimi, A. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Chunichi Hospital (Japan). Dept. of Oral and Maxillofacial Surgery; Okazaki, Y. [Nagoya Univ. (Japan). Dept. of Protective Care for Masticatory Disorders; Nagoya Univ. (Japan). Dept. of Tissue Engineering

    2001-07-01

    Recently, the tissue engineering approach has widespread attention for regeneration. The present study was undertaken to evaluate whether biodegradable porous {beta}-tricalcium phosphate ({beta}-TCP) can be used as a scaffold for cultured bone marrow cells or not. Marrow cells were obtained from bone shaft of rat femur and cultured in a standard medium for 10 days, then trypsinized to combine cells with ceramics. An additional subculture was done for cells/ceramics composite in a standard medium with the addition of {beta}-glycerophosphate, ascorbic acid and dexamethason. The 20 day subcultured composites were implanted into subcutaneous sites of syngeneic rats. These implants were harvested at 4 and 8 weeks postimplantation, and prepared for the histological analysis. In the histological analysis of composites at 4 weeks postimplantation, active bone formation could be found in the composites. The bone formation was evidenced by active osteoblast lining on the surfaces of bone. At 8 weeks, more extensive bone formation was observed in the composites. These results suggested that beta-TCP could play a role as scaffold of tissueengineered bone derived from marrow cells. (orig.)

  5. A Comparative Finite-Element Analysis of Bone Failure and Load Transfer of Osseointegrated Prostheses Fixations

    NARCIS (Netherlands)

    Tomaszewski, P. K.; Verdonschot, N.; Bulstra, S. K.; Verkerke, G. J.

    2010-01-01

    An alternative solution to conventional stump-socket prosthetic limb attachment is offered by direct skeletal fixation. This study aimed to assess two percutaneous trans-femoral implants, the OPRA system (Integrum AB, Goteborg, Sweden), and the ISP Endo/Exo prosthesis (ESKA Implants AG, Lubeck, Germ

  6. A comparative finite-element analysis of bone failure and load transfer of osseointegrated prostheses fixations.

    NARCIS (Netherlands)

    Tomaszewski, P.K.; Verdonschot, N.J.J.; Bulstra, S.K.; Verkerke, G.J.

    2010-01-01

    An alternative solution to conventional stump-socket prosthetic limb attachment is offered by direct skeletal fixation. This study aimed to assess two percutaneous trans-femoral implants, the OPRA system (Integrum AB, Goteborg, Sweden), and the ISP Endo/Exo prosthesis (ESKA Implants AG, Lubeck, Germ

  7. Femoral stiffness after osteosynthesis of a subcapital osteotomy in osteoporotic bone: an in-vitro comparison of nine fixation methods.

    Science.gov (United States)

    Hernefalk, L; Messner, K

    1995-01-01

    Restitution of normal bone mechanics after osteosynthesis of a proximal femoral fracture in the elderly is assumed to be a prerequisite for optimal healing. To find the most appropriate fixation device for this purpose, the stiffness of 79 cadaver femora from donors with a history of osteoporosis was measured during axial loading before and after a subcapital osteotomy stabilized with one of nine different osteosynthesis devices. Only an osteotomy stabilized with an experimental device consisting of 2 von Bahr screws (Ericsson AB, Göteborg, Sweden) supported by acrylic cement gave similar mean values as the intact femur. A femur stabilized with the Deyerle device (Biomet, Bridge End, Wales, U.K.), with cannulated screws type Uppsala (Olmed AB, Uppsala, Sweden), or with von Bahr screws had an approximately 20-30% lower stiffness than tested intact. However, these devices provided a higher femoral stiffness than the hook-pin technique type LiH (Söderström AB, Gothenburg, Sweden), cannulated screws (Smith & Nephew, Memphis, TN, U.S.A.), a sliding screw plate (Smith & Nephew), a compression screw with variable length (Biomet), or an experimental screw providing expansion and compression. Despite attempted compression of the osteotomy by some of the devices, all of the commercially available devices resulted in a decrease of femoral stiffness after fixation, which may adversely influence the healing of femoral neck fractures in the elderly. Only a combination of screws and bone cement resulted in normal femoral stiffness, probably because of better device anchorage in the osteoporotic cancellous bone. However, this combination might have the potential risk of vascular damage.

  8. Effect of implantation of biodegradable magnesium alloy on BMP-2 expression in bone of ovariectomized osteoporosis rats

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Yue, E-mail: 373073766@qq.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Ren, Ling, E-mail: lren@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Liu, Chang, E-mail: meixifan1971@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Yuan, Yajiang, E-mail: yuan925@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Lin, Xiao, E-mail: linx@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Tan, Lili, E-mail: lltan@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Chen, Shurui, E-mail: 272146792@qq.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016 (China); Mei, Xifan, E-mail: meixifan1971@163.com [Liaoning Medical University, 40 Songpo Road, Jinzhou, 121000 (China)

    2013-10-01

    The study was focused on the implantation of a biodegradable AZ31 magnesium alloy into the femoral periosteal of the osteoporosis modeled rats. The experimental results showed that after 4 weeks implantation of AZ31 alloy in the osteoporosis modeled rats, the expression of BMP-2 in bone tissues of the rats was much enhanced, even higher than the control group, which should promote the bone formation and be beneficial for reducing the harmful effect of osteoporosis. Results of HE stains showed that the implantation of AZ31 alloy did not have obvious pathological changes on both the liver and kidney of the animal. - Highlights: • Mg alloy greatly increased expression of BMP-2 in osteoporosis modeled rat bone. • Mg alloy showed good biological safety. • Mg alloy is beneficial for reducing the symptom of osteoporosis.

  9. Aluminum-free glass-ionomer bone cements with enhanced bioactivity and biodegradability.

    Science.gov (United States)

    Gomes, Filipa O; Pires, Ricardo A; Reis, Rui L

    2013-04-01

    Al-free glasses of general composition 0.340SiO2:0.300ZnO:(0.250-a-b)CaO:aSrO:bMgO:0.050Na2O:0.060P2O5 (a, b=0.000 or 0.125) were synthesized by melt quenching and their ability to form glass-ionomer cements was evaluated using poly(acrylic acid) and water. We evaluated the influence of the poly(acrylic acid) molecular weight and glass particle size in the cement mechanical performance. Higher compressive strength (25±5 MPa) and higher compressive elastic modulus (492±17 MPa) were achieved with a poly(acrylic acid) of 50 kDa and glass particle sizes between 63 and 125 μm. Cements prepared with glass formulation a=0.125 and b=0.000 were analyzed after immersion in simulated body fluid; they presented a surface morphology consistent with a calcium phosphate coating and a Ca/P ratio of 1.55 (similar to calcium-deficient hydroxyapatite). Addition of starch to the cement formulation induced partial degradability after 8 weeks of immersion in phosphate buffer saline containing α-amylase. Micro-computed tomography analysis revealed that the inclusion of starch increased the cement porosity from 35% to 42%. We were able to produce partially degradable Al-free glass-ionomer bone cements with mechanical performance, bioactivity and biodegradability suitable to be applied on non-load bearing sites and with the appropriate physical characteristics for osteointegration upon partial degradation. Zn release studies (concentrations between 413 μM and 887 μM) evidenced the necessity to tune the cement formulations to reduce the Zn concentration in the surrounding environment.

  10. In vitro and in vivo evaluation of a polylactic acid-bioactive glass composite for bone fixation devices.

    Science.gov (United States)

    Vergnol, Gwenaelle; Ginsac, Nathalie; Rivory, Pascaline; Meille, Sylvain; Chenal, Jean-Marc; Balvay, Sandra; Chevalier, Jérôme; Hartmann, Daniel J

    2016-01-01

    Poly(lactic acid) is nowadays among the most used bioabsorbable materials for medical devices. To promote bone growth on the material surface and increase the degradation rate of the polymer, research is currently focused on organic-inorganic composites by adding a bioactive mineral to the polymer matrix. The purpose of this study was to investigate the ability of a poly(L,DL-lactide)-Bioglass® (P(L,DL)LA-Bioglass(®) 45S5) composite to be used as a bone fixation device. In vitro cell viability testing of P(l,dl)LA based composites containing different amounts of Bioglass(®) 45S5 particles was investigated. According to the degradation rate of the P(L,DL)LA matrix and the cytocompatibility experiments, the composite with 30 wt % of Bioglass® particles seemed to be the best candidate for further investigation. To study its behavior after immersion in simulated physiological conditions, the degradation of the composite was analyzed by measuring its weight loss and mechanical properties and by proceeding with X-ray tomography. We demonstrated that the presence of the bioactive glass significantly accelerated the in vitro degradation of the polymer. A preliminary in vivo investigation on rabbits shows that the addition of 30 wt % of Bioglass(®) in the P(L,DL)LA matrix seems to trigger bone osseointegration especially during the first month of implantation. This composite has thus strong potential interest for health applications.

  11. Primary fixation and delayed nailing of long bone fractures in severe trauma

    DEFF Research Database (Denmark)

    Friedl, H.P.; Stoker, R.; Czermak, B.

    1996-01-01

    Shaft fractures of the femur or tibia or both are frequent components of multiple trauma. Besides the local fracture impact, they induce considerable systemic distress to remote organs because of pain, blood loss, necrotic or hypoperfused tissues, and mediator release. Additionally, unstable......, and the biomechanically best fixation technique should not be used, in favor of alternative procedures with a lower systemic distress level. We describe a treatment algorithm that appeared to be successful in a number of multitrauma situations....

  12. Biomechanical Evaluation of Different Fixation Methods for Mandibular Anterior Segmental Osteotomy Using Finite Element Analysis, Part Two: Superior Repositioning Surgery With Bone Allograft.

    Science.gov (United States)

    Kilinç, Yeliz; Erkmen, Erkan; Kurt, Ahmet

    2016-01-01

    In this study, the biomechanical behavior of different fixation methods used to fix the mandibular anterior segment following various amounts of superior repositioning was evaluated by using Finite Element Analysis (FEA). The three-dimensional finite element models representing 3 and 5 mm superior repositioning were generated. The gap in between segments was assumed to be filled by block bone allograft and resignated to be in perfect contact with the mandible and segmented bone. Six different finite element models with 2 distinct mobilization rate including 3 different fixation configurations, double right L (DRL), double left L (DLL), or double I (DI) miniplates with monocortical screws, correspondingly were created. A comparative evaluation has been made under vertical, horizontal and oblique loads. The von Mises and principal maximum stress (Pmax) values were calculated by finite element solver programme. The first part of our ongoing Finite Element Analysis research has been addressed to the mechanical behavior of the same fixation configurations in nongrafted models. In comparison with the findings of the first part of the study, it was concluded that bone graft offers superior mechanical stability without any limitation of mobilization and less stress on the fixative appliances as well as in the bone.

  13. Biodegradable polymers and composites in biomedical applications : from catgut to tissue engineering - Part 1 - Available systems and their properties

    OpenAIRE

    Gomes, Manuela E.; Reis, R. L.

    2004-01-01

    Biodegradable polymers form a unique class of materials that created an entirely new concept when originally proposed as biomaterials. That is, for the first time, a material performing a structural application was designed to be completely resorbed and to become weaker over time. This concept was first applied successfully with catgut sutures and later, with more arguable results, on bone fixation plates and pins. Current research on new and improved biodegradable polymers is focused on more...

  14. Low bone mineral density is not related to failure in femoral neck fracture patients treated with internal fixation

    DEFF Research Database (Denmark)

    Viberg, Bjarke; Ryg, Jesper; Overgaard, Søren;

    2014-01-01

    Background and purpose - Internal fixation (IF) in femoral neck fractures has high reoperation rates and some predictors of failure are known, such as age, quality of reduction, and implant positioning. Finding new predictors of failure is an ongoing process, and in this study we evaluated...... the importance of low bone mineral density (BMD). Patients and methods - 140 consecutive patients (105 females, median age 80) treated with IF had a dual-energy X-ray absorptiometry (DXA) scan of the hip performed median 80 days after treatment. The patients' radiographs were evaluated for fracture displacement......, or new hip fracture). A stratified Cox regression model on fracture displacement was applied and adjusted for age, sex, quality of reduction, implant positioning, comorbidity, and walking disability. Results - 49 patients had a T-score below -2.5 (standard deviation from the young normal reference mean...

  15. Fixation of metatarsal fracture with bone plate in a dromedary heifer

    Directory of Open Access Journals (Sweden)

    S. Hashmi

    2013-03-01

    Full Text Available An oblique fracture of the distal third of the right metatarsus in a three-year-old dromedary heifer weighing about 300 kilograms was immobilized with a 4.5 mm broad-webbed 12-hole dynamic compression bone plate and two interfragmental compression screws. The animal showed slight lameness after 16 weeks of surgery that disappeared after removal of the plate. The result was quite encouraging and the fracture healed in 16 weeks without major complications. It is concluded that the fracture of this bone can be successfully handled with bone plating at least in young, light weight animals.

  16. Depot injectable biodegradable nanoparticles loaded with recombinant human bone morphogenetic protein-2: preparation, characterization, and in vivo evaluation

    Directory of Open Access Journals (Sweden)

    Hassan AH

    2015-07-01

    Full Text Available Ali Habiballah Hassan,1 Khaled Mohamed Hosny,2,3 Zuahir A Murshid,1 Adel Alhadlaq,4 Ahmed Alyamani,5 Ghada Naguib6 1Department of Orthodontics, Faculty of Dentistry, 2Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, King Abdulaziz University, Jeddah, Saudi Arabia; 3Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Beni Suef University, Beni Suef, Egypt; 4Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, 5Department of Oral Surgery, 6Department of Restorative Dentistry, Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia Objective: The aim of this study is to utilize the biocompatibility characteristics of biodegradable polymers, viz, poly lactide-co-glycolide (PLGA and polycaprolactone (PCL, to prepare sustained-release injectable nanoparticles (NPs of bone morphogenetic protein-2 (BMP-2 for the repair of alveolar bone defects in rabbits. The influence of formulation parameters on the functional characteristics of the prepared NPs was studied to develop a new noninvasive injectable recombinant human BMP-2 (rhBMP-2 containing grafting material for the repair of alveolar bone clefts.Materials and methods: BMP-2 NPs were prepared using a water-in-oil-in-water double-emulsion solvent evaporation/extraction method. The influence of molar ratio of PLGA to PCL on a suitable particle size, encapsulation efficiency, and sustained drug release was studied. Critical size alveolar defects were created in the maxilla of 24 New Zealand rabbits divided into three groups, one of them treated with 5 µg/kg of rhBMP-2 NP formulations.Results: The results found that NPs formula prepared using blend of PLGA and PCL in 4:2 (w/w ratio showed the best sustained-release pattern with lower initial burst, and showed up to 62.7% yield, 64.5% encapsulation efficiency, 127 nm size, and more than 90% in vitro release. So, this formula was selected for

  17. Transient and residual stresses and displacements in self-curing bone cement - Part II: thermoelastic analysis of the stem fixation system.

    Science.gov (United States)

    Ahmed, A M; Nair, R; Burke, D L; Miller, J

    1982-02-01

    In this second part of a two-part report, an idealized model of the stem fixation system is analyzed to determine the adverse effects of the thermal stresses and displacements of bone cement during its curing process. The Shaffer-Levitsky stress-rate strain-rate law for chemically hardening material has been used. The results show that if the cement is surrounded by cancellous bone, as opposed to cortical bone, then transient tensile circumferential stresses in the cement and similar radial stresses at the stem/cement interface are generated. The former may cause flaws and voids within the still cement, while the latter may cause gaps at the interface.

  18. A CLINICAL STUDY OF MANAGEMENT OF FRACTURE BOTH BONES FOREARM WITH INTERNAL FIXATION BY TWO DIFFERENT METHODS

    Directory of Open Access Journals (Sweden)

    Venkateswara Rao

    2015-09-01

    Full Text Available BACKGROUND AND OBJECTIVES: 60 cases of fracture both bone forearm in adults were operated and fixed using two different instruments in Siddhartha Medical College/Government General Hospital, Vijayawada between May 2013 to April 2015. METHODS: Most of the cases were young adult male with age ranging between 20 - 75yrs. The functional outcome of two different modalities of surgical management of diaphyseal fracture of both bone forearm in adults are interpreted. 30 patients were operated with DCP, and 30 patients were operated with intramedullary nailing. RESULTS : By Anderson Scoring System out of 30 cases of DCP 66.67% were excellent, 33.33% were satisfactory. Out of 30 cases of Intramedullary nailing with Talwalker square nails 50% were excellent, 23.33% were satisfactory, 16.67% were unsatisfactory, 10% had failure results. CONCLUSION : Open reduction and internal fixation can be considered as the treatment of choice if there were no contraindications for this because it is important to maintain length, opposition, axial alignment and rotational alignment if a good range of movement of forearm is to be restored. This is achieved in the present study.

  19. TREATMENT OF CLOSED TIBIAL PILON FRACTURES WITH OPEN REDUCTION, INTERNAL FIXATION AND BONE GRAFTING. A STUDY OF 22 CASES COMPARING THE OBJE CTIVE AND SUBJECTIVE EVALUATION

    Directory of Open Access Journals (Sweden)

    Athmaram

    2015-02-01

    Full Text Available The cases of twenty two fractures of the ankle joint that involved the tibial plafond were reviewed. The fractures were classified in to five types according to the severity of the injury. Open reduction and internal fixation was performed using one third tubular plate for fibula and recon plate for the tibia. Bone grafting was don e to augment the fixation and maintain the reduction . For each fracture treated Objective and Subjective evaluation is done. The objective and subjective scores are compared. With this method we noticed that the Type III & IV fractures also had a good or e xcellent result .

  20. In vivo study of extracellular matrix coating enhancing fixation of the pedicle screw-bone's interface

    Institute of Scientific and Technical Information of China (English)

    LIU Guo-min; ZHANG Xing-yi; XU Chuan-jie; ZHU Xiao-min; WANG Jun; LIU Yi

    2011-01-01

    Background Based on in vivo research on the effect of the coating of the extracellular matrix composition of pedicle screws on the conduction and induction of bone formation in young sheep,the aim of this study was to investigate the application of coated pedicle screws in sheep with scoliosis whose spines are under constant development.Methods Four groups of pedicle screws were randomly implanted into bilateral L2-L5 pedicles of 2.5- to 3-month-old sheep.A static experiment was performed on one side and a loading test was performed on the other side by implanting connecting rods at the L2-L3 and L4-L5 segments.The changes in the force on the coated screws and the combination of the surface of the coated screws with the surrounding bone in the growth process of young sheep's spines with aging were observed.After 3 months,the lumbar vertebrae with the screws were removed and examined by micro-CT,histological,and biomechanical analyses.Results Under nonloading conditions,there is bone formation around the surfaces of coated screws.The bone forming on the surface of collagen/chondroitin sulfate/hydroxyapatite coating of pedicle screws is the most,the one of the collagen / chondrcitin sulfate coating and hydroxyapatite coating is followed,and no significant difference between the two groups.In terms of the trabecular bone morphology parameters of the region of interest around the surface of the pedicle screws,such as bone mineral content,bone mineral density,tissue mineral content,tissue bone mineral density,bone volume fraction,and connection density,those associated with collagen/chondroitin sulfate/hydroxyapatite coatings are largest and those unassociated with coatings are smallest.Under nonloading conditions,the pullout strength of the collagen/chondroitin sulfate/hydroxyapatite-coated screws was largest,and that of the uncoated screws was minimal (P <0.01).Under loading conditions,the maximum pullout strength of each group of pedicle screws was less than that

  1. Modifying bone scaffold architecture in vivo with permanent magnets to facilitate fixation of magnetic scaffolds.

    Science.gov (United States)

    Panseri, S; Russo, A; Sartori, M; Giavaresi, G; Sandri, M; Fini, M; Maltarello, M C; Shelyakova, T; Ortolani, A; Visani, A; Dediu, V; Tampieri, A; Marcacci, M

    2013-10-01

    The fundamental elements of tissue regeneration are cells, biochemical signals and the three-dimensional microenvironment. In the described approach, biomineralized-collagen biomaterial functions as a scaffold and provides biochemical stimuli for tissue regeneration. In addition superparamagnetic nanoparticles were used to magnetize the biomaterials with direct nucleation on collagen fibres or impregnation techniques. Minimally invasive surgery was performed on 12 rabbits to implant cylindrical NdFeB magnets in close proximity to magnetic scaffolds within the lateral condyles of the distal femoral epiphyses. Under this static magnetic field we demonstrated, for the first time in vivo, that the ability to modify the scaffold architecture could influence tissue regeneration obtaining a well-ordered tissue. Moreover, the association between NdFeB magnet and magnetic scaffolds represents a potential technique to ensure scaffold fixation avoiding micromotion at the tissue/biomaterial interface.

  2. Quantifying the Effects of Formalin Fixation on the Mechanical Properties of Cortical Bone Using Beam Theory and Optimization Methodology With Specimen-Specific Finite Element Models.

    Science.gov (United States)

    Zhang, Guan-Jun; Yang, Jie; Guan, Feng-Jiao; Chen, Dan; Li, Na; Cao, Libo; Mao, Haojie

    2016-09-01

    The effects of formalin fixation on bone material properties remain debatable. In this study, we collected 36 fresh-frozen cuboid-shaped cortical specimens from five male bovine femurs and immersed half of the specimens into 4% formalin fixation liquid for 30 days. We then conducted three-point bending tests and used both beam theory method and an optimization method combined with specimen-specific finite element (FE) models to identify material parameters. Through the optimization FE method, the formalin-fixed bones showed a significantly lower Young's modulus (-12%) compared to the fresh-frozen specimens, while no difference was observed using the beam theory method. Meanwhile, both the optimization FE and beam theory methods revealed higher effective failure strains for formalin-fixed bones compared to fresh-frozen ones (52% higher through the optimization FE method and 84% higher through the beam theory method). Hence, we conclude that the formalin fixation has a significant effect on bovine cortical bones at small, elastic, as well as large, plastic deformations.

  3. Design and Optimization of Resorbable Silk Internal Fixation Devices

    Science.gov (United States)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  4. Incorporation of biodegradable electrospun fibers into calcium phosphate cement for bone regeneration.

    NARCIS (Netherlands)

    Zuo, Y.; Yang, F.; Wolke, J.G.C.; Li, Yubao; Jansen, J.A.

    2010-01-01

    Inherent brittleness and slow degradation are the major drawbacks for the use of calcium phosphate cements (CPCs). To address these issues, biodegradable ultrafine fibers were incorporated into the CPC in this study. Four types of fibers made of poly(epsilon-caprolactone) (PCL) (PCL12: 1.1 microm, P

  5. Effects of Composite Formulation on Mechanical Properties of Biodegradable Poly(Propylene Fumarate/Bone Fiber Scaffolds

    Directory of Open Access Journals (Sweden)

    Xun Zhu

    2010-01-01

    Full Text Available The objective of our paper was to determine the effects of composite formulation on the compressive modulus and ultimate strength of a biodegradable, in situ polymerizable poly(propylene fumarate (PPF and bone fiber scaffold. The following parameters were investigated: the incorporation of bone fibers (either mineralized or demineralized, PPF molecular weight, N-vinyl pyrrolidinone (NVP crosslinker amount, benzoyl peroxide (BP initiator amount, and sodium chloride porogen amount. Eight formulations were chosen based on a resolution III two-level fractional factorial design. The compressive modulus and ultimate strength of these formulations were measured on a materials testing machine. Absolute values for compressive modulus varied from 21.3 to 271 MPa and 2.8 to 358 MPa for dry and wet samples, respectively. The ultimate strength of the crosslinked composites varied from 2.1 to 20.3 MPa for dry samples and from 0.4 to 16.6 MPa for wet samples. Main effects of each parameter on the measured property were calculated. The incorporation of mineralized bone fibers and an increase in PPF molecular weight resulted in higher compressive modulus and ultimate strength. Both mechanical properties also increased as the amount of benzoyl peroxide increased or the NVP amount decreased in the formulation. Sodium chloride had a dominating effect on the increase of mechanical properties in dry samples but showed little effects in wet samples. Demineralization of bone fibers led to a decrease in the compressive modulus and ultimate strength. Our results suggest that bone fibers are appropriate as structural enforcement components in PPF scaffolds. The desired orthopaedic PPF scaffold might be obtained by changing a variety of composite formulation parameters.

  6. Effects of composite formulation on the mechanical properties of biodegradable poly(propylene fumarate)/bone fiber scaffolds.

    Science.gov (United States)

    Zhu, Xun; Liu, Nathan; Yaszemski, Michael J; Lu, Lichun

    2010-01-01

    The objective of our study was to determine the effects of composite formulation on the compressive modulus and ultimate strength of a biodegradable, in situ polymerizable poly(propylene fumarate) (PPF) and bone fiber scaffold. The following parameters were investigated: the incorporation of bone fibers (either mineralized or demineralized), PPF molecular weight, N-vinyl pyrrolidinone (NVP) crosslinker amount, benzoyl peroxide (BP) initiator amount, and sodium chloride porogen amount. Eight formulations were chosen based on a resolution III two level fractional factorial design. The compressive modulus and ultimate strength of these formulations were measured on a materials testing machine. Absolute values for compressive modulus varied from 21.3 to 271 MPa and 2.8 to 358 MPa for dry and wet samples, respectively. The ultimate strength of the crosslinked composites varied from 2.1 to 20.3 MPa for dry samples and from 0.4 to 16.6 MPa for wet samples. Main effects of each parameter on the measured property were calculated. The incorporation of mineralized bone fibers and an increase in PPF molecular weight resulted in higher compressive modulus and ultimate strength. Both mechanical properties also increased as the amount of benzoyl peroxide increased or the NVP amount decreased in the formulation. Sodium chloride had a dominating effect on the increase of mechanical properties in dry samples but showed little effects in wet samples. Demineralization of bone fibers led to a decrease in the compressive modulus and ultimate strength. Our results suggest that bone fibers are appropriate as structural enforcement components in PPF scaffolds. The desired orthopaedic PPF scaffold might be obtained by changing a variety of composite formulation parameters.

  7. Do Bone Graft and Cracking of the Sclerotic Cavity Improve Fixation of Titanium and Hydroxyapatite-coated Revision Implants in an Animal Model?

    DEFF Research Database (Denmark)

    Elmengaard, Brian; Baas, Joergen; Jakobsen, Thomas;

    2016-01-01

    (crack, noncrack) using paired contralateral implants while implant surface (Ti6Al4V, HA) was qualitatively compared between the two (unpaired) series. All groups received bone allograft tightly packed around the implant. This revision model includes a cylindrical implant pistoning 500 μm in a 0.75-mm...... gap, with polyethylene particles, for 8 weeks. This engenders a bone and tissue response representative of the metaphyseal cancellous region of an aseptically loosened component. At 8 weeks, the original implants were revised and followed for an additional 4 weeks. Mechanical fixation was assessed...

  8. Coating of biodegradable magnesium alloy bone implants using nanostructured diopside (CaMgSi{sub 2}O{sub 6})

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Mehdi, E-mail: mehdi.razavi@okstate.edu [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); School of Materials Science and Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); School of Electrical and Computer Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Savabi, Omid [Torabinejad Dental Research Center, School of Dentistry, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Beni, Batoul Hashemi [Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Razavi, Seyed Mohammad [School of Dentistry, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Vashaee, Daryoosh [School of Electrical and Computer Engineering, Helmerich Advanced Technology Research Center, Oklahoma State University, Tulsa, OK 74106 (United States); and others

    2014-01-01

    Magnesium alloys with their biodegradable characteristic can be a very good candidate to be used in orthopedic implants. However, magnesium alloys may corrode and degrade too fast for applications in the bone healing procedure. In order to enhance the corrosion resistance and the in vitro bioactivity of a magnesium alloy, a nanostructured diopside (CaMgSi{sub 2}O{sub 6}) film was coated on AZ91 magnesium alloy through combined micro-arc oxidation (MAO) and electrophoretic deposition (EPD) methods. The crystalline structures, morphologies and compositions of the coated and uncoated substrates were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy. Polarization, electrochemical impedance spectroscopy, and immersion test in simulated body fluid (SBF) were employed to evaluate the corrosion resistance and the in vitro bioactivity of the samples. The results of our investigation showed that the nanostructured diopside coating deposited on the MAO layer increases the corrosion resistance and improves the in vitro bioactivity of the biodegradable magnesium alloy.

  9. 骨外固定治疗复杂骨不连与骨缺损的临床效果%External Fixation for the Treatment of Complex Bone Nonunion and Bone Defect of Clinical effect

    Institute of Scientific and Technical Information of China (English)

    徐占辉

    2015-01-01

    目的:探讨骨外固定治疗复杂骨不连及骨缺损临床效果。方法对56例患者采用骨外固定技术治疗复复杂骨不连与骨缺损的效果进行分析。结果56例骨不连与骨缺损患者均实现骨性愈合。17例感染性骨不连患者的伤口得到有效控制。非感染性骨不连患者一般需要4个月左右的时间愈合,感染性骨不连患者一般需要6个月左右的时间愈合,患者重建肢体长度后肢体长度均衡。结论采用骨外固定技术治疗骨不连患者可获得令人满意的疗效。%Objective To study the bone external fixation in treatment of complex bone nonunion and bone defect of clinical effects.Methods colecting effect were treated byexternal fixation for treatment of bone nonunion in 56 cases were analyzed.Results 56 cases of nonunion patients achieved bone healing.Not even the patient's wound infection has been effectively controled in 17 cases of infected bone.The healing of non infectious nonunion Bone patients generaly need 5 months time,healing of infected nonunion Bone patients generaly need about 6 months time,reconstruction in limb length after limb length equalization.Conclusion The use of external fixation for treatment of nonunion has obtained the satisfactory effect.

  10. Biodegradable polymers: emerging excipients for the pharmaceutical and medical device industries.

    Directory of Open Access Journals (Sweden)

    Bhavesh Patel

    2013-12-01

    Full Text Available Worldwide many researchers are exploring the potential use of biodegradable polymerics as carriers for a wide range of therapeutic applications. In the past two decades, considerable progress has been made in the development of biodegradable polymeric materials, mainly in the biomedical and pharmaceutical industries due to their versatility, biocompatibility and biodegradability properties. The present review focuses on the use of biodegradable polymers in various therapeutic areas like orthopedic and contraceptive device, surgical sutures, implants, depot parenteral injections, etc. Biodegradable polymers have also contributed significantly to the development of drug-eluting stents (DES used for the treatment of obstructive coronary artery disease, such as angioplasty. Biodegradable synthetic polymers have potential applications in orthopedic device fixation due to properties that impact bone healing, formation, regeneration or substitution in the human body. The present review also emphasizes areas such as the chemistry of polymer synthesis, factors affecting the biodegradation, methods for the production of biodegradable polymer based formulations, the application of biodegradable polymers in dental implants, nasal drug deliveries, contraceptive devices, immunology, gene, transdermal, ophthalmic and veterinary applications, as well as, the sterilization of biodegradable based formulations and regulatory considerations for product filing.

  11. Magnetic biodegradable Fe{sub 3}O{sub 4}/CS/PVA nanofibrous membranes for bone regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Wei Yan; Zhang Xuehui; Hu Xiaoyang; Deng Xuliang [Department of Geriatric Dentistry, School and Hospital of Stomatology, Peking University, Beijing, 100081 (China); Song Yu; Lin Yuanhua [State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, Tsinghua University, Beijing, 100084 (China); Han Bing [Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, 100081 (China); Wang Xinzhi, E-mail: kqdengxuliang@bjmu.edu.cn [Department of Prosthodontics, School and Hospital of Stomatology, Peking University, Beijing, 100081 (China)

    2011-10-15

    In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. The aim of this study is to develop magnetic biodegradable fibrous materials with potential use in bone regeneration. Magnetic biodegradable Fe{sub 3}O{sub 4}/chitosan (CS)/poly vinyl alcohol (PVA) nanofibrous membranes were achieved by electrospinning with average fiber diameters ranging from 230 to 380 nm and porosity of 83.9-85.1%. The influences of polymer concentration, applied voltage and Fe{sub 3}O{sub 4} nanoparticles loading on the fabrication of nanofibers were investigated. The polymer concentration of 4.5 wt%, applied voltage of 20 kV and Fe{sub 3}O{sub 4} nanoparticles loading of lower than 5 wt% could produce homogeneous, smooth and continuous Fe{sub 3}O{sub 4}/CS/PVA nanofibrous membranes. X-ray diffraction (XRD) data confirmed that the crystalline structure of the Fe{sub 3}O{sub 4}, CS and PVA were maintained during electrospinning process. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the Fe{sub 3}O{sub 4} loading up to 5 wt% did not change the functional groups of CS/PVA greatly. Transmission electron microscopy (TEM) showed islets of Fe{sub 3}O{sub 4} nanoparticles evenly distributed in the fibers. Weak ferrimagnetic behaviors of membranes were revealed by vibrating sample magnetometer (VSM) test. Tensile test exhibited Young's modulus of membranes that were gradually enhanced with the increase of Fe{sub 3}O{sub 4} nanoparticles loading, while ultimate tensile stress and ultimate strain were slightly reduced by Fe{sub 3}O{sub 4} nanoparticles loading of 5%. Additionally, MG63 human osteoblast-like cells were seeded on the magnetic nanofibrous membranes to evaluate their bone biocompatibility. Cell growth dynamics according to MTT assay and scanning electron microscopy (SEM) observation exhibited good cell adhesion and proliferation, suggesting that this magnetic biodegradable Fe{sub 3}O{sub 4}/CS/PVA nanofibrous

  12. Local delivery of siRNA using a biodegradable polymer application to enhance BMP-induced bone formation.

    Science.gov (United States)

    Manaka, Tomoya; Suzuki, Akinobu; Takayama, Kazushi; Imai, Yuuki; Nakamura, Hiroaki; Takaoka, Kunio

    2011-12-01

    Small interfering RNA (siRNA) is useful tool for specific and efficient knockdown of disease-related genes. However, in vivo applications of siRNA are limited due to difficulty in its efficient delivery to target cells. In this study, we investigated the efficacy of a biodegradable hydrogel, poly-d,l-lactic acid-p-dioxanone-polyethylene glycol block co-polymer (PLA-DX-PEG), as a siRNA carrier. PLA-DX-PEG pellets with or without fluorescein-labeled dsRNA were implanted into mouse dosal muscle pouches. The cellular uptake of dsRNA surround the polymer was confirmed by fluorescent microscopy. The fluorescence intensity was dose-dependent of the dsRNA, and exhibited a time-dependent decrease. To investigate its biological efficiency, noggin (antagonoist to BMPs) gene-silencing with siRNA (siRNA/Noggin) was examined by the amount of suppression of BMP-2-induced noggin expression and the level of performance of BMP, indicated by ectopic bone formation. Noggin gene expression induced by BMP-2 was suppressed by addition of siRNA/Noggin to the implant, and the ectopic bone formation induced by implants with both BMP-2 and siRNA/Noggin was significantly greater than those induced by implants with BMP-2 alone. These results indicate the efficacy of local delivery of siRNAs by PLA-DX-PEG polymer, which intensified bone-inducing effects of BMP and promoted new bone formation by suppressing gene expression of Noggin.

  13. Adhesive B-doped DLC films on biomedical alloys used for bone fixation

    Indian Academy of Sciences (India)

    A A Ahmad; A M Alsaad

    2007-08-01

    The long-term failure of the total hip and knee prostheses is attributed to the production of wear particles at the articulating interface between the metals, ceramics and polymers used for surgical implants and bone-fixtures. Therefore, finding an adhesive and inert coating material that has low frictional coefficient should dramatically reduce the production of wear particles and hence, prolong the life time of the surgical implants. The novel properties of the non-toxic diamond-like carbon (DLC) coatings have proven to be excellent candidates for biomedical applications. However, they have poor adhesion strength to the alloys and biomaterials. The addition of a thin interfacial layer such as Si, Ti, TiN, Mo and Cu/Cr and/or adding additives such as Si, F, N, O, W, V, Co, Mo, Ti or their combinations to the DLC films has been found to increase the adhesion strength substantially. In our study, grade 316L stainless steel and grade 5 titanium alloy (Ti–6Al–4V) were used as biomaterial substrates. They were coated with DLC films containing boron additives at various levels using various Si interfacial layer thicknesses. The best film adhesion was achieved at 8% and 20% on DLC coated Ti–6Al–4V and grade 316L substrates, respectively. It has been demonstrated that doping the DLC with boron increases their adhesion strength to both substrates even without silicon interfacial layer and increases it substantially with optimum silicon layer thickness. The adhesion strength is also correlated with the hydrogen contents in the B-DLC films. It is found to reach its maximum value of 700 kg/cm2 and 390 kg/cm2 at 2/7 and 3/6 for CH4/Ar partial pressures (in mTorr ratio) for Ti–6Al–4V and 316L substrates, respectively.

  14. Studies on Poly(propylene fumarate-co-caprolactone diol Thermoset Composites towards the Development of Biodegradable Bone Fixation Devices

    Directory of Open Access Journals (Sweden)

    M. Jayabalan

    2009-01-01

    Full Text Available The effect of reinforcement in the cross-linked poly(propylene fumarate-co-caprolactone diol thermoset composites based on Kevlar fibres and hydroxyapatite was studied. Cross-linked poly(propylene fumarate-co-caprolactone diol was also studied without any reinforcement for comparison. The reinforcing fibre acts as a barrier for the curing reaction leading to longer setting time and lesser cross-link density. The fibre and HA reinforced composites have almost the same compressive strength. Nonreinforced material undergoes greater degree of swelling. Among the reinforced materials, the hydroxyapatite reinforced composite has a much higher swelling percentage than the fibre reinforced one. The studies on in vitro degradation of the cured materials reveal hydrolytic degradation in Ringer's solution and PBS medium during aging. All the three materials are found to swell initially in Ringer's solution and PBS medium during aging and then undergo gradual degradation. Compression properties of these cross-linked composites increase with aging; HA reinforced composite has the highest compressive strength and compressive modulus, whereas the aged fibre-reinforced composite has the least compressive strength and modulus.

  15. Manufacturing of individual biodegradable bone substitute implants using selective laser melting technique.

    Science.gov (United States)

    Lindner, Markus; Hoeges, Simon; Meiners, Wilhelm; Wissenbach, Konrad; Smeets, Ralf; Telle, Rainer; Poprawe, Reinhart; Fischer, Horst

    2011-06-15

    The additive manufacturing technique selective laser melting (SLM) has been successfully proved to be suitable for applications in implant manufacturing. SLM is well known for metal parts and offers direct manufacturing of three-dimensional (3D) parts with high bulk density on the base of individual 3D data, including computer tomography models of anatomical structures. Furthermore, an interconnecting porous structure with defined and reproducible pore size can be integrated during the design of the 3D virtual model of the implant. The objective of this study was to develop the SLM processes for a biodegradable composite material made of β-tricalcium phosphate (β-TCP) and poly(D, L)-lactide (PDLLA). The development of a powder composite material (β-TCP/PDLLA) suitable for the SLM process was successfully performed. The microstructure of the manufactured samples exhibit a homogeneous arrangement of ceramic and polymer. The four-point bending strength was up to 23 MPa. The X-ray diffraction (XRD) analysis of the samples confirmed β-TCP as the only present crystalline phase and the gel permeations chromatography (GPC) analysis documented a degradation of the polymer caused by the laser process less than conventional manufacturing processes. We conclude that SLM presents a new possibility to manufacture individual biodegradable implants made of β-TCP/PDLLA.

  16. Use of stereolithography to manufacture critical-sized 3D biodegradable scaffolds for bone ingrowth.

    Science.gov (United States)

    Cooke, Malcolm N; Fisher, John P; Dean, David; Rimnac, Clare; Mikos, Antonios G

    2003-02-15

    A novel approach to the manufacture of biodegradable polymeric scaffolds for tissue-engineering utilizing stereolithography (SLA) is presented. SLA is a three-dimensional (3D) printing method that uses an ultraviolet laser to photo-crosslink a liquid polymer substrate. The current generation of SLA devices provide a 3D printing resolution of 0.1 mm. The experiments utilized a biodegradable resin mixture of diethyl fumarate (DEF), poly(propylene fumarate) (PPF), and a photoinitiator, bisacylphosphine oxide (BAPO). The PPF is crosslinked with the use of the SLA's UV laser (325-nm wavelength). An SLA device was retrofitted with a custom fixture build tank enclosing an elevator-driven build table. A 3D prototype model testing the manufacturing control this device provides was created in a computer-aided-design package. The resulting geometric data were used to drive the SLA process, and a DEF/PPF prototype part was successfully manufactured. These scaffolds have application in the tissue engineering of bony substrates.

  17. Evaluation of four biodegradable, injectable bone cements in an experimental drill hole model in sheep.

    Science.gov (United States)

    von Rechenberg, Brigitte; Génot, Oliver R; Nuss, Katja; Galuppo, Larry; Fulmer, Mark; Jacobson, Evan; Kronen, Peter; Zlinszky, Kati; Auer, Jörg A

    2013-09-01

    Four cement applications were tested in this investigation. Two dicalcium phosphate dihydrate (DCPD-brushite) hydraulic cements, an apatite hydraulic fiber loaded cement, and a calcium sulfate cement (Plaster of Paris) were implanted in epiphyseal and metaphyseal cylindrical bone defects in sheep. The in vivo study was performed to assess the biocompatibility and bone remodeling of four cement formulations. After time periods of 2, 4, and 6 months, the cement samples were clinically and histologically evaluated. Histomorphometrically, the amount of new bone formation, fibrous tissue, and bone marrow and the area of remaining cement were measured. In all specimens, no signs of inflammation were detectable either macroscopically or microscopically. Cements differed mainly in their resorption time. Calcium sulfate was already completely resorbed at 2 months and showed a variable amount of new bone formation and/or fibrous tissue in the original drill hole over all time periods. The two DCPD cements in contrast were degraded to a large amount at 6 months, whereas the apatite was almost unchanged over all time periods.

  18. Rehabilitation instruction after intervertebral bone graft internal fixation of lumbar spondylolisthesis%腰椎滑脱椎体间植骨固定术后的康复指导

    Institute of Scientific and Technical Information of China (English)

    张晋亭

    2003-01-01

    @@ BACKGROUND:Internal fixation of lumbral spondylolisthesis has resolved the problem caused by vertebral translocation and postoperative rehabilitation instruction can prevent moving of bone.Directed to different stages,suitable posture and rehabilitation function exercises can effectively prevent loose intervertebral grafted bone and adhesion of nerve root.

  19. Mineralization, biodegradation, and drug release behavior of gelatin/apatite composite microspheres for bone regeneration.

    NARCIS (Netherlands)

    Leeuwenburgh, S.C.G.; Jo, J.; Wang, H.; Yamamoto, M.; Jansen, J.A.; Tabata, Y.

    2010-01-01

    Gelatin microspheres are well-known for their capacity to release growth factors in a controlled manner, but gelatin microspheres do not calcify in the absence of so-called bioactive substances that induce deposition of calcium phosphate (CaP) bone mineral. This study has investigated if CaP nanocry

  20. Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation

    Institute of Scientific and Technical Information of China (English)

    Feng Xue; Er-jun Wu; Pei-xun Zhang; Li-ya A; Yu-hui Kou; Xiao-feng Yin; Na Han

    2015-01-01

    We examined the restorative effect of modiifed biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantationin vivo, and differentiated into cells double-positive for S100 (Schwann cell marker) and glial ifbrillary acidic protein (glial cell marker) at 8 weeks. Retrograde tracing showed that more nerve ifbers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our ifndings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvi-ronment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.

  1. 可吸收固定系统在开颅骨瓣复位固定手术中的初步应用%PRELIMINARY APPLICATION OF ABSORBABLE FIXATION SYSTEM ON CRANIAL BONE FLAP REPOSITION AND FIXATION AFTER CRANIOTOMY

    Institute of Scientific and Technical Information of China (English)

    邓跃飞; 郑眉光; 吴锦铨

    2012-01-01

    目的 观察可吸收固定系统对开颅游离骨瓣复位的固定效果及不良反应.方法 2010年7月-2011年12月,对67例开颅游离骨瓣成型切除颅内病变后患者,采用可吸收固定系统进行骨瓣复位固定.其中男38例,女29例;年龄5个月~73岁,中位年龄32岁.病程3个月~6年,中位病程25个月.幕上病变41例,幕下病变26例;其中位于额颞部13例,额顶部12例,颞顶部8例,颞枕部5例,顶枕部4例,后颅窝25例.诊断为胶质瘤15例,脑血管性疾病(动脉瘤、动静脉畸形及海绵状血管瘤)8例,脑膜瘤和蛛网膜囊肿各7例,听神经瘤和原发三叉神经痛各5例,胆脂瘤和脑脓肿各3例,垂体瘤、颅咽管瘤、转移瘤及放射性脑病各2例,髓母细胞瘤、室管膜瘤、生殖细胞瘤、非典型畸胎瘤/横纹肌样瘤、面肌痉挛及硬膜下血肿各1例.颅内病变范围3cm×2cm~7cm×5cm.观察术后局部切口及全身情况变化.结果 术后有2例幕上和3例幕下病变患者少许皮下积液,均经穿刺抽吸2周后消失;术后切口均Ⅰ期愈合,无红肿、发热等表现;术后2周内复查CT或MRI示骨瓣复位良好,内、外颅骨面均平整,无任何影像伪影.67例均获随访,随访时间3~20个月,平均10.3个月.切口无不适,头颅外观正常,无局部凹陷、积液等.CT或MRI复查未见骨瓣移位凹陷及伪影.结论 应用可吸收固定系统进行骨瓣复位固定简便、安全、可靠,且能消除术后CT或MRI复查时金属固定材料导致的伪影,近期疗效较好.%Objective To investigate the effectiveness and adverse effect of the absorbable fixation system on cranial bone flap reposition and fixation after craniotomy. Methods Between July 2010 and December 2011, 67 cases underwent cranial bone flap reposition and fixation with absorbable fixation system after craniotomy and resection of intracranial lesions. There were 38 males and 29 females with a median age of 32 years (range, 5 months to 73

  2. Bone-repair properties of biodegradable hydroxyapatite nano-rod superstructures

    Science.gov (United States)

    D'Elía, Noelia L.; Mathieu, Colleen; Hoemann, Caroline D.; Laiuppa, Juan A.; Santillán, Graciela E.; Messina, Paula V.

    2015-11-01

    Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions of bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblasts and rabbit mesenchymal stem cells. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiated, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (α-SMA) protein. These results highlight the influence of material's surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral components of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures

  3. Biodegradation and bioabsorption innovation of the functionally graded bovine bone-originated apatite with blood permeability.

    Science.gov (United States)

    Akazawa, Toshiyuki; Murata, Masaru; Sasaki, Tomoya; Tazaki, Junichi; Kobayashi, Masayoshi; Kanno, Tohru; Nakamura, Katsuo; Arisue, Makoto

    2006-01-01

    Bioabsorbable and functionally graded apatite (fg-HAp) ceramics were designed using bovine bone by the calcination and partial dissolution-precipitation methods. The fg-HAp ceramics that were developed had gradual distributions of the degree of crystallinity and the grain size of single-phase hydroxyapatite from the surface layer of the pore wall to the bulk structure region. Calcination at 1073 K gave a specific surface area of 30 m2 x g-1 and porosities of 60-80%. The pore structure of the fg-HAp was classified into two regions: a macro-pore region (100-600 microm) originating from spongy bone and a micro-pore region (10-160 nm) related to body fluid permeation and blood permeability. By implantation in subcutaneous tissue of rat, it was confirmed that body fluid permeated the bulk region of the fg-HAp ceramics through the micro-pores. The volumetric populations occupied by body fluid were 60% at 4 weeks and 68% at 8 weeks in the ceramics explants, indicating drastic bioabsorption, although the body fluid was found to be immunopositive for an albumin as the main serum protein in blood. On the fg-HAp ceramics developed here, the bioabsorption rate could be controlled by careful selection of the calcination temperature. These ceramics can be applied as new biomimetic ceramics exhibiting surface and bulk degradations and cellular absorption by giant cells.

  4. PGA-incorporated collagen: Toward a biodegradable composite scaffold for bone-tissue engineering.

    Science.gov (United States)

    Toosi, Shirin; Naderi-Meshkin, Hojjat; Kalalinia, Fatemeh; Peivandi, Mohammad Taghi; HosseinKhani, Hossein; Bahrami, Ahmad Reza; Heirani-Tabasi, Asieh; Mirahmadi, Mahdi; Behravan, Javad

    2016-08-01

    Nowadays composite scaffolds based on synthetic and natural biomaterials have got attention to increase healing of non-union bone fractures. To this end, different aspects of collagen sponge incorporated with poly(glycolic acid) (PGA) fiber were investigated in this study. Collagen solution (6.33 mg/mL) with PGA fibers (collagen/fiber ratio [w/w]: 4.22, 2.11, 1.06, 0.52) was freeze-dried, followed by dehydrothermal cross-linking to obtain collagen sponge incorporating PGA fibers. Properties of scaffold for cell viability, proliferation, and differentiation of mesenchymal stem cells (MSCs) were evaluated. Scanning electron microscopy showed that collagen sponge exhibited an interconnected pore structure with an average pore size of 190 μm, irrespective of PGA fiber incorporation. The collagen-PGA sponge was superior to the original collagen sponge in terms of the initial attachment, proliferation rate, and osteogenic differentiation of the bone marrow-MSCs (BM-MSC). The shrinkage of sponges during cell culture was significantly suppressed by fiber incorporation. Incorporation of PGA fiber is a simple and promising way to reinforce collagen sponge without impairing biocompatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2020-2028, 2016.

  5. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold.

    Science.gov (United States)

    Yang, Bo; Yin, Zhanhai; Cao, Junling; Shi, Zhongli; Zhang, Zengtie; Song, Hongxing; Liu, Fuqiang; Caterson, Bruce

    2010-08-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 microm) than in cortical BMG (5-15 microm), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  6. In vitro cartilage tissue engineering using cancellous bone matrix gelatin as a biodegradable scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Yang Bo; Yin Zhanhai; Cao Junling; Shi Zhongli; Zhang Zengtie; Liu Fuqiang [College of Medicine, Xi' an Jiaotong University, Yanta West Road, No 76, Yanta District, Xi' an, Shaanxi Province 710061 (China); Song Hongxing [Department of Orthopedics, Xuanwu Hospital, Capital Medical University, Beijing 100053 (China); Caterson, Bruce, E-mail: caojl@mail.xjtu.edu.c [Connective Tissue Biology Laboratories, Cardiff School of Biosciences, Cardiff University, Biomedical Building, Museum Avenue, Cardiff, CF10 3US (United Kingdom)

    2010-08-01

    In this study, we constructed tissue-engineered cartilage using allogeneic cancellous bone matrix gelatin (BMG) as a scaffold. Allogeneic BMG was prepared by sequential defatting, demineralization and denaturation. Isolated rabbit chondrocytes were seeded onto allogeneic cancellous BMG, and cell-BMG constructs were harvested after 1, 3 and 6 weeks for evaluation by hematoxylin and eosin staining for overall morphology, toluidine blue for extracellular matrix (ECM) proteoglycans, immunohistochemical staining for collagen type II and a transmission electron microscope for examining cellular microstructure on BMG. The prepared BMG was highly porous with mechanical strength adjustable by duration of demineralization and was easily trimmed for tissue repair. Cancellous BMG showed favorable porosity for cell habitation and metabolism material exchange with larger pore sizes (100-500 {mu}m) than in cortical BMG (5-15 {mu}m), allowing cell penetration. Cancellous BMG also showed good biocompatibility, which supported chondrocyte proliferation and sustained their differentiated phenotype in culture for up to 6 weeks. Rich and evenly distributed cartilage ECM proteoglycans and collagen type II were observed around chondrocytes on the surface and inside the pores throughout the cancellous BMG. Considering the large supply of banked bone allografts and relatively convenient preparation, our study suggests that allogeneic cancellous BMG is a promising scaffold for cartilage tissue engineering.

  7. Fabrication of highly porous biodegradable biomimetic nanocomposite as advanced bone tissue scaffold

    Directory of Open Access Journals (Sweden)

    Abdalla Abdal-hay

    2017-02-01

    Full Text Available Development of bioinspired or biomimetic materials is currently a challenge in the field of tissue regeneration. In-situ 3D biomimetic microporous nanocomposite scaffold has been developed using a simple lyophilization post hydrothermal reaction for bone healing applications. The fabricated 3D porous scaffold possesses advantages of good bonelike apatite particles distribution, thermal properties and high porous interconnected network structure. High dispersion bonelike apatite nanoparticles (NPs rapidly nucleated and deposited from surrounding biological minerals within chitosan (CTS matrices using hydrothermal technique. After that, freeze-drying method was applied on the composite solution to form the desired porous 3D architecture. Interestingly, the porosity and pore size of composite scaffold were not significantly affected by the particles size and particles content within the CTS matrix. Our results demonstrated that the compression modulus of porous composite scaffold is twice higher than that of plain CTS scaffold, indicating a maximization of the chemical interaction between polymer matrix and apatite NPs. Cytocompatibility test for MC3T3-E1 pre-osteoblasts cell line using MTT-indirect assay test showed that the fabricated 3D microporous nanocomposite scaffold possesses higher cell proliferation and growth than that of pure CTS scaffold. Collectively, our results suggest that the newly developed highly porous apatite/CTS nanocomposite scaffold as an alternative of hydroxyapatite/CTS scaffold may serve as an excellent porous 3D platform for bone tissue regeneration.

  8. Investigation of mechanism of bone regeneration in a porous biodegradable calcium phosphate (CaP) scaffold by a combination of a multi-scale agent-based model and experimental optimization/validation.

    Science.gov (United States)

    Zhang, Le; Qiao, Minna; Gao, Hongjie; Hu, Bin; Tan, Hua; Zhou, Xiaobo; Li, Chang Ming

    2016-08-21

    Herein, we have developed a novel approach to investigate the mechanism of bone regeneration in a porous biodegradable calcium phosphate (CaP) scaffold by a combination of a multi-scale agent-based model, experimental optimization of key parameters and experimental data validation of the predictive power of the model. The advantages of this study are that the impact of mechanical stimulation on bone regeneration in a porous biodegradable CaP scaffold is considered, experimental design is used to investigate the optimal combination of growth factors loaded on the porous biodegradable CaP scaffold to promote bone regeneration and the training, testing and analysis of the model are carried out by using experimental data, a data-mining algorithm and related sensitivity analysis. The results reveal that mechanical stimulation has a great impact on bone regeneration in a porous biodegradable CaP scaffold and the optimal combination of growth factors that are encapsulated in nanospheres and loaded into porous biodegradable CaP scaffolds layer-by-layer can effectively promote bone regeneration. Furthermore, the model is robust and able to predict the development of bone regeneration under specified conditions.

  9. Biodegradable Thermogel as Culture Matrix of Bone Marrow Mesenchymal Stem Cells for Potential Cartilage Tissue Engineering

    Institute of Scientific and Technical Information of China (English)

    Yan-bo Zhang; Jian-xun Ding; Wei-guo Xu; Jie Wu; Fei Chang; Xiu-li Zhuang; Xue-si Chen

    2014-01-01

    Poly(lactide-co-glycolide)-poly(ethylene glycol)-poly(lactide-co-glycolide) (PLGA-PEG-PLGA) triblock copolymer was synthesized through the ring-opening polymerization of LA and GA with PEG as macroinitiator and stannous octoate as catalyst.The amphiphilic copolymer self-assembled into micelles in aqueous solutions,and formed hydrogels as the increase of temperature at relatively high concentrations (> 15 wt%).The favorable degradability of the hydrogel was confirmed by in vitro and in vivo degradation experiments.The good cellular and tissular compatibilities of the thermogel were demonstrated.The excellent adhesion and proliferation of bone marrow mesenchymal stem cells endowed PLGA-PEG-PLGA thermogelling hydrogel with fascinating prospect for cartilage tissue engineering.

  10. Two-dimensional nanostructure-reinforced biodegradable polymeric nanocomposites for bone tissue engineering.

    Science.gov (United States)

    Lalwani, Gaurav; Henslee, Allan M; Farshid, Behzad; Lin, Liangjun; Kasper, F Kurtis; Qin, Yi-Xian; Mikos, Antonios G; Sitharaman, Balaji

    2013-03-11

    This study investigates the efficacy of two-dimensional (2D) carbon and inorganic nanostructures as reinforcing agents for cross-linked composites of the biodegradable and biocompatible polymer polypropylene fumarate (PPF) as a function of nanostructure concentration. PPF composites were reinforced using various 2D nanostructures: single- and multiwalled graphene oxide nanoribbons (SWGONRs, MWGONRs), graphene oxide nanoplatelets (GONPs), and molybdenum disulfide nanoplatelets (MSNPs) at 0.01-0.2 weight% concentrations. Cross-linked PPF was used as the baseline control, and PPF composites reinforced with single- or multiwalled carbon nanotubes (SWCNTs, MWCNTs) were used as positive controls. Compression and flexural testing show a significant enhancement (i.e., compressive modulus = 35-108%, compressive yield strength = 26-93%, flexural modulus = 15-53%, and flexural yield strength = 101-262% greater than the baseline control) in the mechanical properties of the 2D-reinforced PPF nanocomposites. MSNP nanocomposites consistently showed the highest values among the experimental or control groups in all the mechanical measurements. In general, the inorganic nanoparticle MSNP showed a better or equivalent mechanical reinforcement compared to carbon nanomaterials, and 2D nanostructures (GONPs, MSNPs) are better reinforcing agents compared to one-dimensional (1D) nanostructures (e.g., SWCNTs). The results also indicated that the extent of mechanical reinforcement is closely dependent on the nanostructure morphology and follows the trend nanoplatelets > nanoribbons > nanotubes. Transmission electron microscopy of the cross-linked nanocomposites indicated good dispersion of nanomaterials in the polymer matrix without the use of a surfactant. The sol-fraction analysis showed significant changes in the polymer cross-linking in the presence of MSNP (0.01-0.2 wt %) and higher loading concentrations of GONP and MWGONR (0.1-0.2 wt %). The analysis of surface area and aspect ratio

  11. High-impact poly(L/D-lactide) for fracture fixation: in vitro degradation and animal pilot study.

    Science.gov (United States)

    Tams, J; Joziasse, C A; Bos, R R; Rozema, F R; Grijpma, D W; Pennings, A J

    1995-12-01

    The impact strength of amorphous lactide copolymers can be significantly improved by blending with biodegradable rubbers. Rubber toughening of amorphous poly(85L/15D -lactide) with the copolymer poly (50/50-trimethylenecarbonate-co-epsilon-caprolactone) results in a high-impact polymer (PDLLA/P(TMC-CL)). In vitro, the PDLLA/P(TMC-CL) blend retained its tensile and impact strength for a long period of time. Up to 45 weeks, the amount of water absorbed by the blend remained very low and no significant mass loss was observed. To test the suitability for fracture fixation, in a dog study mandibular fractures were fixated with PDLLA/P(TMC-CL) bone plates and screws. Bone healing was uneventful without premature failure of the implants. Although long-term degradation studies have to be carried out, PDLLA/P(TMC-CL) seems to be promising for application in fracture fixation.

  12. The role of bone SPECT/CT in the evaluation of lumbar spinal fusion with metallic fixation devices

    DEFF Research Database (Denmark)

    Damgaard, Morten; Nimb, Lars; Madsen, Jan L

    2010-01-01

    PURPOSE: It is difficult to evaluate the stability of the lumbar spondylodesis with metallic fixation devices by conventional imaging methods such as radiography or magnetic resonance imaging. It is unknown whether single photon emission computed tomography/computed tomography (SPECT/CT) may be u...

  13. The role of bone SPECT/CT in the evaluation of lumbar spinal fusion with metallic fixation devices

    DEFF Research Database (Denmark)

    Damgaard, Morten; Nimb, Lars; Madsen, Jan L

    2010-01-01

    PURPOSE: It is difficult to evaluate the stability of the lumbar spondylodesis with metallic fixation devices by conventional imaging methods such as radiography or magnetic resonance imaging. It is unknown whether single photon emission computed tomography/computed tomography (SPECT/CT) may...

  14. A comparative morphometric analysis of biodegradable scaffolds as carriers for dental pulp and periosteal stem cells in a model of bone regeneration.

    Science.gov (United States)

    Annibali, Susanna; Cicconetti, Andrea; Cristalli, Maria Paola; Giordano, Guido; Trisi, Paolo; Pilloni, Andrea; Ottolenghi, Livia

    2013-05-01

    Bone regeneration and bone fixation strategies in dentistry utilize scaffolds containing regenerating-competent cells as a replacement of the missing bone portions and gradually replaced by autologous tissues. Mesenchymal stem cells represent an ideal cell population for scaffold-based tissue engineering. Among them, dental pulp stem cells (DPSCs) and periosteal stem cells (PeSCs) have the potential to differentiate into a variety of cell types including osteocytes, suggesting that they can be used with this purpose. However, data on bone regeneration properties of these types of cells in scaffold-based tissue engineering are yet insufficient.In this study, we evaluated temporal dynamic bone regeneration (measured as a percentage of bone volume on the total area of the defect) induced by DPSCs or PeSCs when seeded with different scaffolds to fill critical calvarial defects in SCID Beige nude mice. Two commercially available scaffolds (granular deproteinized bovine bone with 10% porcine collagen and granular β;-tricalcium phosphate) and one not yet introduced on the market (a sponge of agarose and nanohydroxyapatite) were used. The results showed that tissue-engineered constructs did not significantly improve bone-induced regeneration process when compared with the effect of scaffolds alone. In addition, the data also showed that the regeneration induced by β;-tricalcium phosphate alone was higher after 8 weeks than that of scaffold seeded with the 2 stem cell lines. Altogether these findings suggest that further studies are needed to evaluate the potential of DPSCs and PeSCs in tissue construct and identify the appropriate conditions to generate bone tissue in critical-size defects.

  15. The application of closed reduction internal fixation and iliac bone block grafting in the treatment of acute displaced femoral neck fractures.

    Directory of Open Access Journals (Sweden)

    Zhiyong Li

    Full Text Available OBJECTIVE: This study aimed to evaluate the preliminary clinical and radiographic outcomes of acute displaced femoral neck fracture treated by closed reduction and internal fixation (CRIF with free iliac bone block grafting with comparison to a routine protocol of CRIF without bone grafting. METHODS: From December 2008 to February 2010, 220 adult patients with acute displaced femoral neck fractures were enrolled in this study. In study group, there were 124 patients (57 males, 67 females with a mean age of 44.8 years (range, 20-64 years. There were 70 transcervical fractures and 54 subcapital fractures. The patients were treated by CRIF and free iliac bone block grafting. The control group consisted of 96 adult patients (46 males, 50 females with a mean age of 46.3 years (range, 23-64 years. There were 61 transcervical fractures and 35 subcapital fractures. The patients in control group were treated by CRIF without bone grafting. RESULTS: In study group, 112 patients were followed up for an average of 27.4 months (range, 24-34 months. All fractures healed within 5 months. However, 10 patients presented AVN of the femoral heads. The mean Harris score was 88.6 (range, 41-100. In control group, 68 patients were followed up for an average of 31.2 months (range, 24-42 months. The rates of AVN of the femoral head and fracture nonunion in control group were 26.5% (18/68 and 16.2% (11/68, respectively, significantly higher than those in study group (both P<0.05. The mean Harris score in control group was 83.8 (41-100, significantly lower than that in study group (P<0.05. CONCLUSION: Acute displaced femoral neck fractures can be treated by CRIF and free iliac bone block grafting in a minimally invasive manner. This technique can guarantee uneventful fracture healing and significantly reduce the rate of femoral head osteonecrosis.

  16. Tissue reaction and material biodegradation of a calcium sulfate/apatite biphasic bone substitute in rat muscle

    Directory of Open Access Journals (Sweden)

    Jian-Sheng Wang

    2016-07-01

    Conclusion: Calcium sulfate hydroxyapatite bone substitute can be used as a carrier for antibiotics or other drugs, without adverse reaction due to the fast resorption of the calcium sulfate. No bone formation was seen despite treating the bone substitute with autologous bone marrow.

  17. A dual-task design of corrosion-controlling and osteo-compatible hexamethylenediaminetetrakis- (methylene phosphonic acid) (HDTMPA) coating on magnesium for biodegradable bone implants application.

    Science.gov (United States)

    Zhao, Sheng; Chen, Yingqi; Liu, Bo; Chen, Meiyun; Mao, Jinlong; He, Hairuo; Zhao, Yuancong; Huang, Nan; Wan, Guojiang

    2015-05-01

    Magnesium as well as its alloys appears increasingly as a revolutionary bio-metal for biodegradable implants application but the biggest challenges exist in its too fast bio-corrosion/degradation. Both corrosion-controllable and bio-compatible Mg-based bio-metal is highly desirable in clinic. In present work, hexamethylenediaminetetrakis (methylenephosphonic acid) [HDTMPA, (H2 O3 P-CH2 )2 -N-(CH2 )6 -N-(CH2 -PO3 H2 )2 ], as a natural and bioactive organic substance, was covalently immobilized and chelating-deposited onto Mg surface by means of chemical conversion process and dip-coating method, to fullfill dual-task performance of corrosion-protective and osteo-compatible functionalities. The chemical grafting of HDTMPA molecules, by participation of functional groups on pretreated Mg surface, ensured a firmly anchored base layer, and then sub-sequential chelating reactions of HDTMPA molecules guaranteed a homogenous and dense HDTMPA coating deposition on Mg substrate. Electrochemical corrosion and immersion degradation results reveal that the HDTMPA coated Mg provides a significantly better controlled bio-corrosion/degradation behavior in phosphate buffer saline solution as compared with untreated Mg from perspective of clinic requirement. Moreover, the HDTMPA coated Mg exhibits osteo-compatible in that it induces not only bioactivity of bone-like apatite precipitation but also promotes osteoblast cells adhesion and proliferation. Our well-controlled biodegradable and biocompatible HDTMPA modified Mg might bode well for next generation bone implant application.

  18. Latarjet Fixation

    Science.gov (United States)

    Alvi, Hasham M.; Monroe, Emily J.; Muriuki, Muturi; Verma, Rajat N.; Marra, Guido; Saltzman, Matthew D.

    2016-01-01

    Background: Attritional bone loss in patients with recurrent anterior instability has successfully been treated with a bone block procedure such as the Latarjet. It has not been previously demonstrated whether cortical or cancellous screws are superior when used for this procedure. Purpose: To assess the strength of stainless steel cortical screws versus stainless steel cannulated cancellous screws in the Latarjet procedure. Study Design: Controlled laboratory study. Methods: Ten fresh-frozen matched-pair shoulder specimens were randomized into 2 separate fixation groups: (1) 3.5-mm stainless steel cortical screws and (2) 4.0-mm stainless steel partially threaded cannulated cancellous screws. Shoulder specimens were dissected free of all soft tissue and a 25% glenoid defect was created. The coracoid process was osteomized, placed at the site of the glenoid defect, and fixed in place with 2 parallel screws. Results: All 10 specimens failed by screw cutout. Nine of 10 specimens failed by progressive displacement with an increased number of cycles. One specimen in the 4.0-mm screw group failed by catastrophic failure on initiation of the testing protocol. The 3.5-mm screws had a mean of 274 cycles (SD, ±171 cycles; range, 10-443 cycles) to failure. The 4.0-mm screws had a mean of 135 cycles (SD, ±141 cycles; range, 0-284 cycles) to failure. There was no statistically significant difference between the 2 types of screws for cycles required to cause failure (P = .144). Conclusion: There was no statistically significant difference in energy or cycles to failure when comparing the stainless steel cortical screws versus partially threaded cannulated cancellous screws. Clinical Relevance: Latarjet may be performed using cortical or cancellous screws without a clear advantage of either option. PMID:27158630

  19. Posterior transodontoid fixation: A new fixation (Kotil technique

    Directory of Open Access Journals (Sweden)

    Kadir Kotil

    2011-01-01

    Full Text Available Anterior odontoid screw fixation or posterior C1-2 fusion techniques are routinely used in the treatment of Type II odontoid fractures, but these techniques may be inadequate in some types of odontoid fractures. In this new technique (Kotil technique, through a posterior bilateral approach, transarticular screw fixation was performed at the non-dominant vertebral artery (VA side and posterior transodontoid fixation technique was performed at the dominant VA side. C1-2 complex fusion was aimed with unilateral transarticular fixation and odontoid fixation with posterior transodontoid screw fixation. Cervical spinal computed tomography (CT of a 40-year-old male patient involved in a motor vehicle accident revealed an anteriorly dislocated Type II oblique dens fracture, not reducible by closed traction. Before the operation, the patient was found to have a dominant right VA with Doppler ultrasound. He was operated through a posterior approach. At first, transarticular screw fixation was performed at the non-dominant (left side, and then fixation of the odontoid fracture was achieved by directing the contralateral screw (supplemental screw medially and toward the apex. Cancellous autograft was scattered for fusion without the need for structural bone graft or wiring. Postoperative cervical spinal CT of the patient revealed that stabilization was maintained with transarticular screw fixation and reduction and fixation of the odontoid process was achieved completely by posterior transodontoid screw fixation. The patient is at the sixth month of follow-up and complete fusion has developed. With this new surgical technique, C1-2 fusion is maintained with transarticular screw fixation and odontoid process is fixed by concomitant contralateral posterior transodontoid screw (supplemental screw fixation; thus, this technique both stabilizes the C1-2 complex and fixes the odontoid process and the corpus in atypical odontoid fractures, appearing as an

  20. Bone Regeneration after Treatment with Covering Materials Composed of Flax Fibers and Biodegradable Plastics: A Histological Study in Rats

    Science.gov (United States)

    Gedrange, Tomasz

    2016-01-01

    The aim of this study was to examine the osteogenic potential of new flax covering materials. Bone defects were created on the skull of forty rats. Materials of pure PLA and PCL and their composites with flax fibers, genetically modified producing PHB (PLA-transgen, PCL-transgen) and unmodified (PLA-wt, PCL-wt), were inserted. The skulls were harvested after four weeks and subjected to histological examination. The percentage of bone regeneration by using PLA was less pronounced than after usage of pure PCL in comparison with controls. After treatment with PCL-transgen, a large amount of new formed bone could be found. In contrast, PCL-wt decreased significantly the bone regeneration, compared to the other tested groups. The bone covers made of pure PLA had substantially less influence on bone regeneration and the bone healing proceeded with a lot of connective tissue, whereas PLA-transgen and PLA-wt showed nearly comparable amount of new formed bone. Regarding the histological data, the hypothesis could be proposed that PCL and its composites have contributed to a higher quantity of the regenerated bone, compared to PLA. The histological studies showed comparable bone regeneration processes after treatment with tested covering materials, as well as in the untreated bone lesions. PMID:27597965

  1. Bone Regeneration after Treatment with Covering Materials Composed of Flax Fibers and Biodegradable Plastics: A Histological Study in Rats.

    Science.gov (United States)

    Gredes, Tomasz; Kunath, Franziska; Gedrange, Tomasz; Kunert-Keil, Christiane

    2016-01-01

    The aim of this study was to examine the osteogenic potential of new flax covering materials. Bone defects were created on the skull of forty rats. Materials of pure PLA and PCL and their composites with flax fibers, genetically modified producing PHB (PLA-transgen, PCL-transgen) and unmodified (PLA-wt, PCL-wt), were inserted. The skulls were harvested after four weeks and subjected to histological examination. The percentage of bone regeneration by using PLA was less pronounced than after usage of pure PCL in comparison with controls. After treatment with PCL-transgen, a large amount of new formed bone could be found. In contrast, PCL-wt decreased significantly the bone regeneration, compared to the other tested groups. The bone covers made of pure PLA had substantially less influence on bone regeneration and the bone healing proceeded with a lot of connective tissue, whereas PLA-transgen and PLA-wt showed nearly comparable amount of new formed bone. Regarding the histological data, the hypothesis could be proposed that PCL and its composites have contributed to a higher quantity of the regenerated bone, compared to PLA. The histological studies showed comparable bone regeneration processes after treatment with tested covering materials, as well as in the untreated bone lesions.

  2. Excision of extensive midfoot pigmented villonodular synovitis with microvascular anastamosis of iliac crest bone graft using external fixation: a case report.

    Science.gov (United States)

    Oloff, Lawrence; Miller, Kevin

    2011-10-01

    Pigmented villonodular synovitis (PVNS) is a relatively rare lesion in the foot and ankle, most commonly involving the ankle joint and atypically, the subtalar and midtarsal joints. It is a benign proliferative disease characterized by an increase in villous or nodular synovium in joints. Resection of the tumor is often indicated in most cases because of the potentially aggressive joint destructive nature of this lesion. This report presents a case of chronic enlarging pervasive midtarsal and metatarsal-cuneiform joint PVNS in a 28-year-old male. This patient had a midtarsal mass that enlarged over a period of 2 years, causing increased pain, deformity, and difficulty with ambulation. Cross-sectional imaging studies identified evidence of erosive disease through much of the midfoot articulations, with biopsy confirming the mass as PVNS. The dimensions of the mass approximated 5.5 cm × 4.1 cm × 2.8 cm. Simple resection was problematic because of the size and multiple joints involved. Amputation was most commonly advised by multiple consultants. The patient preferred attempt at limb salvage. En bloc resection and placement of a revascularized iliac crest bone graft was used to fill the defect. The graft was microvascularly anastamosed and fixated with standard external fixation. Pathologic and histologic specimens from surgical biopsy reconfirmed the diagnosis of PVNS postoperatively. Second-stage arthrodesis was performed when the patient was stable and disease free. The patient was followed postoperatively for 10 years without recurrence and was able to return to full function and partake in moderate athletic activity at last visit. This case describes a retrospective review of the procedure and reconstruction, as well as an overview of current surgical management of PVNS.

  3. Technical Report: Correlation Between the Repair of Cartilage and Subchondral Bone in an Osteochondral Defect Using Bilayered, Biodegradable Hydrogel Composites.

    Science.gov (United States)

    Lu, Steven; Lam, Johnny; Trachtenberg, Jordan E; Lee, Esther J; Seyednejad, Hajar; van den Beucken, Jeroen J J P; Tabata, Yasuhiko; Kasper, F Kurtis; Scott, David W; Wong, Mark E; Jansen, John A; Mikos, Antonios G

    2015-12-01

    The present work investigated correlations between cartilage and subchondral bone repair, facilitated by a growth factor-delivering scaffold, in a rabbit osteochondral defect model. Histological scoring indices and microcomputed tomography morphological parameters were used to evaluate cartilage and bone repair, respectively, at 6 and 12 weeks. Correlation analysis revealed significant associations between specific cartilage indices and subchondral bone parameters that varied with location in the defect (cortical vs. trabecular region), time point (6 vs. 12 weeks), and experimental group (insulin-like growth factor-1 only, bone morphogenetic protein-2 only, or both growth factors). In particular, significant correlations consistently existed between cartilage surface regularity and bone quantity parameters. Overall, correlation analysis between cartilage and bone repair provided a fuller understanding of osteochondral repair and can help drive informed studies for future osteochondral regeneration strategies.

  4. Functionality Evaluation of a Novel Smart Expandable Pedicle Screw to Mitigate Osteoporosis Effect in Bone Fixation: Modeling and Experimentation

    Directory of Open Access Journals (Sweden)

    Ahmadreza Eshghinejad

    2013-01-01

    Full Text Available This paper proposes a novel expandable-retractable pedicle screw and analyzes its functionality. A specially designed pedicle screw is described which has the ability to expand and retract using nitinol elements. The screw is designed to expand in body temperature and retract by cooling the screw. This expansion-retraction function is verified in an experiment designed in larger scale using a nitinol antagonistic assembly. The results of this experiment are compared to the results of a finite element model developed in Abaqus in combination with a user material subroutine (UMAT. This code has been developed to analyze the nonlinear thermomechanical behavior of shape memory alloy materials. The functionality of the proposed screw is evaluated with simulation and experimentation in a pullout test as well. The pullout force of a normal screw inserted in a normal bone was simulated, and the result is compared with the results of the expandable screw in osteoporotic bone. Lastly, strength of the designed pedicle screw in a foam block is also verified with experiment. The reported finite element simulations and experiments are the proof for the concept of nitinol expandable-retractable elements on a pedicle screw which validate the functionality in a pullout test.

  5. Biodegradable beta-Tri-Calciumphosphate/hydroxyethyl methacrylate enhanced three component bone adhesive demonstrates biocompatibility without evidence of systemic toxicity in a rabbit model.

    Science.gov (United States)

    Bauer, Natali B; Brinke, Nina; Heiss, Christian; Skorupa, Agnes B; Peters, Fabian; Kraus, Ralf; Schnettler, Reinhard; Moritz, Andreas

    2009-08-01

    Bone gluing is an attractive surgical technique; however, its use in patients is hampered by a variety of side effects. Therefore, it was the aim of this ethically approved study to evaluate a novel biodegradable beta-Tri-Calciumphosphate (beta-TCP, Cerasorb)-enhanced bone adhesive regarding its toxicity and biocompatibility in a rabbit model. Fifty healthy New Zealand White rabbits were assigned in the study (n = 21) and sham-operated control group (n = 29). In the study group, a cylindrical part (4.6 x 10.0 mm) of the proximal tibia and distal femur was removed, reimplanted, and bone adhesive was applied. Blinded physical examination and sampling for hematology, clinical chemistry, and acute phase proteins (haptoglobin, C-reactive protein (CRP)) was performed before surgery and after 12, 24, 48, 72, 240, and 504 h. Significant findings of the physical examination included a slightly higher grading of warmth (p = 0.0019) and pain (p < 0.0001) of the wound 240 h after surgery in the study group. No significant differences between albumin, haptoglobin, CRP, and urea concentrations in both groups were evident, whereas the study group demonstrated significantly lower leukocyte count, total protein, and globulin concentrations (p < 0.0001). As expected, both groups showed a marked transient increase in muscle enzymes (Creatine Kinase and Aspartate Aminotransferase) following the surgery (p < 0.0001). Twelve to 24 h after surgery, a significant decrease in ionized calcium from 1.38 +/- 0.12 mmol/L to 1.06 +/- 0.13 mmol/L was noted in the study group (p < 0.0001). The results clearly indicated that the novel beta-TCP-enhanced bone adhesive showed good biocompatibility without significant evidence of acute or subacute local or systemic toxicity.

  6. Flexible fixation and fracture healing

    DEFF Research Database (Denmark)

    Schmal, Hagen; Strohm, Peter C; Jaeger, Martin

    2011-01-01

    , noncomminuted fractures. External fixation uses external bars for stabilization, whereas internal fixation is realized by subcutaneous placement of locking plates. Both of these "biologic" osteosynthesis methods allow a minimally invasive approach and do not compromise fracture hematoma and periosteal blood...... of articular fractures. They allow for subchondral stabilization using small-diameter angular stable screws as well as buttressing of the joint and the metaphyseal component of a fracture. Biomechanically, they can be far stiffer than external fixators, because subcutaneous plates are located much closer...... to the bone surface than external fixator bars. External fixators have the advantage of being less expensive, highly flexible, and technically less demanding. They remain an integral part of orthopaedic surgery for emergent stabilization, for pediatric fractures, for definitive osteosynthesis in certain...

  7. 骨外固定器在胫腓骨骨折中的应用及护理体会%The Application of External Bone Fixation Device in Tibia and Fibulac Fractures & Nursing Experience

    Institute of Scientific and Technical Information of China (English)

    唐红波; 陈克; 刘莉莉

    2012-01-01

    Objective:discuss the nursing experience when external bone fixation device is applied in tibia and fibulae fractures. Methods:select 58 people who suffered from tibia and fibulae fractures and were treated by external bone fixation device to summarize and analyse methods of treatment for fracture and humanistic nursing measures.Results:it took 7.8 months on average for 58 suffers of tibia and fibulae fractures to unite fractures. Among which, bone union was accomplished by 57 cases, while one wasn't healed.Conclusion:in terms of the treatment for tibia and fibulae fractures, external bone fixation device has been widely applied. Positive and effective measures shall be taken to facilitate the bone healing process and functional recovery of limbs so as to avoid the occurrence of complications.%目的:探讨在胫腓骨骨折中应用骨外固定器的护理体会.方法:选取58例使用骨外固定器治疗的胫腓骨骨折患者,对骨折治疗方法及人性化护理措施进行归纳和分析.结果:58例胫腓骨骨折患者的骨折平均愈合时间为7.8个月,其中,骨性愈合57例,未愈合1例.结论:在胫腓骨骨折的治疗中,骨外固定器已广泛应用,应当采取积极有效的护理措施,以促进骨折的愈合及肢体的功能恢复,防止并发症的发生.

  8. The influence of sacral morphology on the existence of secure S1 and S2 transverse bone corridors for iliosacroiliac screw fixation.

    Science.gov (United States)

    Mendel, T; Noser, H; Kuervers, J; Goehre, F; Hofmann, G O; Radetzki, F

    2013-12-01

    Sacroiliac (SI) screw fixation for unstable pelvic fractures stands out as the only minimally invasive method among all other ORIF procedures. A strictly transverse screw trajectory is needed for central or bilateral fracture patterns up to a complete iliosacroiliac fixation. However, secure screw insertion is aggravated by a narrow sacroiliac bone stock. This study investigates the influence of a highly variable sacral morphology to the existence of S1 and S2 transverse corridors. The analysis contained in this study is based on 125 CT datasets of intact human pelvises. First, sacral dysplasia was identified using the "lateral sacral triangle" method in a lateral 3-D semi-transparent pelvic view. Second, 3-D corridors for a 7.3mm screw in the upper two sacral levels were visualised using a proprietary IT workflow of custom-made programme scripts based on the Amira(®)-software. Shape-describing measurement variables were calculated as output variables. The results show a significant linear correlation between ratioT and the screw-limiting S1 isthmus height (Pearson coefficient of 0.84). A boundary ratio of 1.5 represented a positive predictive value of 96% for the existence of a transverse S1-corridor for at least one 7.3mm screw. In 100 out of 125 pelvises (80%), a sufficient S1 corridor existed, whereas in 124 specimens (99%), an S2 corridor was found. Statistics revealed significantly larger S1 and S2 corridors in males compared to females (pS1 and 1 screw in S2. The expanse of the S1 corridor is highly influenced by the dimensions of the dysplastic elevated upper sacrum, whereas the S2 corridor is not affected. Hence, in dysplastic pelvises, sacroiliac screw insertion should be recommended into the 2nd sacral segment. Our IT workflow for the automatic computation of 3-D corridors may assist in surgical pre-operative planning. Furthermore, the workflow could be implemented in computer-assisted surgery applications involving pelvic trauma.

  9. 石膏固定和空心螺钉内固定修复腕部舟状骨新鲜骨折:功能恢复比较%Plaster fixationversus cannulated screw internal fixation for the wrist scaphoid bone fresh fracture:comparison of functional recovery

    Institute of Scientific and Technical Information of China (English)

    卡依沙尔•买买提明; 赵岩

    2015-01-01

      结果与结论:随访3-6个月对比分析石膏组和空心螺钉组患者腕关节功能Cooney评分,空心螺钉组优9例,良1例,可1例,差0例;石膏组优1例,良5例,可3例,差2例,空心螺钉组患者治疗后优良率为91%,石膏组患者治疗后优良率为55%,空心螺钉组显著高于石膏组(t=4.817,P OBJECTIVE:To compare and analyze functional recovery of the wrist scaphoid bone fresh fracture after plaster fixation and internal fixation. METHODS: Twenty-two patients with wrist scaphoid bone fresh fracture were recruited from the First Affiliated Hospital of Xinjiang Medical University from March 2012 to March 2014, and the injury time was 2 hours to 12 days. Preoperative X-ray films revealed that, the involved patients had no wrist scaphoid bone colapses, lunate bone dislocation, ischemic necrosis of bone and osseous changes. Al the cases showed shift, unstable fractures. According to the patient’s wiling and the surgical method, the involved patients were divided into two groups, receiving plaster fixation and cannulated screw internal fixation respectively. Each group contained 11 cases. Wrist joint function was evaluated using Cooney score system. There was no significant difference in the age distribution and gender between the two groups (P > 0.05). RESULTS AND CONCLUSION: At 3-6 months of folow-up, wrist joint function of patients in the two groups was compared and analyzed with Cooney scores. According to the Cooney scores, nine cases in internal fixation group were excelent, 1 good, 1 fair and none poor; one case in plaster fixation group was excelent, 5 good, 3 fair, and 2 poor. The excelent and good rate in the internal fixation group was significantly higher than that in the plaster fixation group (91%, 55%,t=4.817,P < 0.05). Although plaster fixation has certain effects on wrist scaphoid bone fresh fracture, open reduction and canulated screw fixation has obvious effect and promotes the

  10. Comparative study of safety and efficacy of electrocautery blade with cold scalpel blade for skin opening during fixation of fracture of forearm bone with plate and screws

    Directory of Open Access Journals (Sweden)

    K T Madhukar

    2012-01-01

    Full Text Available Introduction: The art of performing surgeries have improved in recent years with the development of various electrosurgical devices assisting surgeons in performing safer surgeries with better outcomes. Skin incision has traditionally been made with a standard scalpel blade with good primary healing end results of the wound. The electrocautery has been used safely in performing deeper dissections. Use of electrocautery in skin incision has been discouraged in the past for the fear of cutaneous scarring, wound dehiscence, and infections particularly in orthopedic surgeries using internal implants. A review of the literature shows not many studies have been conducted to evaluate the safety and efficacy of electrocautery in skin incisions during orthopedic surgeries using internal implants. Aim: A prospective study was conducted in a tertiary care hospital with the aim to determine whether an electrocautery blade can be used safely for skin incisions. Materials and Methods: Sixty-two patients with single-bone fracture of the forearm undergoing open reduction and internal fixation received one-half of the incision with a standard scalpel blade and another half with electrocautery in pure cutting mode randomly. Analysis: Wounds were compared on operating day for any physical changes and on days 3, 5, and 12, and again on 3 rd and 6 weeks follow-up to know any difference in skin healing between the incised wounds of the two halves. Results: No evidence of any difference in healing of the two halves of skin incision was noted. There was also no increased risk of wound scarring, dehiscence, or infection with electrocautery incision when compared with standard scalpel incision. The time taken for skin incision with electrocautery was significantly less when compared with cold scalpel incision. Conclusion: We propose that electrocautery can be safely used for performing skin incision, with comparable results to that of a standard scalpel skin incision.

  11. Biodegradable Orthopedic Magnesium-Calcium (MgCa Alloys, Processing, and Corrosion Performance

    Directory of Open Access Journals (Sweden)

    Yuebin Guo

    2012-01-01

    Full Text Available Magnesium-Calcium (Mg-Ca alloy has received considerable attention as an emerging biodegradable implant material in orthopedic fixation applications. The biodegradable Mg-Ca alloys avoid stress shielding and secondary surgery inherent with permanent metallic implant materials. They also provide sufficient mechanical strength in load carrying applications as opposed to biopolymers. However, the key issue facing a biodegradable Mg-Ca implant is the fast corrosion in the human body environment. The ability to adjust degradation rate of Mg-Ca alloys is critical for the successful development of biodegradable orthopedic implants. This paper focuses on the functions and requirements of bone implants and critical issues of current implant biomaterials. Microstructures and mechanical properties of Mg-Ca alloys, and the unique properties of novel magnesium-calcium implant materials have been reviewed. Various manufacturing techniques to process Mg-Ca based alloys have been analyzed regarding their impacts on implant performance. Corrosion performance of Mg-Ca alloys processed by different manufacturing techniques was compared. In addition, the societal and economical impacts of developing biodegradable orthopedic implants have been emphasized.

  12. 不同固定方式对腱-骨愈合界面影响的形态学研究%Effect of different fixations on tendon-bone healing interface:a morphological study

    Institute of Scientific and Technical Information of China (English)

    刘建锋; 李艳菊

    2013-01-01

    背景:关节镜下重建交叉韧带已得到广泛应用,关于腱骨愈合状态的研究多集中在患肢功能恢复以及愈合程度及稳定性观察方面。  目的:了解韧带重建过程中各种固定方式对肌腱-骨界面愈合的影响。  方法:2009年7月至2009年9月以长白二号体重100千克左右的八头成年猪的双膝关节作为实验对象进行动物实验,采用四种固定方式对腱-骨进行固定,包括纽扣接骨板悬吊固定、肌腱包裹自体松质骨方式、界面挤压螺钉固定、横穿可吸收钉固定,对手术后6周、12周时界面愈合的情况进行病理切片观察。  结果:纽扣接骨板固定模式腱骨界面愈合均匀,理论抗拉力大,相反固定物对腱骨界面干扰明显的界面愈合不理想,骨纤维细胞排列不整齐,理论拉力降低,尤其表现在界面挤压螺钉方面;对于有自体松质骨植入的在腱骨愈合过程中活性骨质坏死,无促进腱骨愈合的作用。  结论:在腱骨愈合过程中界面固定方式对早期愈合有不同程度的影响,悬吊固定方式腱-骨愈合界面形态学表现理想。%Background:The reconstruction of cruciate ligament under arthroscope has been widely applied. Nowadays, the study on tendon-bone healing is mostly focused on function recovery of patients and stability of healing. Objective:The purpose of the study is to explore the influence of different fixed styles to tendon-bone healing in the process of ligament reconstruction. Methods:From July 2009 to September 2009, eight adult Landrace II pigs weighing 100 kg was used as experiment animal and divided into four groups (n=2). Four tendon-bone fixed methods were applied in both knee in each group respectively, including button-plate suspension fixation, autologous bone tendon wrapped mode, interface extrusion screw, and adsorb-able screw. The healing of interface was observed at 6 and 12 weeks

  13. A biodegradable antibiotic-impregnated scaffold to prevent osteomyelitis in a contaminated in vivo bone defect model

    Directory of Open Access Journals (Sweden)

    JS McLaren

    2014-06-01

    Full Text Available Open fractures are at risk of serious infection and, if infected, require several surgical interventions and courses of systemic antibiotics. We investigated a new injectable formulation that simultaneously hardens in vivo to form a porous scaffold for bone repair and delivers antibiotics at high concentrations to the local site of infection. Duration of antimicrobial activity against Staphylococcus aureus was determined using the serial plate transfer test. Ultimate compressive strength and porosity of the material was measured with and without antibiotics. The material was evaluated in vivo in an ovine medial femoral condyle defect model contaminated with S. aureus. Sheep were sacrificed at either 2 or 13 weeks and the defect and surrounding bone assessed using micro-computed tomography and histology. Antimicrobial activity in vitro persisted for 19-21 days. Sheep with antibiotic-free material and bacteria became infected, while those with antibiotic-containing material and bacteria did not. Similarly, new bone growth was seen in uninoculated animals with plain polymer, and in those with antibiotic polymer with bacteria, but not in sheep with plain polymer and bacteria. The antibiotic-impregnated scaffolds were effective in preventing S. aureus infections whilst supporting bone growth and repair. If translated into clinical practice, this approach might reduce the need for systemic antibiotics.

  14. Femoral Reconstruction Using External Fixation

    Directory of Open Access Journals (Sweden)

    Yevgeniy Palatnik

    2011-01-01

    Full Text Available Background. The use of an external fixator for the purpose of distraction osteogenesis has been applied to a wide range of orthopedic problems caused by such diverse etiologies as congenital disease, metabolic conditions, infections, traumatic injuries, and congenital short stature. The purpose of this study was to analyze our experience of utilizing this method in patients undergoing a variety of orthopedic procedures of the femur. Methods. We retrospectively reviewed our experience of using external fixation for femoral reconstruction. Three subgroups were defined based on the primary reconstruction goal lengthening, deformity correction, and repair of nonunion/bone defect. Factors such as leg length discrepancy (LLD, limb alignment, and external fixation time and complications were evaluated for the entire group and the 3 subgroups. Results. There was substantial improvement in the overall LLD, femoral length discrepancy, and limb alignment as measured by mechanical axis deviation (MAD and lateral distal femoral angle (LDFA for the entire group as well as the subgroups. Conclusions. The Ilizarov external fixator allows for decreased surgical exposure and preservation of blood supply to bone, avoidance of bone grafting and internal fixation, and simultaneous lengthening and deformity correction, making it a very useful technique for femoral reconstruction.

  15. Strain-stress analysis of lower limb with applied fixator

    Directory of Open Access Journals (Sweden)

    Mrázek M.

    2010-07-01

    Full Text Available This paper compares physiological state of tibia before and after application of an external fixator. The fixator systems’ models but also model of tibia are loaded in the direction of body axis. The paper is focused on the examination of differences in stiffness before and after the application of fixation. Two types of axial external fixators are compared. Both fixators differ in their construction. The first fixator is two-frame and fixation rods are used for fixing the bone tissue (variant I. The second one is fixed into tibia with screws (variant II. We have found out that the two-frame external fixator has much bigger stiffness during limb fixation than the fixator with one body. Much higher deformations compared to physiological state of tibia occur in the variant II.

  16. Prosthesis, bone graft and internal fixation and bone cement filling for treatment of giant cell tumor of bone%假体置换、植骨内固定及骨水泥填充治疗骨巨细胞瘤

    Institute of Scientific and Technical Information of China (English)

    广东; 王亚军; 赵凡

    2011-01-01

    BACKGROUND: Artificial joint replacement or allogeneic bone fixation and bone substitute materials filling are common ways torepair bone defects in giant cell tumor of bone after curettage, so which one is more ideal?OBJECTIVE: To understand the staging standard of giant cell tumors through access to Chinese and English literature abouttreatment for giant cell tumor of bone, and to compare different therapies, bone graft, bone cement filling and prosthesis.METHODS: A computer based search of CNKI using keywords of “tumor-type prosthesis, giant cell tumor of bone, bone graft,bone cement” and Elsevier Science and Pringer-Link using keywords of “giant cell tumor of bone, therapy, tumor-type prosthesis”were performed to retrieve relevant articles. Totally 346 articles were retrieved, and finally 26 were included in result analysis.RESULTS AND CONCLUSION: The traditional treatments for giant cell tumor have a higher recurrence rate. The bone graft maynot be able to fill the entire bone cavity, bone cement materials cannot be easy to be fused with the host. Tumor-type prosthesisshows a good effect on giant cell tumor of bone, but it is still inadequate. However, special prosthesis joints can repair bone defectsfollowing giant cell tumor of bone according to individualized treatment needs, which is an effective and reliable surgical method aswell as the main research direction for the future treatment of giant cell tumor of bone.%背景:人工关节置换或同种异体骨内固定及骨组织替代材料填充是修复骨巨细胞瘤刮除后骨缺损的常见方式,那么哪一种更理想呢?目的:通过查阅关于骨巨细胞瘤治疗方面的中英文文献,了解骨巨细胞瘤的分期标准并比较以植骨内固定、骨水泥填充及假体置换为主的治疗方法.方法:中国知网数据库输入中文检索词"肿瘤型假体,骨巨细胞瘤,植骨内固定,骨水泥",Elesvier Science和Springer-Link 数据库输入英文检索词"giant cell

  17. Bone

    Science.gov (United States)

    Helmberger, Thomas K.; Hoffmann, Ralf-Thorsten

    The typical clinical signs in bone tumours are pain, destruction and destabilization, immobilization, neurologic deficits, and finally functional impairment. Primary malignant bone tumours are a rare entity, accounting for about 0.2% of all malignancies. Also benign primary bone tumours are in total rare and mostly asymptomatic. The most common symptomatic benign bone tumour is osteoid osteoma with an incidence of 1:2000.

  18. Options for acetabular fixation surfaces.

    Science.gov (United States)

    Klika, Alison K; Murray, Trevor G; Darwiche, Hussein; Barsoum, Wael K

    2007-01-01

    Aseptic loosening is the most common cause for revision total hip arthroplasty (THA). Due to poor long-term results with cemented acetabular components, cementless implants that rely on biologic fixation became popular in the United States for both primary and revision procedures in the early 1980s. Cementless acetabular components used in THA have been reported to have superior radiographic performance compared with cemented fixation, although the optimal method of acetabular fixation remains controversial. Cementless acetabular components require initial implant stability to allow for bone ingrowth and remodeling into the acetabular shell, providing long-term durability of the prosthesis. Many improved implant materials are available to facilitate bone growth and remodeling, including the 3 most common surface treatments; fibermesh, sintered beads, and plasma spray coatings. Recently added to these are porous metal surfaces, which have increased porosity and optimal pore sizes when compared with titanium fibermesh. The most studied of these materials is the titanium fibermesh fixation surface, which has demonstrated a mechanical failure rate of 1% at 10 to 15 years. This technology utilizes the diffusion bonding process to attach fiber metal pads to a titanium substrate using heat and pressure. The sintered bead fixation surface offers a porous coating of various sizes of spherical beads, achieved by the sintering process, and has been shown to provide long-term fixation. While there are less long-term published data regarding the titanium plasma spray surface, its early results have provided evidence of its durability, even in the face of significant osteolysis. The most recently added alternative fixation surface is porous tantalum metal, which offers potentially greater bone ingrowth and bone graft incorporation due to its high porosity (80%) and low modulus of elasticity (3 MPa). Porous tantalum implants have shown early favorable clinical results and have

  19. Assessment of the influence of Laser phototherapy on the bone repair process of complete fractures in tibiae of rabbits stabilized with semi-rigid internal fixation treated with or without MTA graft: a histological study

    Science.gov (United States)

    Soares, Luiz G. P.; Silva, Aline C. P.; Silva, Anna Paula L. T.; Neves, Bruno Luiz R. C.; Santos, Nicole R. S.; dos Santos, Jean N.; Pinheiro, Antonio L. B.

    2016-03-01

    Beside biomaterials, Laser phototherapy has shown positive effects as auxiliary therapy in bone repair process, especially when involving large bone losses. The aim of this histological study was to evaluate, by light microscopy, the influence of laser phototherapy on the repair of complete tibial fractures in rabbits treated or not with semi-rigid internal fixation and Mineral Trioxide Aggregate - MTA graft. Twelve Rabbits were randomly divided into four groups with three animals each. After general anesthesia, complete fractures were created in one tibia with a carborundum disk. All animals (groups I-IV) had the fracture stabilized with semi-rigid fixation (wire osteosynthesis - WO). Group I was routinely fixed with WO; groups II and IV fracture was filled by blood clot and MTA implant. In Groups III and IV fracture was filled by blood clot and further irradiated with laser (λ780 nm, 70 mW, CW, Φ = 0.04 cm2, 20.4 J/cm2, per session, t = 300s, 142.8 J/cm2 per treatment). The phototherapy protocol was applied immediately after the surgery and repeated each 48 hours during 15 days. Animal death occurred on the 30th postoperative day. After removal of the specimens, the samples were routinely processed, stained with HE and evaluated by light microscopy. Histologically, the group treated with MTA graft and irradiated with laser showed the fracture filled by a more organized and mature trabecular bone, when compared with all other groups. From the results of the present study, it may be concluded that the association of Laser phototherapy + MTA graft in fractures treated with WO improved bone repair when compared with fractures treated only with WO.

  20. Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Isabelle Vroman

    2009-04-01

    Full Text Available Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources or from biological resources (renewable resources. In general natural polymers offer fewer advantages than synthetic polymers. The following review presents an overview of the different biodegradable polymers that are currently being used and their properties, as well as new developments in their synthesis and applications.

  1. Biomechanical evaluation of fixation degree of fragments by periosteal osteosynthesis

    Directory of Open Access Journals (Sweden)

    Barabash Yu.A.

    2010-09-01

    Full Text Available Expansion of indications for surgery and plate osteosynthesis of long bones points to increased number of complications caused by instability of fragments, that can be associated in their turn with constructive features or iatrogenic factors. Insufficient rigidity of fragment fixation is due to incorrect technical treatment and wrong choice of fixator. Biomechanical parameters of periosteal fixation rigidity have been experimentally proved, depending on fixator lever

  2. Preparation of electrospun fiber mats using siloxane-containing vaterite and biodegradable polymer hybrids for bone regeneration.

    Science.gov (United States)

    Fujikura, Kie; Lin, Sen; Nakamura, Jin; Obata, Akiko; Kasuga, Toshihiro

    2013-11-01

    An electrospun fiber mat using a new composite consisting of siloxane-containing vaterite (SiV) and poly(lactic-co-glycolic acid) (PLGA) (denoted by SiPLGVH) was prepared with the aim of applying it as a membrane for use in a guided bone regeneration (GBR) system. Another electrospun fiber mat using a previously described composite consisting of SiV and poly(L-lactic acid) (denoted by SiPVH) was also prepared as a comparative sample. SiPLG VH fiber mats showed superior results in terms of mechanical tensile properties and cellular behavior. Their elongation before failure was about eight times higher than that of SiPVH. The numbers of osteoblast-like cells that proliferated on the SiPLGVH fiber mats, regardless of the hydroxyapatite coating, were comparable to that of SiPVH. The cells spread more, two dimensionally, on the SiPLGVH fiber mats, since the pores between fibers were narrowed down because of swelling of the PLGA matrix during cell culture. This two-dimensional cellular proliferation quality on the SiPLGVH fiber mats is expected to be suitable for materials used in GBR, leading to control of infiltration of the soft tissue and great tissue integration with the surrounding tissue.

  3. 颈椎前路减压植骨钛板内固定治疗颈脊髓损伤%Treatment of Cervical Spinal Cord Injury by Anterior Decompression, Bone Graft and Titanium Plate Internal Fixation

    Institute of Scientific and Technical Information of China (English)

    沈宁江; 王先安; 林庆彪; 林明侠; 陈建

    2013-01-01

    Objective To evaluate the clinical efficacy of anterior decompression, bone graft and internal fixation for cervical spine fracture with cervical spinal cord injury. Methods 215 cases of cervical spine fracture with cervical spinal cord injury had been treated by the method of anterior decompression,iliac bone graft and cervical locking titanium plate fixation. X-rays were taken regularly after surgery and recovery of spinal cord function were recorded. Results 184 cases were followed for an average time of 3. 5 years. Bone graft union was achieved 3 months after surgery. The cervical intervertebral height and the physiological curvature maintained satisfactory without implant complications. Nerve function of 172 patients improved 1 to 2 degree. Only 12 cases with stage A nerve function obtained no recovery. Conclusion Patients of cervical fracture with cervical spinal cord injury should undergo surgery of anterior decompression,bone graft and plate fixation as soon as possible. It is good to spinal cord function recovery. The injured segments can obtain instant and firm stability, which makes care and functional exercises easier.%目的 评价颈椎前路减压植骨内固定治疗颈椎骨折合并颈脊髓损伤的临床疗效.方法 对215例颈椎骨折合并颈脊髓损伤的患者施行颈椎前路减压、自体髂骨植骨和颈椎带锁钛板内固定术.术后定期复查X线片,判定脊髓功能恢复情况.结果 随访184例患者,平均随访时间3.5年.术后3个月植骨块获得骨性愈合,颈椎椎间高度和生理曲度维持满意,无内置物并发症,172例患者神经功能提高1~2级,仅12例A级患者神经功能无恢复.结论 颈椎骨折合并颈脊髓损伤应尽早行前路减压、植骨、钛板内固定术,有利于脊髓功能恢复,能使损伤节段获得即刻、坚强的稳定,方便护理和功能锻炼.

  4. 经前路减压植骨融合内固定术治疗胸腰椎爆裂骨折%The treatment of the thoracolumbar spina burst fracture: planted bones fusion and internal fixation by anterior decompression

    Institute of Scientific and Technical Information of China (English)

    汪红; 刘跃洪; 刘树平; 周宇; 徐巍

    2012-01-01

    目的 探讨经前路减压、椎间植骨融合内固定术治疗胸腰椎爆裂骨折的疗效.方法 对22例胸腰椎爆裂骨折患者行前路减压、推间植骨融合内固定术,并对患者神经功能、骨折愈合情况进行术前术后对比分析.结果 平均手术时间3.5h,平均失血量800ml,平均住院时间10d.平均随访18个月,脊柱稳定性好,序列好,未出现螺钉松动、钛网下沉等并发症,植骨均愈合.末次随访时神经功能均较术前恢复1~3级.结论 经前路减压植骨融合内固定术治疗胸腰椎爆裂骨折能彻底减压,植骨融合率高,固定效果好,神经功能改善明显,具有推广应用价值.%Objective To explore the clinical efficiency of the treatment of the thoracolumbar spina burst fracture through planted bones fusion and internal fixation by anterior decompression. Methods Between January 2008 and December 2010. 22 cases of thoracolumbar spina burst fracture were treated by planted bones fusion and internal fixation by anterior decompression, including 16 males and 6 females with an age range of 22-65 years (44. 5 years on average). The injury was caused by fall from height in 12cases, by traffic accident in 8 cases and by weight crushing in 2 cases. The injury segments were 2 cases of thoracic 11, 8 cases of thoracic 12, 10 cases of lumbar 1 and 2 cases of lumbar 2. Preopera-tive CT showed that all 22 cases suffered from spinal canal occupancy, fracture fragments migrated into spinal canal and spinal dura mater compression. There are 4 cases of Grade A, 6 cases of Grade B. 8 cases of Grade C. 2 cases of Grade D and 2 cases of Grade E according to Frankel grading of neurologic status before surgery. It was an average of 6. 5 days from injury to operation. The mean operative time was 3. 5 hours and the mean blood loss was 800 ml. The mean time in hospital was 10 days and the mean follow-up time was 18 months. The comparative analysis before and after surgery of all patients in

  5. Biodegradation of Absorbable Hydroxyapatite/Poly-DL-lactide Composites in Different Environment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    To develop a new generation of absorbable fracture fixation devices with enhanced biocompatibility, the biodegradation mechanism and its influence on the cellular response at the tissue/implant interface of hydroxyapatite/ poly-DL-lactide (HA/PDLLA) composites were investigated in vitro and in vivo.HA/PDLLA rods were immersed in phosphate-buffered saline,or implanted in muscle and bony tissue for 52 weeks.Scanning electron microscopic and histological studies were done.The degradation rate was the slowest in vitro,slower in muscle tissue and fast in bone.In vitro, the composites degraded heterogeneously and a hollow structure was formed.In bone,the limited clearing capacity leads to the accumulation of oligomeric debris,which contribute totally to the autocatalytic effect.So,the fastest degradation and intense tissue response were seen.In muscle tissue,oligomeric debris migrated into vicinal fibers over a long distance from the original implant cavity and the tissue reactions were,however, quite moderate.For the same size organic/inorganic composite,the environment where it was placed is the major factor in determining its biodegradation process and cellular reaction.In living tissue,factors such as cells,enzymes and mechanical stress have an obvious influence on the biodegradation and biological process at the tissue/implant interface.The biocompatibility of the HA/PDLLA composites is enhanced with the incorporating of the resorbable HA microparticles.

  6. Experience of Clinical the Load of Streptomycin Powder Bone Morselized Bone Fusion and Internal Fixation for the Treatment of Spinal Tuberculosis%负载链霉素粉骨颗粒植骨融合内固定术治疗脊柱结核的治疗体会

    Institute of Scientific and Technical Information of China (English)

    王永松; 王冶; 陈志龙; 王群芳

    2015-01-01

    目的:探讨负载链霉素粉骨颗粒植入融合及内固定术治疗脊柱结核的临床疗效和应用价值。方法对16例脊柱结核使用一期病灶清除,带链霉素粉骨颗粒植入融合和钉棒系统内固定治疗。结果术后腰痛缓解93.2%。术后1年X线片植骨融合率达96.2%。结论治疗腰椎结核采用一期病灶清除,负载链霉素粉骨颗粒植入融合,钉棒系统内固定具有良好的效果。%Objective To evaluate the load streptomycin powder particles are bone fusion and internal fixation in the treatment of spinal tuberculosis curative ef ect and application value. Methods 16 cases of spinal tuberculosis using a phase lesions cleared, with streptomycin powder particles are bone fusion and good nail internal fixation treatment system. Results 93.2% postoperative back pain relief. A year after X line piece of bone graft fusion rate was 96.2%. Conclusion Treatment of lumbar spinal tuberculosis using a phase lesions cleared, load streptomycin powder particles are bone fusion and internal fixation of screw rod system has a good ef ect.

  7. Stability of unicortical locked fixation versus bicortical non-locked fixation for forearm fractures

    Institute of Scientific and Technical Information of China (English)

    Timothy J.Pater; Steve I Grindel; Gregory J.Schmeling; Mei Wang

    2014-01-01

    Locking plate fixation is being widely applied for fixation of forearm fractures and has many potential advantages, such as fixed angle fixation and improved construct stability, especially in osteoporotic bone. Biomechanical data comparing locking devices to commonly used Low Contact Dynamic Compression (LCDCP) plates for the fixation of forearm fractures has been lacking. The purpose of this study was to compare the fixation stability of a 3.5-mm unicortical locked plate with bicortical non-locked LCDCP plates. Six matched pairs of fresh frozen cadaveric forearms were randomly assigned to unicortical locked and bicortical unlocked groups. Non-destructive four-point bending and torsional test was performed on the ulna and radius separately, using a servohydraulic testing system to obtain construct stiffness of the intact specimens and specimens after osteotomy and plating. The specimens were then loaded to failure to test the fixation strength. The locked unicortical fixation showed significantly higher bending stiffness than the unlocked bicortical fixation, but with significantly lower stiffness and strength in torsion. Fixation strength was comparable between the two groups under bending, but significantly greater in the bicortical non-locked group under torsion. Findings from this study suggest that postoperative rehabilitation protocols may need modification to limit torsional loading in the early stage when using locked unicortical fixation. The study also points out the potential advantage of a hybrid fixation that combines locked unicortical and unlocked bicortical screws.

  8. Complications of rigid internal fixation.

    Science.gov (United States)

    Campbell, Chris A; Lin, Kant Y

    2009-03-01

    Over the past 20 years, there have been many advances in the development of bone fixation systems used in the practice of craniomaxillofacial surgery. As surgical practices have evolved, the complications of each technologic advance have changed accordingly. Interfragmentary instability of interosseous wiring has been replaced by the risk of exposure, infection, and palpability of plate and screw fixation systems. The improved rigidity of plate fixation requires anatomic alignment of fracture fragments. Failure to obtain proper alignment has led to the phenomenon known as "open internal fixation" of fracture fragments without proper reduction. The size of the plates has decreased to minimize palpability and exposure. However limitations in their application have been encountered due to the physiologic forces of the muscles of mastication and bone healing. In the pediatric population, the long-standing presence of plates in the cranial vault resulted in reports of transcranial migration and growth restriction. These findings led to the development of resorbable plating systems, which are associated with self-limited plate palpability and soft tissue inflammatory reactions. Any rigid system including these produces growth restriction in varying amounts. In this discussion, we review the reported complication rates of miniplating and microplating systems as well as absorptive plating systems in elective and traumatic craniofacial surgery.

  9. Peri-implant tissue response and biodegradation performance of a Mg-1.0Ca-0.5Sr alloy in rat tibia.

    Science.gov (United States)

    Berglund, Ida S; Jacobs, Brittany Y; Allen, Kyle D; Kim, Stanley E; Pozzi, Antonio; Allen, Josephine B; Manuel, Michele V

    2016-05-01

    Biodegradable magnesium (Mg) alloys combine the advantages of traditional metallic implants and biodegradable polymers, having high strength, low density, and a stiffness ideal for bone fracture fixation. A recently developed Mg-Ca-Sr alloy potentially possesses advantageous characteristics over other Mg alloys, such as slower degradation rates and minimal toxicity. In this study, the biocompatibility of this Mg-Ca-Sr alloy was investigated in a rat pin-placement model. Cylindrical pins were inserted in the proximal tibial metaphyses in pre-drilled holes orthogonal to the tibial axis. Implant and bone morphologies were investigated using μCT at 1, 3, and 6 weeks after implant placement. At the same time points, the surrounding tissue was evaluated using H&E, TRAP and Goldner's trichrome staining. Although gas bubbles were observed around the degrading implant at early time points, the bone remained intact with no evidence of microfracture. Principle findings also include new bone formation in the area of the implant, suggesting that the alloy is a promising candidate for biodegradable orthopedic implants.

  10. Biological fixation in anterior cruciate ligament surgery

    Directory of Open Access Journals (Sweden)

    Chih-Hwa Chen

    2014-04-01

    Full Text Available Successful anterior cruciate ligament (ACL reconstruction with tendon graft requires extensive tendon-to-bone healing in the bone tunnels and progressive graft ligamentization for biological, structural, and functional recovery of the ACL. Improvement in graft-to-bone healing is crucial for facilitating early, aggressive rehabilitation after surgery to ensure an early return to pre-injury activity levels. The use of various biomaterials for enhancing the healing of tendon grafts in bone tunnels has been developed. With the biological enhancement of tendon-to-bone healing, biological fixation of the tendon graft in the tunnel can be achieved in ACL reconstruction.

  11. Management of subtrochanteric femur fractures with internal fixation and recombinant human bone morphogenetic protein-7 in a patient with osteopetrosis: a case report

    Directory of Open Access Journals (Sweden)

    Golden Robert D

    2010-05-01

    Full Text Available Abstract Introduction Osteopetrosis is a group of conditions characterized by defects in the osteoclastic function of the bone resulting in defective bone resorption. Clinically, the condition is characterized by a dense, sclerotic, deformed bone which, despite an increased density observable by radiography, often results in an increased propensity to fracture and delayed union. Case Presentation We report the case of a 27-year-old Asian man presenting with bilateral subtrochanteric femur fractures. He had a displaced right subtrochanteric femur fracture after a low-energy fall, which was treated surgically. The second fracture that our patient endured was diagnosed as a stress fracture ten weeks later when he complained of pain in the contralateral left thigh. By that time, the right-sided fracture exhibited no radiographic evidence of healing, and when the left-sided stress fracture was being treated surgically, bone grafting with recombinant human bone morphogenetic protein-7 was also performed on the right side. Conclusion While there are no data supporting the use of bone morphogenic proteins in the management of delayed healing in patients with osteopetrosis, no other reliable osteoinductive grafting options are available to treat this condition. Both fractures in our patient healed, but based on the serial radiographic assessment it is uncertain to what degree the recombinant human bone morphogenetic protein-7 may have contributed to the successful outcome. It may have also contributed to the formation of heterotopic bone around the fracture site. Further investigation of the effectiveness and indications of bone morphogenic protein use for the management of delayed fracture healing in patients with osteopetrosis is warranted.

  12. Study on rehabilitative exercise for patients with long bone comminuted fractures of lower limbs after operation of external fixation combined with auto-graft bone implantation%下肢长骨粉碎性骨折进行髓腔内自体骨支撑并外固定后的康复治疗

    Institute of Scientific and Technical Information of China (English)

    石蛟; 刘殿梅; 曹国恒; 司志军

    2012-01-01

    Objective To study the effect of early rehabilitative exercise for patients with long bone comminuted fractures of lower limbs after operation of external fixation combined with auto - graft bone implantation. Methods Twelve patients with long bone comminuted fractures of lower limbs were allocated into this study. After operation by using external fixation combined with auto - graft bone implantation, early rehabilitative exercise had been applied to reinforce the strength of muscles in lower limbs and range of movement ( ROM ) in knees of these patients. After treatment for 12 months, the strength of muscles in lower limbs and ROM in knees were assessed for evaluating the effect of treatment. Results After rehabilitative therapy for 12 months, all patients obtained their normal muscle strength of lower limbs and ROM in knees. Conclusion Early rehabilitative therapy is an efficient method to improve activities of daily living for patients with long bone comminuted fractures of lower limbs after operation of external fixation combined with auto - graft bone implantation.%目的 探讨下肢长骨粉碎性骨折患者进行髓腔内自体骨支撑并外固定支架固定术后早期患肢进行康复训练的疗效.方法 对12例下肢长骨粉碎性骨折采用髓腔内自体骨支撑并外固定支架固定,术后1~3天采用镇痛、早期运动疗法及主、被动关节功能练习等综合康复锻炼.结果 12例经有效康复治疗关节的活动度达到生理要求,肌肉萎缩程度明显减轻.结论 下肢长骨粉碎性骨折进行髓腔内自体骨支撑并外固定支架固定术后早期康复治疗是保证肢体早期功能恢复的有效方法.

  13. Biomechanical analysis of fracture fixation with external fixator in vivo

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Objective: To investigate the different ways of measuring the main axial strain during treatment with an external fixator and to find the suitable compression loaded by the external fixator at an early stage.Methods: Eighteen healthy big-ear rabbits were randomly divided into two groups according to different measuring methods: Group A and Group B. In Group A,a strain gauge was affixed to the external tibial cortex with 502 glue, and in Group B, a bone cement-coated strain gauge was installed on the internal tibial cortex. Groups A and B were divided into two subgroups A1, A2 and B1,B2, respectively, according to the pressure of half of and the same as the body weight. A Z-shaped left mid-shaft tibial osteotomy was performed and fixed by an external fixator. Results: The scaler curves of Group A changed dramatically during the early stage. The trendlines of the internal and external cortex went consistently after reaching the stable stage while the latter strain value was higher than the former. The time for Group B reaching the stable stage was short, but its absolute strain value was less than that of Group A. Before they were pressed to the stable stage, the declined speed of Subgroup A1 was more slowly than that of Subgroup A2 while the results of Subgroups B1 and B2 were same. Group A had an ascending trend after it declined while Group B didn't have. After they reached the stable stage, both Subgroups A1 and A2 had a declining trend while Subgroup A2 was more quickly than Subgroup Al, Subgroup B1 was kept at a definite level while Subgroup B2 fluctuated.Conclusions: The axial strain under external fixator can be measured by bone cement coated-strain gauge in vivo. The data may suggest that half of the body weight load was suitable for external fixator.

  14. Evaluation of the Biodegradable Plates (PG910/PDO) for Reconstruction of Various Sizes of Orbital Floor Defects in the Blow-Out Fractures.

    Science.gov (United States)

    Tabrizi, Reza; Langner, Nicole J; Pouzesh, Ayatollah; Arabion, Hamidreza

    2013-09-01

    The aim of our study was to evaluate the biodegradable plates (PG910/PDO) for reconstruction of various sizes of the orbital floor defects in the blow-out fractures. We included patients who had an impure blow-out fracture. All patients had a recent trauma and also the surgical intervention was done between 1 and 10 days after trauma. The amount of the orbital floor defect was measured in each case through computed tomography scan. In the surgical intervention, a biodegradable plate was used for the reconstruction of the orbital floor defect along with titanium miniplates used for bone fixation in orbital rim. Due to aesthetic reasons, all patients underwent secondary surgery including removal of titanium miniplates after 18 months. The orbital floor was reevaluated during the removal of the miniplates. The clinical evaluation of remnant defects and biodegradable plates (presence of complete or partial resorption) were documented for each patient. In our study a total of 15 patients (10 males and 5 females) underwent the orbital floor reconstruction using biodegradable miniplates. The size of the orbital floor defects was meanly 3.51 ± 1.29 cm(2). Results demonstrated that 4 out of 15 patients had a remnant defect after resorption of the biodegradable plate. In 10 out of 15 patients, the biodegradable plates completely replaced with fibrous tissues after 18 months. Remaining five patients had partial resorption of plates. There was not any relationship between the defect size and the remnant defects (p > 0.05). A significant relationship was seen between the defect size and the plates' resorption rate (p biodegradable plates is an appropriate option for reconstruction of the orbital floor defects. The defect size does not have any effect on the stability of the plate. However, incomplete plate resorption increases the risk of remnant defects in the orbital floor. The larger defects lead to slow degradation of biodegradable plates.

  15. A 10-year follow-up of transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or intervertebral B-Twin system in failed back surgery syndrome

    Science.gov (United States)

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    Background: The spine surgeons have been combining anterior and posterolateral fusion (circumferential fusion) as the final solution to treat spinal disorders and many have been using it to treat failed back surgery syndrome (FBSS). In present study, we analyzed and compared the clinical and radiological outcomes in patients with transpedicular screw fixation and intervertebral autogenous posterior iliac crest bone graft or in patients with transpedicular screw fixation and intervertebral B-Twin system for FBSS with a follow-up period of 10 years after the surgery. Materials and Methods: This study was a retrospective case study performed on 55 patients with FBSS. Clinical and radiological changes were compared between the two groups of patients on the basis of improvement of back pain, radicular pain, and work capacity. Outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year from before surgery until 2012. We analyzed the evolution of 55 cases of FBSS those underwent segmental circumferential posterior fusions from June 2001 to February 2003, operated by a single surgeon and followed up during 10 years until February 2012. The patients were divided into 2 groups: In 25 patients, posterolateral fusions with Legacy™ (Medtronic, Inc. NYSE: MDT) screws and intersomatic autogenous posterior iliac crest bone graft was performed, and, in 30 patients, posterolateral fusions with the same screws and intersomatic fusion B-Twin (Biomet Spain Orthopaedics, S.L.) system was performed. In all cases, we used posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) approach for intervertebral graft, and the artrodesis was supplemented at intertransverse level with Autologus Growth Factor (AGF-MBA INCORPORADO, S.A.). The outcome was measured in terms of Oswestry Low Back Pain Disability Index, and the changes in pain and function were documented every year and compared

  16. 前路减压植骨可吸收螺钉内固定治疗颈椎病%The anterior decompression and bone grafting with bio-absorbable screw fixation for cervical spondylosis

    Institute of Scientific and Technical Information of China (English)

    王栋; 贺西京; 李浩鹏; 张健; 徐思越; 杨平林; 王国毓

    2009-01-01

    Objective:To observe the early clinical effect of the cervical spendylosis treated by the fixation with bio-absorbable screw after cervical anterior decompression and bone grafting.Method:26 cases suffered from cervical spondylosis who were treated by anterior compression,bone grafting and fixating with 2 bio-ab-serbable screws from Mar. 2007 to Sep. 2008,including 16 males and 10 females with an average age of 49.4 years (38-70 years ).There were 11 cases with cervical spondylotic myelopathy,5 with cervical spendylofic radieulopathy and 10 with mixed type of cervical spondylosis.Clinical data of these patients was analyzed ret-rospectively.One intervertebral space involvement was in 8 cases,and two spaces involvement in 18 cases.All patients underwent anterior decompression and bone grafting,in which the grafted bone was fixated by 2 bio-absorptive screws (PLLA,diameter:2.7mm) from the midline of graft bone to the bone surface of upper and lower vertebrae in 45°.Cervical collar was commonly used for 4-6 weeks after operation.All cases were fol-lowed-up every month in outpatient department to observe the improvement of symptoms and evaluate the fu-sion of bone graft.Neurological function recovery was observed by JOA score.Result:Operations of all cases were finished and screws were placed successfully.The operative incisions healed well.The excellent and good rate of symptom improvement was 84.2%,the graft fusion time was 3.3±0.6 months (range,3.2-4.6 months).No obvious complications were found.Conclusion:The cervical spendylosis with one or two-level involvement can be effectively treated by anterior decompression and bone grafting with bio-absorbable screw fixation.This operative method is safe and can avoid the complications induced by metal implants.%目的:观察颈椎前路减压植骨可吸收螺钉内同定治疗颈椎病的初步临床疗效.方法:2007年3月~2008年9月我院应用颈椎前路减压植骨可吸收螺钉

  17. Computational investigations of mechanical failures of internal plate fixation.

    Science.gov (United States)

    Chen, G; Schmutz, B; Wullschleger, M; Pearcy, M J; Schuetz, M A

    2010-01-01

    This paper investigated the biomechanics of two clinical cases of bone fracture treatments. Both fractures were treated with the same locking compression plate but with different numbers of screws as well as different plate materials. The fracture treated with 12 screws (rigid fixation) failed at 7 weeks with the plate breaking; the fracture with six screws (flexible fixation) endured the entire healing process. It was hypothesized that the plate failure in the unsuccessful case was due to the material fatigue induced by stress concentration in the plate. As the two clinical cases had different fracture locations and different plate materials, finite element simulations were undertaken for each fractured bone fixed by both a rigid and a flexible method. This enabled comparisons to be made between the rigid and flexible fixation methods. The fatigue life was assessed for each fixation method. The results showed that the stress in the rigid fixation methods could be significantly higher than that in flexible fixation methods. The fatigue analyses showed that, with the stress level in flexible fixation (i.e. with fewer screws), the plate was able to endure 2000 days, and that the plate in rigid fixation could fail by fatigue fracture in 20 days. The paper concludes that the rigid fixation method resulted in serious stress concentrations in the plate, which induced fatigue failure. The flexible fixation gave sufficient stability and was better for fracture healing.

  18. Study of Bone Grafting like Cone Pedicle for Thoracic and Lumbar Fracture in GSS Internal Fixation%胸腰段椎体骨折GSS内固定术经锥弓根等植骨的研究

    Institute of Scientific and Technical Information of China (English)

    唐凯

    2015-01-01

    Objective:To research on bone grafting like cone pedicle for thoracic and lumbar fracture in GSS internal fixation.Method:From February 2011 to February 2014,60 patients with thoracic and lumbar fracture in our hospital were given the fusion treatment of GSS internal fixation of pedicle screw-rod system, bone grafting in vertebral arch and posterolateral bone grafting.Result:After the operation, these patients were given postoperative follow-up.It was found that incision of 60 cases was primary healing.The X-ray showed that their spinal sequence and physiological curvature largely returned to normal.The height of vertebral body returned to 78%- 98% of the normal height.The reset rate was as high as 98%.Improvement in pain symptom and function was over 96%.No loose or fractured screw rods and no complications of spinal cord and nerve root injury were found.Conclusion:After the research, it is found that for the operation of thoracic and lumbar fracture, the application of vertebral arch bone grafting and vertebral plate posterior bone grafting, which stabilized the front, middle and posterior column of vertebral body, can avoid fractured screw as well as rod and loose pedicle screw.At the same time, it can avoid the vertebral body lose its height and also lighten the pain of the patients.Therefore, it will be the main trend of treatment of thoracic and lumbar fracture.%目的:对胸腰段椎体骨折GSS内固定术经锥弓根等植骨的研究。方法:回顾性分析本院2011年2月-2014年2月采用GSS椎弓根钉棒系统内固定加经椎弓椎椎体内植骨及后外侧植骨融合术治疗的60例胸腰椎骨折患者的临床资料。结果:术后随访,伤口均一期愈合,X线片显示脊柱序列和生理曲度基本恢复正常,椎体高度恢复到正常椎体高度的78%~98%,复位率达到98%,疼痛症状及功能改善96%以上,无脊髓及神经根损伤加重并发症,无螺钉棒松动、断裂,无矫形丢失无脊髓及

  19. Surgical treatment of the osteoporotic spine with bone cement-injectable cannulated pedicle screw fixation: technical description and preliminary application in 43 patients

    Directory of Open Access Journals (Sweden)

    Fei Dai

    2015-02-01

    Full Text Available OBJECTIVES: To describe a new approach for the application of polymethylmethacrylate augmentation of bone cement-injectable cannulated pedicle screws. METHODS: Between June 2010 and February 2013, 43 patients with degenerative spinal disease and osteoporosis (T-score <-2.5 underwent lumbar fusion using cement-injectable cannulated pedicle screws. Clinical outcomes were evaluated using a Visual Analog Scale and the Oswestry Disability Index. Patients were given radiographic follow-up examinations after 3, 6, and 12 months and once per year thereafter. RESULTS: All patients were followed for a mean of 15.7±5.6 months (range, 6 to 35 months. The Visual Analog Scale and Oswestry Disability Index scores showed a significant reduction in back pain (p = 0.018 and an improvement in lower extremity function (p = 0.025 in patients who underwent lumbar fusion using the novel screw. Intraoperative cement leakage occurred in four patients, but no neurological complications were observed. Radiological observation indicated no loosening or pulling out of the novel screw, and bone fusion was excellent. CONCLUSIONS: The described polymethylmethacrylate augmentation technique using bone cement-injectable cannulated pedicle screws can reduce pain and improve spinal dysfunction in osteoporotic patients undergoing osteoporotic spine surgery.

  20. Transosseous osteosynthesis with annular external fixator for the treatment of long bone defect after tibial traumatic%环形外固定架骨搬运治疗胫骨创伤后大段骨缺损

    Institute of Scientific and Technical Information of China (English)

    龙超; 刘炳胜; 王玮; 沈作佳

    2013-01-01

    Objective:To investigate the efficacy of the application of transosseous osteosynthesis with annular external fixator for the treatment of traumatic large bone defects of the tibia. Methods: From 2002 to 2011,17 cases of traumatic tibial long bone defect were treated by transosseous osteosynthesis with annular external fixator including 11 males and 6 females with an average age of (31.00±2.35) years old ranging from 22 to 45 years. The length of defect was from 5 to 13.1 cm with an average of (7.50+1.01) cm. The fixed time, bone healing time and the extend length of the affected limb were observed, and the degree of recovery of limb function after surgery were assessed ccording to the Paley's limb function evaluation. Results:All patients were followed up from 12 to 48 months with an average of (30.00±2.35) months,the bone defects of 17 patients achieved bone healing. The average bone healing time was (10.10±0.59) months (8 to 15 months) ;the average time of fixed time was (14.10±0.65 ) months (12 to 16 months) ;the average extend length of the affected limb was (7.50±1.01) cm. The results of Paley's functional evaluation was excellent in 9 cases,good in 6,fair in 2. Conclusion:Transosseous osteosynthesis with annular external fixator is an effective method for treatment of large bone defects of the tibia. It is successful reconstruction of limb length, simple operation, less soft tissue injury, and is clinical worthy of promotion.%目的:探讨应用环形外固定架辅助骨搬运术治疗创伤后胫骨大段骨缺损的疗效.方法:自2002年至2011年采用骨搬运术对17例创伤性胫骨长段骨缺损进行治疗,男11例,女6例;年龄22 ~45岁,平均(31.00±2.35)岁.骨缺损范围5~13.1 cm,平均(7.50±1.01) cm.观察外固定时间、骨性愈合时间、术后患肢延长长度.术后患肢功能恢复程度参照Paley评价标准进行功能评价.结果:全部病例获随访,时间12~48个月,平均(30.00±2.35)个月.17例

  1. Fiber-matrix interface studies on bioabsorbable composite materials for internal fixation of bone fractures. I. Raw material evaluation and measurement of fiber-matrix interfacial adhesion.

    Science.gov (United States)

    Slivka, M A; Chu, C C; Adisaputro, I A

    1997-09-15

    The objective of this study was to characterize and evaluate the performance of various fiber-matrix composite systems by studying the mechanical, thermal, and physical properties of the fiber and matrix components, and by studying the fiber-matrix interface adhesion strength using both microbond and fragmentation methods. The composites studies were poly(L-lactic acid) (PLLA) matrix reinforced with continuous fibers of either nonabsorbable AS4 carbon (C), absorbable calcium phosphate (CaP), poly(glycolic acid) (PGA), or chitin. Carbon and CaP single fibers had high Young's moduli and failed in a brittle manner. PGA and chitin single fibers had relatively lower Young's moduli and relatively higher ductility. Upon in vitro hydrolysis, CaP fibers retained 17% of their tensile strength and 39% of their Young's modulus after 12 h, PCA fibers retained 10% of their tensile strength and 52% of their Young's modulus after 16 days, and chitin fibers retained 87% of their tensile strength and 130% of their Young's modulus after 25 days. PLLA films had much lower strength and Young's moduli, but much higher ductility relative to the single fibers. Using the microbond method, the initial fiber-matrix interfacial shear strength (IFSS) of C/PLLA and CaP/PLLA microcomposites was 33.9 and 12.6 MPa, respectively. Upon in vitro hydrolysis, C/PLLA retained 49% of IFSS after 15 days and CaP/PLLA retained 46% of IFSS after 6 h. Using a fiber fragmentation method, the initial IFSS of C/PLLA, CaP/PLLA, and chitin/ PLLA was 22.2, 15.6, and 28.3 MPa, respectively. The performance of carbon fibers and C/PLLA composites was superior to the other fibers and fiber/PLLA systems, but the carbon fiber was nonabsorbable. CaP had the most suitable modulus of the absorbable fibers for fixing cortical bone fracture, but its rapid deterioration of mechanical properties and loss of IFSS limits its use. PGA and chitin fibers had suitable mechanical properties and their retention for fixing cancellous

  2. 一期后路病灶清除植骨融合内固定治疗胸椎结核%ONE-STAGE POSTERIOR DEBRIDEMENT, BONE GRAFT, AND INTERNAL FIXATION FOR THORACIC TUBERCULOSIS

    Institute of Scientific and Technical Information of China (English)

    陈宣维; 林建华; 陈雷; 陈飞; 许卫红; 韦超

    2011-01-01

    Objective To evaluate the clinical effectiveness and advantages of one-stage posterior debridement, bone graft, and internal fixation for thoracic tuberculosis. Methods The data were retrospectively analysed, from 21 cases of thoracic tuberculosis undergoing one-stage posterior debridement, bone graft, and internal fixation between June 2007 and November 2009. There were 16 males and 5 females with an average age of 42.2 years (range, 22-73 years). The average disease duration was 13.2 months (range, 7-21 months). The lesions were located at the level of T5,6 (1 case), T6,7 (1 case), T8,9 (4 cases), T9,10 (3 cases), Tio, n (5 cases), Tn, 12 (6 cases), and T9-11 (1 case). According to the Frankel grading criterion, the neurological function was rated as grade B in 2 cases, grade C in 6 cases, grade D in 10 cases, and grade E in 3 cases. The preoperative Cobb angle was (26.3 ± 9.2)°. The erythrocyte sedimentation rate (ESR) was (35.9 ± 11.2) mm/1 hour. Results Thoracic tuberculosis was confirmed in postoperative pathological examination in all 21 cases. All incisions healed primarily without fistules formation. The average follow-up time for 21 patients was 16.2 months (range, 1-3 years). Bony fusion was achieved within 7-12 months (mean, 9 months) without pseudoarthrosis. No loosening and breakage of internal fixation were found, and no local recurrence occurred. The ESR decreased to (25.1 ± 8.9) mm/1 hour at 1 week postoperatively, showing significant difference when compared with preoperative value (t=5.935, P < 0.01); it decreased to (14.1± 4.6) mm/1 hour at 3 months postoperatively. According to Frankel grade, the neurological function was significantly improved at 1 year after operation (x2=13.689, P=0.003). The average Cobb angle was (17.1 ± 4.5)° at 1 years postoperatively, showing significant difference when compared with preoperative value (t=7.476, P < 0.01). Conclusion One-stage posterior debridement, bone graft, and internal fixation has a

  3. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

    A variety of test procedures for determination of anaerobic biodegradability has been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Anaerobic biodegradability of micro-pollutants is not included. Furthermore, factors import...

  4. When Planning Screw Fracture Fixation Why the 5.5 mm Screw is the Goldilocks Screw. An Observational Computer Tomographic Study of Fifth Metatarsal Bone Anatomy in a Sample of Patients.

    Science.gov (United States)

    Iselin, Lukas D; Ramawat, Sunil; Hanratty, Brian; Klammer, Georg; Stavrou, Peter

    2015-05-01

    We wanted to verify our clinical experience that the 5.5 mm screw was ideal in the majority of fifth metatarsal fracture fixation. The size of a screw is important for the successful surgical treatment of these fractures in order to obtain the maximal stability while reducing the risk for iatrogenic fracture.A sample of patients undergoing computer tomographic imaging of the foot for investigation other than fifth metatarsal pathology were recruited. The parameters of the fifth metatarsal bone anatomy were measured.These parameters of the 5.5 mm screw were correlated with this data. The upper parameter (the diameter of the threads) was 5.5 and the lower parameter (the diameter of the shank) was 4.0 mm.Twenty seven patients were recruited.The proximal third internal diameter ranged from 3.6 to 7.0 mm with a mean of 5.0 mm. 93% of the metatarsals could easily accommodate the 5.5 mm screw. Two of the metatarsals had an internal diameter of < 4 mm (7%).It is our belief that the 5.5 mm screw may be used safely in the majority of patients with fifth metatarsal fractures.

  5. Complicaciones de los tornillos de bloqueo intermaxilar en el tratamiento de las fracturas mandibulares Complications of self-tapping bone screws for maxillomandibular fixation in the treatment of jaw fracture

    Directory of Open Access Journals (Sweden)

    J. Molina Montes

    2008-08-01

    Full Text Available Durante la última década se ha introducido el tornillo de bloqueo intermaxilar como método de fijación maxilomandibular en el tratamiento de las fracturas de mandíbula. El propósito del estudio es evaluar las complicaciones de la técnica y la yatrogenia dental que derivan de su aplicación durante un periodo de 4 años. Se han revisado un total de 62 pacientes y 272 tornillos y, aunque han aparecido complicaciones, su incidencia es baja.In the last decade, self-tapping bone screws have been used widely as a temporary maxillomandibular fixation method in the treatment of jaw fractures. The purpose of the present study was to evaluate the complications of the technique and potential dental iatrogenesis over a period of 4 years. We reviewed a total of 62 patients and 272 screws. Although complications appeared, the complication rate was low.

  6. THE FUNCTIONAL OUTCOME OF MANAGEMENT OF SCHATZKER TYPE II AND III TIBIAL PLATEAU FRACTURES TREATED WITH INDIRECT ELEVATION, PERCUTANEOUS FIXATION AND BONE GRAFTING

    Directory of Open Access Journals (Sweden)

    Sheshagiri

    2016-02-01

    Full Text Available INTRODUCTION Damage to the joint is more extensive in tibia plateau fractures than the roentgenograms Indicate. It may be associated with soft tissue trauma, ligament injuries (4-33% medial Collateral ligament being the most common, meniscal injuries (20%, lateral collateral Ligament injury (3%, peroneal nerve injuries (3%. Posttraumatic arthritis is associated with residual instability or axial malalignment rather than joint depression. So we use minimally invasive approach to the depressed tibial plateau fractures (Schatzker type II & III. MATERIALS AND METHODS 32 patients were studied. They were followed up for maximum of 3yrs and a minimum of 1.5yrs with an average of 2.2yrs. Inclusion criteria included those patients with an age group between 20yrs and 60yrs, joint depression more than 3mm. Patients with open fracture, severe osteoporotic bones and with radiographic evidence of osteoarthritis are excluded from the study. CT was done in all patients. Mean age group was 28.8yrs and 19(76% were males; the mean articular depression was 11.32 mm measured in CT. Pre-op evaluation includes x-rays of the knee, stress x-rays if needed, and CT was done with 2mm limited cuts. Cancellous Bone graft was taken from opposite tibia through a 3-4cm long incision made below the tibial tuberosity over the medial aspect of the tibia. Cortical window was made in the affected limb, just enough to introduce the punch, and its position was confirmed under c-arm and depressed fragment was elevated with punch and reduction was held with k wires in subarticular plane and later two cannulated cancellous screws was introduced and the defect packed with bone grafts, Post-operatively all patients were immobilized with plaster of Paris (POP for 3 weeks and then mobilized. RESULTS The mean duration of the follow up was 2.2yrs. Results were excellent in 21 patients (84%, good 3(12% and fair in 1 patients (4% according to anatomic and functional criteria by Hohl and Luck

  7. Biodegradation and bioremediation

    DEFF Research Database (Denmark)

    Albrechtsen, H.-J.

    1996-01-01

    Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994......Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994...

  8. Correção de falhas ósseas diafisárias: trasnporte ósseo fixado com placa Corretive procedure in diaphyseal bone gaps: bone trasnpot fixated with plate

    Directory of Open Access Journals (Sweden)

    Celso Hermínio Ferraz Picado

    2007-01-01

    Full Text Available O objetivo deste estudo é descrever um novo sistema de transporte ósseo que dispensa o uso de fios transfixantes. O sistema, constituído por uma placa, um carro móvel e por um dispositivo tracionador, foi instalado na tíbia direita de 17 ovelhas para preencher um defeito ósseo de 1 cm. O transporte ósseo foi iniciado 7 dias após a cirurgia numa taxa de 0,8 mm/dia, dividido em 0,2 mm a cada 6 horas. Radiografias em ântero-posterior e perfil foram realizadas imediatamente após a cirurgia e semanalmente até o término do transporte. Em todos os 12 animais que completaram o estudo, o defeito ósseo foi preenchido com formação do regenerado e consolidação do foco alvo. O estudo demonstra que o sistema aqui apresentado realiza o transporte ósseo de maneira efetiva, eliminando o uso de fios ou pinos transfixantes.The objective of this study is to describe a new bone transport system not requiring the use of transfixating wires. The system, which is constituted by a plate, a movable conveyor and a hauling device, was set up on the right tibia of 17 sheep intending to fill a 1-cm bone gap. Bone transport started 7 days after surgery on a rate of 0.8 mm/day, divided into 0.2 mm at each 6 hours. X-ray images of anteroposterior and lateral planes were taken immediately after surgery and on a weekly basis until transport was finished. In all 12 animals completing the study, the bone gap was filled with regenerated formation and target focus consolidation. The study shows that the system presented here effectively performs bone transport, eliminating the use of transfixating wires or pins.

  9. The influence on the contact condition and initial fixation stability of the main design parameters of a self-expansion type anterior cruciate ligament fixation device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Dae [Jeonju University, Jeonju (Korea, Republic of); Oh, Chae Youn; Kim, Cheol Sang [Chonbuk National University, Jeonju (Korea, Republic of)

    2008-12-15

    This paper proposes a self-expansion type anterior cruciate ligament fixation device. The proposed fixation device provides graft fixation force by maintaining contact with the bone tunnel. Since the device maintains contact with the bone tunnel by the force that expands by the self-driven elastic force of the device, the main design parameters that determine the performance of this device are the ring thickness and expansion angle. This paper develops the three-dimensional finite element models of the fixation device and bone. By simulation with the developed finite element model, this paper studies the influence of the main design parameters of the device on the maximum stress around the ring when grasping the fixation device. Through the analysis of the stress on the bone tunnel wall when the fixation device comes in contact with the bone tunnel, this paper shows the influence of the main design parameters of the fixation device on the contact condition. In addition, through the analysis of the migration that occur upon application of the pull-out force, this paper studies the influence of the main design parameters on the initial fixation stability of the fixation device

  10. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  11. 儿童前臂双骨折选择髓内钉固定还是切开复位钢板内固定?%Both-bone forearm fractures in children Intramedullary nailing or open reduction with plate fixation?

    Institute of Scientific and Technical Information of China (English)

    Joseph R Dettori; 王簕; 杨云峰

    2011-01-01

    Six small retrospective cohort studies shed little light on whether intramedullary nailing (IMN) or open reduction internal fixation (ORIF) with plate fixation is more effective in treating both-bone forearm fractures in children. No statistically significant difference between treatment groups was found with regard to functional outcomes or the average magnitude of radial bowing.Small sample sizes may have precluded detection of statistically significant differences. In one study, a statistically significant difference was found in the average radial bow location in the IMN group as compared with both the ORIF group and normative values. Cosmetically,IMN provided significantly better results (ie, smaller incision/scar length) than ORIF as assessed by two studies. For both nonunion/delayed healing and complications, rates varied widely between studies and did not consistently favor one treatment method over the other. Randomized controlled studies with larger sample sizes and longer follow-up periods are needed to determine which treatment option is optimal. Use of validated outcomes measures is recommended.%@@ 根据6项小样本回顾性队列研究的结果,在评价髓内钉固定(IMN)和切开复位钢板内固定(ORIF)治疗儿童前臂双骨折的疗效时证据较弱.研究结果显示,在患肢功能和桡骨弓的恢复方面,两种治疗方法差异无统计学意义.由于样本量较小,本身就排除了产生统计学差异的可能性.一项研究显示,IMN组桡骨弓的顶点位置与ORIF组相比差异均有统计学意义.2项研究认为,与ORIF组相比,IMN组术后结果更好(如手术切口、瘢痕更小).在骨折不愈合或延迟愈合和并发症发生率方面,各研究结论不一,无法说明哪种方法更优.综上所述,仍需大样本的随机对照研究并进行长期随访,采用有效的评价方法,以便更好地评价哪种治疗方法更好.

  12. 前方入路病灶清除植骨融合内固定治疗颈胸段结核%Debridement and bone grafting with internal fixation via the anterior approach for treatment of cervicothoracic tuberculosis

    Institute of Scientific and Technical Information of China (English)

    蓝旭; 许建中; 刘雪梅; 葛宝丰

    2012-01-01

    Objective:To investigate the outcome of radical debridement,reconstruction with bone autograft or allograft and plate internal fixation via the anterior approach for the treatment of cervicothoracic tuberculosis. Methods: From Jun. 2000 to Dec. 2010,20 patients with cervicothoracic tuberculosis were treated by debridement and bone grafting with internal fixation via the anterior approach. They included 17 males and 3 females who ranged in age from 25 to 46 years (mean 38 years). The course of disease ranged from 3 months to 2 years (mean 12 months). The onset of the disease was chronic in all patients,with main complaints of persistent pain, and cervical stiffness and deformity accompanied with low fever, night sweating and pathologic leanness. Preoperative X-ray,CT or MRI showed that the pathologic change occurred in C7-T| segment in 10 cases,T, segment in 6 cases,T1-T3 segment in 3 cases, and T2-T3 segment inl case. The Cobb angle ranged from 25?to 60?mean 35? before surgery. The Frankel classification was as follows:2 cases at grade A,4 cases at grade B,7 cases at grade C,2 cases at grade D,and 5 cases at grade E. All the patients underwent a standard cervical approach by combined partial median steotomy and transverse steotomy through the aynostosis between the manubrium and body of the sternum to expose the lesion adequately. Radical debridement was performed ,and then a tricortical iliac crest bone autograft or allograft was placed and secured by internal fixation to reconstruct the spinal column. The change in Cobb angle and fusion of bone grafting were reexamined by X-ray regularly. The clinical symptoms and neurological function were evaluated according to NDI (neck disability index) score and Frankel classification. Results:There was no injury to blood vessels,spinal cord or recurrent nerve during surgery. All patients were followed-up from 16 to 39 (mean 25) months. The tuberculosis symptoms disappeared after surgery and there was no tuberculosis

  13. Photographic fixative poisoning

    Science.gov (United States)

    Photographic developer poisoning; Hydroquinone poisoning; Quinone poisoning; Sulfite poisoning ... Quinones Sodium thiosulfate Sodium sulfite/bisulfite Boric acid Photographic fixative can also break down (decompose) to form ...

  14. Effect of varied release kinetics of the osteogenic thrombin peptide TP508 from biodegradable, polymeric scaffolds on bone formation in vivo

    NARCIS (Netherlands)

    Hedberg, E.L.; Kroese-Deutman, H.C.; Shih, C.K.; Crowther, R.S.; Carney, D.H.; Mikos, A.G.; Jansen, J.A.

    2005-01-01

    This study was designed to assess the influence of varied release kinetics of the osteogenic thrombin peptide TP508 from osteoconductive poly(propylene fumarate)-based (PPF) composite scaffolds on bone formation in vivo. Four classes of scaffolds were constructed with different TP508 dosages (200, 1

  15. 探讨后路椎间盘摘除椎弓根钉内固定结合Cage植骨治疗腰椎间盘突出症的临床效果%Clinical Effect of Posterior Lumbar Interbody Fusion and Pedicle Screw Fixation Combined With Cage Bone Graft in the Treatment of Lumbar Disc Herniation

    Institute of Scientific and Technical Information of China (English)

    梁涛

    2016-01-01

    Objective To explore the feasibility of posterior lumbar interbody fusion and pedicle screw fixation combined with Cage bone graft in the treatment of lumbar disc herniation. Methods 86 patients with lumbar disc herniation were col ected. The patients in the study group were treated with posterior lumbar interbody fusion and pedicle screw fixation combined with Cage bone graft. The control group was treated with simple bone graft. Results There were significant differences in the treatment effect of the two groups after 6 months. Conclusion The treatment of lumbar disc herniation by posterior lumbar interbody fusion with pedicle screw fixation combined with Cage bone graft is effective and safe.%目的:探究腰椎间盘突出症使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗的可行性。方法收集腰椎间盘突出症患者86名,研究组使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗方案,对照组使用单纯植骨治疗方案。结果术后6个月两组患者治疗效果的差异具有统计学意义。结论腰椎间盘突出症使用后路椎间盘摘除椎弓根钉内固定结合 Cage 植骨治疗,具有较高的有效率和安全性。

  16. Femoral Aperture Fixation Improves Anterior Cruciate Ligament Graft Function When Added to Cortical Suspensory Fixation

    Science.gov (United States)

    Porter, Mark D.; Shadbolt, Bruce

    2016-01-01

    Background: Recommendations for bone tunnel placement during anterior cruciate ligament (ACL) reconstruction have become more precise. However, these recommendations differ neither with the choice of graft nor with the method of fixation used. The influence of the method of femoral fixation used on the biomechanical function of a soft tissue ACL graft remains unknown. Hypothesis: Our null hypothesis was that adding femoral aperture fixation to femoral cortical fixation, using the same bone tunnels, will not alter the control of anterior translation (AT) and internal rotation (IR) during ACL reconstruction using a hamstring graft. Study Design: Controlled laboratory study. Methods: A total of 22 patients with an acute isolated ACL rupture underwent reconstruction using a single-bundle autologous hamstring graft. Computer navigation was used intraoperatively to plot the AT and IR during the pivot-shift test before reconstruction, after ACL reconstruction using cortical suspensory fixation, and after the addition of femoral aperture fixation. Statistical analysis (analysis of variance) was used to compare the AT and IR during the pivot shift at each stage in the procedure. Results: Before ACL reconstruction, the mean (±SD) AT was 14.2 ± 7.3 mm and mean IR was 17.2° ± 5.5°. After reconstruction using femoral cortical suspension, these figures were significantly reduced to 6.2 ± 3.5 mm and 12.5° ± 3.20°, respectively (P < .001). The addition of the aperture fixation was associated with a further significant reduction to 4.6 ± 3.2 mm and 10.4° ± 2.7°, respectively (P < .001). Conclusion: The addition of femoral aperture fixation to suspensory fixation results in a significant reduction in both the AT and IR that occurs during the pivot-shift assessment immediately after ACL reconstruction using autologous hamstring graft. Clinical Relevance: The most precise positioning of bone tunnels during soft tissue ACL reconstruction needs to take into consideration

  17. Comparison of the effect of transplantation of fibula flap with vascular pedicle vs. Ilizarov external fixation in the treatment of nonunion of tibial bone defect%带血管蒂的腓骨瓣移植和Ilizarov外固定骨牵引术治疗胫骨骨缺损骨不连的比较

    Institute of Scientific and Technical Information of China (English)

    陈时高; 孙军锁; 景斗星; 蔡雅楠; 杨森; 王铁涛

    2016-01-01

    Objective To analyze and compare the curative effect of transplantation of fibula flap with vascular pedicle vs. Ilizarov external fixation in the treatment of nonunion of tibia bone defect. Methods The clinical data of 64 patients with nonunion of tibial bone defect from May 2009 to May 2013 were analyzed retro-spectively. From May 2009 to April 2012, 30 patients were given Ilizarov external fixation and bone traction therapy (bone traction group); from May 2012 to May 2013, 34 patients were subjected to vascularized fibula flap transplantation (fibula flap transplantation group). The medical indicators and Johner-Wruhs tibial shaft fracture efficacy evaluation criteria were compared between two groups. Results As compared with fibula flap transplantation group, operative time and hospital stay were significantly shortened in bone traction group ( P0.05). The healing time was significantly reduced in the fibula flap transplantation group as compared with bone traction group (P0.05).治疗后的Johner-Wruhs评分,腓骨瓣移植术组优良率为82.4%(28/34),骨牵引术组为60.0%(18/30),差异有统计学意义(P<0.05).结论 对比Ilizarov外固定骨牵引术,带血管蒂的腓骨瓣移植术治疗胫骨骨缺损骨不连患者具有骨折愈合时间短、疗效更佳的特点,但是其手术时间以及住院时间均显著延长.

  18. 两种不同内固定材料和植骨材料治疗胸腰椎椎体骨折的疗效分析%Effect of two different internal fixation and bone graft on patients with thoracic or lumbar spinal fracture

    Institute of Scientific and Technical Information of China (English)

    孟新文; 边江; 禹晓东

    2011-01-01

    目的:研究经后路复位内固定并行伤椎植骨对胸、腰椎骨折的治疗效果.方法:对椎体压缩性骨折和爆裂性骨折使用AF或钉棒系统复位固定后,经伤椎椎弓根向伤椎植入自固化磷酸钙人工骨和同种异体骨的治疗结果进行分析.结果:治疗432例 468椎,手术后椎体高度即刻恢复100%的319椎;95%以上80椎;90%以上60椎;80%以上的9椎.398例获得随访,随访10月~8年,伤椎均获得骨性愈合,脊柱稳定性及运动功能恢复良好.结论:胸、腰椎椎体骨折经AF或钉棒系统复位固定后,伤椎植入自固化磷酸钙人工骨和同种异体骨的疗效确切,效果优良.%Objective:To investigate the effect of two different internal fixation system and bone graft on patients with thoracic or lumbar spinal fracture. Methods: From April,2001 to June,2008, 468 body of vertebral in 432 patients suffered from compression fracture or blowout fracture were randomly selected to be treated with AF fixation system and screw - baculum fixation system, then artificial bone of calcium acid phosphate and homogeneity bone were transplanted into the vertebral body of fracture through neck of vertebra. Postoperatively, radiographic finding and clinical results were observed. Results: Instantly after operation, the height of 319 vertebral body were recovered completely ( 100% ), 80 recovered 95%, 60 recovered 90% and 9 recovered 80%. A total of 398 patients were followed - up after surgery, ranging from 10 months to 8 years. Radiographs showed all patients have got the bone union, the movement function of spine was significantly relieved and none suffered from low back pain or radicular pain. Neither complications nor instrumentation failure were observed. Conclusion:Internal fixation system and transplantation of bone graft through neck of vertebra could be recommended for treatment of thoracic or lumbar spinal fracture.

  19. Biodegradable thermogels.

    Science.gov (United States)

    Park, Min Hee; Joo, Min Kyung; Choi, Bo Gyu; Jeong, Byeongmoon

    2012-03-20

    All living creatures respond to external stimuli. Similarly, some polymers undergo conformational changes in response to changes in temperature, pH, magnetic field, electrical field, or the wavelength of light. In one type of stimuli-responsive polymer, thermogel polymers, the polymer aqueous solution undergoes sol-to-gel transition as the temperature increases. Drugs or cells can be mixed into the polymer aqueous solution when it is in its lower viscosity solution state. After injection of the solution into a target site, heating prompts the formation of a hydrogel depot in situ, which can then act as a drug releasing system or a cell growing matrix. In this Account, we describe key materials developed in our laboratory for the construction of biodegradable thermogels. We particularly emphasize recently developed polypeptide-based materials where the secondary structure and nanoassembly play an important role in the determining the material properties. This Account will provide insights for controlling parameters, such as the sol-gel transition temperature, gel modulus, critical gel concentration, and degradability of the polymer, when designing a new thermogel system for a specific biomedical application. By varying the stereochemistry of amino acids in polypeptides, the molecular weight of hydrophobic/hydrophilic blocks, the composition of the polypeptides, the hydrophobic end-capping of the polypeptides, and the microsequences of a block copolymer, we have controlled the thermosensitivity and nanoassembly patterns of the polymers. We have investigated a series of thermogel biodegradable polymers. Polymers such as poly(lactic acid-co-glycolic acid), polycaprolactone, poly(trimethylene carbonate), polycyanoacrylate, sebacic ester, polypeptide were used as hydrophobic blocks, and poly(ethylene glycol) and poly(vinyl pyrrolidone) were used as hydrophilic blocks. To prepare a polymer sensitive to pH and temperature, carboxylic acid or amine groups were introduced

  20. Surgical Revision after Sacroiliac Joint Fixation or Fusion

    Science.gov (United States)

    Holt, Timothy

    2017-01-01

    Background Minimally invasive sacroiliac joint (SIJ) fusion has been shown to be safe and effective for the treatment of SIJ dysfunction. Multiple devices are available to perform SIJ fixation or fusion. Surgical revision rates after these procedures have not been directly compared. Methods We retrospectively identified all patients in our practice who underwent SIJ fixation or fusion between 2003 and 2015. Using both chart review and focused contact with individual patients, we determined the likelihood of surgical revision. Revision rates were compared using Kaplan-Meier survival analysis. Results Thirty-eight patients underwent SIJ fixation with screws and 274 patients underwent SIJ fusion using triangular titanium implants. Four-year cumulative revision rates were 30.8% for fixation and 5.7% for fusion. Conclusions In our study, SIJ fixation with screws had a much higher revision rate compared to SIJ fusion with triangular titanium implants designed for bone adherence.

  1. Principles of intramedullary pin and wire fixation.

    Science.gov (United States)

    Howard, P E

    1991-02-01

    Knowledge and experience in the proper use of IM pins, K-wires, and orthopedic wire is a valuable asset to the veterinarian's ability to successfully repair a variety of long bone fractures. Most long bone fractures are amenable to repair with this form of fixation. When the principles of application are violated or the implants are used when contraindicated, complications often occur. Proper use of these implants results in the successful management of complex fractures to the satisfaction of both the animal owner and the veterinarian (Fig 10).

  2. Choice of the loading stress during the fracture fixation of humerus using Swain Memory Compression Bone Reduction Apparatus%天鹅记忆加压接骨器对肱骨骨折加载应力的选择

    Institute of Scientific and Technical Information of China (English)

    苏佳灿; 王瑞官; 张春才; 薛召军; 吴建国; 丁祖泉

    2005-01-01

    背景:肱骨骨折治疗中经常遇到的主要问题在于应力加载的方向与应力加载的力值.目的:分析天鹅记忆加压接骨器固定肱骨时不同应力加载的选择,为今后肱骨骨折治疗时内固定器械的放置部位、载荷的施加方向及大小等提供力学依据.设计:进行不同应力加载的条件下,构建肱骨骨折的三维有限元模型.单位:解放军第二军医大学附属长海医院骨科和同济大学生命科学与生物工程学院.材料:实验于2001-01/2003-05在解放军第二军医大学长海医院骨科实验室和同济大学生命科学与生物工程学院实验室完成.选取湿成年尸体肱骨标本和与之相对应型号的天鹅型记忆接骨器.方法:选择湿肱骨标本行CT成像得到肱骨每层横截面图像,采用大型有限元分析软件ANSYS 5.6建立肱骨、天鹅型记忆接骨器以及天鹅型记忆接骨器固定肱骨的三维模型.主要观察指标:对比不同加载方式下肱骨的受力情况,寻求临床治疗的参考数值.结果:所构建天鹅型记忆接骨器固定肱骨三维模型,逼真反映真实解剖形态及生物力学行为,同时获得不同加载方式下肱骨的受力情况.结论:天鹅型记忆接骨器固定肱骨三维有限元模型的构建,可以为肱骨正常力学行为以及骨折后内固定的力学基础研究提供精确模型.%BACKGROUND: During the therapy of the fracture of humerus, the main problem is the loading direction and power of the stress.OBJECTIVE: To analyze the choice of the different loading manners using Swain Memory Compression Bone Reduction Apparatus so as to provide the clinical evidence for the set position of the internal fixation apparatus, the loading direction and power during the therapy of the fracture of humerus.DESIGN: To construct the three-dimensional finite element model of the fracture of humerus with different loading manners.SETTING: Department of Orthopaedics of Changhai Hospital of

  3. Improved Reactive Dye-fixation in Pad-Steam Process of Dyeing Cotton Fabric Using Tetrasodium N, NBiscarboxylatomethyl- L-Glutamate

    OpenAIRE

    Awais Khatri; Mazhar Hussain Peerzada

    2012-01-01

    Pad steam process of dyeing cotton with reactive dyes is known to give lower levels of dye-fixation on the fiber because of excessive dye-hydrolysis. This research presents improved reactive dye-fixation in padsteam process of dyeing cotton found in an effort of using biodegradable organic salts to improve the effluent quality. The CI Reactive Blue 250, a bissulphatoethylsulphone dye and the Tetrasodium N, Nbiscarboxylatomethyl- L-Glutamate, a biodegradable organic salt, were used...

  4. CGF 联合骨代用品及口腔修复膜在颌骨囊肿手术中的应用%Application of CGF combined with biodegradable coral-hydroxyapatite ceramic and oral biofilm in reconstruction of bone defects after removal of jaw cysts

    Institute of Scientific and Technical Information of China (English)

    李伯友; 苏铭扬; 李阳; 林璇; 吴熙凤; 高永波

    2016-01-01

    Objective:To investigate the clinical effect of CGF combined with biodegradable coral-hydroxyapatite ceramic and oral biofilm on guiding bone regeneration after removal of jaw cysts.Methods:Forty-five cases of jaw cysts were treated by curettage.The diameter of bone defect ranged from 1.0-4.0 cm.Bone de-fects were filled with CGF and biodegradable coral-hydroxyapatite ceramic.CGF and oral repairing film The area of bone defect were covered by CGF and oral repairing film.All cases were followed-up for 3-12 months.According to the clinical observation and radiological examination,the effect of the treatment was evalua-ted.Results:Forty-five patients were healed by first intention after operation.Three months followed-up after op-eration,the line between biodegradable coral-hydroxyapatite ceramic and surrounding bone disappeared,and bone reticulate structure were observed in jaw cysts with diameter less than 2 cm.The line between coral-hydroxyapa-tite ceramic and surrounding bone were blurry with nine months followed-up.Biodegradable coral-hydroxyapatite ceramic,the new bone tissue and the surrounding bone grown well in jaw cysts with diameter greater than 2 cm in 1 years followed-up.Conclusion:CGF combined with biodegradable coralline hydroxyapatite and oral repairing film could have good effect on reconstruction of bone defects.%目的:观察浓缩生长因子( CGF)联合羟基磷灰石生物陶瓷及口腔修复膜在颌骨囊肿手术中促进骨组织愈合的临床效果。方法:45例颌骨囊肿患者行囊肿刮除术,采用浓缩生长因子及羟基磷灰石生物陶瓷混合物填充骨腔,CGF膜及口腔修复膜双层覆盖在骨缺损区表面。术后随访3~12个月,通过临床和影像学检查评估治疗效果。结果:45例患者术后伤口均为Ⅰ期愈合。直径<2 cm的骨缺损在术后3个月羟基磷灰石生物陶瓷与周围骨组织界限消失,可见正常网纹结构的骨小梁。直径>2 cm

  5. 病灶清除植骨内固定加灌注冲洗局部化疗治疗胸腰椎结核24例临床分析%Debridement Bone Graft and Internal Fixation with Irrigation and Local Chemotherapy in the Treatment of Thoracic and Lumbar Tuberculosis:Clinical Analysis of 24 Cases

    Institute of Scientific and Technical Information of China (English)

    王剑龙; 孙建锋

    2013-01-01

    Objectives To summary the curative effect of lesion clearance , bone transplantation internal fixation ,local chemotherapy and persistent local drainage on spinal tuberculosis. Methods 24 cases of spinal tuberculosis with abscess, all given systemic chemotherapy, were accepted lesion clearance, posterior (anterior) internal fixation ,auto-iliac bone graft, placing perfusion tube for local drainage and putting into a epidural catheter for local chemotherapy. Results 24 cases of spinal tuberculosis with abscess ,followed up for 6 months to 30 months, of which 23 cases had satisfactory effects,had no relapse ,had stable internal fixation without fixation relaxation and fracture, and got solid fusion within 6 months .Only one case occurred wound dehiscence one month after the surgery , and healed after debridement and wound dressing . Conclusion The curative effect of lesion clearance , bone transplantation internal fixation ,local chemotherapy and persistent local drainage had obvious effect in treatment of spinal tuberculosis. Lesion clearance bone transplantation internal fixation could effectively correct the spine deformity, stabilize the spine,promote spinal bone transplantation crasis, shorten in-bed time, walk as soon as possible,reduce complications. local chemotherapy and persistent local drainage could clear the focus away thoroughly,reduce the chance of relapse.%  目的总结病灶清除植骨内固定术加置管灌注冲洗局部化疗治疗脊柱结核的疗效。方法24例脊柱结核并脓肿患者,全部患者在全身化疗的同时,采用病灶清除(前路),后路(或前路)内固定,取髂骨植骨,病灶部位放置灌注冲洗管进行灌注冲洗和持续局部化疗,并同时置一硬膜外导管于体外,局部注射抗结核药物。结果24例脊柱结核并脓肿患者经过6~30个月随访,其中1例术后1个月出现伤口裂开,清创换药20天后痊愈。余23例疗效满意,无结核复发。所

  6. The effect on implant fixation of soaking tricalcium phosphate granules in bisphosphonate

    DEFF Research Database (Denmark)

    Jakobsen, Thomas; Baas, Jørgen; Bechtold, Joan E;

    2012-01-01

    biomechanical implant fixation and osseointegration of experimental implant grafted with β-TCP granules (Conduit) could be improved by soaking the β-TCP granules in bisphosphonate (zoledronate). In 10 dogs, a pair of titanium coated implants surrounded by a 2.5 mm gap was inserted into the proximal part of each......The use of bone grafting is a well-established way to enhance initial implant fixation in situations with reduced bone stock. Ceramic bone substitutes are inferior alternatives to autogenous or allogeneic bone graft. Improvement of bone graft substitutes is needed. We investigated whether...

  7. 脊柱结核内植物置入后基于C-反应蛋白及红细胞沉降率多样性与植骨融合时间的相关分析%C-reactive protein and erythrocyte sedimentation rate associate with bone graft union in patients with spinal tuberculosis following internal fixation

    Institute of Scientific and Technical Information of China (English)

    蓝常贡; 唐毓金; 陆敏安; 韦玮; 谢克恭; 潘生才; 卢贤哲

    2012-01-01

    背景:脊柱结核行结核病灶清除、植骨、加或不加钢板内固定后患者C-反应蛋白及红细胞沉降率变化与植骨块骨性融合时间有一定的联系.目的:分析脊柱结核内置物置入后C-反应蛋白及红细胞沉降率动态多样性和植骨融合时间的相关性.方法:60例脊柱结核患者均行结核病灶清除、自体髂骨植骨、加或不加钢板内固定治疗,其中内固定38例,无内固定22例.根据术后C-反应蛋白水平及红细胞沉降率分别分为轻度升高、中度升高、高度升高组和极度升高组.分析术后C-反应蛋白、红细胞沉降率和植骨块骨性融合时间差异性和相关性.结果与结论:①C-反应蛋白:轻度升高18例,中度升高21例,高度升高13例,极度升高8例.4组骨性愈合时间差异有非常显著性意义(P=0.003).Spearman相关分析显示相关系数为r=0.420,P=0.001,说明术后C-反应蛋白水平多样性与骨性融合时间长短呈正相关.②红细胞沉降率:轻度升高16例,中度升高20例,高度升高13例,极度升高11例.4组骨性愈合时间差异有非常显著性意义(P=0.003).Spearman相关分析显示相关系数为r=0.414,P=0.001,说明术后红细胞沉降率多样性与骨性融合时间长短呈正相关.③内固定组植骨融合时间快于无内固定组,说明即时坚强内固定有利于促进骨性愈合.%BACKGROUND: Tuberculosis clearance, bone graft, internal fixation with or without plate for patients with spinal tuberculosis always lead to C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) changes, which are associated with bone graft union time to certain degree.OBJECTIVE: To analyze the correlation between CRP, ESR and bone graft union time in patients with spinal tuberculosis.METHODS: A total of 60 patients with spinal tuberculosis underwent tuberculose focus clearance, autologous iliac bone grafting, and internal fixation without or with plate, including 38 undergoing fixation

  8. [Biodegradation of polyethylene].

    Science.gov (United States)

    Yang, Jun; Song, Yi-ling; Qin, Xiao-yan

    2007-05-01

    Plastic material is one of the most serious solid wastes pollution. More than 40 million tons of plastics produced each year are discarded into environment. Plastics accumulated in the environment is highly resistant to biodegradation and not be able to take part in substance recycle. To increase the biodegradation efficiency of plastics by different means is the main research direction. This article reviewed the recent research works of polyethylene biodegradation that included the modification and pretreatment of polyethylene, biodegradation pathway, the relevant microbes and enzymes and the changes of physical, chemical and biological properties after biodegradation. The study directions of exploiting the kinds of life-forms of biodegradation polyethylene except the microorganisms, isolating and cloning the key enzymes and gene that could produce active groups, and enhancing the study on polyethylene biodegradation without additive were proposed.

  9. Treatment of thoracolumbar fractures with vertebral body bone graft through pedicle and transpedicular fixation via fractured vertebra%伤椎置钉并椎体内植骨内固定术在胸腰椎骨折治疗中的应用

    Institute of Scientific and Technical Information of China (English)

    秦入结; 宋波; 李垠; 盛路新; 刘建; 孙晓

    2012-01-01

    目的 观察伤椎置钉并椎体内植骨内固定术在胸腰椎骨折治疗中的应用效果.方法 至少一侧椎弓根完整的胸腰椎骨折26例,予伤椎撬拨复位置钉、椎体内植骨、椎弓根内固定,据胸腰段正侧位片比较术前、术后即刻、术后6个月的椎体高度及Cobb's角,并评估脊髓神经功能和融合情况.结果 术后随访7~28个月.患者术后即刻伤椎椎体前缘高度占正常高度百分比及Cobb's角优于术前(P均<0.05);伤椎外形恢复满意;按ASIA脊髓神经功能分级,伴神经损伤者15例中,A级1例无恢复,余均改善1~3级(P均<0.05),内固定无失效,植骨皆融合.结论 伤椎置钉并椎体内植骨内固定术治疗胸腰椎骨折可重建椎体结构,增强脊柱稳定,近期疗效较好.%Objective To observe the outcome of vertebral body bone grafting throughpedicle combined with transpedicular fixation via fractured vertebra in the treatment of thoracolumbar fractures, and explore the operation methods. Methods 26 cases of thoracolumbar fractures, which had at least one side pedicle complete , were treated with posterior pedicle fixation by leverage, bone graft through pedicle and transpedicular fixation via fractured vertebra. According to the data of thoracolumbar radiograph, the anterior vertebral height and Cobb's angle of preoperation, postoperation instantly and after 6 monthswere compared. Their fusion results and neurological functions were observed. Results The follow-up period was 7 to 28 months . There were significant differences in the percentage of anterior vertebral height to the normal and Gobb's angle between preoperation and postoperation instantly (all P <0. 05). The shape of injured vertebra were restored satisfactorily . The spinal cord function was classified by ASIA's scale, it was improved 1 to 3 degree in all cases( 15 cases) of pre-operative neurological injury except of one case of grade A (all P < 0. 05). There was no case of fixation

  10. Removal of lumbar disc with cage bone graft fusion and internal fixation for the treatment of lumbar disc herniation%腰椎间盘摘除加cage植骨融合内固定治疗腰椎间盘突出症

    Institute of Scientific and Technical Information of China (English)

    张亚; 冯虎; 李健华; 刁天月; 蒋学军; 杨挺

    2016-01-01

    目的:探讨腰椎间盘摘除加cage植骨融合内固定治疗腰椎间盘突出症的临床疗效。方法对32例腰椎间盘突出症患者行腰椎间盘摘除加cage植骨融合内固定术,采用Oswestry功能障碍指数( ODI)和疼痛视觉模拟评分( VAS)对手术疗效进行评估。结果患者均获得随访,时间12~36(18±6.5)个月。患者术后疼痛均明显缓解,功能改善,术后ODI与VAS评分均较术前明显降低,差异有统计学意义( P<0.05)。术后融合节段均骨性愈合。随访期间内cage位置正常,内固定物无断裂及滑脱。结论腰椎间盘摘除加cage植骨融合内固定术能增加脊柱的稳定性及脊柱融合率,缓解患者症状及改善功能,临床疗效满意。%Objective To investigate the clinical effect of removal of lumbar disc with cage bone graft fusion and in-ternal fixation for the treatment of lumbar disc herniation. Methods 32 patients with lumbar disc herniation who un-derwent removal of lumbar disc with cage bone graft fusion and internal fixation systems. Oswestry disability index ( ODI) and visual analogue scale ( VAS) were used to evaluate the surgical effect. Results All patients were fol-lowed up for 12 ~36 ( 18 ± 6. 5 ) months. The postoperative pain was significantly relieved and function was im-proved, postoperative ODI and VAS decreased significantly comparing with that of the preoperation (P<0. 05). All fusion segments achieved solid fusion, all these implants were in good places without displacement or internal fixation failure. Conclusions Removal of lumbar disc with cage bone graft fusion and internal fixation for the treatment of lumbar disc herniation can increase the stability of the spine and the rate of fusion, significantly relieve symptoms and improve patients′function, which can obtain a satisfactory clinical effect.

  11. Plate fixation of paediatric fractures of the distal tibia and fibula.

    Science.gov (United States)

    He, Bingshu; Wang, Jun

    2012-10-01

    The role of surgery in the management of paediatric long-bone shaft fractures remains a matter of debate. We present a series of paediatric patients with unstable fractures of the distal tibia and fibula, treated with titanium plate fixation. Excellent results were obtained after plate fixation.

  12. Porous Biodegradable Metals for Hard Tissue Scaffolds: A Review

    Directory of Open Access Journals (Sweden)

    A. H. Yusop

    2012-01-01

    Full Text Available Scaffolds have been utilized in tissue regeneration to facilitate the formation and maturation of new tissues or organs where a balance between temporary mechanical support and mass transport (degradation and cell growth is ideally achieved. Polymers have been widely chosen as tissue scaffolding material having a good combination of biodegradability, biocompatibility, and porous structure. Metals that can degrade in physiological environment, namely, biodegradable metals, are proposed as potential materials for hard tissue scaffolding where biodegradable polymers are often considered as having poor mechanical properties. Biodegradable metal scaffolds have showed interesting mechanical property that was close to that of human bone with tailored degradation behaviour. The current promising fabrication technique for making scaffolds, such as computation-aided solid free-form method, can be easily applied to metals. With further optimization in topologically ordered porosity design exploiting material property and fabrication technique, porous biodegradable metals could be the potential materials for making hard tissue scaffolds.

  13. 后路经伤椎植骨内固定治疗胸腰椎骨折的疗效分析%Effect of Posterior Vertebral Bone Graft Internal Fixation for the Treatment of Thoracic and Lumbar Fracture Analysis

    Institute of Scientific and Technical Information of China (English)

    曾德清; 熊福生; 万仲贤; 喻刚; 廖华; 吴威甫

    2015-01-01

    Objective To observe the ef icacy,indication and clinical outcome of fixation via injured vertebra for the treatment of thoracolumbar fracture.Methods From March 2012 to March 2014,30 patients with thinacolumbar fracture underwent surgical procedure of reduction and pediele screw at the fracture level,X-rays and CT scans were performed after operation,Cobb angle of the injured vertebral segment,the percentage of vertebral compression,and sagit al diameter stenosis rate of the injured spinal canal were observed for radiographic evaluation.Neurological function was evaluated by the Frankel scale.Results Al patients were fol1owed-up from 12 to 36 months.There was no pseudoarticulation,solid bone fusion was achieved in al cases.Cobb angle of the injured vertebral segment was cor ected from preoperative (25.6±9.7)degree to postoperative (9.1±4.1)degree and (10.2±4.7)degree at last fol ow-up.The percentage of vertebral compression was cor ected from preoperative (48.3±10.1)%to postoperative(6.5±3.2)%and(7.5±3.7)%at last fol ow-up.Spinal canal sagit al diameter stenosis rate was cor ected from preoperative(36.9±11.2)%to postoperative(6.3±4.7)%and(6.4±4.5)%one year after operation.The spinal cord function was improved 1 to 2 degree in al patients except 1 patients of grade A.Conclusion Indirect reduction and fixation with pedicle screw to treat thoracolumbar vertebral fracture have several advantages:less trauma,less stif ness,less complications with more stable vertebral column,which can rectify or prevent kyphosis ef ectively.%目的探讨经伤椎椎弓根螺钉内固定治疗胸腰椎骨折的可行性、适应症及临床疗效。方法自2012年3月~2014年3月采用后路经伤椎植骨内固定治疗胸腰椎骨折30例,分别于术后3~5d、12个月、末次随访时复查X线片及CT,对伤椎Cobb角、椎体压缩百分比、椎管占位、内固定物状况进行随访;通过Frankel标准对脊髓神经功能进行评定。

  14. Validation of a finite element model of a unilateral external fixator in a rabbit tibia defect model.

    Science.gov (United States)

    Karunratanakul, Kavin; Kerckhofs, Greet; Lammens, Johan; Vanlauwe, Johan; Schrooten, Jan; Van Oosterwyck, Hans

    2013-07-01

    In case of large segmental defects in load-bearing bones, an external fixator is used to provide mechanical stability to the defect site. The overall stiffness of the bone-fixator system is determined not only by the fixator design but also by the way the fixator is mounted to the bone. This stiffness is an important factor as it will influence the biomechanical environment to which tissue engineering scaffolds and regenerating tissues are exposed. A finite element (FE) model can be used to predict the system stiffness. The goal of this study is to develop and validate a 3D anatomical FE model of a bone-fixator system which includes a previously developed unilateral external fixator for a large segmental defect model in the rabbit tibia. It was hypothesized that the contact interfaces between bone and fixator screws play a major role for the prediction of the stiffness. In vitro mechanical testing was performed in order to measure the axial stiffness of cortical bone from mid-shaft rabbit tibiae and of the tibia-fixator system, as well as the bending stiffness of individual fixator screws, inserted in bone. μCT-based case-specific FE models of cortical bone and SCREW-BONE specimens were created to simulate the corresponding mechanical test set-ups. The Young's modulus of rabbit cortical bone as well as appropriate screw-bone contact settings were derived from those FE models. We then used the derived settings in an FE model of the tibia-fixator system. The difference between the FE predicted and measured axial stiffness of the tibia-fixator system was reduced from 117.93% to 7.85% by applying appropriate screw-bone contact settings. In conclusion, this study shows the importance of screw-bone contact settings for an accurate fixator stiffness prediction. The validated FE model can further be used as a tool for virtual mechanical testing in the design phase of new tissue engineering scaffolds and/or novel patient-specific external fixation devices.

  15. 空心拉力螺钉加镍钛聚髌器置入内固定重建骨折髌骨的生物力学条件%Biomechanical requirement for the reconstruction of patellar fracture treated with cancellous bone screw and nickel-titanium-patellar concentrator internal fixation

    Institute of Scientific and Technical Information of China (English)

    高振巢; 刘德昌; 蔡国平

    2013-01-01

    BACKGROUND: There are various internal fixation methods for the clinical treatment of patel ar fractures, but each method has advantages and disadvantages, respectively. The selection of proper internal fixation method wil directly affect the healing time and recovery of knee joint function. OBJECTIVE: To investigate the biomechanical reconstruction effect on patel ar fracture treated with cancel ous bone screw and nickel-titanium-patel ar concentrator internal fixation. METHODS: A retrospective analysis was performed on 27 cases of acute patel ar fracture patients from January 2011 to January 2012 in the Department of Orthopedics, Jinshan Hospital, Fudan University, including 13 cases of transverse fracture, 11 cases of comminuted fracture and three cases of upper or lower pole fracture. Al the 27 patients received cancel ous bone screw and nickel-titanium-patel ar concentrator internal fixation without plaster external fixation, and then the quadriceps active contraction training was performed from the 2nd day after internal fixation, and bed knee flexion and extension exercises were performed at 1 week after internal fixation. The knee joint function was evaluated with Böstman score system. RESULTS AND CONCLUSION: Al the 27 patients were fol owed-up for 4-14 months. Incisions obtained stage Ⅰ healing, and there was no fracture fixation or shedding, wound infection, skin necrosis or other complications. The average healing time was 8.5 weeks without delayed healing. According to clinical grading scale of Böstman score system, the mean score was 27.9, included 27 cases of excel ent (81%), four cases of good (15%), one case of poor (4%), and the excel ent and good rate was 96%. The results suggest that cancel ous bone screw combined with nickel-titanium-patel ar concentrator internal fixation can maintain the advantages of traditional internal fixation method, and can avoid the disadvantages of the traditional internal fixation method.%  背景:目前

  16. Biodegradable Magnesium Alloys for Orthopaedic Applications: A Review on Corrosion, Biocompatibility and Surface Modifications.

    OpenAIRE

    Agarwal, Sankalp; Curtin, James; Duffy, Brendan; Jaiswal, Swarna

    2016-01-01

    Magnesium (Mg) and its alloys have been extensively explored as potential biodegradable implant materials for orthopaedic applications (e.g. Fracture fixation). However, the rapid corrosion of Mg based alloys in physiological conditions has delayed their introduction for therapeutic applications to date. The present review focuses on corrosion, biocompatibility and surface modifications of biodegradable Mg alloys for orthopaedic applications. Initially, the corrosion behaviour of Mg alloys an...

  17. Fixação de fraturas ilíacas em cães com parafusos, fios de aço e cimento ósseo de polimetilmetacrilato Canine iliac fracture fixation with screws, orthopedic wire and polymethylmethacrylate bone cement

    Directory of Open Access Journals (Sweden)

    Claudio Roehsig

    2008-09-01

    Full Text Available O presente trabalho teve como objetivo verificar a recuperação da locomoção e o tempo para cicatrização óssea de fraturas ilíacas fixadas com parafusos, fios de aço e cimento ósseo de polimetilmetacrilato. Dezesseis cães de ambos os sexos, com peso de 1,8 a 16kg e idade entre sete meses e 11 anos, foram submetidos à osteossíntese da fratura de ílio, provocadas por acidente automobilístico. Em dois animais, realizou-se osteossíntese bilateral, totalizando 18 ossos ilíacos operados. A abordagem ao ílio foi lateral e quando necessária estendida caudalmente através da osteotomia do trocanter maior. As fraturas foram reduzidas e, em cada segmento ósseo, foram implantados dois a três parafusos e banda de tensão com fio de aço entre os parafusos adjacentes à linha de fratura. Sobre esses implantes aplicou-se cimento ósseo misturado com cefazolina sódica e após o endurecimento prosseguiu-se com a síntese dos tecidos moles com suturas rotineiramente utilizadas na clinica cirúrgica. No período pós-operatório, foram realizadas avaliações até 90 dias após a osteossíntese e observou-se locomoção apropriada em 15 animais. Avaliações radiográficas demonstraram sinais de completa consolidação óssea entre 60 e 90 dias. Falha da estabilização ocorreu em dois casos, obrigando a reintervenção cirúrgica em um deles. A partir dos resultados obtidos, é possível concluir que, em cães com até 16kg de peso, a fixação de fraturas ilíacas utilizando parafusos cimentados com PMMA constitui uma eficiente técnica, que proporciona adequada estabilidade, precoce recuperação funcional e cicatrização óssea.The present study aimed to verify the time for locomotion recovery and bone healing in canine iliac fractures fixated with screws, orthopedic wires and methylmetacrylate bone cement. Sixteen dogs from both genders accidentally hit by a car and showing iliac fractures were included. Dogs aged from 7 months to 11

  18. [Development of biodegradable magnesium-based biomaterials].

    Science.gov (United States)

    Zhu, Shengfa; Xu, Li; Huang, Nan

    2009-04-01

    Magnesium is a macroelement which is indispensable to human bodies. As a lightweight metal with high specific strength and favorable biocompatibility, magnesium and its alloys have been introduced in the field of biomedical materials research and have a broad application prospect. It is possible to develop new type of biodegradable medical magnesium alloys by use of the poor corrosion resistance of magnesium. Bioabsorbable magnesium stents implanted in vivo could mechanically support the vessel in a short term, effectly prevent the acute coronary occlusion and in-stent restenosis, and then be gradully biodegraded and completely absorbed in a long term. Osteoconductive bioactivity in magnesium-based alloys could promote the apposition growth of bone tissue. This paper reviews the progress of magnesium and its alloys applied in bone tissue and cardiovascular stents, and the prospect of the future research of magnesium-based biomaterials is discussed.

  19. Calcium orthophosphate coatings on magnesium and its biodegradable alloys.

    Science.gov (United States)

    Dorozhkin, Sergey V

    2014-07-01

    Biodegradable metals have been suggested as revolutionary biomaterials for bone-grafting therapies. Of these metals, magnesium (Mg) and its biodegradable alloys appear to be particularly attractive candidates due to their non-toxicity and as their mechanical properties match those of bones better than other metals do. Being light, biocompatible and biodegradable, Mg-based metallic implants have several advantages over other implantable metals currently in use, such as eliminating both the effects of stress shielding and the requirement of a second surgery for implant removal. Unfortunately, the fast degradation rates of Mg and its biodegradable alloys in the aggressive physiological environment impose limitations on their clinical applications. This necessitates development of implants with controlled degradation rates to match the kinetics of bone healing. Application of protective but biocompatible and biodegradable coatings able to delay the onset of Mg corrosion appears to be a reasonable solution. Since calcium orthophosphates are well tolerated by living organisms, they appear to be the excellent candidates for such coatings. Nevertheless, both the high chemical reactivity and the low melting point of Mg require specific parameters for successful deposition of calcium orthophosphate coatings. This review provides an overview of current coating techniques used for deposition of calcium orthophosphates on Mg and its biodegradable alloys. The literature analysis revealed that in all cases the calcium orthophosphate protective coatings both increased the corrosion resistance of Mg-based metallic biomaterials and improved their surface biocompatibility.

  20. The clinical research of posterior transpedicular screw fixation combined with intervertebral bone grafting fusion in the treatment of Ⅱ degree and Ⅲ degree lumbar spondylolisthesis%后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱的临床研究

    Institute of Scientific and Technical Information of China (English)

    宁凯; 车立新; 王志刚; 李坤; 吉喆

    2012-01-01

    目的 探讨后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱临床疗效.方法 回顾性分析我院2009年1月~2011年1月收治入院的30例腰椎滑脱症患者临床资料,所有病例均为Ⅱ、Ⅲ度腰椎滑脱.患者均采用后路椎弓根螺钉内固定联合椎间植骨融合治疗,观察手术前后临床症状及滑脱恢复情况、术后复位、疗效评价、材料生物相容性、术后椎间隙高度及BFS评分.结果 30例患者术前均为Ⅱ、Ⅲ度腰椎滑脱,其中,19例行椎管、神经根管减压、复位固定、植骨融合治疗,11例只行复位固定、植骨融合治疗.获得随访30例,均超过12个月.30例椎间植骨全部融合,融合率为100%.BFS评分优良率达90.0%.结论 后路椎弓根螺钉内固定联合椎间植骨融合治疗Ⅱ、Ⅲ度腰椎滑脱,操作简便、固定可靠,是临床治疗中的一种值得推广的方法.%Objective To explore the curative effect of posterior transpedicular screw fixation combined with intervertebral bone grafting fusion in the treatment of Ⅱ degree and Ⅲ degree lumbar spondylolisthesis. Methods The clinical data of 30 patients with lumbar spondylolisthesis from January 2009 to January 2011 in our hospital were analyzed retrospectively. All cases were suffered with Ⅱ degree or Ⅲ degree lumbar spondylolisthesis. All patients were adopted posterior transpedicular screw fixation combined with intervertebral bone grafting fusion treatment. The clinical symptoms, slippage recovery condition before and after operation, postoperative restoration, therapeutic effect evaluation, material biocompatibility, postoperative intervertebral height and BFS score were observed. Results 30 patients all suffered with Ⅱ degree or Ⅲ degree lumbar spondylolisthesis before surgery, among whom 19 cases were treated with canalis vertebralis and nerve root canal decompression, reduction and fixation and bone graft fusion. Other 11 cases were

  1. Mechanical and degradation properties of biodegradable Mg strengthened poly-lactic acid composite through plastic injection molding.

    Science.gov (United States)

    Butt, Muhammad Shoaib; Bai, Jing; Wan, Xiaofeng; Chu, Chenglin; Xue, Feng; Ding, Hongyan; Zhou, Guanghong

    2017-01-01

    Full biodegradable magnesium alloy (AZ31) strengthened poly-lactic acid (PLA) composite rods for potential application for bone fracture fixation were prepared by plastic injection process in this work. Their surface/interfacial morphologies, mechanical properties and vitro degradation were studied. In comparison with untreated Mg rod, porous MgO ceramic coating on Mg surface formed by Anodizing (AO) and micro-arc-oxidation (MAO)treatment can significantly improve the interfacial binding between outer PLA cladding and inner Mg rod due to the micro-anchoring action, leading to better mechanical properties and degradation performance of the composite rods.With prolonging immersion time in simulated body fluid (SBF) solution until 8weeks, the MgO porous coating were corroded gradually, along with the disappearance of original pores and the formation of a relatively smooth surface. This resulted in a rapidly reduction in mechanical properties for corresponding composite rods owing to the weakening of interfacial binding capacity. The present results indicated that this new PLA-clad Mg composite rods show good potential biomedical applications for implants and instruments of orthopedic inner fixation.

  2. Treatment of the thoracolumbar spine fracture with posterior monosegment pedicle fixation and transpedicular impacted bone graft at injured level%单节段椎弓根固定椎体内打压植骨治疗胸腰椎压缩骨折

    Institute of Scientific and Technical Information of China (English)

    邢飞; 樊道斌; 陈宏赋; 张林胜; 朱敏

    2012-01-01

    Objective To explore the clinical effects of posterior monosegmental pedicle screw fixation in selective treatment of thoracolumbar vertebral fractures. Methods 15 patients with thoracolumbar fractures were treated with posterior monosegmental pedicle screw fixation and transpedicle impacted bone graft. The Cobb's angle and reduction of injured vertebral body height were observed. Results All cases were followed up for 6 ~ 18months. Clinical evaluation revealed that 11 cases had no pain, 4 cases with occasional pain but required no medication and all patients had a high level of satisfaction with the final results. Radiographic evaluation revealed reduction rate of the injured vertebral height was 95%. The Cobb's angle was restored from 14° ~25° to 3° ~8°. There was no implant breakage, and no signs of pseudoarthrosis were observed. Conclusions Posterior monosegmental fixation might be an adequate and effective procedure to be used in specific types of thoracolumbar spine fractures. Transpedicular impacted grafting after bone loss calculation combined with pedicle fixation has better biomechanical properties.%目的 探讨单节段椎弓根固定结合伤椎打压植骨治疗胸腰椎屈曲压缩骨折的疗效.方法 对15例胸腰椎压缩性骨折(Denis B型)患者行后路单节段经伤椎复位固定、经椎弓根伤椎打压植骨手术.测量术前术后Cobb角,计算伤椎高度恢复率,进行ODI评分,分析疗效.结果 15例患者均获随访,时间6~18个月.伤椎高度矫正率约95%,Cobb角由术前的14°~25°改善为术后的3°~8°.未出现内固定断裂、神经损伤等并发症.结论 单节段椎弓根固定椎体内植骨治疗胸腰椎压缩性骨折手术创伤小,仅固定1个运动节段;椎体内打压植骨有效解决椎体复位后产生的椎体内骨缺损.

  3. Biodegradability of plastics.

    Science.gov (United States)

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  4. Rigid internal fixation of zygoma fractures: A comparison of two-point and three-point fixation

    Directory of Open Access Journals (Sweden)

    Parashar Atul

    2007-01-01

    Full Text Available Background: Displaced fractures of the zygomatic bone can result in significant functional and aesthetic sequelae. Therefore the treatment must achieve adequate and stable reduction at fracture sites so as to restore the complex multidimensional relationship of the zygoma to the surrounding craniofacial skeleton. Many experimental biophysical studies have compared stability of zygoma after one, two and three-point fixation with mini plates. We conducted a prospective clinical study comparing functional and aesthetic results of two-point and three-point fixation with mini plates in patients with fractures of zygoma. Materials and Methods: Twenty-two patients with isolated zygomatic fractures over a period of one year were randomly assigned into two-point and three-point fixation groups. Results of fixation were analyzed after completion of three months. This included clinical, radiological and photographic evaluation. Results: The three-point fixation group maintained better stability at fracture sites resulting in decreased incidence of dystopia and enophthalmos. This group also had better malar projection and malar height as measured radiologically, when compared with the two-point fixation group. Conclusion: We recommend three-point rigid fixation of fractured zygoma after accurate reduction so as to maintain adequate stabilization against masticatory forces during fracture healing phase.

  5. A cell shrinkage artefact in growth plate chondrocytes with common fixative solutions: importance of fixative osmolarity for maintaining morphology

    Directory of Open Access Journals (Sweden)

    MY Loqman

    2010-05-01

    Full Text Available The remarkable increase in chondrocyte volume is a major determinant in the longitudinal growth of mammalian bones. To permit a detailed morphological study of hypertrophic chondrocytes using standard histological techniques, the preservation of normal chondrocyte morphology is essential. We noticed that during fixation of growth plates with conventional fixative solutions, there was a marked morphological (shrinkage artifact, and we postulated that this arose from the hyper-osmotic nature of these solutions. To test this, we fixed proximal tibia growth plates of 7-day-old rat bones in either (a paraformaldehyde (PFA; 4%, (b glutaraldehyde (GA; 2% with PFA (2% with ruthenium hexamine trichloride (RHT; 0.7%, (c GA (2% with RHT (0.7%, or (d GA (1.3% with RHT (0.5% and osmolarity adjusted to a ‘physiological’ level of ~280mOsm. Using conventional histological methods, confocal microscopy, and image analysis on fluorescently-labelled fixed and living chondrocytes, we then quantified the extent of cell shrinkage and volume change. Our data showed that the high osmolarity of conventional fixatives caused a shrinkage artefact to chondrocytes. This was particularly evident when whole bones were fixed, but could be markedly reduced if bones were sagittally bisected prior to fixation. The shrinkage artefact could be avoided by adjusting the osmolarity of the fixatives to the osmotic pressure of normal extracellular fluids (~280mOsm. These results emphasize the importance of fixative osmolarity, in order to accurately preserve the normal volume/morphology of cells within tissues.

  6. Analysis of Spinal Fixation System and Intervertebral Bone Grafting Treating Lumbar Spondylolisthesis in 30 Cases%脊椎钉棒固定系统并椎体间植骨治疗腰椎滑脱症30例分析

    Institute of Scientific and Technical Information of China (English)

    梁世勋

    2013-01-01

      目的:探讨脊椎钉棒固定系统并椎体间植骨治疗腰椎滑脱症的临床疗效。方法:对30例腰椎滑脱症患者采用后路椎弓根螺钉将滑脱椎体复位、提位,减轻椎管压力,并接受椎间植骨融合治疗。结果:30例患者接受手术治疗后麻木明显得到改善,腰腿疼痛症状消失,没有一例出现感染、植骨块移位、神经根损伤等严重并发症;完全复位率达96.67%。结论:椎弓根螺钉脊柱钉棒固定系统并结合减压植骨术是治疗椎体滑脱复位的一种有效方法,疗效确切,能够很好地维持椎间高度并且植骨融合率高,有利于患者的尽早康复。%Objective:To investigate the clinical efficacy of spinal fixation system and intervertebral bone grafting treating lumbar spondylolisthesis. Methods:30 cases of patients with lumbar spondylolisthesis were treated with posterior pedicle screw to reset the spondylolisthesis, lift and reduce pressure of canalis vertebralis, and they were accepted intervertebral bone grafting. Results:Anaesthesia was significantly improved, and symptoms of low back pain disappeared after the therapy of 30 patients receiving the operation, without serious complications of infection, bone grafting dis-placement, nerve root injury and so on;the complete reset rate was 96.67%. Conclusion:Spinal fixation system with pedicle screw combined with de-compression and bone grafting is an effective method for treating reduction of spondylolisthesis, the curative effects of which are exact, it can well maintain the height of intervertebral, and its fusion rate of bone grafting is high, in favour of patients’early rehabilitation.

  7. Computer navigated percutaneous screw fixation for traumatic pubic symphysis diastasis of unstable pelvic ring injuries

    Institute of Scientific and Technical Information of China (English)

    MU Wei-dong; WANG Hong; ZHOU Dong-sheng; YU Ling-zhi; JIA Tang-hong; LI Lian-xin

    2009-01-01

    Displaced and unstable pelvic ring injuries have been treated mainly by open reduction and internal fixation. The goal of treatment relies on restoration of pelvic anatomy with stable internal fixation, allowing early mobilization of the patient.1,2 The symphysis pubis dislocation (>25 mm) is consistent indication for anterior internal fixation.3 In most situations, the fixation of the displaced symphysis pubis requires extensive exposure, which may lead to complications including blood loss, neural or vascular injury, postoperative infections, wound healing problems and heterotopic bone formation.

  8. Biodegradable fiksasyon malzemeleri

    OpenAIRE

    Seber, Sinan

    2004-01-01

    Problems related to metallic implant had increased the interest to biodegradables. In this paper, the physical and chemical properties, degradation modalities, implant design, clinical studies with techniques, and complications of biodegradable implants, especially polylactic and polyglycolic acid, were reviewed. Also our studies, on the antibiotic delivery capacities of these implants; and the prediction of immunological reactions with our clinical experiences were presented.

  9. Hydrolytic And Enzymatic Degradation Characteristics Of Biodegradable Aliphatic Polysters

    Institute of Scientific and Technical Information of China (English)

    LI Suming

    2004-01-01

    Aliphatic polyesters, especially those derived from lactide (PLA), glycolide (PGA) and ε-caprolactone (PCL), are being investigated worldwide for applications in the field of surgery (suture material, devices for internal bone fracture fixation), pharmacology (sustained drug delivery systems), and tissue engineering (scaffold for tissue regeneration) [1,2]. This is mainly due to their good biocompatibility and variable degradability. These polymers present also a growing interest for environmental applications in agriculture (mulch films) and in our everyday life (packaging material)as the development of biodegradable materials is now considered as one of the potential solutions to the problem of plastic waste management.For both biomedical and environmental applications, it is of major importance to understand the degradation characteristics of the polymers. The hydrolytic degradation of aliphatic polyesters has been investigated by many research groups. Our group has shown that degradation of PLAGA large size devices is faster inside than at the surface. This heterogeneous degradation is due to the autocatalytic effect of carboxylic endgroups formed by ester bond cleavage. Moreover,degradation-induced morphological and compositional changes were also elucidated. In the case of PCL, the hydrolytic degradation is very slow due to its hydrophobicity and crystallinity.The enzymatic degradation of these polymers has been investigated by a number of authors. A specific enzyme, proteinase K, has been shown to have significant effects on PLA degradation. This enzyme preferentially degrade L-lactate units as opposed to D-lactate ones, amorphous zones as opposed to crystalline ones [3]. The enzymatic degradation of PCL polymers has also been investigated. A number of lipase-type enzymes were found to significantly accelerate the degradation of PCL despite its high crystallinity. In the case of PLA/PCL blends, the two components exhibited well separated crystalline domains

  10. 后路固定椎间碎骨植骨与髂骨块植骨融合术治疗退行性腰椎不稳的临床研究%Clinical study of posterior internal fixation and iliac crest or granular bone grafting lumbar interbody fusion for the treatment of the degenerative lumbar instability

    Institute of Scientific and Technical Information of China (English)

    林斌; 林秋燕; 邵泽豹

    2012-01-01

    [Objective] To compare the clinical outcome of posterior pedicle screw fixation and iliac crest or granular bone grafting lumbar interbody fusion for the treatment of degenerative lumbar instability. [ Methods] There were 75 patients with degenerative lumbar disease. They were 41 males and 34 females, aged from 27 to 68 years with an average of 55. 6 years. Clinical manifestation; there were 72 cases with lower back pain and 47 cases with intermittent claudication. All of 75 cases had leg pain, including 37 cases of unilateral kg pain, 23 cases of bilateral leg pain and 15 cases of alternative leg pair.. Fifty - seven cases were positive with straight leg raising test, 66 cases had sensory disturbance, 58 cases had movement disorders, and 45 cases had abnormal achilles tendon reflex and knee jerk reflex, and 45 cases had injuries of cauda equina. There were 32 cases with degeneration of L4、5 , 26 cases with degeneration of L5S1 , 6 cases with degeneration of L3、4, and 11 cases with degeneration more than 2 segments. They were divided into two groups randomly: iliac bone group and granular bone group. The iliac bone group were treated with decompression, internal fixation for degenerative lumbar instability with pedicle screw and interbody fusion with iliac crest grafting. The granular bone group were treated with decompression, internal fixation and with granular bone grafting fusion. All of the cases had X -ray in routine and oblique view, CT and MRI preoperatively. The Japanese Orthopedic Association (JOA) score, Oswestry Disability Index (ODI) were evaluated before and 3, 6, 12 months after surgery. And fusion situation was evaluated by reviewing the roentgenographic film. [ Results] ( I ) Significant difference of JOA score and 0D1 were founded in each group before and after surgery. But it was no significant different between two groups. (2) The loss of intervertebral height was significant different between two group before and after surgery. The loss of

  11. Improving Carbon Fixation Pathways

    OpenAIRE

    Ducat, Daniel C.; Silver, Pamela A

    2012-01-01

    A recent resurgence in basic and applied research on photosynthesis has been driven in part by recognition that fulfilling future food and energy requirements will necessitate improvements in crop carbon-fixation efficiencies. Photosynthesis in traditional terrestrial crops is being reexamined in light of molecular strategies employed by photosynthetic microbes to enhance the activity of the Calvin cycle. Synthetic biology is well-situated to provide original approaches for compartmentalizing...

  12. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  13. Evaluation of inherent toxicology and biocompatibility of magnesium phosphate bone cement.

    Science.gov (United States)

    Yu, Yonglin; Wang, Jing; Liu, Changsheng; Zhang, Bingwen; Chen, Honghong; Guo, Han; Zhong, Gaoren; Qu, Weidong; Jiang, Songhui; Huang, Huangyuan

    2010-04-01

    Magnesium phosphate cement (MPC) is a kind of novel biodegradable bone adhesive for its distinct performance. However, there is few research work concerning on the systemic biocompatibility and genetic toxicological evaluation of MPC. In this study, the investigation on the inherited toxicology of MPC including gene mutation assay (Ames test), chromosome aberration assay (micronucleus test), and DNA damage assay (unscheduled DNA synthesis test) were carried out. Fracture healing and degradation behavior were explored for the evaluation of the biocompatibility of MPC, using macroscopical histological, histomorphometrical, and scanning electron microscopical methods. The results of mutagenicity and potential carcinogenicity of MPC extracts were negative, and the animal implantation illustrated no toxicity and good resorption. The study suggested that bioresorbable MPC was safe for application and might have potential applications for physiological fracture fixation.

  14. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    Science.gov (United States)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  15. Southwick Osteotomy Stabilised with External Fixator

    Science.gov (United States)

    Grubor, Predrag; Mitkovic, Milorad; Grubor, Milan

    2014-01-01

    ABSTRACT Introduction: Epiphysiolysis of the femoral head is the most common accident occurring towards the end of pre-puberty and puberty growth. Case report: The author describes the experience in the treatment of chronic epiphysiolysis in two patients treated by Southwick osteotomy. The site is accessed by way of a 15-cm long lateral skin incision and the trochanteric region is reached through the layers. The osteotomy angles prepared beforehand on a thin aluminium model are used to mark the Southwick osteotomy site on the anterior and lateral sides at the level of the lesser trochanter. Before performing the trochanteric osteotomy, two Mitković convergent pins type M20 are applied distally and proximally, above the planned osteotomy site. A tenotomy of the iliopsas muscle is performed, and then the previously marked bone triangle is redissected up to three quarters of the width of the femur. The distal part of the femur is rotated inwards, so that the patella is turned towards the ceiling. The osteotomised fragments of the femur are adapted, repositioned and fixated by installing an external fixator on the previously placed pins. Two more pins are placed, one proximally and one distally, with a view to adequately stabilising the femur. The patient was mobile from day two after the surgery. If, after the surgery, the lead surgeon realises that there is a requirement to make a correction of 5, 10 and 15 degrees of the valgus, varus, anteversion or retroversion deformity, the correction shall be performed without surgically opening the patient, using the fixator pins. Conclusion: After performing a Southwick osteotomy it is easier to adapt, reposition and fixate the osteotomised fragments of the femur using a fixator type M20. Adequate stability allows regaining mobility quickly, which in turn is the best prevention of chondrolysis of the hip. It is possible to make post-operative valgus, varus, anteversion and retroversion corrections of 5, 10 and 15 degrees

  16. Augmentation of Pedicle Screw Fixation with Calcium Phosphate Cement

    Institute of Scientific and Technical Information of China (English)

    YANG Shu-hua; FU De-hao; LI Jin; XU Wei-hua; YANG Cao; YE Zhe-wei; ZUO Xiao-yan

    2004-01-01

    To determine whether a biodegradable calcium phosphate cement(CPC) provides significant augmentation of pedicle screw fixation or not,an in vitro biomechanical study was carried out to evaluate the biomechanical effect of CPC in the restoration and augmentation of pedicle screw fixation.Axial pullout test and cyclic bending resistance test were employed in the experiment,and polymethylmethacrylate (PMMA) was chosen as control.The results demonstrate that the pullout strengths following CPC restoration and augmentation are 74% greater on an average than those of the control group,but less than those of PMMA restoration group and augmentation group respectively (increased by 126% versus control).In cyclic bending resistance test,the CPC augmented screws are found to withstand a greater number of cycles or greater loading with less displacement before loosening,but the augmentation effect of PMMA is greater than that of CPC.

  17. Subtrochanteric femur fracture treated by intramedullary fixation

    Institute of Scientific and Technical Information of China (English)

    Zu-Bin Zhou; Song Chen; You-Shui Gao; Yu-Qiang Sun; Chang-Qing Zhang; Yao Jiang

    2015-01-01

    Purpose: To discuss surgical technique, operative efficacy and clinical outcome of intramedullary fixation in the treatment of subtrochanteric femur fractures.Methods: From February 2011 to February 2013, 76 cases of subtrochanteric femur fractures were treated by intramedullary fixation in our hospital, including 53 males and 23 females, with the age range of 37 -72 years (mean 53.5 years).According to Seinsheimer classification, there were 2 cases of type Ⅰ, 7 type Ⅱ,15 type Ⅲ, 23 type Ⅳ and 29 type Ⅴ.Firstly, all patients underwent closed reduction with the guidance of C-arm fluoroscopy in a traction table.Two cases of type Ⅰ and 3 cases of type Ⅲ fractures had ideal closed reduction followed by internal fixation.The others needed additional limited open reduction.Radiographic examination was used to evaluate callus formation and fracture healing in postoperative 1, 3, 6 and 12 months follow-up.Functional recovery was evaluated by Harris Hip Scoring (HHS) system.Results: Patients were followed up for 6-12 months.All fractures were healed except one patient with delayed union.The average bone union time was 4.5 months.According to HHS system, 65 cases were considered as excellent in functional recovery, 8 good, 2 fair and 1 poor.The proportion of the patients with excellent and good recovery was 96.05%.Conclusion: Intramedullary fixation is feasible for the treatment of subtrochanteric femur fracture.The accuracy of intraoperative reduction and surgical skill are important for the clinical outcome and the patients' prognosis.

  18. Combined application of vascularized pedicled pectoralis major clavicular periosteal flap and locking plate fixation plus bone morphogenetic protein implantation in the treatment of clavicular defect and nonunion after operation%带血管胸大肌蒂锁骨膜联合锁定钛板固定BMP植入治疗锁骨术后骨不愈合及骨缺损

    Institute of Scientific and Technical Information of China (English)

    孙强; 郑加法

    2009-01-01

    目的 探讨锁骨骨折术后骨缺损、骨折不愈合的临床特点,评价锁定钛板固定骨形态发生蛋白(bone morphogenetic protein,BMP)植入联合带血管胸大肌蒂锁骨膜转位的治疗效果.方法 2004年1月-2008年4月,锁骨骨折不愈合12例,平均年龄42.8岁,均行内固定物取出,清除骨折端纤维瘢痕及硬化骨,锁定钛板同定BMP植入,带血管胸大肌蒂锁骨膜转位覆盖,术后进行功能康复锻炼. 结果 12例患者术后均获得随访,时间8~24个月,平均1.2年,应用Constant-Murley肩关节评分系统进行评价,所有患者均在4~7个月达到临床愈合,部分患者已将内固定物取出. 结论 锁定钛板固定BMP植入联合带血管胸大肌蒂锁骨膜转位治疗锁骨骨缺损、骨不连,可取得良好的临床效果.%Objective To investigate the clinical characteristics of clavicular defect and nonunion after operation and evaluate the clinical effects of vascularized pedicled pectoralis major clavicular periosteal flap and locking plate fixation plus bone morphogenetic protein (BMP) implantation. Methods From January 2004 to April 2008, 12 patients (mean age, 42.8 years old) with clavicular defect and nonunion were treated in Zhongshan Hospital. The internal fixators were removed, and then fibrous scars and sclerotic bones were cleared. The clavicular detects were fixed with locking plate, with implantation of the BMP. The wound was covered with vascularized pedicled pectoralis major clavicular periosteal flap. Postoperative functional rehabilitation exercises were performed. Results All patients were followed up for 8-24 months (mean 1.2 years). The clinical results were evaluated by Constant-Murley scoring system. The clavicular defects were healed in all patients within 4-7 months, and the internal fixators were successfully removed from some of the patients. Conclusions Vascularized pedicled pectoralis major clavicular periosteal flap combined with locking plate fixation

  19. Estudo experimental da influência da altura do enxerto ósseo intersomático na estabilidade da fixação monossegmentar anterior da coluna cervical Experimental study of the impact of intersomatic bone graft height on the stability of anterior monosegmental fixation of the cervical spine

    Directory of Open Access Journals (Sweden)

    Jorge Alfredo Léo

    2008-06-01

    Full Text Available OBJETIVO: Estudar experimentalmente a influência da altura do enxerto ósseo intersomático da coluna cervical na estabilidade mecânica da fixação cervical anterior. MÉTODOS: Foram realizados ensaios mecânicos utilizando a coluna cervical de suínos (C3-C4. Foram formados três grupos experimentais compostos por 20 segmentos da coluna cervical (C3-C4, de acordo com o grau de instabilidade produzido e a fixação do segmento vertebral. Grupo I: retirada do disco intervertebral e colocação de enxerto intersomático. Grupo II: retirada do disco intervertebral, colocação de enxerto intersomático e fixação anterior com placa. Grupo III: retirada do disco intervertebral, secção dos ligamentos posteriores e cápsulas articulares bilateralmente, colocação do enxerto intersomático e fixação anterior com placa. Cada grupo experimental foi dividido em dois subgrupos, de acordo com a altura do enxerto ósseo utilizado (3,0mm ou 6,0mm. Os segmentos vertebrais foram submetidos a ensaios mecânicos de flexão, flexão lateral e torção em máquina universal de ensaio. Os parâmetros analisados foram força máxima (N e o momento (Nm para produzir uma deflexão preestabelecida. RESULTADOS: Não foi observada em todos os grupos experimentais diferença estatística dos valores da força máxima (N e do momento (Nm, entre as diferentes alturas (3,0mm e 6,0mm do enxerto ósseo intersomático. Conclusões: A estabilidade mecânica imediata da artrodese cervical monossegmentar anterior não sofreu influência da altura do enxerto ósseo intersomático nos ensaios de flexão, flexão lateral e torção.OBJECTIVE: To perform an experimental study of the impact of intersomatic bone graft height of the cervical spine on the mechanical stability of anterior cervical fixation. METHODS: Mechanical assays were performed using swine cervical spine (C3-C4. Three experimental groups were formed with 20 cervical spine segments (C3-C4 according to the degree

  20. Surgery Locking Compression Plate Fixation for the Treatment of Long Bone Comminuted Fracture of the Limbs%锁定加压钢板内固定手术对四肢长骨粉碎性骨折的治疗价值

    Institute of Scientific and Technical Information of China (English)

    封小东

    2016-01-01

    Objective Application in patients with limb long bone comminuted fracture internal fixation with locking compression plate (LCP) analysis, this paper discusses the clinical effect of surgical treatment. Methods In our hospital in 2014-2015 were a total of 60 patients with limbs long bone comminuted fracture as a clinical research data, the patients were randomly divided into two groups: treatment group and control group, 30 cases of patients in each group. The control group used the traditional plaster external fixation + manual reduction treatment, treatment group application of LCP internal fixation surgery reset, compare two methods of surgical treatment effect. Results After treatment, the treatment group was significantly higher than the control group, after statistics, a significant statistical significance (P<0.05). Follow-up survey was performed after the surgery, two groups of anatomical repositioning effect is good, none of the patients with complications. Treatment group patients average healing time was significantly shorter than the control group the average healing time of, the statistics, a significant statistical significance (P<0.05). Conclusion Limbs long bone comminuted fracture surgery treatment, application of locking compression plate fixation can achieve significant treatment effect, worthy of popularization and application in clinic.%目的:对四肢长骨粉碎性骨折患者应用锁定加压钢板(LCP)内固定手术治疗的临床效果进行分析探讨。方法将本院在2014-2015年收治的四肢长骨粉碎性骨折患者共计60例作为临床研究资料,将患者随机分为两组:治疗组与对照组,每组患者有30例。对照组应用传统的石膏外固定+手法复位治疗,治疗组应用 LCP 内固定手术复位,比较两种手术方法的治疗效果。结果经过治疗后,治疗组的优良率显著高于对照组,经统计,有显著的统计学意义(P<0.05)。手术后对患者进行

  1. COMBINATION OF FIXATION TECHNIQUES IN THE MANAGEMENT OF COMPLEX DISTAL RADIUS FRACTURE- OUR EXPERIENCES

    Directory of Open Access Journals (Sweden)

    Isaac Sunder Sen

    2016-10-01

    Full Text Available BACKGROUND The aim of the study is to categorically suggest the apt method of surgical technique for a particular type of distal radius fracture (Frykman’s type III-VI. Distal radius fracture are among the most common fractures of the upper extremity inspite of increased focus on regular prevention of osteoporosis, early identification and its prompt management. Most distal radius fractures are the result of low energy mechanisms that can be successfully treated either nonoperatively or with a variety of operative techniques if indicated. Complex distal radius fractures occur most commonly in high-energy injuries with extensive comminution or bone loss and associated soft tissue or vascular injuries. These high-energy fractures can present challenges in reconstructing the distal radius. Effective restoration of the bony architecture requires a thorough knowledge of distal radius anatomy, understanding of the goals of treatment, versatility in surgical approaches and familiarity with multiple fixation options. Although, majority of the extra-articular fracture without signs of instability can be successfully managed with POP immobilisation for a period of 4-5 weeks followed by active physiotherapy, other types (Frykman’s III-VI need surgical management that too with combination of surgical techniques namely augmented spanning external fixator with supplemented K-wire fixation or external fixation followed by fragment specific volar locking compression plate osteosynthesis. MATERIALS AND METHODS I have studied 50 cases of distal radius fractures classified using Frykman’s classification using combination of techniques namely augmented spanning external fixator application with K-wire supplementation and spanning external fixator application followed by volar LCP fixation in which external fixator had been used as a reduction tool in majority of the cases and external fixator had been removed after plate osteosynthesis. In some cases retained

  2. BIODEGRADABLE MICROSPHERES: A REVIEW

    Directory of Open Access Journals (Sweden)

    Kaur Dupinder

    2012-12-01

    Full Text Available Microspheres are characteristically free flowing powders consisting of proteins or synthetic polymers having a particle size ranging from 1-1000 μm. The range of techniques for the preparation of microspheres offers a variety of opportunities to control aspects of drug administration and enhance the therapeutic efficacy of a given drug. Of the many polymeric drug delivery systems, biodegradable polymers have been used widely as drug delivery systems because of their biocompatibility and biodegradability. The majority of biodegradable polymers have been used in the form of microparticles, from which the incorporated drug is released to the environment in a controlled manner. They can be employed to deliver medication in a rate-controlled and sometimes targeted manner. Medication is released from a microsphere by drug leaching from the polymer or by degradation of the polymer matrix. This review discusses characteristics and degradation behaviors of biodegradable polymers which are currently used in drug delivery.

  3. Comparative study of bone repair in mandibular body osteotomy between metallic and absorbable 2.0 mm internal fixation systems. Histological and histometric analysis in dogs: a pilot study.

    Science.gov (United States)

    Sverzut, C E; Kato, R B; Rosa, A L; Trivellato, A E; Sverzut, A T; da Silveira, K M; de Oliveira, P T

    2012-11-01

    The objective of this study was to compare the bone repair along a mandibular body osteotomy stabilized with 2.0 mm absorbable and metallic systems. 12 male, adult mongrel dogs were divided into two groups (metallic and absorbable) and subjected to unilateral osteotomy between the mandibular third and fourth premolars, which was stabilized by applying two 4-hole plates. At 2 and 18 weeks, three dogs from each group were killed and the osteotomy sites were removed and divided equally into three parts: the upper part was labelled the tension third (TT), the lower part the compression third (CT), and the part between the TT and CT the intermediary third (IT). Regardless of the treatment system, union between the fragments was observed at 18 weeks and the CT showed more advanced stages of bone repair than the TT. Histometric analysis did not reveal any significant differences among the 3 parts or systems in the distance between bone fragments at 2 weeks. Although at 18 weeks the proportions of newly formed bone did not differ among TT, IT and CT, significantly enhanced bone formation was observed in all sections for the metallic group. The patterns of repair were distinct between treatments.

  4. In vivo implant fixation of carbon fiber-reinforced PEEK hip prostheses in an ovine model.

    Science.gov (United States)

    Nakahara, Ichiro; Takao, Masaki; Bandoh, Shunichi; Bertollo, Nicky; Walsh, William R; Sugano, Nobuhiko

    2013-03-01

    Carbon fiber-reinforced polyetheretherketone (CFR/PEEK) is theoretically suitable as a material for use in hip prostheses, offering excellent biocompatibility, mechanical properties, and the absence of metal ions. To evaluate in vivo fixation methods of CFR/PEEK hip prostheses in bone, we examined radiographic and histological results for cementless or cemented CFR/PEEK hip prostheses in an ovine model with implantation up to 52 weeks. CFR/PEEK cups and stems with rough-textured surfaces plus hydroxyapatite (HA) coatings for cementless fixation and CFR/PEEK cups and stems without HA coating for cement fixation were manufactured based on ovine computed tomography (CT) data. Unilateral total hip arthroplasty was performed using cementless or cemented CFR/PEEK hip prostheses. Five cementless cups and stems and six cemented cups and stems were evaluated. On the femoral side, all cementless stems demonstrated bony ongrowth fixation and all cemented stems demonstrated stable fixation without any gaps at both the bone-cement and cement-stem interfaces. All cementless cases and four of the six cemented cases showed minimal stress shielding. On the acetabular side, two of the five cementless cups demonstrated bony ongrowth fixation. Our results suggest that both cementless and cemented CFR/PEEK stems work well for fixation. Cup fixation may be difficult for both cementless and cemented types in this ovine model, but bone ongrowth fixation on the cup was first seen in two cementless cases. Cementless fixation can be achieved using HA-coated CFR/PEEK implants, even under load-bearing conditions.

  5. Treatment of multiple base unstable fractures of metatarsal bone combined with tarsometatarsal joint injury by open reduction and internal fixation%切开复位内固定治疗多发跖骨基底部不稳定骨折合并跖跗关节损伤

    Institute of Scientific and Technical Information of China (English)

    张海波; 李勇; 蔡友芳

    2013-01-01

    [Objective] To explore the therapy and the clinical effectiveness of open reduction and internal fixation in the treatment of multiple base unstable fractures of metatarsal bone combined with tarsometatarsal joint injury. [ Method] From January 2003 to July 2001,35 patients with multiple base unstable fractures of metatarsal bone combined with tarsometatarsal joint injuries underwent open reduction and internal fixation. There were 22 males and 13 females with an average age of 37.4 years (range,20 -58 years) ,with total of 89 base fractures. There were 9 cases in the second to third metatarsal bone,7 in the third to fourth metatarsal bone and 19 in the second to fourth metatarsal bone. The classification of tarsometatarsal joint injury showed that there were 2 case of simple middle column ,7 cases of inner and middle columns, 10 cases of lateral and middle colums ,16 cases of three columns. The second and third base fractures of metatarsal bone were treated with transarticular fixation by miniplate. [Result]All the patients were followed up,the duration ranged from 12 to 30 months (averaged 22. 5 months). No complications such as wound infection, skin necrosis and fixture breakage were found postoperatively. The clinical fracture healing time was 8 to 17 weeks (mean ,13.9 weeks). The results were excellent in 11 cases, good in 18 cases, fair in 4 cases, and poor in 2 cases according to American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score system,with excellent and good result rate of 82. 9%. [ Conclusion ] The anatomical reduction and stable fixation of tarsometatarsal joint and metatarsal base are also important to rebuild the function of foot, can reduce incidence rate of osteoarthritis at midfoot and obtain very good clinical effect. Reasonable internal fixation should be selected according to injury type.%[目的]探讨切开复位内固定治疗多发跖骨基底部不稳定骨折合并跖跗关节损伤的方法及临床疗效.[方法]2003年1

  6. Mechanical evaluation of external skeletal fixator-intramedullary pin tie-in configurations applied to cadaveral humeri from red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Van Wettere, Arnaud J; Redig, Patrick T; Wallace, Larry J; Bourgeault, Craig A; Bechtold, Joan E

    2009-12-01

    Use of external skeletal fixator-intramedullary pin (ESF-IM) tie-in fixators is an adjustable and effective method of fracture fixation in birds. The objective of this study was to determine the contribution of each of the following parameters to the compressive and torsional rigidity of an ESF-IM pin tie-in applied to avian bones with an osteotomy gap: (1) varying the fixation pin position in the proximal bone segment and (2) increasing the number of fixation pins in one or both bone segments. ESF-IM pin tie-in constructs were applied to humeri harvested from red-tailed hawks (Buteo jamaicensis) (n=24) that had been euthanatized for clinical reasons. Constructs with a variation in the placement of the proximal fixation pin and with 2, 3, or 4 fixation pins applied to avian bone with an osteotomy gap were loaded to a defined displacement in torque and axial compression. Response variables were determined from resulting load-displacement curves (construct stiffness, load at 1-mm displacement). Increasing the number of fixation pins from 1 to 2 per bone segment significantly increased the stiffness in torque (110%) and compression (60%), and the safe load in torque (107%) and compression (50%). Adding a fixation pin to the distal bone segment to form a 3-pin fixator significantly increased the stiffness (27%) and safe load (20%) in torque but not in axial compression. In the configuration with 2 fixation pins, placing the proximal pin distally in the proximal bone segment significantly increased the stiffness in torque (28%), and the safe load in torque (23%) and in axial compression (32%). Results quantified the relative importance of specific parameters affecting the rigidity of ESF-IM pin tie-in constructs as applied to unstable bone fracture models in birds.

  7. Treatment of Gustilo grade Ⅲ leg fractures by external fixation associated with limited internal fixation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-qiang; ZHENG Hong-yu; WANG Bing; HUANG He; HE Fei; ZHAO Xue-ling

    2010-01-01

    Objective: To explore the clinical ef-fects of external fixation associated with limited internal fixa-tion on treatment of Gustilo grade Ⅲ leg fractures.Methods: From July 2006 to December 2008, 40 cases of Gustilo grade Ⅲ leg fiactures were emergently treated in our unit with external fixation frames.Soft tissue injuries were grouped according to the Gustilo classification as ⅢA in 17 cases, ⅢB in 13 cases, and ⅢC in 10 cases.All the patients were debrided within 8 hours, and then fracture reposition was preformed to reestablish the leg alignment.Limited internal fixation with plates and screws were per-formed on all the Gustilo Ilia cases and 10 Gustilo ⅢB cases at the first operation.But all the Gustilo ⅢC cases and 3 Gustilo ⅢB cases who had severe soft tissue injuries and bone loss only received Vacuum-sealing drainage (VSD).Broad-spectrum antibiotics were regularly used and VSD must be especially maintained easy and smooth for one week or more after operation.Limited internal fixation and transplanted free skin flaps or adjacent musculocutaneous flaps were not used to close wounds until the conditions of the wounds had been improved.Results: The first operations were completed within 90-210 minutes (170 minutes on average).The blood trans-fusions were from 400 ml to 1500 ml (those used for anti-shock preoperatively not included).All the 40 patients in this study were followed up for 6-28 months, 20.5 months on average.The lower limb function was evaluated accord-ing to the comprehensive evaluation standards of leg func-tion one year after operation and the results of 28 cases were excellent, 9 were good and 3 were poor.Conclusion: External fixation associated with limited internal fixation to treat Gustilo grade Ⅲ leg fractures can get satisfactory early clinical therapeutic effects.

  8. Bone tumor

    Science.gov (United States)

    Tumor - bone; Bone cancer; Primary bone tumor; Secondary bone tumor; Bone tumor - benign ... The cause of bone tumors is unknown. They often occur in areas of the bone that grow rapidly. Possible causes include: Genetic defects ...

  9. Novel anterior cruciate ligament graft fixation device reduces slippage.

    Science.gov (United States)

    Lopez, Mandi J; Borne, Allen; Monroe, W Todd; Bommala, Prakash; Kelly, Laura; Zhang, Nan

    2013-01-01

    Clinically significant laxity occurs in 10%-30% of knees after anterior cruciate ligament reconstruction. Graft slippage and tension loss at the hamstring graft tibial fixation site during and after reconstruction surgery contribute to postoperative joint laxity and are detrimental to long-term knee stability and graft properties. Limiting graft slippage will reduce associated complications. We sought to compare the in vitro mechanical properties and in vivo joint stabilization, postoperative limb use, and graft incorporation of the novel GraftGrab™ (GG) device designed to reduce hamstring graft tibial fixation slippage with the commercially available bioabsorbable Bio-Post™ and spiked washer (BP). Mechanical testing was performed on canine tibia-hamstring graft constructs to quantify initial fixation properties. In vivo joint stabilization, postoperative limb use and graft incorporation of hamstring graft reconstructions were determined in a canine model. Outcomes included tibial translation and ground reaction forces preoperatively and 4 and 8 weeks postoperatively, three-dimensional graft and bone tunnel dimensions at the latter two time points, and graft-bone microstructure, as well as mechanical properties 8 weeks after implantation. Immediately after fixation, all grafts slipped from the BP constructs versus about 30% of GG constructs. In vivo limb use remained low, and tibial translation increased with time in the BP cohort. These results together confirm that initial graft slippage is lower with GG versus BP extracortical hamstring graft tibial fixation. In addition, postoperative recovery and joint stability are more consistent with the GG. This information supports the GG as an alternative to extracortical tibial hamstring graft fixation that has procedural advantages over current implants and reduces graft failure from slippage.

  10. Biodegradable nanofiber-membrane for sustainable release of lidocaine at the femoral fracture site as a periosteal block: In vitro and in vivo studies in a rabbit model.

    Science.gov (United States)

    Chou, Ying-Chao; Cheng, Yi-Shiun; Hsu, Yung-Heng; Yu, Yi-Hsun; Liu, Shih-Jung

    2016-04-01

    The aim of this study was to evaluate the efficacy of a biodegradable, lidocaine-embedded, nanofibrous membrane for the sustainable analgesic release onto fragments of a segmental femoral fracture site. Membranes of three different lidocaine concentrations (10%, 30%, and 50%) were produced via an electrospinning technique. In vitro lidocaine release was assessed by high-performance liquid chromatography. A femoral segmental fracture, with intramedullary Kirschner-wire fixation and polycaprolactone stent enveloping the fracture site, was set-up in a rabbit model for in vivo assessment of post-operative recovery of activity. Eighteen rabbits were randomly assigned to three groups (six rabbits per group): group A comprised of rabbits with femoral fractures and underwent fixation; group B comprised of a comparable fracture model to that of group A with the implantation of lidocaine-loaded nanofibers; and group C, the control group, received only anesthesia. The following variables were measured: change in body weight, food and water intake before and after surgery, and total activity count post-surgery. All membranes eluted effective levels of lidocaine for more than 3 weeks post-surgery. Rabbits in group B showed faster recovery of activity post-operatively, compared with those in group A, which confirmed the pain relief efficacy of the lidocaine-embedded nanofibers. Nanofibers with sustainable lidocaine release have adequate efficacy and durability for pain relief in rabbits with segmental long bone fractures.

  11. Biodegradable mesoporous delivery system for biomineralization precursors

    Science.gov (United States)

    Yang, Hong-ye; Niu, Li-na; Sun, Jin-long; Huang, Xue-qing; Pei, Dan-dan; Huang, Cui; Tay, Franklin R

    2017-01-01

    Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration. PMID:28182119

  12. Gelation and biocompatibility of injectable alginate-calcium phosphate gels for bone regeneration

    NARCIS (Netherlands)

    Cardoso, D.A.; Beucken, J.J.J.P van den; Both, L.L.; Bender, J.; Jansen, J.A.; Leeuwenburgh, S.C.G.

    2014-01-01

    An emerging approach toward development of injectable, self-setting, and fully biodegradable bone substitutes involves the combination of injectable hydrogel matrices with a dispersed phase consisting of nanosized calcium phosphate particles. Here, novel injectable composites for bone regeneration h

  13. Immunological Response to Biodegradable Magnesium Implants

    Science.gov (United States)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  14. Eighth international congress on nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  15. The role of AO external fixation in proximal femoral osteotomies in the pediatric neuromuscular population.

    Science.gov (United States)

    Handelsman, John E; Weinberg, Jacob; Razi, Afshin; Mulley, Debra A

    2004-09-01

    Internal fixation in proximal femoral osteotomies using traditional devices may be sub-optimal in children with neuromuscular disorders who have small or osteopenic bone. In this population, between 1988 and 2000, we performed 36 proximal femoral varus osteotomies in 28 patients. These were controlled by the AO external fixator. The average age at surgery was 7 years (range, 2-13 years). A mean varus correction of 34 degrees (range, 15-90 degrees) was obtained. Complications consisted of one superficial pin tract infection, one skin breakdown, and one non-union. Other than the non-union, all osteotomies were stable at the time of the fixator removal. The AO external fixator is an effective alternative in maintaining corrective proximal femoral osteotomies in children with fragile bones.

  16. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization. PMID:28071745

  17. Molecularly Imprinted Biodegradable Nanoparticles

    Science.gov (United States)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  18. 微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折%Open reduction and miniplate fixation with autogenous cancellous bone graft for comminuted talar neck fractures

    Institute of Scientific and Technical Information of China (English)

    魏世隽; 蔡贤华; 刘曦明; 陈家; 张志文; 汪波

    2013-01-01

    目的 探讨切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折的手术方法及疗效.方法 2010年1月~2012年1月,对我院收治的15例闭合性距骨颈粉碎性骨折患者,根据Hawkins分型:Ⅱ型11例,Ⅲ型4例.术前常规行CT三维重建明确骨折类型和粉碎程度,择期行切开复位微型接骨板内固定加自体松质骨移植术.术后定期复查X片及CT观察骨折愈合情况,并记录相关并发症,采用Hawkins评分标准评估疗效.结果 本组14例获得随访,随访时间12~24m,,平均16.4m.术后外侧切口边缘部分坏死1例,经局部清创换药后治愈,无并发感染,骨折均在8~12w内获得愈合,平均愈合时间11.3w,无畸形愈合发生,距骨体部分坏死1例(Ⅲ型),轻度创伤性关节炎3例(Ⅱ型1例,Ⅲ型2例),末次随访时未发现内固定松动断裂.Hawkins 评分:优7例(Ⅱ型),良5例(Ⅱ型4例,Ⅲ型1例),可2例(Ⅲ型).结论 采用切开复位微型接骨板内固定结合自体松质骨移植治疗距骨颈粉碎性骨折,术中可获得满意复位,牢靠的内固定可有效维持骨折复位,自体松质骨移植可促进骨折愈合,是治疗距骨颈粉碎性骨折的有效方法.%Objective To evaluate the surgical technique and clinical outcome of open reduction and miniplate fixation with autogenous cancellous bone graft for comminuted talar neck fractures.Method 15 patients with closed comminuted talar neck fractures were included between Jan 2010 and Jan 2012.According to Hawkins classification,11 cases were type Ⅱ fractures and 4 cases type Ⅲ fractures.All cases were evaluated carefully with X-ray and CT scan preoperatively to define the type and displacement of fractures.Open reduction and miniplate fixation with autogenous cancellous bone graft was performed until the swelling of soft tissue was vanished.The surgical wound healing was assessed after the surgery.X-ray and CT scan were taken in the follow

  19. Effect of PFNA fixation combined with salmon calcitonin in the treatment of senile femoral intertrochanteric fracture and the influence on bone mineral density%PFNA固定联合鲑鱼降钙素治疗老年股骨粗隆间骨折的效果及对骨密度的影响

    Institute of Scientific and Technical Information of China (English)

    应挺君

    2015-01-01

    目的:研究股骨近端防旋髓内钉(PFNA)内固定与鲑鱼降钙素(SCT)联合治疗老年股骨粗隆间骨折的效果及其对骨密度(BMD)的影响。方法将老年股骨粗隆间骨折患者82例随机分成SCT组与对照组,各41例。两组均行PFNA内固定术,对照组术后应用钙尔奇D600,SCT组在对照组的基础上加用SCT,比较两组的手术时间、术中出血量、术后住院时间及骨折愈合时间等手术指标,随访比较两组手术前后Harris评分、视觉模拟评分(VAS)、BMD以及髋关节功能。结果 SCT组的住院时间与骨折愈合时间明显短于对照组,VAS降低较对照组明显(P0.05)。结论 PFNA内固定治疗老年股骨粗隆间骨折具有显著效果,配合SCT治疗可提高BMD,促进骨折愈合,改善患者的生活质量。%Objective To investigate the efficacy of PFNA fixation combined with salmon calcitonin (SCT) in the treat-ment of senile femoral intertrochanteric fracture and the effects on bone mineral density (BMD). Methods 82 cases of senile femoral intertrochanteric fracture patients were randomly divided into SCT group and control group, with 41 cas-es in each group. Both groups underwent PFNA fixation, the control group received caltrate D600 treatment, SCT group received SCT on the basis of the control group, the surgical indexes such as operative time, blood loss, hospitai stay time and bone healing time of the two groups were compared, the Harris score, VAS score, BMD and hip function be-fore and after surgery of the two groups were followed and compared. Results The hospital stay time and bone healing time in SCT group was significantly shorter than the control group, and the VAS reduction was significantly better than the control group (P0.05). Conclusion PFNA fixation in the treatment of senile femoral intertrochanteric fracture has a signif-icant effect, combined with salmon calcitonin can improve BMD, promote healing and improve

  20. Treatment of anterior decompression, bone grafting and internal fixation combined with coblation neucleoplasty for patients with cervical spondylosis involved multilevel%前路减压植骨内固定联合髓核成形术治疗多节段受累颈椎病

    Institute of Scientific and Technical Information of China (English)

    张非; 李青; 张爱明; 梁道臣

    2013-01-01

    目的:探讨前路减压植骨内固定联合等离子髓核成形术治疗多节段受累颈椎病的临床效果。方法回顾性分析2012年3月至12月中山市人民医院采用前路减压植骨内固定结合等离子髓核成形术治疗的30例多节段受累颈椎病患者的临床资料,采用日本骨科学会(JOA)评分对术后临床症状改善情况进行评价。结果30例患者均获得有效随访,随访时间4~9个月(平均6.8个月)。患者术前不适症状均有不同程度改善,无神经功能加重及内固定松动、骨笼脱出等严重并发症发生。术后3个月JOA评分为(14±1)分,较术前的(10±2)分明显改善(t =8.143,P=0.000),JOA改善率为45%。结论前路减压植骨内固定结合等离子髓核成形术治疗多节段受累颈椎病近期效果稳定,并发症少。%Objective To explore clinical effect of anterior decompression, bone grafting and internal fixation combined with coblation neucleoplasty in the treatment of multilevel cervical spondylosis. Methods Clinical data of 30 patients with multilevel cervical spondylosis from March 2012 to December 2012 were retrospectively analyzed and all of them were treated by mono-segmented cervical anterior decompression, bone grafting and internal fixation combined with coblation neucleoplasty in Zhongshan People's Hospital. Clinical effects were evaluated by Japanese Orthopaedic Association (JOA) score. Results All patients obtained follow-up with the average time of 6.8 months (4-9 months). Discomfort symptoms were improved after the operation. No nerve function aggravation occurred, also, no serious complications such as internal fixation loosening or cage pull-out had happened. Compared to preoperative JOA score, JOA score at 3 months postoperatively was improved from (10 ± 2) to (14 ± 1) (t = 8.143,P = 0.000), JOA improvement rate was 45%. Conclusions Mono-segmented cervical anterior decompression, bone graft fusion

  1. 自固化磷酸钙人工骨植骨联合可塑形钛板内固定治疗 Sanders Ⅲ,Ⅳ型跟骨骨折%Autosetting Calcium Phosphate Cement Bone-Grafting and Internal Fixation with Shaping Titanium Plate for Treatment of SandersⅢ,ⅣCalcaneal Fractures

    Institute of Scientific and Technical Information of China (English)

    韩振学; 李志仙

    2014-01-01

    [ ABSTRACT] Objective To investigate the curative effect of Sanders Ⅲ,Ⅳ calcaneal fractures by autosetting calcium phosphate cement bone-grafting and internal fixation with shaping titanium plate.Methods Twenty-eight cases(28 feet) SandersⅢ,Ⅳcalcaneal frac-tures adopted open reduction with shaping titanium plate internal fixation combined with autosetting calcium phosphate cement bone-grafting, the shaping titanium plate were placed at the outward of calcaneus,reset evaluation of calcaneal fractures by measuring Bohler's Angle,Gis-sane's Angle in postoperation.Results All patients were followed up,postoperative skin necrosis in 2 cases and sural nerve injury in 1 case. After 6 months,Bohler's Angle in 20 foot≥35°,in 8 foot≥30°,Gissane Angle fully recovered to normal range and calcaneal varus deformity on axial were not seen.Fracture healing time was 2~3 months,according to Maryland foot scoring system,treatment effects of all patients were as follows:excellent in 15 feet,good in 5 feet,normal in 3 feet and poor in 2 feet,the total excellent and good rate was 83.7%,the excel-lent and good rate ofⅣtype was 56.2%.Conclusion The treatment of SandersⅢ,Ⅳcalcaneal fractures by autosetting calcium phosphate cement bone-grafting and internal fixation with shaping titanium plate is simple and its curative effect is satisfied.%目的:探讨自固化磷酸钙人工骨植骨联合可塑形钛板内固定治疗Sanders Ⅲ,Ⅳ型跟骨骨折的疗效。方法对28例(28足) SandersⅢ,Ⅳ型跟骨骨折均采用切开复位可塑形钛板固定联合自固化磷酸钙人工骨治疗,跟骨外侧放置可塑形钛板,术后测量Bohler's 角、Gissane's角,评价跟骨骨折的复位情况。结果所有患者均得到随访,术后皮缘坏死2例,腓肠神经损伤1例。术后6个月Bohler's 角20足≥35°,8足≥30°,Gissane角全部恢复至正常范围,轴位片上未见跟骨内翻畸形。骨折愈合时间2~3个月,

  2. Influence of internal fixation systems on radiation therapy for spinal tumor.

    Science.gov (United States)

    Li, Jingfeng; Yan, Lei; Wang, Jianping; Cai, Lin; Hu, Dongcai

    2015-07-08

    In this study, the influence of internal fixation systems on radiation therapy for spinal tumor was investigated in order to derive a theoretical basis for adjustment of radiation dose for patients with spinal tumor and internal fixation. Based on a common method of internal fixation after resection of spinal tumor, different models of spinal internal fixation were constructed using the lumbar vertebra of fresh domestic pigs and titanium alloy as the internal fixation system. Variations in radiation dose in the vertebral body and partial spinal cord in different types of internal fixation were studied under the same radiation condition (6 MV and 600 mGy) in different fixation models and compared with those irradiated based on the treatment planning system (TPS). Our results showed that spinal internal fixation materials have great impact on the radiation dose absorbed by spinal tumors. Under the same radiation condition, the influence of anterior internal fixation material or combined anterior and posterior approach on radiation dose at the anterior border of the vertebral body was the greatest. Regardless of the kinds of internal fixation method employed, radiation dose at the anterior border of the vertebral body was significantly different from that at other positions. Notably, the influence of posterior internal fixation material on the anterior wall of the vertebral canal was the greatest. X-ray attenuation and scattering should be taken into consideration for most patients with bone metastasis that receive fixation of metal implants. Further evaluation should then be conducted with modified TPS in order to minimize the potentially harmful effects of inappropriate radiation dose.

  3. Traumatic lumbar hernia repair: a laparoscopic technique for mesh fixation with an iliac crest suture anchor.

    Science.gov (United States)

    Links, D J R; Berney, C R

    2011-12-01

    Traumatic lumbar hernia (TLH) is a rare presentation. Traditionally, these have been repaired via an open approach. Recurrence can be a problem due to the often limited tissue available for mesh fixation at the inferior aspect of the hernia defect. We report the successful use of bone suture anchors placed in the iliac crest during transperitoneal laparoscopy for mesh fixation to repair a recurrent TLH. This technique may be particularly useful after previous failed attempts at open TLH repair.

  4. Ⅰ期手术经后路病灶清除内固定治疗儿童胸椎结核%One-stage debridement and bone grafting with internal fixation via posterior approach for treatment of children thoracic spine tuberculosis

    Institute of Scientific and Technical Information of China (English)

    蓝旭; 许建中; 罗飞; 刘雪梅; 葛宝丰

    2013-01-01

    目的:探讨Ⅰ期手术经后路结核病灶清除植骨融合内固定治疗儿童胸椎结核的效果.方法:2005年6月至2010年12月采用病灶清除植骨融合内固定治疗儿童胸椎结核9例,其中男7例,女2例;年龄3~12岁,平均7岁;病史3个月~1年,平均6个月.患儿均有不同程度胸背痛、肋间神经痛以及脊柱后凸畸形,同时伴有低热、盗汗、消瘦等全身症状.术前X线片、CT、MRI检查提示病变部位多发生于T4-T9节段.胸段后凸角35°~72°,平均48.2°.术前脊髓功能ASIA分级:B级2例,C级5例,D级2例.术后定期复查X线片了解后凸角变化和椎间植骨融合情况,采用ASIA分级评定术后脊髓功能恢复情况.结果:术中无大血管或脊髓损伤,术后随访16~38个月,平均24个月.所有患儿结核症状消失,无结核复发、切口感染、窦道形成或内固定失败等并发症,复查血沉正常.术后4~8个月复查X线片提示椎间植骨均获骨性愈合,内固定位置正常.最后随访后凸角12°~30°,平均19.5°,脊髓功能ASIA分级:C级2例,D级2例,E级5例.脊髓功能均有不同程度改善.结论:Ⅰ期经后路清除胸椎结核病灶彻底,椎管减压可靠,矫形效果显著,行自体或同种异体骨植骨钉棒系统内固定可有效重建胸段脊柱的稳定性.%Objective:To investigate the outcome of the children with thoracic spine tuberculosis who underwent radical debridement,reconstruction with bone autograft or allograft and internal fixation via posterior approach. Methods: From June 2005 to December 2010,9 children with thoracic spine tuberculosis underwent radical debridement,reconstruction with bone autograft or allograft and internal fixation via posterior approach including 7 males and 2 females with an average age of 7 years old ranging from 3 to 12 years. The course of the disease ranged from 3 months to 1 year (averaged 6 months). All the patients had continuous thoracic and back pain

  5. A Preliminary Study of the Osteogenic Potential of a Biodegradable Alloplastic-Osteoinductive Alloimplant

    Science.gov (United States)

    1987-06-01

    Glowacki, J., and Mulliken, J. B.: Demineralized bone implants. Clin. Plast. Surg. 12:233, 1985. 12. Higashi, S., Yamamuro , T., Nakamura, T., Ikada... Yamamuro , T., Nakamura, T. , Ikada, Y., Hyon, p S. H., and Jamshidi, K.: Polymer-hydroxyapatite composites for biodegradable bone fillers

  6. Green and biodegradable electronics

    Directory of Open Access Journals (Sweden)

    Mihai Irimia-Vladu

    2012-07-01

    Full Text Available We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials suggest they will be useful in biofunctional electronics; demonstrating functions that would be inaccessible for traditional inorganic compounds. Such materials may lead to fully biodegradable and even biocompatible/biometabolizable electronics for many low-cost applications. This review highlights recent progress in these classes of material, covering substrates and insulators, semiconductors, and finally conductors.

  7. Rigid internal fixation of zygoma fractures: A comparison of two-point and three-point fixation

    OpenAIRE

    2007-01-01

    Background: Displaced fractures of the zygomatic bone can result in significant functional and aesthetic sequelae. Therefore the treatment must achieve adequate and stable reduction at fracture sites so as to restore the complex multidimensional relationship of the zygoma to the surrounding craniofacial skeleton. Many experimental biophysical studies have compared stability of zygoma after one, two and three-point fixation with mini plates. We conducted a prospective clinical study comparing...

  8. The Role of Minimally Invasive Plate Osteosynthesis in Rib Fixation: A Review.

    Science.gov (United States)

    Bemelman, Michael; van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-02-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950's, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation. Since the introduction of plate fixation for fractures, several plates and screws have been developed, all with their own characteristics. To accomplice more fracture stability, it was thought the bigger the plate, the better. The counter side was a compromised blood supply of the bone, often resulting in bone necrosis and ultimately delayed or non-union. With the search and development of new materials and techniques for fracture fixation, less invasive procedures have become increasingly popular. This resulted in the minimally invasive plate osteosynthesis (MIPO) technique for fracture fixation. With the MIPO technique, procedures could be performed with smaller incisions and thus with less soft tissue damage and a better preserved blood supply. The last 5 years rib fixation has become increasingly popular, rising evidence has become available suggesting that surgical rib fixation improves outcome of patients with a flail chest or isolated rib fractures. Many surgical approaches for rib fixation have been described in the old literature, however, most of these techniques are obscure nowadays. Currently mostly large incisions with considerable surgical insult are used to stabilize rib fractures. We think that MIPO deserves a place in the surgical treatment of rib fractures. We present the aspects of diagnosis, preoperative planning and operative techniques in regard to MIPO rib fixation.

  9. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  10. Shape modifications of porous hydroxyapatite prostheses to improve rigid implant fixation: Experience in 12 cases

    Science.gov (United States)

    Rienzo, Alessandro Di; Iacoangeli, Maurizio; di Somma, Lucia G. M.; Alvaro, Lorenzo; Nocchi, Niccolò; Scerrati, Massimo

    2012-01-01

    Background: Various methods of fixation have been described for custom made hydroxyapatite cranial implants. Their poor malleability limits most of the common used fixation techniques because of the high risk of cranioplasty's fracturing or higher exposure to infections. We present our experience with a new fixation technique, based on an appositely premodified hydroxyapatite implants. Methods: In a 2-year time period, 12 patients underwent cranioplasty by a modified custom made porous hydroxyapatite implant. Once the three-dimensional computer model of the prostheses was performed, three semicircular extensions placed at strategic positions were drawn and the final prosthesis was realized. At surgery, holes fitting the extensions were drilled into the skull borders and the implant was easily embedded inside the defect. Small titanium meshes overlying the extensions were fixed by screws to the surrounding bone. Results: A minimal increase of operative times was recorded, with drilling and fixation requiring additional 30 and 15 minutes, respectively. Optimal contact between cranioplasty and skull borders was always observed at control computed tomography (CT) scans. Permanent rigid fixation was obtained in all cases, with good functional and aesthetic results at follow-up. Conclusions: Modifications of hydroxyapatite implants are obtained without additional costs. The minimal increase of operative times is largely counterbalanced by optimal fixation results. Finally, the bone drilling and the immediate proximity of bone to prosthesis might enhance the potential for osteogenesis and osteointegration. PMID:23372977

  11. 后路经伤椎固定联合伤椎及后外侧植骨治疗胸腰椎爆裂性骨折脊髓神经功能恢复研究%Study on posterior vertebral fixation combined with vertebral-posterolateral bone grafting in treatment of tho-racolumbar burst fractures

    Institute of Scientific and Technical Information of China (English)

    朱鑫; 徐海斌

    2015-01-01

    Objective To assess the clinical efficacy and safety for thoracolumbar fracture by the method of vertebral pedi‐cle screw fixation with transpedicular bone graft ,and consider its indications.Methods A total of 60 cases of patients with tho‐racolumbar unilateral or bilateral pedicle intact burst fracture ,were divided into the experimental group (posterior vertebral fix‐ation combined with vertebral bone posterolateral bone grafting) and control group (trauma with pedicle screw fixation and pos‐terolateral bone) with 30 cases in each group. We observed vertebral restoration degree (R) values (vertebral body height‘near the mean height of the anterior vertebral × 100% ) ,vertebral Cobb angle ,the fixed rate of complications ,spinal sequence re‐set ,neurological function recovery (Frankel score) in pre‐operation and at 1 week ,3 months ,12 months after opera‐tion.Results 60 cases were followed up for 12‐20 months (experimental group 16.4 ± 2.3 months;the control group of 16.1 ± 2.7 months). Vertebral fixation complications ,spinal sequence reset and neurological function recovery (Frankel score) were without statistical significance in pre‐operation and at 1 week ,3 months ,12 months after operation between the two groups (P>0.05). 12 months after operation ,two groups of Cobb angle and R value were statistically significant (P0.05). Conclusion Posterior vertebral fixation combined with vertebral‐posterolateral bone grafting in treatment of thoracolumbar burst fractures ,can effectively recover the support of the anterior column ,reduce the loss of the vertebral and kyphosis. The surgical methods in treatment of burst thora‐columbar fractures is a safe and effective method.%目的:探讨伤椎内植骨联合伤椎固定术治疗胸腰椎爆裂性骨折的安全性和临床疗效。方法将60例一侧或双侧椎弓根完好的胸腰椎爆裂性骨折患者,分为实验组(后路经伤椎固定联合伤椎植骨后外侧植骨)和

  12. A review of locking compression plate biomechanics and their advantages as internal fixators in fracture healing.

    Science.gov (United States)

    Miller, Danielle L; Goswami, Tarun

    2007-12-01

    Metallic implants are often involved in the open reduction and internal fixation of fractures. Open reduction and internal fixation is commonly used in cases of trauma when the bone cannot be healed using external methods such as casting. The locking compression plate combines the conventional screw hole, which uses non-locking screws, with a locking screw hole, which uses locking head screws. This allows for more versatility in the application of the plate. There are many factors which affect the functionality of the plate (e.g., screw placement, screw choice, length of plate, distance from bone, etc.). This paper presents a review of the literature related to the biomechanics of locking compression plates and their use as internal fixators in fracture healing. Furthermore, this paper also addresses the materials used for locking compression plates and their mechanical behavior, parameters that control the overall success, as well as inherent bone quality results.

  13. In vivo bone biocompatibility and degradation of porous fumarate-based polymer/alumoxane nanocomposites for bone tissue engineering.

    NARCIS (Netherlands)

    Mistry, A.S.; Pham, Q.P.; Schouten, C.; Yeh, T.; Christenson, E.M.; Mikos, A.G.; Jansen, J.A.

    2010-01-01

    The objective of this study was to determine how the incorporation of surface-modified alumoxane nanoparticles into a biodegradable fumarate-based polymer affects in vivo bone biocompatibility (characterized by direct bone contact and bone ingrowth) and in vivo degradability. Porous scaffolds were f

  14. Complicaciones de los tornillos de bloqueo intermaxilar en el tratamiento de las fracturas mandibulares Complications of self-tapping bone screws for maxillomandibular fixation in the treatment of jaw fracture

    OpenAIRE

    J. Molina Montes; J. González-Lagunas; J. Mareque Bueno; J.A. Hueto Madrid; G. Raspall Martí

    2008-01-01

    Durante la última década se ha introducido el tornillo de bloqueo intermaxilar como método de fijación maxilomandibular en el tratamiento de las fracturas de mandíbula. El propósito del estudio es evaluar las complicaciones de la técnica y la yatrogenia dental que derivan de su aplicación durante un periodo de 4 años. Se han revisado un total de 62 pacientes y 272 tornillos y, aunque han aparecido complicaciones, su incidencia es baja.In the last decade, self-tapping bone screws have been use...

  15. Biodegradable calcium polyphosphate/polyvinyl-urethane carbonate composites for osteosynthesis applications

    Science.gov (United States)

    Ramsay, Scott Desmond

    The formation of biodegradable implants for use in osteosynthesis has been a major goal of biomaterials research for the past two to three decades. Self-reinforced polylactide systems represent the most significant success of this research to date, however with elastic constants of, at most, 12--15 GPa, they fail to provide the necessary initial stiffness required of devices designed for stabilizing fractures of major load-bearing bones. One objective of this study has been the development of a biodegradable composite suitable for fabrication of implants for the repair of fractures of major load-bearing bones. Specifically, this research has focussed on the use of calcium polyphosphate (CPP), an uiorganic polymer in combination with polyvinyl-urethane carbonate (PVUC) organic polymers. Composite samples were formed as interpenetrating phase composites (IPC), particle-reinforced composites (PRC), and fibre-reinforced composites (FRC). Additionally, the IPCs were produced as both monolithic and laminated specimens. PRC samples exhibit too low asmade elastic constant for fracture fixation applications, while the IPC and FRC samples exhibit desired as-made strength and bending stiffness but lose these properties too rapidly when exposed to aqueous-based in vitro aging, simulating in vivo conditions. An investigation to determine the mechanism of the rapid in vitro degradation was undertaken using a model IPC system to study the effect of the interfacial strength on the mechanical properties of the composite. In addition, these studies provided further support for a hypothesis to explain the observed high mechanical properties of the as-made CPP-PVUC interpenetrating phase composites. It was found that strong interfacial strength is very significant in obtaining appropriate mechanical properties in the IPC system. Results support the conclusion that a rapid loss of the CPP-PVUC interface through exposure to an aqueous environment, as well as stresses imposed on the CPP

  16. Molecular Biology of Nitrogen Fixation

    Science.gov (United States)

    Shanmugam, K. T.; Valentine, Raymond C.

    1975-01-01

    Reports that as a result of our increasing knowledge of the molecular biology of nitrogen fixation it might eventually be possible to increase the biological production of nitrogenous fertilizer from atmospheric nitrogen. (GS)

  17. Biodegradable Materials for Nonwovens

    Science.gov (United States)

    Demand for nonwovens is increasing globally, particularly in the disposable products area. As the consumption of nonwoven products with short life increases, the burden on waste disposal also rises. In this context, biodegradable nonwovens become more important today and for the future. Several new ...

  18. Grey water biodegradability

    NARCIS (Netherlands)

    Abu Ghunmi, L.; Zeeman, G.; Fayyad, M.; Van Lier, J.B.

    2010-01-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different condi

  19. Grey water biodegradability

    NARCIS (Netherlands)

    Abu Ghunmi, L.; Zeeman, G.; Fayyad, M.; Lier, van J.B.

    2011-01-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different condi

  20. Porous surface modified bioactive bone cement for enhanced bone bonding.

    Directory of Open Access Journals (Sweden)

    Qiang He

    defect. CONCLUSIONS: Our findings suggested a new bioactive bone cement for prosthetic fixation in total joint replacement.

  1. Successful operative rib fixation of traumatic flail chest in a patient with osteogenesis imperfecta.

    Science.gov (United States)

    Kulaylat, Afif N; Chesnut, Charles H; Santos, Ariel P; Armen, Scott B

    2014-09-01

    Increasing attention has been directed towards operative rib fixation of traumatic flail chest; reported benefits include more rapid weaning from the ventilator, decreased intensive care unit stays, decreased complications and improved functional results. The outcomes of this surgical intervention in patients with osteogenesis imperfecta, a rare condition characterized by low bone density and bone fragility, are unknown. This case demonstrates that, in the management of traumatic flail chest in a patient with osteogenesis imperfecta, surgical fixation can be successful and should be considered early.

  2. Risk factors for breakage of biodegradable plate systems after bilateral sagittal split mandibular setback surgery.

    Science.gov (United States)

    Yoshioka, Izumi; Igawa, Kaori; Nagata, Jyunko; Yoshida, Maho; Baba, Takashi; Ichiki, Takeshi; Kondoh, Yudai; Takamori, Koichi; Kashima, Koji; Sakoda, Sumio

    2013-06-01

    The aim of this retrospective study was to evaluate the risk factors associated with breakage of biodegradable plate systems after bilateral sagittal split mandibular setback. We studied 169 Japanese adults (62 men, 107 women; age range 16-53 years) with deformities of the jaw diagnosed as mandibular prognathism. All patients were treated by bilateral sagittal split osteotomy (BSSO) with 2 biodegradable fixation plates and screws at the anterior mandibular ramus. We collected the following data from the medical records and radiological findings: sex; age; degree of setback; presence of asymmetry; presence of open bite; operation; design of the plate; operating time; and blood loss. Multiple logistic regression analysis was used to find the factors that were independently associated with the dependent variable: breakage of the biodegradable plate system. In 10 of the 169 patients (6%) the biodegradable plate system for the BSSO broke. Factors that influenced whether or not the biodegradable plate system fractured were if they were asymmetrical (odds ratio (OR) 5.35; P=0.02) and had an open bite (OR 5.20; P=0.02). Asymmetry or open bite was significantly associated with breaks in the biodegradable plate system. Biodegradable plates should be used only when loading is minimal.

  3. Arthroscopic assisted percutaneous bone grafting and screw fixation for the treatment of lateral tibial plateau fractures:A 4-year follow-up%胫骨外侧平台骨折关节镜下经皮复位植骨螺钉内固定:4年随访★

    Institute of Scientific and Technical Information of China (English)

    曾润铭; 吴盛荣; 林少彬

    2013-01-01

      BACKGROUND: Studies have shown the knee secondary osteoarthritis may occur after the treatment of tibial plateau fractures with open reduction and internal fixation, but the researches on the middle- and long-term effect of arthroscopic assisted tibial plateau fracture fixation are stil rare. OBJECTIVE: To evaluate the outcomes of lateral tibial plateau fractures after treated with arthroscopic assisted percutaneous bone grafting and screw fixation for 1 and 4 years through clinical and radiological assessment. METHODS: Between March 2007 and March 2009, with the information of the patients with lateral tibial plateau fractures undergoing arthroscopic assisted percutaneous bone grafting and screw fixation were enrol ed. The data of the type of fractures in the Schatzker classification, the accompanying lesions of the cartilage defect on the lateral tibial plateau, the cartilage damage on the femoral condyle, intra-articular soft tissue lesions and insufficient reduction of the fracture, as wel as postoperative subsidence in the lateral tibial plateau were col ected. The Lysholm score, Ahlback osteoarthritis classification, Rasmussen function score and radiological score were assessed at 1 and 4 years after treated with percutaneous bone grafting and screw fixation. RESULTS AND CONCLUSION: Twenty-three patients finished the fol ow-up. At 1 and 4 years after percutaneous bone grafting and screw fixation, the mean Lysholm score was 90 and 87 points respectively (P=0.23), and the mean Rasmussen function score was 26 and 24 points respectively (P=0.30). At 4 years after surgery, 11 cases (47.8%) presented osteoarthritis and the Rasmussen radiological score was decreased from early postoperative 17.4 points to 4-year postoperatively 13.6 points (P=0.01). No correlation could be observed between the various types of fractures and their prognosis. The elder cases, cartilage damage and/or defect, intra-articular soft tissue lesions and postoperative subsidence in the

  4. Preliminary study of biodegradation of AZ31B magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    REN Yibin; HUANG Jingjing; ZHANG Bingchun; YANG Ke

    2007-01-01

    Magnesium alloys are potential to be developed as a new type of biodegradable implant material by use of their active corrosion behavior.Both in vitro and in vivo biodegradation properties of an AZ31B magnesium alloy were investigated in this work.The results showed that AZ31B alloy has a proper degradation rate and much lower hydrogen release in Hank's solution,with a degradation rate of about 0.3 mm/year and hydrogen release below 0.15mL/cm2.The animal implantation test showed that the AZ31B alloy could slowly biodegrade in femur of the rabbit and form calcium phosphate around the alloy sample,with the Ca/P ratio close to the natural bone.

  5. Ultrastructural evaluation of shrinkage artefacts induced by fixatives and embedding resins on osteocyte processes and pericellular space dimensions.

    Science.gov (United States)

    Shah, Furqan A; Johansson, Bengt R; Thomsen, Peter; Palmquist, Anders

    2015-04-01

    The integrity of the interface between the osteocyte (Ot) process and the canalicular wall was investigated in terms of change in the lateral dimensions of the Ot process in relation to the canalicular width, i.e., widening of the pericellular space. This has been interpreted as shrinkage of the Ot process relative to the canalicular wall during sample preparation stages of fixation, dehydration, and resin embedding. Sprague-Dawley rat tibial cross-sections were prepared for transmission electron microscopy (TEM). Four different fixative preparations: paraformaldehyde (PF), modified Karnovsky's (MK), glutaraldehyde (GRR) with ruthenium red (GRR), and zinc formalin (ZF); and two different embedding resins: LR Gold (LRG) and Epon812 (Epon) were evaluated. It was found that for LRG embedding, formalin-only fixatives (PF and ZF) induced lower shrinkage than GRR-containing fixatives (MK and GRR). In contrast, for Epon embedding, MK showed the highest shrinkage, while no differences were found between the remaining fixatives (PF, ZF, and GRR). All formalin-containing fixatives (MK, PF, and ZF) induced similar shrinkage in both embedding media. The most dramatic difference was for GRR fixation, which in combination with LRG embedding showed ∼ 62% more shrinkage than with Epon embedding, suggesting that the combination of GRR fixation and LRG embedding synergistically amplifies Ot shrinkage. These differences likely suggest a role of the resin in secondarily influencing the tissue structure following fixation. Further, the work confirms LRG as a poor embedding medium for bone specimens, as it causes large variations in shrinkage depending on fixation.

  6. Lumbopelvic fixation: a surgical alternative for lumbar stability

    Directory of Open Access Journals (Sweden)

    Gabriel Virgilio Ortiz García

    2014-09-01

    Full Text Available OBJECTIVE: Lumbopelvic fixation is a valid surgical option to achieving great stability in cases where it is particularly demanded, such as in patients with poor quality bone, degenerative scoliosis, and revision surgeries with modern materials and techniques. It enables simple integration of the iliopelvic systems with the rest of the spinal structure, maintaining hemorrhagia at acceptable levels, as well as surgery time. METHODS: We analyzed a case series of 15 patients of our center, who required major construction and/or presented poor quality bone. RESULTS: A total of 15 patients was studied, of which 12 (80% were women and three (20%, men. Nine (60% of these were revision surgeries, maintaining a surgery time of 5 hours (±1 h, with average blood loss of 1380 ml (±178 ml. All the patients received six to eight transpedicular screws, including iliac screws, and in all cases, a bone graft was inserted. CONCLUSION: Lumbopelvic fixation in patients with characteristics associated with osteopenia and osteoporosis, and in major instrumentations, particularly revision surgeries, three-dimensional correction is achieved, constructing a strong, stable pelvic base that is very useful, in patients with fragile surgical anatomy, for changes of implant or extensive decompression, provided the arthrodesis technique is adequate and with the insertion of a sufficient bone graft, and obviously, taking care to maintain the sagittal balance.

  7. Disckectomy, Partial Adjacent Centrum Resection, Bone Graft with Titanium Mesh and Titanium Plate Fixation for the Treatment of Single Segment Cervical Disc Degeneration with Adjacent Vertebral Posterior Osteophyte%椎间盘及部分椎体切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘突出伴椎体后缘骨赘

    Institute of Scientific and Technical Information of China (English)

    孙继飞; 何强; 刘振利; 陈庆胜

    2012-01-01

    目的 评价颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘退变突出伴相邻椎体后缘骨赘的疗效. 方法 应用颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘退变突出伴相邻椎体后缘骨赘22例.取颈椎前路手术切口,术中仅切除突出的椎间盘及相邻椎体的1/3~ 1/2,使脊髓得到彻底的减压.再用填满碎骨的钛网植于骨缺损处加用钛板螺丝钉内固定,固定范围仅限于相邻椎体.术前和术后通过神经功能JOA评分、颈部轴性症状、颈椎动态侧位片和颈椎MRI比较临床疗效. 结果 均获随访,平均15(6 ~24)个月,术后JOA评分优良率86.4%,颈部轴性症状减轻,脊髓功能明显得到恢复.颈椎活动度良好.X线检查见钛网植骨及钛板内固定良好,未见不稳现象.MRI示颈髓压迫解除. 结论 颈椎椎间盘及相邻椎体部分切除加钛网植骨钛板内固定术治疗单节段颈椎椎间盘突出伴相邻椎体骨赘效果显著,可最大限度地保留颈椎节段的活动度.%Objective To evaluate the clinical effects of disckectomy, partial adjacent centrum resection , bone graft with titanium mesh and titanium plate fixation for the treatment of single segment cervical disc degeneration with adjacent vertebral posterior osteophyte. Methods There were 22 cases received this kind of surgical procedure. By anterior cervical incision, the herniated disc and only 1/3 to 1/2 of the adjacent vertebral body were removed for the decompression of the spinal cord. Then the titanium mesh filled with the small bones was implanted in the bone defect followed by titanium screw fixation. The fixation was limited to the adjacent vertebral bodies. Preoperative and postoperative neurological functions of the JOA score, the cervical axial symptoms, the cervical dynamic radiographs and cervical spine MRI were used to compare the clinical

  8. Treatment of Lumbar Degenerative Disease with Unilateral Decompression,Bone Graft Fusion and Unilateral Pedicle Screw Fixation%经单侧减压融合、单边椎弓根螺钉内固定治疗腰椎退变性疾病

    Institute of Scientific and Technical Information of China (English)

    宋晋刚; 崔易坤; 苗艳; 尹振宇; 羊刚毅; 黄海锋

    2016-01-01

    目的:探讨经单侧行病变节段椎管减压、椎间植骨融合、单边椎弓根螺钉内固定治疗腰椎退变性疾病的临床疗效。方法我院2010年1月~2013年12月对35例腰椎退变性疾病采用经单侧减压、椎间植骨融合、单边椎弓根螺钉固定手术治疗。根据 JOA 评分法评估术后腰椎功能改善情况,采用视觉模拟评分(visual analog scale,VAS)评估术后疼痛缓解情况,腰椎正侧位 X 线片及 CT 扫描了解植骨融合情况。结果随访12~18个月,平均15个月。术前 JOA 评分(8.2±2.1)分,显著低于术后3个月(20.8±3.8)分(q =22.123,P <0.05)和术后12个月(21.7±3.9)分(q =23.703,P <0.05);VAS 评分术前(7.9±2.1)分,显著高于术后3个月(2.4±0.4)分(q =26.107,P <0.05)和12个月(2.3±0.3)分(q =26.582,P <0.05);JOA 评分和 VAS 评分随访期间无显著变化(P >0.05)。1年后椎间植骨融合率100%,未发现椎弓根螺钉松动、断裂、拔钉等异常。结论经单侧减压、椎间植骨融合联合单边椎弓根螺钉内固定治疗腰椎退变性疾病疗效满意,可在合适病例中推广应用。%Objective To investigate the clinical effects of unilateral vertebral canal decompression,intervertebral bone graft fusion,and unilateral pedicle screw fixation in the treatment of lumbar degenerative disease. Methods From January 2010 to December 2013,a total of 35 cases of lumbar degenerative disease were treated with unilateral decompression,intervertebral bone graft fusion,and unilateral pedicle screw fixation.The postoperative spine functions were evaluated with the JOA scores,the postoperative pain relief was evaluated with the VAS scores,and bone graft fusion was reviewed with lumbar X-ray and CT scanning. Results The patients were followed up for 12 -18 months (mean,15 months).The preoperative JOA scores (8.2 ±2

  9. Fixador esquelético pino-resina acrílica e enxerto ósseo esponjoso no tratamento de complicações secundárias à imobilização inadequada de fratura do rádio e ulna em cães Acrylic-pin external fixator and cancellous bone graft in the treatment of complications caused by inadequate immobilization of radius and ulna fracture in dogs

    Directory of Open Access Journals (Sweden)

    Sheila Canevese Rahal

    2005-10-01

    Full Text Available O objetivo do estudo foi avaliar a eficácia do fixador esquelético pino-resina, configuração tipo II, coadjuvado pelo enxerto ósseo esponjoso autólogo, no tratamento das complicações secundárias à imobilização inadequada de fraturas do rádio e ulna em 10 cães, com peso entre 1,8 e 33,6 kg. Detectou-se não-união (n=4, osteomielite (n=1, má-união (n=1, falência ou quebra de implante (n=4, sendo 60% das lesões referente ao uso prévio de pino intramedular no rádio. A montagem do fixador foi realizada com transfixação de pinos lisos em sua maioria angulados, cujas extremidades excedentes foram dobradas e estabilizadas com resina acrílica. Em todos os casos, utilizou-se enxerto esponjoso autólogo fresco, após debridamento do foco de fratura. O tempo de permanência do aparelho variou entre 45 dias e 5 meses e a maior complicação foi o afrouxamento dos pinos transfixantes. A consolidação das fraturas ocorreu por formação de calo periosteal de mínimo a moderado, indicando boa rigidez da montagem.The aim of this study was to evaluate the acrylic-pin external fixator, type II-configuration, and cancellous bone autograft for treating complications of radius and ulna fractures in 10 dogs weighing between 1.8 and 33.6 kg. Nonunion (n=4, osteomyelitis (n=1, malunion (n=1, failure or breakage of implant (n=4 were detected, and 60 % of them were associated with previous intramedullary pin placement in the radius. The fixator frame was constructed using most of the smooth transfixation pins angled. The fixation rods were constructed by placing acrylic resin over the ends of the transfixation pins that were previously bent. In all cases fresh cancellous bone autograft was used after cleaning of the fracture site. The permanence time of the external fixator ranged from 45 days to 5 months, and the most important complication was pin loosening. Fracture healing was by minimal to moderate periosteal callus, suggesting good rigidity

  10. Bone Biopsy

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Biopsy Bone biopsy uses a needle and imaging ... the limitations of Bone Biopsy? What is a Bone Biopsy? A bone biopsy is an image-guided ...

  11. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  12. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  13. Biodegradation of Silk Biomaterials

    OpenAIRE

    Bochu Wang; Yang Cao

    2009-01-01

    Silk fibroin from the silkworm, Bombyx mori, has excellent properties such as biocompatibility, biodegradation, non-toxicity, adsorption properties, etc. As a kind of ideal biomaterial, silk fibroin has been widely used since it was first utilized for sutures a long time ago. The degradation behavior of silk biomaterials is obviously important for medical applications. This article will focus on silk-based biomaterials and review the degradation behaviors of silk materials.

  14. Anterior transarticular screw fixation as a conventional operation for rigid stabilization

    Directory of Open Access Journals (Sweden)

    Manabu Sasaki

    2014-01-01

    Full Text Available Background: Anterior transarticular screw (ATS fixation is a useful surgical option for atlantoaxial (AA stabilization. This report presents a revised ATS method for AA fusion. Methods: A 79-year-old male presented with AA instability attributed both to an old odontoid fracture and severe degeneration of the lateral atlantoaxial joints (LAAJs. ATS fixation was performed through the conventional anterior cervical approach. The longest screw trajectories were planned preoperatively using multiplanar reconstruction computed tomography (CT scans, with entry points of the screws situated at the midpoint on the inferior border of the axial body. The surgical exposure was limited to opening at the entry points alone. Our retractor of choice was the Cusco speculum; it sufficiently secured space for utilizing the required instruments for screw placement while offering sufficient protection of soft tissues. Cannulated full-threaded bicortical screws stabilized the LAAJs. Screw insertion required a significant amount of coronal angulation up to the superior articular process of the atlas under open-mouth and lateral fluoroscopy image guidance. After ATS fixation, bone grafting was performed between the posterior laminae of the axis and the atlas through a conventional posterior approach. Results: Bony fusion between the atlas and the axis was confirmed radiographically. Arthrodesis of the LAAJs occurred despite no bone grafting. Conclusions: Rigid fixation of the LAAJs was obtained by our ATS technique, indicating that it is an alternative method for AA fixation when posterior rigid internal fixation is not applicable.

  15. The relationship between interfragmentary movement and cell differentiation in early fracture healing under locking plate fixation.

    Science.gov (United States)

    Miramini, Saeed; Zhang, Lihai; Richardson, Martin; Mendis, Priyan; Oloyede, Adekunle; Ebeling, Peter

    2016-03-01

    Interfragmentary movement (IFM) at the fracture site plays an important role in fracture healing, particularly during its early stage, via influencing the mechanical microenvironment of mesenchymal stem cells within the fracture callus. However, the effect of changes in IFM resulting from the changes in the configuration of locking plate fixation on cell differentiation has not yet been fully understood. In this study, mechanical experiments on surrogate tibia specimens, manufactured from specially formulated polyurethane, were conducted to investigate changes in IFM of fractures under various locking plate fixation configurations and loading magnitudes. The effect of the observed IFM on callus cell differentiation was then further studied using computational simulation. We found that during the early stage, cell differentiation in the fracture callus is highly influenced by fracture gap size and IFM, which in turn, is highly sensitive to locking plate fixation configuration. The computational model predicted that a small gap size (e.g. 1 mm) under a relatively flexible configuration of locking plate fixation (larger bone-plate distances and working lengths) could experience excessive strain and fluid flow within the fracture site, resulting in excessive fibrous tissue differentiation and delayed healing. By contrast, a relatively flexible configuration of locking plate fixation was predicted to improve cartilaginous callus formation and bone healing for a relatively larger gap size (e.g. 3 mm). If further confirmed by animal and human studies, the research outcome of this paper may have implications for orthopaedic surgeons in optimising the application of locking plate fixations for fractures in clinical practice.

  16. Machining of a bioactive nanocomposite orthopedic fixation device.

    Science.gov (United States)

    Sparnell, Amie; Aniket; El-Ghannam, Ahmed

    2012-08-01

    Bioactive ceramics bond to bone and enhance bone formation. However, they have poor mechanical properties which restrict their machinability as well as their application as load bearing implants. The goal of this study was to machine bioactive fixation screws using a silica-calcium phosphate nanocomposite (SCPC50). The effect of compact pressure, holding time, and thermal treatment on the microstructure, machinability, and mechanical properties of SCPC50 cylinders were investigated. Samples prepared by powder metallurgy technique at compact pressure range of 100-300 MPa and treated at 900°C/1 h scored a poor machinability rating of (1/5) due to the significant formation of amorphous silicate phase at the grain boundaries. On the other hand, lowering of compact pressure and sintering temperature to 30 MPa/3 h and 700°C/2 h, respectively, minimized the formation of the amorphous phase and raised the machinability rating to (5/5). The modulus of elasticity and ultimate strength of machinable SCPC50 were 10.8 ± 2.0 GPa and 72.8 ± 22.8 MPa, respectively, which are comparable to the corresponding values for adult human cortical bone. qRT-PCR analyses showed that bone cells attached to SCPC50 significantly upregulated osteocalcin mRNA expression as compared to the cells on Ti-6Al-4V. Moreover, cells attached to SCPC50 produced mineralized bone-like tissue within 8 days. On the other hand, cells attached to Ti-6Al-4V failed to produce bone mineral under the same experimental conditions. Results of the study suggest that machinable SCPC50 has the potential to serve as an attractive new material for orthopedic fixation devices.

  17. 内窥镜辅助下前路经寰枢关节螺钉固定植骨融合术治疗上颈椎不稳%Endoscopy-assisted anterior transarticular screw fixation and bone grafting for upper cervical instability

    Institute of Scientific and Technical Information of China (English)

    姚女兆; 王文军; 王麓山; 晏怡果; 李学林; 欧阳智华

    2012-01-01

    目的:探讨内窥镜辅助下前路经寰枢关节螺钉固定植骨融合术治疗上颈椎不稳的临床可行性及其疗效.方法:2006年1月至2009年12月采用内窥镜辅助下前路经寰枢关节螺钉固定植骨融合术治疗上颈椎不稳患者13例,男8例,女5例;年龄17~65岁,平均46.8岁.JeffersonⅡ型骨折6例,JeffersonⅢ型骨折1例,寰枢椎脱位3例,陈旧性齿状突骨折3例.患者均有枕颈部不适和活动受限,术前VAS评分为3.2~4.1分,平均3.8分;2例伴有不同程度脊髓功能损害者,按Frankel分级C级1例,D级1例.随访患者临床症状改善和植骨融合情况.结果:均在内镜辅助下顺利完成手术,13例患者共置入26枚螺钉;手术时间60~130min,平均80min;术中出血110~290ml,平均190ml.术中无脊髓、椎动脉损伤等并发症.术后复查CT显示1枚螺钉位置欠佳,螺钉外斜角偏小且上斜角偏大,螺钉部分进入椎管,但未损伤脊髓,未做处理;25枚位置良好.寰枢关节基本复位,固定可靠.术后随访12~60个月,平均18个月,末次随访时VAS评分降至1.0~2.0分,平均1.3分,与术前比较有统计学差异(P<0.05).2例伴颈髓损伤患者的症状均有改善,Frankel分级C级者恢复到D级,D级者恢复到E级.12例患者术后3个月开始出现植骨融合,末次随访时寰枢关节间隙植骨均达到融合;1例患者未见明显植骨融合,但寰枢关节稳定性良好,未出现断钉等并发症.结论:内窥镜辅助下前路经寰枢关节螺钉固定植骨融合术治疗上颈椎不稳是可行的,能取得较好的治疗效果,且在一定程度上克服了传统手术显露困难的缺点,从而减少手术并发症.%Objectives: To evaluate the operation method and clinical outcome of atlantoaxial joint fusion using endoscopy-assisted anterior transarticular screw fixation and bone grafting for upper cervical instability. Methods: 13 cases with upper cervical instability who underwent anterior release

  18. Anaerobic Biodegradation of Detergent Surfactants

    Directory of Open Access Journals (Sweden)

    Erich Jelen

    2009-03-01

    Full Text Available Detergent surfactantscan be found in wastewater in relevant concentrations. Most of them are known as ready degradable under aerobic conditions, as required by European legislation. Far fewer surfactants have been tested so far for biodegradability under anaerobic conditions. The natural environment is predominantly aerobic, but there are some environmental compartments such as river sediments, sub-surface soil layer and anaerobic sludge digesters of wastewater treatment plants which have strictly anaerobic conditions. This review gives an overview on anaerobic biodegradation processes, the methods for testing anaerobic biodegradability, and the anaerobic biodegradability of different detergent surfactant types (anionic, nonionic, cationic, amphoteric surfactants.

  19. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Bone Densitometry (DEXA) Bone densitometry, also called dual-energy ... limitations of DEXA Bone Densitometry? What is a Bone Density Scan (DEXA)? Bone density scanning, also called ...

  20. Double calcaneal osteotomy with percutaneous Steinmann pin fixation as part of treatment for flexible flatfoot deformity: a review of consecutive cases highlighting our experience with pin fixation.

    Science.gov (United States)

    Boffeli, Troy J; Abben, Kyle W

    2015-01-01

    Surgical correction of flexible flatfoot deformity and posterior tibial tendon dysfunction has been extensively reported in published studies. When appropriate, calcaneal osteotomies for flatfoot correction have been a favorite of foot and ankle surgeons because of the corrective power achieved without the need to fuse any rearfoot joints. The medial displacement calcaneal osteotomy and Evans calcaneal osteotomy, together termed the double calcaneal osteotomy, have been reported several times by various investigators with a wide variety of fixation options. We undertook an institutional review board-approved retrospective review of 9 consecutive patients (11 feet), who had undergone double calcaneal osteotomy with 2 percutaneous Steinmann pin fixation for the correction of flexible flatfoot deformity, with or without posterior tibial tendon dysfunction. All patients had radiographic evidence of bone healing of the posterior calcaneal osteotomy and incorporation of the Evans osteotomy bone graft at 6 weeks and demonstrated clinical healing at 6 weeks. All patients had 2 percutaneous Steinmann pins placed through both osteotomies, and these were removed an average of 6 weeks postoperatively. No patient developed pin site complications. The only complication noted was sural neuritis, which was likely incision related. No patients had delayed union or nonunion, and we did not identify any graft shifting postoperatively. The present retrospective series highlights our experience with 2 percutaneous Steinmann pin fixation, demonstrating equal or better results than many previous published fixation methods for double calcaneal osteotomy. It is cost-effective and minimizes the potential risk of iatrogenic Achilles pathologic features associated with screw fixation.

  1. Analysis and an overview of fixators in medicine and the methods of processing materials for producing fixators

    Directory of Open Access Journals (Sweden)

    Dalibor Milojko Đenadić

    2013-06-01

    Full Text Available The fixator is a medical device that provides support to fractured biological structures. Metal biomaterials are mainly used for replacing broken or damaged hard tissues such as bones because of their high strenght, toughness and corrosion resistance. Materials such as stainless steel, titanium and aluminium alloys (Ti-6Al-4V, cobalt and chromium alloys, composite materials and other biocompatible materials are used in orthopedy for the stabilization of connective tissue injuries or as a substitute for the bone tissues. Fixators are classified according to the place of installation to external and internal fixators. Widely used medical fixators are pins, rods plates, screws, pipes, wires, nails and external fixators. Conventional and non-conventional methods of processing are used in the production process for all types of fixators. Introduction Fixators are medical devices manufactured to support damaged biological structures. In the field of orthopedic surgery that deals with skeletal disorders such as bone, spine, joints, muscles and tendons injuries and diseases, various metals, titanium and cobalt alloys etc. are used to stabilize the supporting tissue injuries or as a substitute for bone tissues. Metallic implants are frequently used in orthopedic surgery as joint prosthesis (hip, knee and elbow fracture fixation devices (plates, screws, external fixators and devices for the fixation of the spine. In principle, fixators are devided into external and internal ones, depending on the place of installation (outside or inside the body. The most common types of medical fixators are pins, rods and plates. This paper presents some of the most common materials used for the production of fixators, their processing and possibilties of use in medicine for various purposes. Types of fixators and materials used for their production Nowadays, biocompatible materials are usually used for the production of fixators and implants. These materials show good

  2. Ankle fusion stability: a biomechanical comparison of external versus internal fixation.

    Science.gov (United States)

    Hoover, Justin R; Santrock, Robert D; James, William C

    2011-04-11

    This biomechanical study compares bimalleolar external fixation to conventional crossed-screw construct in terms of stability and compression for ankle arthrodesis. The goals of the study were to determine which construct is more stable with bending and torsional forces, and to determine which construct achieves more compression.Fourth-generation bone composite tibia and talocalcaneal models were made to 50th percentile anatomic specifications. Fourteen ankle fusion constructs were created with bimalleolar external fixators and 14 with crossed-screw constructs. Ultimate bend, torque, and compression testing were completed on the external fixator and crossed-screw constructs using a multidirectional Materials Testing Machine (MTS Systems Corp, Eden Prairie, Minnesota). Ultimate bend testing revealed a statistically significant difference (P=.0022) with the mean peak load to failure for the external fixator constructs of 973.2 N compared to 612.5 N for the crossed-screw constructs. Ultimate torque testing revealed the mean peak torque to failure for the external fixator construct was 80.2 Nm and 28.1 Nm for the crossed-screw construct, also a statistically significant difference (P=.0001). The compression testing yielded no statistically significant difference (P=.9268) between the average failure force of the external fixator construct (81.6 kg) and the crossed-screw construct (81.2 kg).With increased stiffness in both bending and torsion and comparable compressive strengths, bimalleolar external fixation is an excellent option for tibiotalar ankle arthrodesis.

  3. Posterior atlantoaxial transpedicle screw fixation for traumatic atlatoaxial instability

    Directory of Open Access Journals (Sweden)

    Zheng-lei WANG

    2015-10-01

    Full Text Available Objective To explore the clinical efficacy of posterior atlantoaxial pedicle screw fixation for traumatic atlantoaxial instability. Methods From September 2009 to March 2013, 17 patients with atlantoaxial instability received posterior atlantoaxial pedicle screw fixation. There were 12 males and 5 females, with a mean age of 42 years old (ranged from 19 to 63 years old. Transpedicle screw fixation was employed in 8 patients with atlantoaxial fracture and dislocation, in 2 with traumatic disruption of transverse atlantal ligament, and in 7 with odontoid fracture. The Japanese Orthopaedic Association (JOA score before operation was from 5 to 14, with a mean of 11.2. Preoperative CT, MRI and radiographs, as well as intraoperative screw placement and bone graft were administered in all the patients. Results In all the patients, complete reduction was achieved without injury to the vertebral artery, spinal cord or never root, and they started to be ambulatory on the first day after the operation. The patients were followed up for 6-36 months (mean 21 months, and clinical symptoms were seen to be improved significantly. Imaging reexamination 6 months after the surgery showed satisfactory healing of implanted bone and position of all the screws without loosening of the implant. The mean JOA scores was 15.5(11.0-17.0 twelve months after the operation. Conclusion Atlantoaxial pedicle screw fixation for traumatic atlantoaxial instability is safe and reliable with a favorable clinical result. DOI: 10.11855/j.issn.0577-7402.2015.09.14

  4. External fixation combined with limited internal fixation for Pilon fractures%外固定支架结合有限内固定治疗Pilon骨折

    Institute of Scientific and Technical Information of China (English)

    周淮; 徐晓军

    2011-01-01

    Objective To investigate the clinical effect of Pilon fractures treated with external fixation and limited internal fixation.Methods 24 cases of Pilon fractures of tibia were treated with external fixation combined limited internal fixation.Results 24 cases were followed up for 10 ~ 20 months.No bone nonumon or skin necrosis complication was found.According to Mazur ankle joint scoring system, the results were excellent in 14, good in 7 , and fair in 3.Conclusions External fixation combined with limited internal fixation can immohilize the sections of fracture and achieve excellent ankle joint function,so it is an effective surgical treatment of Pilon fractures.%目的 探讨外固定支架结合有限内固定治疗Pilon骨折的疗效.方法 采用外固定支架结合有限内固定治疗24例Pilon骨折.结果 24例均获得随访,时间10~20个月.无骨不连、皮肤坏死发生.踝关节功能Mazur评分:优14例,良7例,可3例.结论 外固定支架结合有限内固定可以获得术后骨折稳定,取得良好踝关节功能,是治疗Pilon骨折有效的手术方案.

  5. First metatarsophalangeal joint arthrodesis: current fixation options.

    Science.gov (United States)

    Moon, Jared L; McGlamry, Michael C

    2011-04-01

    This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available.

  6. Surgical treatment of neglected clubfoot using external fixator

    Directory of Open Access Journals (Sweden)

    Rodrigo Mota Pacheco Fernandes

    Full Text Available ABSTRACT The definition of neglected clubfoot (NC includes a variable range of complex deformities of the foot that are refractory to conventional treatments or are treated inappropriately. Several etiologies may be related to this. The Ilizarov method has become established as a tool for treating these deformities. It minimizes soft-tissue damage through gradual correction of the deformity, with a high success rate in relation to achieving a plantigrade foot, with low incidence of recurrence. The indications for treatment include severe rigid deformities (Dimeglio III and IV, or adverse skin conditions. Careful clinical and radiological examination is fundamental for proper planning and installation of the external fixator. The techniques used include selection of external fixation assemblies, which can be closed when there is a connection between the leg, hindfoot and forefoot. This closed assembly may or may not be constricted, according to whether hinges are provided or whether use of the natural anatomical hinges during correction of the deformity is envisaged. An open assembly makes it possible to add flexibility to the foot through histogenesis, while allowing closed corrections of greater precision later on. Hexapod fixators are an innovation with high potential for accuracy in correcting deformities. Procedures associated with external fixation include soft-tissue release and bone procedures. These procedures enable corrections that are more anatomical, for different degrees of severity and stiffness of deformity. It can be concluded from analyzing this case series that treatment of neglected clubfoot using an external fixator has a high rate of good and excellent results, with low frequency of complications.

  7. Novel anterior cruciate ligament graft fixation device reduces slippage

    Directory of Open Access Journals (Sweden)

    Lopez MJ

    2013-05-01

    Full Text Available Mandi J Lopez,1 Allen Borne,2 W Todd Monroe,3 Prakash Bommala,1 Laura Kelly,1 Nan Zhang11Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, 2Louisiana State University, New Orleans Health Sciences Center, School of Medicine, New Orleans, 3Department of Biological and Agricultural Engineering, Agricultural Center, Louisiana State University, Baton Rouge, LA, USAAbstract: Clinically significant laxity occurs in 10%–30% of knees after anterior cruciate ligament reconstruction. Graft slippage and tension loss at the hamstring graft tibial fixation site during and after reconstruction surgery contribute to postoperative joint laxity and are detrimental to long-term knee stability and graft properties. Limiting graft slippage will reduce associated complications. We sought to compare the in vitro mechanical properties and in vivo joint stabilization, postoperative limb use, and graft incorporation of the novel GraftGrab™ (GG device designed to reduce hamstring graft tibial fixation slippage with the commercially available bioabsorbable Bio-Post™ and spiked washer (BP. Mechanical testing was performed on canine tibia-hamstring graft constructs to quantify initial fixation properties. In vivo joint stabilization, postoperative limb use and graft incorporation of hamstring graft reconstructions were determined in a canine model. Outcomes included tibial translation and ground reaction forces preoperatively and 4 and 8 weeks postoperatively, three-dimensional graft and bone tunnel dimensions at the latter two time points, and graft-bone microstructure, as well as mechanical properties 8 weeks after implantation. Immediately after fixation, all grafts slipped from the BP constructs versus about 30% of GG constructs. In vivo limb use remained low, and tibial translation increased with time in the BP cohort. These results together

  8. 四肢长骨干骨折治疗的有限接触动力加压钢板和动力加压钢板临床比较%Clinical comparison of dynamic compression plate and limited contact dynamic compression plate fixation in the treatment of limbs long bone fracture

    Institute of Scientific and Technical Information of China (English)

    张星华

    2014-01-01

    目的 对比动力加压钢板(DCP)与有限接触动力加压钢板(LC-DCP)内固定治疗四肢长骨干骨折的临床疗效,为临床内固定的选择提供一定依据.方法 回顾性分析采用DCP和LC-DCP内固定治疗的172例四肢长骨干骨折患者的临床资料.其中LC-DCP组101例,DCP组71例,比较两组手术时间、术中出血量、住院时间、骨折愈合时间、骨折不愈合发生率、日常活动能力和关节功能评分及临床疗效.结果 LC-DCP组手术时间、骨折愈合时间、骨折不愈合发生率均优于DCP组[(62±13) min比(88±20) min、(60.0±20.5)d比(85.0±25.5)d、1.0%(1/101)比7.0%(5/71)],差异有统计学意义(P<0.05),而两组术中出血量与住院时间比较差异无统计学意义(P>0.05).LC-DCP组Barthel和Harris评分分别为(72.61±8.63)分和(69.28±7.63)分,均优于DCP组的(52.58±5.53)分和(55.07±6.26)分,差异有统计学意义(P<0.05).LC-DCP组优良率优于DCP组[99.0%(100/101)比90.1%(64/71)],差异有统计学意义(x2=15.71,P<0.01).结论 四肢长骨干骨折采用LC-DCP治疗,能提高临床疗效,减少手术并发症,提高患者的日常关节功能,值得临床推广使用.%Objective To compare the clinical effect of dynamic compression plate (DCP) and limited contact dynamic compression plate (LC-DCP) fixation in the treatment of limbs long bone fracture,provide certain basis for the choice of clinical internal fixation.Methods The clinical data of 172 patients with limbs long bone fracture treated with DCP and LC-DCP fixation were retrospectively analyzed.One hundred and one cases in LC-DCP group,and 71 cases in DCP group,the operation time,intraoperative blood loss,hospitalization time,fracture healing time,incidence of nonunion,daily activity ability and joint function score and clinical curative effect in two groups were compared.Results The operation time,fracture healing time,incidence of nonunion in LC-DCP group were better than those in DCP

  9. 皮质骨螺钉内固定治疗下胫腓联合分离的 CT 研究%Internal fixation with cortical bone screws for the treatment of distal tibiofibular syndesmosis separation:a CT study of 32 patients

    Institute of Scientific and Technical Information of China (English)

    鲁建作; 林央央; 杨杰; 董晓敏

    2015-01-01

    Objective:To explore the effect of internal fixation with cortical bone screws on the distal tibiofibular syndesmosis. Methods:The clinical records of 32 patients who were treated with cortical bone screws internal fixation for distal tibiofibular syndesmosis were analyzed retrospectively.The patients consisted of 18 males and 14 females,and ranged in age from 28 to 64 years (Median =43.5 yrs).The distal tibiofibular syndesmosis separation located in left leg for 14 cases and right leg for 18 cases.According to the Danis -Weber classification,the injuries belonged to types B(12)and C(20).Fibula fracture combined with posterior malleolus injury and medial malleolus injury or deltoid ligament injury were found in 11 patients,and fibula fracture combined with medial malleolus injury or deltoid ligament injury were found in 21 patients.Bilateral distal tibiofibular transverse CT films were taken in all patients.The tibiofibula congru-ence angle,fibular outward displacement and backward displacement relative to peroneal sinus of tibia were measured on the CT films and were analyzed.Results:The tibiofibula congruence angle and fibular outward displacement relative to peroneal sinus of tibia of affected side were less than those of uninjured side(68.66 +/-9.28 vs 79.49 +/-14.66 degrees,t =2.998,P =0.025;5.65 +/-1.79 vs 7.66 +/-2.05 mm,t =2.131,P =0.012),while fibular backward displacement relative to peroneal sinus of tibia of affected side was greater than that of uninjured side(4.94 +/-1.49 vs 1.90 +/-3.34 mm,t =14.089,P =0.002).Conclusion:After cortical bone screws internal fixa-tion for the treatment of distal tibiofibular syndesmosis separation,there is a trend for anteromedial rotation of distal tibiofibular syndesmosis of affected side compared to uninjured side.%目的:探讨皮质骨螺钉内固定对下胫腓联合的影响。方法:回顾性分析32例行皮质骨螺钉内固定术治疗的下胫腓联合分离患者的临床资料,男18例、女14

  10. The treatment of AO type C fractures of the distal radius with dynamic external fixation combined with minimally invasive reset and bone gratting and locking compression plate%动力型外固定支架结合微创复位植骨与锁定钢板内固定治疗桡骨远端骨折的比较研究

    Institute of Scientific and Technical Information of China (English)

    付炳金; 朱晓东

    2014-01-01

    reset and bone grafting and open reduction combined with locking compression plate internal fixation .To evaluate the merit and demerit of the two methods .Methods From September 2010 to March 2014 , we choose 62 cases with AO type C2 and C3 fractures of the distal radius ,and make a retrospective study of these patients'fol-low -up data .32 cases were treated with dynamic external fixation combined with minimally invasive reset and bone grafting , 30 cases were treated with open reduction combined with locking compression plate internal fixation .Collected and sorted out the patients'X-ray measurement data ,the common surgery complications ,as well as the wrists'Gartland-Werley function scores ,for statistical analysis .Results 62 cases of distal radius fractures have received bone healing .After surgeries ,the com-mon surgery complications showed that ,in the external fixation group ,nail track infection 2 ,wrist joint pain 1 ,wrist joint stiffness 1;whilein the LCP group ,wound infection 2 ,wrist joint pain 2 .At 24 months after the treatments ,the wrists'Gart-land-Werley function scores showed that ,in the external fixation group ,excellent /good 28;whilein the LCP group ,excel-lent /good 28 .After statistical analysis ,The external fixation group and the LCP group was pointless to cast (P>0.05) .Con-clusions The treatment of AO type C2 and C3 fractures of the distal radius with dynamic external fixation combined with mini-mally invasive reset and bone grafting is an effective method .This method is simple ,less invasive .It can effectively correct the shortening deformity and angular deformity of the distal radius ,making an anatomical reduction of the distal radius fractures , and increasing the stability of the fractures .The treatment of AO type C2 and C3 fractures of the distal radius with locking com-pression plate is an effective method ,too .This surgery has a good reset effect ,and a high fixation strength .It can effectively avoid reset losing of the

  11. Understanding Nitrogen Fixation

    Energy Technology Data Exchange (ETDEWEB)

    Paul J. Chirik

    2012-05-25

    synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from

  12. Combining of small fragment screws and large fragment plates for open reduction and internal fixation of periprosthetic humeral fractures.

    Science.gov (United States)

    Seybold, Dominik; Citak, Mustafa; Königshausen, Matthias; Gessmann, Jan; Schildhauer, Thomas A

    2011-10-01

    Operative treatment of periprosthetic humeral fractures in elderly patients with osteoporotic bone requires a stable fixations technique. The combination of 3.5 cortical screws with washers in a 4.5 Arbeitsgemeinschaft für Osteosynthesefragen, Limited-contact dynamic compression plate or Locking plate, allows a stable periprosthetic fixation with the small 3.5 screws and 4.5 screws above and below the prosthesis, respectively. This combination is a cost-effective technique to treat periprosthetic humeral fractures.

  13. Experimental model for the study of soft tissue fixation methods on skin-pericranium flaps in rats

    OpenAIRE

    Cavazana,William César; Cuman, Roberto Kenji Nakamura; Takeshita, Wilton Mitsunari; Passeri, Luis Augusto

    2013-01-01

    PURPOSE: To develop an experimental model to study and radiologically monitor displacement of skin flaps in the pericranium of rats subjected to traction and surgical fixation using suture anchored in a skull bone tunnel or with N-butyl-2-cyanoacrylate (HistoacrylTM) surgical adhesive. METHODS: Radiological markers were placed in the subcutis of Wistar rats undergoing subperiosteal detachment of the pericranium with pulling and fixation of the flap. We performed radiography on postoperative d...

  14. Bone tissue engineering: from bench to bedside

    Directory of Open Access Journals (Sweden)

    Maria A. Woodruff

    2012-10-01

    Full Text Available The drive to develop bone grafts for the filling of major gaps in the skeletal structure has led to a major research thrust towards developing biomaterials for bone engineering. Unfortunately, from a clinical perspective, the promise of bone tissue engineering which was so vibrant a decade ago has so far failed to deliver the anticipated results of becoming a routine therapeutic application in reconstructive surgery. Here we describe our bench to bedside concept, the first clinical results and a detailed analysis of long-term bone regeneration studies in preclinical animal models, exploiting methods of micro- and nano analysis of biodegradable composite scaffolds.

  15. The research of degradability of a novel biodegradable coralline hydroxyapatite after implanted into rabbit.

    Science.gov (United States)

    Ning, Yuan; Wei, Tian; Defu, Chen; Yonggang, Xing; Da, He; Dafu, Chen; Lei, Sun; Zhizhong, Gao

    2009-03-01

    To examine the biodegradability and bone healing effect of a novel biodegradable coralline hydroxyapatite after implanting into the proximal tibia of rabbit. Seventy New Zealand white rabbits were enrolled, bone defects about 10 x 5 x 3 mm(3) of bilateral proximal tibias were prepared by drilling, then coralline hydroxyapatite and iliac crest bone were grafted into bilateral bone defects, respectively. Each time five rabbits were sacrificed at 1, 2, 3, 4, 6, 8, 10, 12, 20, 24, 32, 36, 40, and 60 weeks after surgery. Then a series of examination were carried out, including eye view, roentgenographically, and nondecalcification histological examination. Eye view and roentgenographical examination indicate that all the defects grafted with coralline hydroxyapatite exhibited bone fusion, similar to the iliac crest autograft. The bone density of the graft site decreases with time on the X-ray film. Nondecalcification histological examination results are as followed: In the early time on the sections, the coralline hydroxyapatite looks like interlinked trabecula. Few lymphocytes infiltrate around the trabecula. With time extending, coralline hydroxyapatite looks like thin line or thin circle remnant. The degradation sites are filled with renascence bone. Medulla cavity can be seen in the degradation sites. After grafted in body, coralline hydroxyapatite exhibits little local and general abnormal reaction. It conducts good bone fusion of fracture. Coralline hydroxyapatite can be degraded after grafted into body, which is good for remodeling of bone healing. Hence coralline hydroxyapatite is an ideal bone graft substitute of autograft.

  16. Microbial biosurfactants and biodegradation.

    Science.gov (United States)

    Ward, Owen P

    2010-01-01

    Microbial biosurfactants are amphipathic molecules having typical molecular weights of 500-1500 Da, made up of peptides, saccharides or lipids or their combinations. In biodegradation processes they mediate solubilisation, mobilization and/or accession of hydrophobic substrates to microbes. They may be located on the cell surface or be secreted into the extracellular medium and they facilitate uptake of hydrophobic molecules through direct cellular contact with hydrophobic solids or droplets or through micellarisation. They are also involved in cell physiological processes such as biofilm formation and detachment, and in diverse biofilm associated processes such as wastewater treatment and microbial pathogenesis. The protection of contaminants in biosurfactants micelles may also inhibit uptake of contaminants by microbes. In bioremediation processes biosurfactants may facilitate release of contaminants from soil, but soils also tend to bind surfactants strongly which makes their role in contaminant desorption more complex. A greater understanding of the underlying roles played by biosurfactants in microbial physiology and in biodegradative processes is developing through advances in cell and molecular biology.

  17. Mechanical Comparison of Headless Screw Fixation and Locking Plate Fixation for Talar Neck Fractures.

    Science.gov (United States)

    Karakasli, Ahmet; Hapa, Onur; Erduran, Mehmet; Dincer, Cemal; Cecen, Berivan; Havitcioglu, Hasan

    2015-01-01

    For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues.

  18. Finite Element Simulation and Additive Manufacturing of Stiffness-Matched NiTi Fixation Hardware for Mandibular Reconstruction Surgery

    Directory of Open Access Journals (Sweden)

    Ahmadreza Jahadakbar

    2016-12-01

    Full Text Available Process parameters and post-processing heat treatment techniques have been developed to produce both shape memory and superelastic NiTi using Additive Manufacturing. By introducing engineered porosity, the stiffness of NiTi can be tuned to the level closely matching cortical bone. Using additively manufactured porous superelastic NiTi, we have proposed the use of patient-specific, stiffness-matched fixation hardware, for mandible skeletal reconstructive surgery. Currently, Ti-6Al-4V is the most commonly used material for skeletal fixation devices. Although this material offers more than sufficient strength for immobilization during the bone healing process, the high stiffness of Ti-6Al-4V implants can cause stress shielding. In this paper, we present a study of mandibular reconstruction that uses a dry cadaver mandible to validate our geometric and biomechanical design and fabrication (i.e., 3D printing of NiTi skeletal fixation hardware. Based on the reference-dried mandible, we have developed a Finite Element model to evaluate the performance of the proposed fixation. Our results show a closer-to-normal stress distribution and an enhanced contact pressure at the bone graft interface than would be in the case with Ti-6Al-4V off-the-shelf fixation hardware. The porous fixation plates used in this study were fabricated by selective laser melting.

  19. Effect of induced aniseikonia on fixation performance.

    Science.gov (United States)

    Remole, A

    1988-01-01

    The purpose of the study was to determine to what extent induced aniseikonia affects fixation performance. Aniseikonia was induced in the vertical meridian only, whereas fixation alignment was monitored in the horizontal meridian. A previously developed technique based on the dependency of border enhancement bandwidth on fixation eccentricity was used to monitor deviations from central fixation during fusion. Stress on the fusion mechanism was supplied by controlled increments of forced horizontal vergence. It was found that deviation from central fixation in the horizontal meridian generally increases with increasing amounts of vertical aniseikonia. The effect is particularly pronounced for small amounts of aniseikonia.

  20. Bone within a bone

    Energy Technology Data Exchange (ETDEWEB)

    Williams, H.J.; Davies, A.M. E-mail: wendy.turner@roh.nhs.uk; Chapman, S

    2004-02-01

    The 'bone within a bone' appearance is a well-recognized radiological term with a variety of causes. It is important to recognize this appearance and also to be aware of the differential diagnosis. A number of common conditions infrequently cause this appearance. Other causes are rare and some remain primarily of historical interest, as they are no longer encountered in clinical practice. In this review we illustrate some of the conditions that can give the bone within a bone appearance and discuss the physiological and pathological aetiology of each where known.

  1. 一期前路病灶清除植骨重建钛板内固定术治疗腰骶段脊柱结核%Clinical efficacy of one-stage anterior debridement, bone graft and reconstruction titanium plate internal fixation in treating lumbosacral spinal tuberculosis

    Institute of Scientific and Technical Information of China (English)

    夏曦; 唐绍锋; 曹志武; 王辉; 姚女兆; 王文军

    2016-01-01

    Objective To evaluate clinical outcomes following one-stage anterior radical debridement, interbody fusion, and reconstruction titanium plate internal fixation for the treatment of lumbosacral spinal tuberculosis.Methods The clinical data of 30 patients(17 males and 13 females,aged range from 27 to 65 years, mean 37. 5 years) with tuberculosis of the lumbosacral segments(including L5 -S1 ) who were treated with anterior radical debridement, autologous iliac bone graft,and internal fixation with reconstruction titanium plate at Department of Spinal Surgery of the First Affiliated Hospital of University of South China from August 2011 to August 2014 were retrospectively reviewed. All patients routinely received antitubercular drugs for 2 to 3 weeks before operation. Operation was performed when the general condition improved. All patients were systematically and routinely treated with antituberculous drug for 12-18 months after operation. The preoperative, 3 months after operation, last follow up erythrocyte sedimentation rate ( ESR) , C reactive protein( CRP) , visual analog scale ( VAS) , as well as Oswestry disability index ( ODI) were analyzed.Results Thirty patients were followed up for 12-36 months,mean 18 months.At last follow-up, no lower limb radiation pain and tuberculosis recurrence were found in all cases. The VAS scores were significantly decreased from 7. 8 ± 1. 7 at preoperation to 1. 7 ± 0. 6 at 3 months after operation, and 1.5±0.5 at last follow-up(all P values0.05).Conclusions Based on systemic and routine antituberculosis treatment,the surgical treatment of lumbosacral spinal tuberculosis with one-stage anterior debridement, bone graft and reconstruction titanium plate internal fixation have a direct and safe access to lesions of lumbosacral tuberculosis, and eradicate tuberculosis kitchen, reconstruct spinal stability and achieve good clinical outcome.%目的:探讨一期前路结核病灶清除植骨重建钛板内固定治疗腰骶段脊

  2. Curative effect of anatomical Ti-plate fixation combining with bone graft in the treatment of intra-articular calcaneal fractures%解剖型跟骨钛板并植骨治疗跟骨关节内骨折的临床疗效

    Institute of Scientific and Technical Information of China (English)

    王怀斌; 袁志; 裴国献; 刘建; 毕龙; 王连军; 孙克理; 隋天棋

    2014-01-01

    Objective To investigate the curative effect of anatomical Ti-plate combined with bone graft in treatment of intra-articular calcaneal fractures .Methods Retrospective analysis was conducted in 25 patients with 33 feet from Mar.2009 to May 2012,who were diagnosed as Sanders typeⅡ-Ⅳintra-articular calcaneal fractures .There were 20 males(26 feet) and 5 females (7 feet) with average age of (36.16 ±14.63)years(ranged from 15 to 65 years old) .There were 17 cases of single foot injury and 8 cases of double feet injury .All the patients were treated with Ti-plate fixation combined with bone graft and their calcaneal anatomic forms were recovered during operation .Mary-land foot score was used to evaluate the postoperative function .Results All the 25 cases (33 feet) were followed up for 12-36 months,with a mean time of 19.3 months.According to Maryland foot score ,17 feet were rated as excellent , 12 feet as good,4 feet as moderate.The excellent and good rate was 87.88 %.Conclusion Anatomical Ti-plate combined with bone graft for treatment of intra-articular calcaneal fractures can restore the smoothness of subtalar joint surface,help patients take earlier functional exercise and obtain a reliable curative effect .%目的:探讨解剖型跟骨钛板并植骨治疗跟骨关节内骨折的临床疗效。方法选择2009年3月~2012年5月期间收治的25例(33足)SanderslⅡ~Ⅳ型跟骨关节内骨折患者,男性20例(26足),女性5例(7足);年龄15~65岁,平均(36.16±14.63)岁。单足17例,双足8例,采用切开复位解剖型跟骨钛板内固定并植骨进行治疗,术中恢复跟骨解剖形态,按Maryland足部评分系统进行术后功能评分,评价手术效果,进行系统的回顾性总结分析。结果本组25例(33足)术后均获12~36个月随访(平均19.3个月),按Maryland足部评分标准:优17足、良12足、可4足,差0足;优良率为87.88%。

  3. Evaluation of pediatric lower extremity fractures managed with external fixation: outcomes in a deployed environment.

    Science.gov (United States)

    Eichinger, Josef K; McKenzie, Colin S; Devine, John G

    2012-01-01

    External fixation of pediatric lower extremity fractures is usually reserved for severe, open fractures in polytraumatized patients, but it is often the only available treatment option for deployed military surgeons. We analyzed the outcomes and complications of 17 consecutive pediatric long bone fractures treated with external fixation at a Forward Surgical Team facility in an austere environment during Operation Enduring Freedom in Afghanistan during a 12-month period. Treatment consisted of uniplanar external fixation for 12 femoral shaft fractures (11 closed), 4 tibial shaft fractures (all open), and 1 subtrochanteric fracture (closed) in 14 males and 3 females with an average age of 7.4 years. All 17 fractures went on to union with no incidences of refracture. Complications included 1 broken pin and 3 pin site infections treated with wound care and oral antibiotics. In a deployed environment, external fixation is the treatment method of choice for lower extremity fractures by virtue of patient, environment, equipment, and mission factors. This case series validates the usage of a simple, uniplanar external fixator for a variety of open and closed pediatric long bone fractures as evidenced by the successful union rate and low number of complications.

  4. Treatment of neglected elbow dislocations with the help of hinged external fixator: Report of two cases

    Directory of Open Access Journals (Sweden)

    Özgür Karakoyun

    2014-06-01

    Full Text Available Elbow dislocations are cases that have to be treated in emergency conditions. Neglected elbow dislocations are seen very rarely and the treatment of such cases are more complicated than acute cases. We present two cases of neglected elbow dislocations treated with open reduction and hinged external fixators. Case 1: 23 year old female patient had a neglected posterior dislocation of left elbow with ipsilateral humeral shaft fracture caused by car accident. The patient was treated after 3 months of initial trauma. We have performed open reduction for the joint. After that we fixed the joint whit a hinged external fixator. The humeral shaft fracture was also fixed with the components of the external fixator. Case 2: 33 year male patient had a large bone and soft tissue defect around the left elbow accompanying with neglected medial elbow dislocation. He presented to our clinic with a delay of 2 months. The patient was treated with open reduction and hinged external fixator after reconstruction of bone defect of distal humerus. Conclusion: The treatment of neglected cases is quite challenging. Open reduction and external fixation has satisfactory results in treatment of late cases of elbow dislocation with the possibility of early rehabilitation. This method can be considered as an option for such cases. J Clin Exp Invest 2014; 5 (2: 443-446

  5. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  6. Nitrogen fixation by marine cyanobacteria.

    Science.gov (United States)

    Zehr, Jonathan P

    2011-04-01

    Discrepancies between estimates of oceanic N(2) fixation and nitrogen (N) losses through denitrification have focused research on identifying N(2)-fixing cyanobacteria and quantifying cyanobacterial N(2) fixation. Previously unrecognized cultivated and uncultivated unicellular cyanobacteria have been discovered that are widely distributed, and some have very unusual properties. Uncultivated unicellular N(2)-fixing cyanobacteria (UCYN-A) lack major metabolic pathways including the tricarboxylic acid cycle and oxygen-evolving photosystem II. Genomes of the oceanic N(2)-fixing cyanobacteria are highly conserved at the DNA level, and genetic diversity is maintained by genome rearrangements. The major cyanobacterial groups have different physiological and ecological constraints that result in highly variable geographic distributions, with implications for the marine N-cycle budget.

  7. Biodegradable plastics from renewable sources.

    Science.gov (United States)

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  8. Lung toxicity of biodegradable nanoparticles.

    Science.gov (United States)

    Fattal, Elias; Grabowski, Nadége; Mura, Simona; Vergnaud, Juliette; Tsapis, Nicolas; Hillaireau, Hervé

    2014-10-01

    Biodegradable nanoparticles exhibit high potentialities for local or systemic drug delivery through lung administration making them attractive as nanomedicine carriers. However, since particulate matter or some inorganic manufactured nanoparticles exposed to lung cells have provoked cytotoxic effects, inflammatory and oxidative stress responses, it becomes important to investigate nanomedicine toxicity towards the lungs. This is the reason why, in the present review, the behavior of biodegradable nanoparticles towards the different parts of the respiratory tract as well as the toxicological consequences, measured on several models in vitro, ex vivo or in vivo, are described. Taken all together, the different studies carried out so far conclude on no or slight toxicity of biodegradable nanoparticles.

  9. Osteoporotic Hip Fractures: The Burden of Fixation Failure

    Directory of Open Access Journals (Sweden)

    J. M. Broderick

    2013-01-01

    Full Text Available Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

  10. Osteoporotic hip fractures: the burden of fixation failure.

    Science.gov (United States)

    Broderick, J M; Bruce-Brand, R; Stanley, E; Mulhall, K J

    2013-01-01

    Osteoporotic hip fractures are a major cause of morbidity and mortality in the elderly. Furthermore, reduced implant anchorage in osteoporotic bone predisposes towards fixation failure and with an ageing population, even low failure rates represent a significant challenge to healthcare systems. Fixation failure in fragility fractures of the hip ranges from 5% in peritrochanteric fractures through to 15% and 41% in undisplaced and displaced fractures of the femoral neck, respectively. Our findings, in general, support the view that failed internal fixation of these fragility fractures carries a poor prognosis: it leads to a twofold increase in the length of hospital stay and a doubling of healthcare costs. Patients are more likely to suffer a downgrade in their residential status upon discharge with a consequent increase in social dependency. Furthermore, the marked disability and reduction in quality of life evident before salvage procedures may persist at long-term followup. The risk, of course, for the elderly patient with a prolonged period of decreased functioning is that the disability becomes permanent. Despite this, however, no clear link between revision surgery and an increase in mortality has been demonstrated in the literature.

  11. APPLICATION OF ACETABULAR TRIDIMENSIONAL MEMORY ALLOY-FIXATION SYSTEM IN TREATMENT OF OLD ACETABULAR POSTERIOR WALL FRACTURE WITH BONE DEFECT%髋臼镍钛记忆合金三维内固定系统治疗陈旧性髋臼后壁骨折合并骨缺损

    Institute of Scientific and Technical Information of China (English)

    曹烈虎; 鲍广全; 张春才; 刘欣伟; 牛云飞; 许硕贵; 苏佳灿

    2011-01-01

    Objective To investigate the effectiveness of acetabular tridimensional memory alloy-fixation system (ATMFS) combined with autologous iliac bone in the treatment of old acetabular posterior wall fracture with bone defect. Methods Between January 2002 and February 2009, 17 patients with old acetabular posterior wall fracture and bone defect were treated, including 11 males and 6 females with an average age of 41.7 years (range, 20-60 years). The time from fracture to admission was 14-180 days (mean, 63 days). The displacement of the acetabular articular surface was more than or equal to 3 mm. According to the America Association of Orthopedic Surgeon (AAOS) acetabular fracture and defect classification standard, there were 4 cases of type I, 6 cases of type II, 5 cases of type III, and 2 cases of type IV. After the residual fracture fragments of the acetabular posterior wall and soft tissue hyperplasia were removed, the femoral head was reducted, and posterior wall defect was repaired with autologous iliac bone graft; ATMFS was used to fix acetabular posterior wall and artificial capsular ligament to reconstruct the hip so as to prevent re-dislocation of the femoral head. Results According to Matta imaging assessment standard, the results were excellent in 8 cases, good in 6 cases, fair in 2 cases, and poor in 1 case with an excellent and good rate of 82.3%. All incisions healed by first intention, and no sciatic nerve injury occurred. All patients were followed up 1-8 years (mean, 3.9 years). The mean time of fracture union was 3.6 months (range, 2-6 months). Avascular necrosis of femoral head occurred in 1 case, heterotopic ossification around the acetabulum in 1 case. According to Merle d'Aubign6-Postel scoring system evaluation, the clinical results were excellent in 9 cases, good in 6 cases, fair in 1 case, and poor in 1 case with an excellent and good rate of 88.2%. Conclusion ATMFS combined with autologous iliac bone graft and artificial ligament

  12. Pedicle screw fixation for thoracolumbar fracture with spinal cord injury:a comparison of the selective injury segment and the whole bone graft fusion%椎弓根置钉修复胸腰椎骨折合并脊髓损伤:选择性损伤节段及全部固定节段植骨融合的比较

    Institute of Scientific and Technical Information of China (English)

    史晓林; 张昊; 刘磊; 史晓东; 金晓宁; 刘清阁; 袁伟东

    2016-01-01

    BACKGROUND:Spinal canal decompression is needed in posterior pedicle screw fixation surgery for thoracolumbar burst fractures combine with spinal cord injury. The structure of posterior spine is often damaged. The posterolateral bone fusion in al fixed segment is stil the main surgery. In order to further reduce fusion segment and maintain motor unit, it is necessary to perform selective segmental bone graft fusion during fixation and decompression. OBJECTIVE: To discuss the advantages of selective posterolateral vertebral fusion for thoracolumbar fracture with spinal injury through comparing with posterolateral vertebral fusion. METHODS: Data of 83 thoracolumbar burst fracture cases, who received posterior lumbar decompression and short segment fixation with pedicle screws and bone graft through injured vertebra from January 2006 to July 2013, were analyzed retrospectively. According to fusion segments, above patients were divided into selective posterolateral vertebral fusion group (n=42) and the whole posterolateral vertebral fusion group (n=41). Perioperative index, internal fixation, vertebral height loss rate, Cobb angle, spinal nerve recovery and Oswestry Disability Index were compared between the two groups. RESULTS AND CONCLUSION:(1) Al cases were folowed up for 25-32 months. (2) There was no statistical significance in operation time, intraoperative blood loss and ambulation time between the two groups (P > 0.05). Postoperative drainage volume was less in the selective posterolateral vertebral fusion group than in the whole posterolateral vertebral fusion group (P 0.05). (4) There was no significant difference in fusion rate at 6 months after treatment between the two groups (P > 0.05). Fusion was achieved in both groups before removal of the fixator. (5) Spinal nerve recovery was found after treatment in both groups. No significant difference in Oswestry Disability Index was detected in final folow-up (P > 0.05). (6) Results verified that compared with

  13. Biodegradable micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Greve, Anders; Schmid, Silvan

    The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization of mechani......The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization...... of biopolymers to microfabrication is challenging, as these polymers are affected by common processes such as photolithography or wet etching. Here, we present two methods for fabrication of biodegradable micromechanical sensors. First, we fabricated bulk biopolymer microcantilevers using nanoimprint lithography...

  14. Biodegradation of propellant ingredients

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.Z.; Sundaram, S.T.; Sharma, A. [Geo-centers, Inc., Lake Hopatcong, NJ (United States)] [and others

    1995-12-31

    This paper summarizes efforts to degrade nitrocellulose (NC) and nitroglycerin (NG) with fungi. Screening experiments were performed to determine the ability of mycelial fungi to biodegrade NC. The greatest amount of NC degradation was obtained with Sclerotium rolfsii ATCC 24459 and Fusarium solani IFO 31093. These fungi were then tested for NG degradation. It was found that the combined culture aerobically degraded 100% of the NG to form a mixture of 55% dinitroglycerin (DNG) and 5% of mononitroglycerin (MNG) in two days, with no further change observed afterward. In the presence of 1.2% glucose and 0.05% ammonium nitrate, NG was completely degraded in two days and a mixture of 20% DNG and 16% MNG was formed after 11 days. Based on these results, it appears that the combination of the fungi in a one to one ratio can be used to degrade both of these energetic compounds.

  15. Experimental micromechanics of the cement-bone interface.

    NARCIS (Netherlands)

    Mann, K.A.; Miller, M.A.; Cleary, R.J.; Janssen, D.; Verdonschot, N.J.J.

    2008-01-01

    Despite the widespread use of cement as a means of fixation of implants to bone, surprisingly little is known about the micromechanical behavior in terms of the local interfacial motion. In this work, we utilized digital image correlation techniques to quantify the micromechanics of the cement-bone

  16. REVERSE ENGINEERING OF THE MITKOVIC TYPE INTERNAL FIXATOR FOR LATERAL TIBIAL PLATEAU

    Directory of Open Access Journals (Sweden)

    Nikola Vitković

    2015-12-01

    Full Text Available In orthopaedic surgery it is very important to use proper fixation techniques in the treatment of various medical conditions, i.e. bone fractures or other traumas. If an internal fixation method, such as plating, is required, it is possible to use Dynamic Compression Plates (DCP or Locking Compression Plates (LCP and their variants. For DCP implants it is important to match the patient's bone shape with the most possible accuracy, so that the most frequent implant bending is applied in the surgery. For LCP implants it is not so important to match the patient’s bone shape, but additional locking screw holes are required. To improve the geometrical accuracy and anatomical correctness of the shape of DCP and to improve the LCP geometric definition, new geometrical modelling methods for the Mitkovic type internal fixator for Lateral Tibia Plateau are developed and presented in this research. The presented results are quite promising; it can be concluded that these methods can be applied to the creation of geometrical models of internal fixator customized for the given patient or optimized for a group of patients with required geometrical accuracy and morphological correctness.

  17. Cheek drooping in 2 patients with maxillary fractures after rigid fixation with bioabsorbable mesh.

    Science.gov (United States)

    Oh, Seung Hyun; Kim, Chung Hun; Choi, Hyun Gon; Hwang, Euna

    2014-03-01

    Bioabsorbable plate-screw systems are commonly used for the internal fixation of facial bone fractures. The anterior maxilla has a unique curved shape, and fractured bony fragments tend to be small and fragile; therefore, more effective rigid fixation can be achieved using a molded bioabsorbable mesh rather than a bioabsorbable plate. Herein, we describe 2 patients with cheek drooping after a rigid fixation of comminuted maxillary fracture using bioabsorbable meshes and screws.The postoperative courses were uneventful, but both showed soft tissue bulging in the cheek area of the operation site for 12 to 13 months after the operation. No other symptom or sign related to inflammation or foreign body reaction was noted.In comminuted maxillary fractures, bone fragments are more conveniently fixed with a 1-piece molded bioabsorbable mesh. However, it is believed that a single large mesh may interfere with adhesion between the maxillary surface and the overlying soft tissue. Therefore, we recommend using the least amount of mesh to fixate maxillary bone fragments.

  18. The Clinical Usefulness of Ultrasound-Aided Fixation Using an Absorbable Plate System in Patients with Zygomatico-Maxillary Fracture

    Directory of Open Access Journals (Sweden)

    Jong Hun Lee

    2013-07-01

    Full Text Available Background  Ultrasound-aided fixation is a recently developed alternative method of treatment of zygomatico-maxillary (ZM fracture, and it can resolve the problems of excessivetorsion force and subsequent fractures of screws. We conducted this study to evaluate theclinical usefulness of ultrasound-aided fixation as compared with the conventional fixationmethod using a drill and an expanderin patientswith ZMfracture.Methods  We conducted a retrospective study in 35 patientswith ZMfracturewho had beentreated at our hospital during a period ranging fromMarch of 2008 toDecember of 2010. Wedivided them into two groups: an ultrasound-aided fixation group, comprising 13 patientswho underwent ultrasound-aided fixation (SonicWeld Rx, KLS Martin, and a conventionalgroup, comprising 22 patients who underwent conventional fixation (Biosorb FX, LinvatecBiomaterials Ltd.. We compared such variables as sex, direction, age at operation, follow-upperiod, operation duration, number of fixed holes, and time to discharge between the twogroups.Results  The ultrasound-aided fixation reduced the operation duration by about 30 minutesas comparedwith that of conventional fixation. Therewas no significant difference in followup period, number of fixed holes, ortime to discharge between the two groups. Furthermore,therewere no complicationsin either group.Conclusions  The ultrasound-aided fixation offractured ZMbone using an absorbable implantsystemissafe and effective in promptly reducing the bone fracture and providing satisfactorycosmetic outcomes overtime.

  19. Posteromedial approach of gastrocnemius for reduction and internal fixation of avulsed tibial attachment of posterior cruciate ligament

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-li; XU Hu; LI Ming-quan

    2006-01-01

    Objective:To introduce a posteromedial approach through the medial border of the medial head of gastrocnemius for reduction and reattachment of bony avulsion of the posterior cruciate ligament (PCL) from the tibia.Methods: Eleven patients with avulsed tibial attachment of the PCL underwent an operative reduction and internal fixation through the posteromedial approach of the gastrocnemius in our department from February 1998 to March 2000. The skin incision was reversed L-shaped along the medial border of the medial head of the gastrocnemius and the posterior capsule was exposed by dissecting the medial border and lateral retraction, avoiding the damage of the popliteal neurovascular structures. After that, the posterior capsule was vertically dissected a little medially to the posterior intercondylar sulcus and just on the posterior medial tibial eminence positioned by finger palpation. Then the PCL and its tibial attachment were easily accessible. In the delayed cases, PCL peripheral releasing was necessary to overcome the ligament retraction and to refresh the fracture bed for optimal reduction and bony healing. At last, one or two biodegradable screws were used to fix the avulsed bone segment and 30° flexion knee plaster cast immobilization was regularly applied after the wound was closed. The evaluation included X-ray, posterior sag sign and posterior drawer test compared with the contralateral side. The functional assessment of the low limbs was not available because of concomitant injuries.Results: The posteromedial approach of the gastrocnemius used in repair of tibial attachment avulsed injury of the PCL could provide benefit of clear anatomical exposure, few blood loss (20 ml on average), no need for detachment or reattachment of any structure. The patients were followed up for 11 months on an average (ranging from 6 months to 2 years ). It demonstrated that bony healing was achieved within 4-6 weeks in cases of fresh injury and 7-9 weeks in cases of

  20. Absorbable fixation in forefoot surgery: a viable alternative to metallic hardware.

    Science.gov (United States)

    Nielson, David L; Young, Nathan J; Zelen, Charles M

    2013-07-01

    After 4 to 8 weeks of normal primary bone healing, rigid internal fixation is no longer required. Newer generation absorbable implants have become reliable and cost-effective alternatives to metallic hardware. Modern implants are formulated to have increased strength and smoother resorption over the course of 18 to 24 months, which decreases the possibility of local inflammation. Historically, bioresorbable screws can be time consuming to insert, but newer devices are being developed that help ease their insertion. A case of a bunionectomy is presented with double osteotomy on a 40-year-old nurse fixated with polyglycolic acid and poly-l-lactic acid copolymer screws.

  1. Closed hip and long bone fractures The regimen effectiveness of antibiotic prophylaxis in surgical fixation%闭合性髋部骨折或长骨骨折围手术期抗生素预防性应用的疗效分析

    Institute of Scientific and Technical Information of China (English)

    Dan C Norvell; 王簕; 杨云峰

    2009-01-01

    对22项随机对照研究进行Meta分析,以评价在闭合性髋部骨折或长骨骨折的围手术期中,静脉预防性抗生素应用的疗效.与未应用静脉抗生素组相比,术前静脉应用抗生素(术前单剂量抗生素应用或术前联合术后多次应用)可以明显降低术后深部感染、浅表感染、泌尿道感染的发生率.当应用短效抗生素预防术中感染时,多次剂量应用可以明显降低感染的发生率.但是,当应用长效抗生素预防感染时,单剂量应用组与多剂量应用其他短效抗生素组效果相当.在比较抗生素多剂量给药疗法间或不同给药方式间(口服或静脉给药)对预防感染的疗效时发现,不论采取何种方法 ,预防感染的效果均无明显差异.%A metaanalysis of 22 randomized controlled trials found evidence to support parenteral antibiotic prophylaxis regimens for patients undergoing surgical fixation of closed hip and long bone fractures. Preoperative parenteral antibiotic doses (single or combined with multiple postoperative doses) resulted in decreased risk of deep, superficial, and urinary tract infections compared with no antibiotic. Single doses of short acting agents may be less effective than multiple doses of the same agent in decreasing the risk of any of the infections evaluated. By contrast, there was no significant difference in infection risk between a single dose of a long acting agent and multiple doses of other agents with shorter half lives. No significant differences were found when multiple dose regimens were compared or when administration routes (oral versus parenteral) were compared.

  2. Biomedical Applications of Biodegradable Polyesters

    OpenAIRE

    Iman Manavitehrani; Ali Fathi; Hesham Badr; Sean Daly; Ali Negahi Shirazi; Fariba Dehghani

    2016-01-01

    The focus in the field of biomedical engineering has shifted in recent years to biodegradable polymers and, in particular, polyesters. Dozens of polyester-based medical devices are commercially available, and every year more are introduced to the market. The mechanical performance and wide range of biodegradation properties of this class of polymers allow for high degrees of selectivity for targeted clinical applications. Recent research endeavors to expand the application of polymers have be...

  3. Lumbar pedicle cortical bone trajectory screw

    Institute of Scientific and Technical Information of China (English)

    Song Tengfei; Wellington K Hsu; Ye Tianwen

    2014-01-01

    Objective The purpose of this study was to demonstrate the lumbar pedicle cortical bone trajectory (CBT) screw fixation technique,a new fixation technique for lumbar surgery.Data sources The data analyzed in this review are mainly from articles reported in PubMed published from 1994 to 2014.Study selection Original articles and critical reviews relevant to CBT technique and lumbar pedicle fixation were selected.Results CBT technique was firstly introduced as a new fixation method for lumbar pedicle surgery in 2009.The concepts,morphometric study,biomechanical characteristics and clinical applications of CBT technique were reviewed.The insertional point of CBT screw is located at the lateral point of the pars interarticularis,and its trajectory follows a caudocephalad path sagittally and a laterally directed path in the transverse plane.CBT technique can be used for posterior fixation during lumbar fusion procedures.This technique is a minimally invasive surgery,which affords better biomechanical stability,fixation strength and surgical safety.Therefore,CBT technique has the greatest benefit in lumbar pedicle surgery for patients with osteoporosis and obesity.Conclusion CBT technique is a better alternative option of lumbar pedicle fixation,especially for patients with osteoporosis and obesity.

  4. Backgrounds of antibiotic-loaded bone cement and prosthesis-related infection

    NARCIS (Netherlands)

    Hendriks, JGE; van Horn, [No Value; van der Mei, HC; Busscher, HJ

    2004-01-01

    Antibiotic-loaded bone cement has been in use for over 30 years for the fixation of total joint arthroplasties, although its mechanism of action is still poorly understood. This review presents the backgrounds of bone cements, prosthesis-related infection and antibiotic-loaded bone cements. It is sh

  5. Biodegradable mesoporous delivery system for biomineralization precursors

    Directory of Open Access Journals (Sweden)

    Yang HY

    2017-01-01

    Full Text Available Hong-ye Yang,1 Li-na Niu,2 Jin-long Sun,2 Xue-qing Huang,3 Dan-dan Pei,4 Cui Huang,1 Franklin R Tay5 1The State Key Laboratory Breeding Base of Basic Science of Stomatology, Key Laboratory for Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, Hubei, People’s Republic of China; 2State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Shaanxi Key Laboratory of Oral Diseases, Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University, Xi’an, Shaanxi, People’s Republic of China; 3Department of Prosthodontics, Guanghua School and Hospital of Stomatology, Guangdong Key Laboratory of Stomatology, Yat-sen University, Guangzhou, Guangdong, People’s Republic of China; 4Department of Prosthodontics, College of Stomatology, Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China; 5Department of Endodontics, College of Dental Medicine, Augusta University, Augusta, GA, USA Abstract: Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP

  6. Biodegradable intestinal stents:A review

    Institute of Scientific and Technical Information of China (English)

    Zhanhui Wang; Nan Li; Rui Li; Yawei Li; Liqun Ruan

    2014-01-01

    Biodegradable stents are an attractive alternative to self-expanding metal stents in the treatment of intestinal strictures. Biodegradable stent can be made of biodegradable polymers and biodegradable metals (magnesium alloys). An overview on current biodegradable intestinal stents is presented. The future trends and perspectives in the development of biodegradable intestinal stents are proposed. For the biodegradable polymer intestinal stents, the clinical trials have shown promising results, although improved design of stents and reduced migration rate are expected. For the biodegradable magnesium intestinal stents, results of preliminary studies indicate magnesium alloys to have good biocompatibility. With many of the key fundamental and practical issues resolved and better methods for adjusting corrosion resistance and progressing biocompatibilities of magnesium alloys, it is possible to use biodegradable intestinal stents made of magnesium alloys in hospital in the not too distant future.

  7. Intramedullary foot fixation for midfoot Charcot neuroarthropathy.

    Science.gov (United States)

    Lamm, Bradley M; Siddiqui, Noman A; Nair, Ajitha K; LaPorta, Guido

    2012-01-01

    Midfoot Charcot collapse commonly occurs through the tarsometatarsal and/or midtarsal joints, which creates the characteristic "rocker bottom" deformity. Intramedullary metatarsal fixation spanning the tarsus into the talus and/or calcaneus is a recently developed method for addressing unstable midfoot Charcot deformity. The intramedullary foot fixation technique has various advantages when addressing midfoot Charcot deformity in the neuropathic patient. These advantages include anatomical realignment, minimally invasive fixation technique, formal multiple joint fusion, adjacent joint fixation beyond the level of Charcot collapse, rigid interosseus fixation, and preservation of foot length. The goals of the intramedullary foot fixation procedure are to create a stable, plantigrade, and ulcer-free foot, which allows the patient to ambulate with custom-molded orthotics and shoes.

  8. The evaluation of curative effect for lumbar spondylolisthesis by posterior lumbar intervertebral compression bone graft fusion and pedicle screw internal fixation%椎间打压植骨融合椎弓根钉内固定术治疗腰椎滑脱症疗效评价

    Institute of Scientific and Technical Information of China (English)

    黄久勤; 王传文

    2009-01-01

    Objective To investigate the curative effect for lumbar spondylolisthesis by posterior lumbar intervertebral compression bone graft fusion and pedicle screw internal fixation.Method All 39 cases with lumbar spondylolisthesis accepted treatment during January 2003 to October 2007.There were cataplasia spondylolisthesis in 14 cases and isthmic spondylolisthesis in 25 cases.Twenty-two cases had spondylolisthesis in L4 and 17 cases had spondylolisthesis in L5.According to Meyerding grading,11 patients were classified as degree Ⅰ lesion.27 patients as degree Ⅱ lesion and 1 patient as degree Ⅲ lesion.By the help of X-ray machine,pedicle screw Was embedded in the vertebral spondylolisthesis and it Was lower vertebra.Laminectomy decompress was administered in vertebral spondylolisthesis and hold-down bars was placed to open intervertebral space.Then restored the vertebral spondylolisthesis and fixed it temporary.Next,intervertebral compression bone graft fusion was finished and was adjusted.Results Follow-up period was 5 months to 4 years.Clinical outcomes were measured with Prolo evaluation scale,35 cases were cured,4 cases were good effect.Conclusions This operation has been found to be asafe,rapid and effective method for lumbar spondylolisthesis and it produces a high fusion rate and lower expense.%目的 评价椎间打压植骨融合椎弓根钉内固定术治疗腰椎滑脱症的临床疗效.方法 2003年1月至2007年10月收治的腰椎滑脱症患者39例,其中退变性滑脱14例,峡部裂性滑脱25例.L4椎体滑脱22例,L5k椎体滑脱17例.按Meyerding滑脱程度分级标准:Ⅰ度滑脱11例,Ⅱ度滑脱27例,Ⅲ度滑脱1例.C型臂X线机透视定位下在滑脱椎体及其下位椎体间植入椎弓根螺钉,行滑脱椎体全椎板减压术,安放固定棒并撑开椎间隙,进行滑脱椎体复位及临时固定,处理椎间隙,行椎间打压植骨融合术,调整钉棒进行椎间适度加压,以植骨块稳定为度.结果 本组患者

  9. Preliminary fabrication of tissue engineered veins containing valves using bone marrow mesenchymal stem cells and biodegradable scaffolds in vitro%骨髓间充质干细胞联合可降解支架体外构建组织工程带瓣静脉

    Institute of Scientific and Technical Information of China (English)

    刘池拽; 殷恒讳; 吕伟明; 曾晨光; 刘畅; 王文见; 全大萍; 项鹏; 王深明

    2014-01-01

    Beagle dogs by density gradient centrifugation and adherence methods. Bone marrow mesenchymal stem cells were cultured in vitro. Fol owing isolation and culture the cells were examined using flow cytometry and identified by direct induction towards the osteogenic and adipogenic lineages. We fabricated biodegradable venous scaffold containing valves using the method of injection molding combined with thermal y induced phase separation. Based on the self-made cast, a three-dimensional biodegradable vein scaffold containing valves was constructed from poly(lactic-co-glycolic acid). Morphological structure was tested. Bone marrow mesenchymal stem cells were used as seed cells to be seeded onto the lumen of the tissue engineered vein scaffold containing valves in vitro and then incubated for 2 weeks. RESULTS AND CONCLUSION:Scanning electron microscopy images showed that the scaffold demonstrated sufficient porosity. Cultured cells expressed mesenchymal cellmarkers, CD44 and CD29, but did not express hematopoietic cellmarkers, CD34 and CD45 at the same time point. Scaffolds were nontoxic to cells and were favorable for the growth and migration of bone marrow mesenchymal stem cells. cells attached on the surface of poly(lactic-co-glycolic acid) scaffolds formed a confluent layer after incubation. The cellular constructs were tested in vitro, and the valve leaflets were functional y capable of opening and closing when stimulated. These results suggested that the tissue engineered vein containing valves have been successful y constructed by using a three-dimensional poly(lactic-co-glycolic acid) scaffold and bone marrow mesenchymal stem cells as seed cells. Tissue engineered vein containing valves is potential y useful for the substitution and regeneration of vein valves.

  10. Modeling fixation locations using spatial point processes.

    Science.gov (United States)

    Barthelmé, Simon; Trukenbrod, Hans; Engbert, Ralf; Wichmann, Felix

    2013-10-01

    Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation.

  11. Metallic Fixation of Mandibular Segmental Defects: Graft Immobilization and Orofacial Functional Maintenance

    Science.gov (United States)

    Shayesteh Moghaddam, Narges; Jahadakbar, Ahmadreza; Amerinatanzi, Amirhesam; Elahinia, Mohammad; Miller, Michael

    2016-01-01

    Background: The aim of this study is to investigate the behavior of the healthy mandible under maximum molar bite force to demonstrate the problems associated with the current standard of care procedures for mandibular segmental defect reconstruction (ie, use of Ti–6Al–4V hardware and either a single- or double-barrel fibular graft). With current Ti–6Al–4V mandibular reconstruction hardware, there is a significant stiffness mismatch among the hardware, graft, and the remaining host anatomy. How the distribution of mechanical forces through the mandible is altered after a segmental bone loss and reconstruction is incompletely understood. Methods: We studied a healthy adult mandible for stress, strain, and reaction force distribution during normal mastication. Stress distribution of this model was then used to study problems encountered after mandibular segmental defect reconstructive surgery. We model the use of both single- and double-barrel fibular grafts to repair the loss of the left M1–3 containing segment of the mandible. These simulations were done using 2 sets of plates with different thicknesses. Results: We found that the stiffness mismatching between the fixation hardware and the graft and host bone causes stress shielding of that bone and stress concentrations in the fixation hardware and screws. These effects are expected, especially during the bone healing period. However, long term, this abnormal stress–strain distribution may lead to either the hardware’s failure due to stress concentration or graft failure due to bone resorption as a result of stress shielding. We found that the stress–strain distribution is more normal with a double-barrel fibular graft. Additionally, we found that thinner fixation plates can reduce stress shielding. Conclusion: The proposed model can be used to evaluate the performance and optimization of the fixation device.

  12. Treatment of infected non-unions with segmental defects with a rail fixation system.

    Science.gov (United States)

    Mudiganty, Srikanth; Daolagupu, Arup Kumar; Sipani, Arun Kumar; Das, Satyendra Kumar; Dhar, Arijit; Gogoi, Parag Jyoti

    2017-04-01

    We conducted this study to evaluate the use of rail fixation system in infected gap non-union of femur and tibia as an alternative to the established Ilizarov circular fixator technique. Prospective study. The study was done in the Department of Orthopaedic surgery in a medical school and level I trauma center to which the authors are/were affiliated. Between June 2010 and June 2015, 40 patients with infected gap non-union of femur and tibia were treated with the rail fixation system. Patients who were willing to undergo surgery and participate in the post-operative rehabilitation were included in the study. After radical debridement, the system was applied and corticotomy done. For closure of bone gap, acute docking and distraction was done in 18 cases and segmental bone transport in 22 cases. Early mobilization of patient was done along with aggressive physiotherapy. Bone and functional results were calculated according to ASAMI scoring system, and complications were classified according to Paley classification. The mean follow-up period was 22.56 months (range 8-44). Bone union with eradication of infection was achieved in all but 1 case (97.5%). Bone results were excellent in 57.5%, good 40%, fair 0% and poor in 2.5% cases, while functional result was excellent in 32.5%, good 65%, fair 0% and poor in 2.5% cases. The rail fixation system is an excellent alternative method to treat infected gap non-union of femur and tibia. It is simple, easy to use and patient-friendly.

  13. 胸腰椎结核伴重度后凸畸形:矫形内固定与植骨融合后的脊柱稳定性%Thoracolumbar tuberculosis complicated with severe kyphosis:spinal stability after orthopedic fixation and bone grafting fusion

    Institute of Scientific and Technical Information of China (English)

    邓强; 帕尔哈提·热西提; 张亚楼; 盛伟斌

    2015-01-01

    BACKGROUND:At present, there was lack of reports on the efficacy of thoracolumbar tuberculosis complicated with severe kyphosis (>90°). Choice of surgical treatment is necessary for patients with severe spinal tuberculosis kyphosis, affected heart and lung function and neurological disorders. OBJECTIVE:To retrospectively analyze the repair effect of I-stage posterior osteotomy orthopedic fixation and II-stage anterior debridement interbody bone grafting fusion in repair of patients with thoracolumbar tuberculosis complicated with severe kyphosis. METHODS:Total y 53 patients with spinal tuberculosis complicated with severe kyphosis were enrol ed. Patients underwent posterior osteotomy orthopedic fixation in the first stage, and underwent anterior debridement interbody bone grafting fusion in the second stage. X-ray, CT, MRI and other imaging examinations were conducted before and after the treatment. Erythrocyte sedimentation rate, C-reactive protein, pain visual analog scale scores, kyphosis and ASIA spinal cord injury classification before and after the treatment were compared and analyzed for clinical evaluation of efficacy. RESULTS AND CONCLUSION:Al patients had a successful surgery. The operative time was 290 (195-420) minutes, and the intra-operative amount of blood loss was 1800 (1 100-3 300) mL, the average number of fixed segments were 11.8 (9-16). Al these 53 patients were fol owed up for 26-28 months. The erythrocyte sedimentation rate and C-reactive protein of patients after treatment gradual y recovered to normal, and recovered to normal levels at the final fol ow-up. The mean correction of sagittal Cobb angle was 77.92°, the correction rate reached to 74.6%at the final fol ow-up. Til the final fol ow-up, the average loss of corrective angle was 1.35°. The lower back pain and limitation of function obtained varying degrees of al eviating after treatment. The visual analog scale scores in the final fol ow-up were significantly lower than those before

  14. Epoxy putty external skeletal fixation in a tibiotarsal fracture of a wild choroy parakeet (Enicognathus leptorhynchus

    Directory of Open Access Journals (Sweden)

    J. I. Arias

    2015-06-01

    Full Text Available Tibiotarsal fractures are common in birds because in most birds this is the longest, most exposed bone in the leg. Transverse fractures are most common and rotational and shear forces must be stabilized in order to achieve good bone regeneration. A 230g male Slender-billed Parakeet or Choroy parakeet (Enicognathus leptorhynchus, with more than five years of age, was received with non-weight bearing lameness with 24 hours duration. X-rays were taken, and these revealed a closed, complete, non-comminuted transverse fracture of the distal diaphysis of the left tibiotarsal bone. Fixation was planned with 10-minute fast-setting epoxy putty. In order to assess the temperature of polymerization of the epoxy dough and the possibility of heat-bone necrosis, the temperature was recorded every 30 seconds for 12 minutes with three different amounts of the epoxy material in an ex vivo test. The temperature of the pieces reached a peak of 50-60ºC, where the highest peak corresponds to the highest amount of material. When approximately 6g of putty were used, the peak temperature reached only 51ºC. This peak changed to 58ºC when 4 times more epoxy was mixed and measured. If the temperature of the pins inserted in the bone exceeds 70ºC, bone necrosis could occur. In light of these results, the fracture was treated with 6 g of epoxy putty that was allowed to polymerize over a 1A 2/2 external skeletal fixation, with 1-mm pins bent at 90º and joined together with cerclage wire. At 6 weeks after surgery the bird had formed a good primary bone callus, and the external fixators were therefore removed. With this approach a satisfactory recovery of the patient was achieved with normal use of the affected limb.

  15. Progress of biodegradable metals

    Institute of Scientific and Technical Information of China (English)

    Huafang Li; Yufeng Zheng; Ling Qin

    2014-01-01

    Biodegradable metals (BMs) are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompat-ibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  16. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  17. Biodegradation of polyethoxylated nonylphenols.

    Science.gov (United States)

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively.

  18. Bone Markers

    Science.gov (United States)

    ... markers may be seen in conditions such as: Osteoporosis Paget disease Cancer that has spread to the bone (metastatic bone disease) Hyperparathyroidism Hyperthyroidism Osteomalacia in adults and rickets in children—lack of bone mineralization, ...

  19. Bone scan

    Science.gov (United States)

    ... legs, or spine fractures) Diagnose a bone infection (osteomyelitis) Diagnose or determine the cause of bone pain, ... 2015:chap 43. Read More Broken bone Metabolism Osteomyelitis Review Date 12/10/2015 Updated by: Jatin ...

  20. Bone Cancer

    Science.gov (United States)

    Cancer that starts in a bone is uncommon. Cancer that has spread to the bone from another ... more common. There are three types of bone cancer: Osteosarcoma - occurs most often between ages 10 and ...

  1. Bone Diseases

    Science.gov (United States)

    Your bones help you move, give you shape and support your body. They are living tissues that rebuild constantly ... childhood and your teens, your body adds new bone faster than it removes old bone. After about ...

  2. Intraoperative CT navigation for glenoid component fixation in reverse shoulder arthroplasty

    Directory of Open Access Journals (Sweden)

    Ashok S Gavaskar

    2013-01-01

    Full Text Available CT navigation has been shown to improve component positioning in total shoulder arthroplasty. The technique can be useful in achieving strong initial fixation of the metal backed glenoid in reverse shoulder arthroplasty. We report a 61 years male patient who underwent reverse shoulder arthroplasty for rotator cuff arthropathy. CT navigation was used intraoperatively to identify best possible glenoid bone and to maximize the depth of the fixation screws that anchor the metaglene portion of the metal backed glenoid component. Satisfactory positioning of screws and component was achieved without any perforation or iatrogenic fracture in the scapula. CT navigation can help in maximizing the purchase of the fixation screws that dictate the initial stability of the glenoid component in reverse shoulder arthroplasty. The technique can be extended to improve glenoid component position [version and tilt] with the availability of appropriate software.

  3. Prolonged Unilateral Disuse Osteopenia 14 Years Post External Fixator Removal: A Case History and Critical Review

    Directory of Open Access Journals (Sweden)

    Karen M. Knapp

    2010-01-01

    Full Text Available Disuse osteopenia is a complication of immobilisation, with reversal generally noted upon remobilisation. This case report focuses on a patient who was seen 18 years following a road traffic collision when multiple fractures were sustained. The patient had an external fixator fitted for a tibia and fibula fracture, which remained in situ for a period of 4 years. Following removal, the patient was mobilised but, still required a single crutch to aid walking. Fourteen years post removal of the fixator, the patient had a DXA scan which, demonstrated a T-score 2.5 SD lower on the affected hip. This places the patient at an increased risk of hip fracture on this side, which requires monitoring. There appear to be no current studies investigating prolonged disuse-osteopenia in patients following removal of long-term external fixators. Further research is required to quantify unilateral long-term effects to bone health and fracture risk in this population.

  4. Improved Reactive Dye-fixation in Pad-Steam Process of Dyeing Cotton Fabric Using Tetrasodium N, NBiscarboxylatomethyl- L-Glutamate

    Directory of Open Access Journals (Sweden)

    Awais Khatri

    2012-04-01

    Full Text Available Pad steam process of dyeing cotton with reactive dyes is known to give lower levels of dye-fixation on the fiber because of excessive dye-hydrolysis. This research presents improved reactive dye-fixation in padsteam process of dyeing cotton found in an effort of using biodegradable organic salts to improve the effluent quality. The CI Reactive Blue 250, a bissulphatoethylsulphone dye and the Tetrasodium N, Nbiscarboxylatomethyl- L-Glutamate, a biodegradable organic salt, were used. The new dye-bath formulation using the organic salt gave more than 90% dye-fixation. Traditional pad-steam process of dyeing cotton with reactive dyes requires the use of inorganic electrolyte, sodium-chloride, and alkali, sodium-carbonate, to ensure effective dye consumption and fixation. These inorganic chemicals when drained generate heavy contents of dissolved solids and oxygen demand in the effluent leading to environmental pollution. Thus, Tetrasodium N, N-biscarboxylatomethyl-L-Glutamate was used in place of inorganic electrolyte and alkali to improve effluent quality. A significant increase in dye-fixation and ultimate color-yield was obtained with same colorfastness properties of the dyed fabric comparing to the traditional pad-steam dye-bath formulation.

  5. Biodegradability engineering of biodegradable Mg alloys: Tailoring the electrochemical properties and microstructure of constituent phases

    Science.gov (United States)

    Cha, Pil-Ryung; Han, Hyung-Seop; Yang, Gui-Fu; Kim, Yu-Chan; Hong, Ki-Ha; Lee, Seung-Cheol; Jung, Jae-Young; Ahn, Jae-Pyeong; Kim, Young-Yul; Cho, Sung-Youn; Byun, Ji Young; Lee, Kang-Sik; Yang, Seok-Jo; Seok, Hyun-Kwang

    2013-08-01

    Crystalline Mg-based alloys with a distinct reduction in hydrogen evolution were prepared through both electrochemical and microstructural engineering of the constituent phases. The addition of Zn to Mg-Ca alloy modified the corrosion potentials of two constituent phases (Mg + Mg2Ca), which prevented the formation of a galvanic circuit and achieved a comparable corrosion rate to high purity Mg. Furthermore, effective grain refinement induced by the extrusion allowed the achievement of much lower corrosion rate than high purity Mg. Animal studies confirmed the large reduction in hydrogen evolution and revealed good tissue compatibility with increased bone deposition around the newly developed Mg alloy implants. Thus, high strength Mg-Ca-Zn alloys with medically acceptable corrosion rate were developed and showed great potential for use in a new generation of biodegradable implants.

  6. Favorable outcome of a total hip arthroplasty with insufficient bone coverage of the roof reinforcement ring

    Directory of Open Access Journals (Sweden)

    Fernando M. Judas

    2015-01-01

    Conclusion: This result can be supported by the good fixation of the metal ring to the pelvis with screws, the adequate orientation of both components of the total hip arthroplasty, and the bone graft incorporation.

  7. Hydroxyapatite-enhanced tibial prosthetic fixation.

    Science.gov (United States)

    Toksvig-Larsen, S; Jorn, L P; Ryd, L; Lindstrand, A

    2000-01-01

    Sixty-two knees (60 patients) were randomized to four noncemented groups. In Groups 1, 3, and 4, the bone cuts were made with a cooled saw blade. In Group 1, 15 patients were operated on with the porous coated Osteonic 7000 tibial component. In Group 2, 15 patients were operated on with the same tibial component as in Group 1 but with the use of a standard saw blade. In Group 3, 16 patients were operated on with the hydroxyapatite-coated Osteonic tibial component, and in Group 4, 16 patients were operated on with the hydroxyapatite Duracon tibial component. All patients were followed up clinically and with roentgenstereometric analysis. There were no differences among the groups regarding clinical outcome. One knee was revised (Group 2) after 1 year because of loosening of the tibial component. The maximum migration at 1 year was 1.7 mm in Group 1, 1.9 mm in Group 2, 1.3 mm in Group 3, and 1 mm in Group 4. At the 2-year followup, the migrations were 1.8 mm, 1.5 mm, 1.4 mm, and 1 mm in Groups 1, 2, 3, and 4, respectively. The inducible displacement that occurred at 1 year was 0.6 mm in Group 1, 0.5 mm in Group 2, 0.4 mm in Group 3, and 0.4 mm in Group 4. The hydroxyapatite coating had a strong positive effect on the tibial component fixation. No prosthesis in the hydroxyapatite groups showed continuous migration.

  8. Adhesion of biocompatible and biodegradable micropatterned surfaces

    NARCIS (Netherlands)

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  9. 3D artificial bones for bone repair prepared by computed tomography-guided fused deposition modeling for bone repair.

    Science.gov (United States)

    Xu, Ning; Ye, Xiaojian; Wei, Daixu; Zhong, Jian; Chen, Yuyun; Xu, Guohua; He, Dannong

    2014-09-10

    The medical community has expressed significant interest in the development of new types of artificial bones that mimic natural bones. In this study, computed tomography (CT)-guided fused deposition modeling (FDM) was employed to fabricate polycaprolactone (PCL)/hydroxyapatite (HA) and PCL 3D artificial bones to mimic natural goat femurs. The in vitro mechanical properties, in vitro cell biocompatibility, and in vivo performance of the artificial bones in a long load-bearing goat femur bone segmental defect model were studied. All of the results indicate that CT-guided FDM is a simple, convenient, relatively low-cost method that is suitable for fabricating natural bonelike artificial bones. Moreover, PCL/HA 3D artificial bones prepared by CT-guided FDM have more close mechanics to natural bone, good in vitro cell biocompatibility, biodegradation ability, and appropriate in vivo new bone formation ability. Therefore, PCL/HA 3D artificial bones could be potentially be of use in the treatment of patients with clinical bone defects.

  10. [Angle-fixed plate fixation or double-plate osteosynthesis in fractures of the proximal humerus: a biomechanical study].

    Science.gov (United States)

    Hessmann, Martin H; Korner, Jan; Hofmann, Alexander; Sternstein, Werner; Rommens, Pol M

    2008-06-01

    Internal fixation of fractures of the proximal humerus needs a high stability of fixation to avoid secondary loss of fixation. This is especially important in osteoporotic bone. In an experimental study, the biomechanical properties of the angle-fixed Philos plate (internal fixator) and a double-plate osteosynthesis using two one-third tubular plates were assessed. The fracture model was an unstable three-part fracture (AO type B2). Eight pairs of human cadaveric humeri were submitted to axial load and torque. In the first part of the study, it was assessed to which degree the original stiffness of the humeri could be restored after the osteotomy by the osteosynthesis procedure. Subsequently, subsidence during 200 cycles of axial loading and torque was analysed. During axial loading, the Philos plate was significantly stiffer and showed less irreversible deformation. Two double-plate fixations, but none of the Philos plate osteosynthesis, failed. During torsion, there were no significant differences between the two implants. From the biomechanical point of view, the angle-fixed Philos plate represents the implant of choice for the surgical fixation of highly unstable three-part fractures of the proximal humerus, as the internal fixator system is characterised by superior biomechanical properties.

  11. MANAGEMENT OF INFECTED NON UNION TIBIAL FRACTURES WITH ILIZAROV EXTERNAL FIXATION

    Directory of Open Access Journals (Sweden)

    Nageshwara Rao

    2015-10-01

    Full Text Available BACKGROUND & OBJECTIVES: Infected non - union of tibia per se is a challenge to treat. Subcutaneous bone causes susceptibility to compartment syndrome, non - responsive infection, non - union, fibrosis, sinuses, deformities, shortening and various other sets of problems which are assoc iated with it. Ilizarov External fixation provides correction of all the complications associated with non - union, bone gap, infection, shortening, and deformities. Objective of this study is to assess the efficacy and safety of Ilizarov fixator method of t reatment in infected non - union tibia and to study various complications associated with Ilizarov external fixation. MATERIALS AND METHODS: 23 patients admitted and treated in Government General Hospital under the Department of Orthopaedics during the perio d of May 2010 to December 2012 were included in the study. Results were evaluated according to ASAMI criteria . 1 RESULTS : 59% patients had excellent bony results, 27.3% had good bony results, 9.1% had fair bony results, 4.6% had poor bony results. 68.1% had excellent functional results, 9.1% had good functional results, 9.1% had fair functional results, 13.7% had poor functional results. CONCLUSION : Ilizarov external fixator system is the best device and best solution for infected non - union tibia management.

  12. Finite Element-Derived Surrogate Models of Locked Plate Fracture Fixation Biomechanics.

    Science.gov (United States)

    Wee, Hwabok; Reid, J Spence; Chinchilli, Vernon M; Lewis, Gregory S

    2017-03-01

    Internal fixation of bone fractures using plates and screws involves many choices-implant type, material, sizes, and geometric configuration-made by the surgeon. These decisions can be important for providing adequate stability to promote healing and prevent implant mechanical failure. The purpose of this study was to develop mathematical models of the relationships between fracture fixation construct parameters and resulting 3D biomechanics, based on parametric computer simulations. Finite element models of hundreds of different locked plate fixation constructs for midshaft diaphyseal fractures were systematically assembled using custom algorithms, and axial, torsional, and bending loadings were simulated. Multivariate regression was used to fit response surface polynomial equations relating fixation design parameters to outputs including maximum implant stresses, axial and shear strain at the fracture site, and construct stiffness. Surrogate models with as little as three regressors showed good fitting (R (2) = 0.62-0.97). Inner working length was the strongest predictor of maximum plate and screw stresses, and a variety of quadratic and interaction terms influenced resulting biomechanics. The framework presented in this study can be applied to additional types of bone fractures to provide clinicians and implant designers with clinical insight, surgical optimization, and a comprehensive mathematical description of biomechanics.

  13. Dual fibular grafting - A new technique of fixation of the femoral neck fractures

    Directory of Open Access Journals (Sweden)

    Yadav S

    2005-01-01

    Full Text Available Background: To achieve osteosynthesis of femoral neck fractures is a challenge to the treating surgeon. Plethora of devices and methods has been described. Method: A new technique of achieving union of femoral neck fractures by dual-fibular fixation has been reported in 150 patients. The age of the patients ranged from 6-75 years. Results: Nearly two-third of these were Garden type II and III with an average follow-up of 120 months. In this series 67% had good to excellent long term results. Conclusion: Two fibular struts provide autologous bone, filling the whole of the osteopenic femoral neck and prevent the rotational forces. Since the total fixation is biologically active, the technique has proved advantageous even when stable / desirable reduction is not possible and adequate fixation is not achieved, because of posterior communition at the fracture site or due to osteoporosis. Being autologous bone, the twin-fibular graft is advantageous even when there is ′subsequent loss of reduction′ of the fracture. It is, therefore, suggested that this simple, inexpensive and biological technique has many advantages over the existing methods of fixation of these fractures.

  14. Rigid internal fixation with titanium versus bioresorbable miniplates in the repair of mandibular fractures in rabbits.

    Science.gov (United States)

    Hochuli-Vieira, E; Cabrini Gabrielli, M A; Pereira-Filho, V A; Gabrielli, M F R; Padilha, J G

    2005-03-01

    The purpose of this study was to compare by qualitative histology the efficacy of rigid internal fixation with titanium system and the Lacto Sorb system in mandibular fractures in rabbits. Thirty male adult rabbits Oryctolagus cuniculus were used. Unilateral mandibular osteotomies were performed between the canine and first premolar. The animals were divided into two groups: for Group I-rigid internal fixation was performed with titanium system 1.5 mm (Synthes, Oberdorf, Switzerland), with two screws of 6 mm (bicortical) on each side of the osteotomy. For Group II-rigid internal fixation was performed with PLLA/PGA system 1.5 mm (Lacto Sorb, WLorenz, Jacksonville, FL, USA). The histological analysis evaluated the presence of inflammatory reaction, degree of bone healing and degree of resorption of the Lacto Sorb screws. The results of both fixation systems were similar, only with a small difference after 15 and 30 days. In Group I a faster bony healing was noted. But after 60 days, bony healing was similar in both groups. It is concluded that both PLLA/PGA and titanium plates and screws provide sufficient strength to permit mandibular bone healing. The resorption process of PLLA/PGA osteosynthesis material did not cause acute or chronic inflammatory reaction or foreign body reaction during the studied period.

  15. Ready to Use Tissue Construct for Military Bone & Cartilage Trauma

    Science.gov (United States)

    2014-10-01

    supplied cell- permeable green fluorescent dye (Ex/Em = 488/518 nm) and propidium iodide (PI), a cell non- permeable red fluorescent dye (Ex/Em = 488/615...fixation is commonly used for forearm bone fractures. For femur and tibia, intramedullary nailing is a common choice of internal fixation. For the...humerus, both plate and screws and intramedullary nailing are used. However, for skeletal defects following resection of malignant tumors, intramedullary

  16. Prevention of pin tract infection in external stainless steel fixator frames using electric current in a goat model

    NARCIS (Netherlands)

    van der Borden, Arnout J.; Maathuis, Patrick G. M.; Engels, Eefje; Rakhorst, Gerhard; van der Mei, Henny C.; Busscher, Henk J.; Sharma, Prashant Kumar

    2007-01-01

    Pin tract infections of external fixators used in orthopacclic reconstructive bone surgery are serious cornplications that can eventually lead to periostitis and osteomyelitis. In vitro experiments have demonstrated that bacteria adhering to stainless steel in a biotilm mode of growth detach under t

  17. Eighth international congress on nitrogen fixation. Final program

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  18. Effect of Additive on Sulfur-fixation Process of Sulfur-fixation Agent

    Institute of Scientific and Technical Information of China (English)

    XIE Jun-lin; QIU Jian-rong; ZHAO Gai-ju; LOU Jin-ping; HAN Chun-hua

    2003-01-01

    The crystallization behavior of desulfurization product is directly related to its high-temperatureresistant ability. Effects of the additive on the sulfur-fixation efficiency of the Ba-sulfur-fixation agent and also on the crystallization behavior of the sulfur-fixation product were studied when CaCO3 and BaCO3 were used as the desulfurization agent and MgO and SrCO3 used as the assistant sulfur-fixation agent. The result shows that increase of sulfur-fixation capability for the additive is not owe to their directly react to form sulfate or interact with CaCO3 and BaCO3 to form composite mineral heat-resistant in high temperature, but owe to their activation to sulfur-fixation reaction of the sulfur-fixation agent.

  19. Opportunities and challenges for the biodegradable magnesium alloys as next-generation biomaterials.

    Science.gov (United States)

    Ding, Wenjiang

    2016-06-01

    In recent years, biodegradable magnesium alloys emerge as a new class of biomaterials for tissue engineering and medical devices. Deploying biodegradable magnesium-based materials not only avoids a second surgical intervention for implant removal but also circumvents the long-term foreign body effect of permanent implants. However, these materials are often subjected to an uncontrolled and fast degradation, acute toxic responses and rapid structural failure presumably due to a localized, too rapid corrosion process. The patented Mg-Nd-Zn-based alloys (JiaoDa BioMg [JDBM]) have been developed in Shanghai Jiao Tong University in recent years. The alloy series exhibit lower biodegradation rate and homogeneous nanophasic degradation patterns as compared with other biodegradable Mg alloys. The in vitro cytotoxicity tests using various types of cells indicate excellent biocompatibility of JDBM. Finally, bone implants using JDBM-1 alloy and cardiovascular stents using JDBM-2 alloy have been successfully fabricated and in vivo long-term assessment via implantation in animal model have been performed. The results confirmed the reduced degradation rate in vivo, excellent tissue compatibility and long-term structural and mechanical durability. Thus, this novel Mg-alloy series with highly uniform nanophasic biodegradation represent a major breakthrough in the field and a promising candidate for manufacturing the next generation biodegradable implants.

  20. Osseointegration: a review of the fundamentals for assuring cementless skeletal fixation

    Directory of Open Access Journals (Sweden)

    Isaacson BM

    2014-04-01

    Full Text Available Brad M Isaacson,1,2 Sujee Jeyapalina3,4 1Henry M Jackson Foundation for the Advancement of Military Medicine, 2The Center for Rehabilitation Sciences Research, Department of Physical Medicine and Rehabilitation, Uniformed Services University of Health Sciences, Bethesda, MD, USA; 3Department of Orthopedics, 4Orthopedic Research Laboratory, University of Utah, Salt Lake City, UT, USA Abstract: Direct skeletal fixation, termed osseointegration, has expanded in the last century and includes use in total joint replacements, the edentulous mandible and maxilla, and percutaneous osseointegrated prosthetics. Although it is well known that titanium and bone have the ability to form a durable bone–implant interface, new applications have emerged in the field of orthopedics, which requires a more thorough assessment of the literature. This review aims to introduce the basic biological principles for attaining osseointegration and discusses the major factors for assuring successful cementless fixation. Keywords: osseointegration, bone, skeletal attachment, total joint replacements, dental implants, percutaneous

  1. External fixation combined with limited internal fixation in the treatment of pilon tibia fractures

    Directory of Open Access Journals (Sweden)

    Golubović Zoran

    2007-01-01

    Full Text Available Background/Aim. Intraarticular fractures of the tibial plafond (pilon fractures belong to the group of most severe fractures. They are usually caused by high-energy trauma and frequently associated with a marked soft-tissue damage. Surgical treatment has replaced the traditional nonoperative treatment. The aim of this study was to present the results of the treatment of distal tibial intraarticular fracture by the use of internal fixation, as well as the combination of minimal internal fixation and external fixation. Methods. The study included 47 patients with pilon tibia fractures who went through at the Clinic for Orthopedics and Traumatology, School of Medicine, Niš (1995-2004. Within the analyzed group there were 33 (70.2% males and 14 (29.8% females. The patients mean age was 45.8 years. In the first group, which consisted of 22 patients, open reduction and internal fixation of both the tibia and the fibula was performed in the two separate incisions. The second group consisted of 25 patients managed with external fixation by external fixator "Mitković" with limited internal fixation. Besides external fixation, a minimal internal fixation was performed by the use of Kirschner wires and screws. The patients were followed-up inside a 24-months-period. Results. The obtained was a substantially high number of complications after open reduction and internal fixation in the group of patients. There was no difference in a long-term clinical outcome. Postoperative osteitis, as the most severe complication in the management of closed pilon tibia fractures, was not registered in the second group. Conclusion. Considering the results obtained in this study, it can be concluded that external fixation by the "Mitković" external fixator with the minimal internal fixation is a satisfactory method for the treatment of fractures of the tibial plafond causing less complications than internal fixation. .

  2. Fibula fracture stabilization with a guide wire as supplementary fixation in tibia fractures.

    Science.gov (United States)

    Dombroski, Derek; Scolaro, John A; Pulos, Nicholas; Beingessner, Daphne M; Dunbar, Robert; Mehta, Samir

    2012-05-01

    The tibia is the most commonly fractured long bone. Although the goals of fracture management are straightforward, methods for achieving anatomical alignment and stable fixation are limited. Type of management depends on fracture pattern, local soft-tissue involvement, and systemic patient factors. Tibial shaft fractures with concomitant fibula fractures, particularly those at the same level, may be difficult to manage because of their inherent instability. Typically, management of lower extremity fractures is focused on the tibia fixation, and the associated fibula fracture is managed without fixation. In this article, we describe a novel technique for intramedullary fixation of the fibula, using a humeral guide wire as an adjunct to tibia fixation in the setting of tibial shaft fracture. This technique aids in determining length, alignment, and rotation of the tibia fracture and may help support the lower extremity as whole by stabilizing the lateral column. In addition, this technique can be used to help maintain reduction of the fibula when there is concern about the soft tissues of the lower extremity secondary to swelling or injury. Our clinical case series demonstrates the safety, effectiveness, and cost-sensitivity of this technique in managing select concurrent fractures of the tibia and fibula.

  3. Temporomandibular joint ankylosis fixation technique with ultra thin silicon sheet

    Directory of Open Access Journals (Sweden)

    G S Kalra

    2011-01-01

    Full Text Available Background: Temporomandibular joint ankylosis is a highly distressing condition in which the joint space is obliterated by scar tissue and the patient has an inability to open the mouth. Different autogenous and alloplastic interposition materials have been used after the resection of the ankylotic bone to achieve desirable and long lasting results. The recurrence of disease is most distressing for both patients and surgeon. We have been using ultra thin silicon sheet as our preferred material for providing proper fixation and cover to the joint. We have been encouraged by good patient compliance, no implant extrusion and favourable outcome. Materials and Methods: The clinical study included 80 patients with temporomandibular joint ankylosis, treated between April 2001 and March 2009. In all patients, temporomandibular joint ankylosis had resulted following trauma. Diagnosis was based on clinical assessment supplemented by radiographic examination consisting of a panoramic radiograph, axial and coronal computer tomography. The technique of using ultra thin silicon sheet covering whole of the joint space fixed with non-absorbable nylon 3-0 suture both medially to medial pterygoid muscle and laterally to periosteum of zygomatic arch was employed in all patients. Results: A total of 80 patients were in this study (59 males and 21 females. The aetiology of temporomandibular joint ankylosis was post-traumatic in all cases. The patients′ age ranged from 5 to 45 years. The disease was unilateral in 61 cases and bilateral in 19 cases. Twelve patients, who had previous surgery done in the form of gap arthroplasty in 6 cases, costochondral graft in 4 cases and temporalis muscle in 2 cases, presented with recurrence on the same side. The pre-op inter-incisal mouth opening ranged from 4 to 12 mm. The intraoperative inter-incisal mouth opening ranged from 28 to 46 mm. An additional procedure was done in 13 patients, including placement of costochondral

  4. Revision of Minimally Invasive Sacroiliac Joint Fixation: Technical Considerations and Case Studies Using Decortication and Threaded Implant Fixation

    Science.gov (United States)

    Fielding, Louis C

    2017-01-01

    Background Sacroiliac joint (SIJ) disease is increasingly recognized as a common source of low back pain. Arthrodesis of the SIJ has been shown to be clinically effective for this condition. In the last decade, minimally invasive (MI) SIJ fusion procedures have been developed to achieve the clinical effectiveness of open fusion procedures, with lower operative morbidity and faster recovery. However, SIJ fusion patients occasionally present with symptomatic nonunions necessitating revision. Methods Four patients who previously underwent MI SIJ arthrodesis returned with complaints of SIJ related pain confirmed by examination. Radiographic assessment showed lucency after fixation with triangular titanium interference implants. Loose implants were removed, and the patients were revised with a different MI SIJ fusion system that utilizes decortication, placement of autograft and graft extender, and fixation with cannulated threaded implants. The trajectory of the revision implants was in a more ventral-to-dorsal and caudal-to-cranial trajectory to place the implants perpendicularly through the articular portion of the SIJ. Results The triangular implants typically exhibited haloing lucency on radiographs and CT scans, and most were easily removed using the manufacturer’s instrumentation; only one implant was left in place as it was well-fixed. The removed implants exhibited little or no bony ongrowth. Decortication of the SIJ was performed, followed by placement of local autograft and fixation with 12.5 mm or 14.5mm diameter implants, as required. A more ventral-todorsal and caudal-to-cranial trajectory was established for the revision implants through the center of the articular region of the joint in order to maximize implant purchase in residual bone stock and achieve bony fusion through the articular portion of the SIJ. By six to twelve months post-revision, the presenting symptoms were successfully resolved in all patients. Conclusions Patients demonstrating

  5. Appraisal of logicality and safety of intramedullary fixation of paediatric diaphyseal fractures by titanium elastic nails

    Directory of Open Access Journals (Sweden)

    Arun Vashisht

    2016-03-01

    Conclusions: The intramedullary fixation of paediatric bones with TENs appears quite logical in terms of fracture stability for early mobilisation, early return to school, lesser hospital stay, and lesser parental off-duty. The technique is safe, does not interfere with fracture healing and does not violate the physis as nails are not passed through the physis. [Int J Res Med Sci 2016; 4(3.000: 866-870

  6. Treatment of Early Post-op Wound Infection after Internal Fixation

    Science.gov (United States)

    2015-10-01

    Jefferson Davis Highway, Suite 1204, Arlington, VA 22202- 4302. Respondents should be aware that notwithstanding any other provision of law, no person shall...DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release; distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Severe fractures are...common in modern warfare with fractures being fixed via internal fixation of plates and screws to hold the fracture stable while the bone heals

  7. Comparison of the mechanical performance of different frame configurations of the Ilizarov fixator

    OpenAIRE

    Sarpel, Yaman; Gulsen, Mahir; Togrul, Emre; Capa, Mehmet; Gulmez, Turgut

    2004-01-01

    The circular frame of Ilizarov fixator could be modified due to anatomical variations and treatment aims. But these modifications in the frame system cannot always obtain the mechanical performance of the standard frame system. A standard system has two rings in each bone fragment which are connected by four longitudinal bars on each side of the ring. In this study, mechanical performance of one standard and eight modified frame systems were compared. Each system was loaded on a Material Test...

  8. Compacted cancellous bone has a spring-back effect

    DEFF Research Database (Denmark)

    Kold, S; Bechtold, JE; Ding, Ming;

    2003-01-01

    A new surgical technique, compaction, has been shown to improve implant fixation. It has been speculated that the enhanced implant fixation with compaction could be due to a spring-back effect of compacted bone. However, such an effect has yet to be shown. Therefore we investigated in a canine...... model whether implant cavities prepared with compaction had spring back. Before killing the animals, we used one of two surgical techniques to make implant cavities of identical dimensions in both lateral femoral condyles of 7 dogs. One side had the implant cavity prepared with compaction, the other....... Thus we found a spring-back effect of compacted bone, which may be important for increasing implant fixation by reducing initial gaps between the implant and bone....

  9. Dinitrogen fixation in aphotic oxygenated marine environments

    Directory of Open Access Journals (Sweden)

    Eyal eRahav

    2013-08-01

    Full Text Available We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO3--rich, waters of the oligotrophic Levantine Basin (LB and the Gulf of Aqaba (GA. N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L-1 d-1 to 0.38 nmol N L-1 d-1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2to 3.5 and N2 fixation rates by ~ 2 fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2 to 6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP an heterotrophic N2 fixation are carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particles (TEP concentration and N2 fixation rates. This suggests that sinking organic material and high carbon (C: nitrogen (N micro-environments (such as TEP-based aggregates or marine snow could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75 % of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets.

  10. Bone grafting simultaneous to implant placement. Presentation of a case.

    Science.gov (United States)

    Peñarrocha-Diago, Miguel; Gómez-Adrián, Maria Dolores; García-Mira, Berta; Ivorra-Sais, Mariola

    2005-01-01

    Bone defects at mandibular alveolar crest level complicate the placement of dental implants in the ideal location. Surgical reconstruction using autologous bone grafts allows implant fixation in an esthetic and functional manner. We describe a patient with large mandibular bone loss secondary to periodontal inflammatory processes. Reconstruction of the mandibular alveolar process was carried out using onlay block bone grafts harvested from the mandible. The grafts were stabilized by positioning the dental implants through them--a procedure that moreover afforded good primary implant fixation. After two years of follow-up the clinical and radiological outcome is good. In the lower jaw, where bone regeneration is complicated, we were able to achieve good results in this patient--minimizing the corresponding waiting time by grafting and placing the implants in the same surgical step.

  11. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  12. Experimental and Numerical Analysis of Screw Fixation in Anterior Cruciate Ligament Reconstruction

    Science.gov (United States)

    Chizari, Mahmoud; Wang, Bin; Snow, Martyn; Barrett, Mel

    2008-09-01

    This paper reports the results of an experimental and finite element analysis of tibial screw fixation in anterior cruciate ligament (ACL) reconstruction. The mechanical properties of the bone and tendon graft are obtained from experiments using porcine bone and bovine tendon. The results of the numerical study are compared with those from mechanical testing. Analysis shows that the model may be used to establish the optimum placement of the tunnel in anterior cruciate ligament reconstruction by predicting mechanical parameters such as stress, strain and displacement at regions in the tunnel wall.

  13. Bioactive, mechanically favorable, and biodegradable copolymer nanocomposites for orthopedic applications.

    Science.gov (United States)

    Victor, Sunita Prem; Muthu, Jayabalan

    2014-06-01

    We report the synthesis of mechanically favorable, bioactive, and biodegradable copolymer nanocomposites for potential bone applications. The nanocomposites consist of in situ polymerized biodegradable copolyester with hydroxyapatite (HA). Biodegradable copolyesters comprise carboxy terminated poly(propylene fumarate) (CT-PPF) and poly(trimethylol propane fumarate co mannitol sebacate) (TF-Co-MS). Raman spectral imaging clearly reveals a uniform homogenous distribution of HA in the copolymer matrix. The mechanical studies reveal that improved mechanical properties formed when crosslinked with methyl methacrylate (MMA) when compared to N-vinyl pyrrolidone (NVP). The SEM micrographs of the copolymer nanocomposites reveal a serrated structure reflecting higher mechanical strength, good dispersion, and good interfacial bonding of HA in the polymer matrix. In vitro degradation of the copolymer crosslinked with MMA is relatively more than that of NVP and the degradation decreases with an increase in the amount of the HA filler. The mechanically favorable and degradable MMA based nanocomposites also have favorable bioactivity, blood compatibility, cytocompatibility and cell adhesion. The present nanocomposite is a more promising material for orthopedic applications.

  14. Silk fibroin membrane used for guided bone tissue regeneration.

    Science.gov (United States)

    Cai, Yurong; Guo, Junmao; Chen, Cen; Yao, Chenxue; Chung, Sung-Min; Yao, Juming; Lee, In-Seop; Kong, Xiangdong

    2017-01-01

    With the aim to develop a novel membrane with an appropriate mechanical property and degradation rate for guided bone tissue regeneration, lyophilized and densified silk fibroin membrane was fabricated and its mechanical behavior as well as biodegradation property were investigated. The osteoconductive potency of the silk fibroin membranes were evaluated in a defect rabbit calvarial model. Silk fibroin membrane showed the modulated biodegradable and mechanical properties via ethanol treatment with different concentration. The membrane could prevent soft tissue invasion from normal tissue healing, and the amounts of new bone and defect closure with silk fibroin membrane were similar to those of commercially available collagen membrane.

  15. Pitfalls during biomechanical testing - Evaluation of different fixation methods for measuring tendons endurance properties.

    Science.gov (United States)

    Hangody, Gy; Pánics, G; Szebényi, G; Kiss, R; Hangody, L; Pap, K

    2016-03-01

    The goal of the study was to find a proper technique to fix tendon grafts into an INSTRON loading machine. From 8 human cadavers, 40 grafts were collected. We removed the bone-patella tendon-bone grafts, the semitendinosus and gracilis tendons, the quadriceps tendon-bone grafts, the Achilles tendons, and the peroneus longus tendons from each lower extremity. We tested the tendon grafts with five different types of fixation devices: surgical thread (Premicron 3), general mounting clamp, wire mesh, cement fixation, and a modified clamp for an INSTRON loading machine. The mean failure load in case of surgical thread fixation was (381N ± 26N). The results with the general clamp were (527N ± 45N). The wire meshes were more promising (750N ± 21N), but did not reach the outcomes we desired. Easy slippages of the ends of the tendons from the cement encasements were observed (253N ± 18N). We then began to use Shi's clamp that could produce 977N ± 416N peak force. We combined Shi's clamp with freezing of the graft and the rupture of the tendon itself demonstrated an average force of 2198 N ± 773N. We determined that our modified frozen clamp fixed the specimens against high tensile forces.

  16. Effects of Lateral Mass Screw Rod Fixation to the Stability of Cervical Spine after Laminectomy

    Science.gov (United States)

    Rosli, Ruwaida; Kashani, Jamal; Kadir, Mohammed Rafiq Abdul

    There are many cases of injury in the cervical spine due to degenerative disorder, trauma or instability. This condition may produce pressure on the spinal cord or on the nerve coming from the spine. The aim of this study was, to analyze the stabilization of the cervical spine after undergoing laminectomy via computational simulation. For that purpose, a three-dimensional finite element (FE) model for the multilevel cervical spine segment (C1-C7) was developed using computed tomography (CT) data. There are various decompression techniques that can be applied to overcome the injury. Usually, decompression procedures will create an unstable spine. Therefore, in these situations, the spine is often surgically restabilized by using fusion and instrumentation. In this study, a lateral mass screw-rod fixation was created to stabilize the cervical spine after laminectomy. Material properties of the titanium alloy were assigned on the implants. The requirements moments and boundary conditions were applied on simulated implanted bone. Result showed that the bone without implant has a higher flexion and extension angle in comparison to the bone with implant under applied 1Nm moment. The bone without implant has maximum stress distribution at the vertebrae and ligaments. However, the bone with implant has maximum stress distribution at the screws and rods. Overall, the lateral mass screw-rod fixation provides stability to the cervical spine after undergoing laminectomy.

  17. Bone Densitometry (Bone Density Scan)

    Science.gov (United States)

    ... of DXA Bone Densitometry? What is a Bone Density Scan (DXA)? Bone density scanning, also called dual-energy x-ray absorptiometry ( ... is today's established standard for measuring bone mineral density (BMD). An x-ray (radiograph) is a noninvasive ...

  18. Immaturity of Visual Fixations in Dyslexic Children.

    Science.gov (United States)

    Tiadi, Aimé; Gérard, Christophe-Loïc; Peyre, Hugo; Bui-Quoc, Emmanuel; Bucci, Maria Pia

    2016-01-01

    To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this article is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, 55 chronological age-matched non-dyslexic children and 55 reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain(®) T2). The fixation task consisted in fixating a white-filled circle appearing in the center of the screen for 30 s. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 s of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

  19. Immaturity of Visual Fixations in Dyslexic Children.

    Directory of Open Access Journals (Sweden)

    TIADI eBi Kuyami Guy Aimé

    2016-02-01

    Full Text Available To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this paper is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, fifty-five chronological age-matched non-dyslexic children and fifty-five reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain® T2. The fixation task consisted in fixating a white-filled circle appearing in the centre of the screen for 30 seconds. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 sec of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

  20. Poly (3-Hydroxyalkanoates): Biodegradable Plastics

    OpenAIRE

    2013-01-01

    During the 1920’s, a polyester called poly (3-hydroxybutyrate) was discovered in bacterial cells. This compound, otherwise known as PHB, is part of a polyester family called polyhydroxyalkanoates (PHAs). Polyhydroxyalkanoates are used as an energy and carbon sto rage compound within certain bacterial cells. Polyhydroxyalkanoates (PHAs) are thermoplastic, biodegradable polyesters synthesized by some bacteria from rene...

  1. Biodegradable polymeric prodrugs of naltrexone

    NARCIS (Netherlands)

    Bennet, D.B.; Li, X.; Adams, N.W.; Kim, S.W.; Hoes, C.J.T.; Feijen, J.

    1991-01-01

    The development of a biodegradable polymeric drug delivery system for the narcotic antagonist naltrexone may improve patient compliance in the treatment of opiate addiction. Random copolymers consisting of the ¿-amino acids N5-(3-hydroxypropyl--glutamine and -leucine were synthesized with equimolar

  2. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization...

  3. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  4. A kinetic model for predicting biodegradation.

    Science.gov (United States)

    Dimitrov, S; Pavlov, T; Nedelcheva, D; Reuschenbach, P; Silvani, M; Bias, R; Comber, M; Low, L; Lee, C; Parkerton, T; Mekenyan, O

    2007-01-01

    Biodegradation plays a key role in the environmental risk assessment of organic chemicals. The need to assess biodegradability of a chemical for regulatory purposes supports the development of a model for predicting the extent of biodegradation at different time frames, in particular the extent of ultimate biodegradation within a '10 day window' criterion as well as estimating biodegradation half-lives. Conceptually this implies expressing the rate of catabolic transformations as a function of time. An attempt to correlate the kinetics of biodegradation with molecular structure of chemicals is presented. A simplified biodegradation kinetic model was formulated by combining the probabilistic approach of the original formulation of the CATABOL model with the assumption of first order kinetics of catabolic transformations. Nonlinear regression analysis was used to fit the model parameters to OECD 301F biodegradation kinetic data for a set of 208 chemicals. The new model allows the prediction of biodegradation multi-pathways, primary and ultimate half-lives and simulation of related kinetic biodegradation parameters such as biological oxygen demand (BOD), carbon dioxide production, and the nature and amount of metabolites as a function of time. The model may also be used for evaluating the OECD ready biodegradability potential of a chemical within the '10-day window' criterion.

  5. Bone marrow aspiration

    Science.gov (United States)

    Iliac crest tap; Sternal tap; Leukemia - bone marrow aspiration; Aplastic anemia - bone marrow aspiration; Myelodysplastic syndrome - bone marrow aspiration; Thrombocytopenia - bone marrow aspiration; Myelofibrosis - bone marrow aspiration

  6. SURVEY SUBAXIAL CERVICAL VERTEBRAE FOR TRANSPEDICULAR SCREW FIXATION

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Objective In this study, the pedicles of subaxial vertebrae from C3 to C7 were measured to provide some morphometric data for cervical transpedicular screw fixation. Methods 20 dried bone cervical spinal columns (C3-C7), pedicle dimensions (pedicle height, width, length), and transverse and sagittal angles of the pedicles were performed with vernier in linear and angular measurements. Results The obtained data revealed that the mean values were approximately ranging from 6.7 to 7.2 mm for pedicle height, 4.4 to 4.9 mm for pedicle width, 22.2 to 27.7 mm for pedicle axis length, 42.3° to 51.5° for transverse angle, and 5.2° to 14.1° for sagittal angle. Conclusion Linear measurements of pedicle dimensions and also axial angles from horizontal and vertical planes may provide some anatomic limitations for subaxial cervical transpedicular screw fixation, and also contribute to the safety of the surgical procedure.

  7. Effects of gold coating on experimental implant fixation

    DEFF Research Database (Denmark)

    Zainali, Kasra; Danscher, Gorm; Jakobsen, Thomas

    2009-01-01

    -kinase activation. The present study investigated whether gilding implant Surfaces augmented early implant osseointegration and implant fixation by its modulatory effect on the local inflammatory response. Ion release was traced by autometallographic silver enhancement. Gold-coated cylindrical porous coated Ti6Al4V....... Histomorphometrical analyses showed gold-coated implants had a decrease in overall total bone-to-implant contact of 35%. Autometallographic analysis revealed few cells loaded with gold close to the gilded implant surface. The findings demonstrate that gilding of implants negatively, affects mechanical strength...... implants Were inserted press-fit in the proximal part of tibiae in nine canines and control implants without gold inserted contralateral. Observation time was 4 weeks. Biomechanical push-out tests showed that implant,,, with gold coating had decrease in mechanical strength and stiffness...

  8. Biodegradable radioactive implants for glaucoma filtering surgery produced by ion implantation

    Energy Technology Data Exchange (ETDEWEB)

    Assmann, W. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany)]. E-mail: walter.assmann@lmu.de; Schubert, M. [Department fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, 85748 Garching (Germany); Held, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany); Pichler, A. [Augenklinik, Technische Universitaet Muenchen, 81675 Muenchen (Germany); Chill, A. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Kiermaier, S. [Zentralinstitut fuer Medizintechnik, Technische Universitaet Muenchen, 85748 Garching (Germany); Schloesser, K. [Forschungszentrum Karlsruhe, 76021 Karlsruhe (Germany); Busch, H. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Schenk, K. [NTTF GmbH, 53619 Rheinbreitbach (Germany); Streufert, D. [Acri.Tec GmbH, 16761 Hennigsdorf (Germany); Lanzl, I. [Augenklinik, Technische Universitaet Muenchen, 81675 Munich (Germany)

    2007-04-15

    A biodegradable, {beta}-emitting implant has been developed and successfully tested which prevents fresh intraocular pressure increase after glaucoma filtering surgery. Ion implantation has been used to load the polymeric implants with the {beta}-emitter {sup 32}P. The influence of ion implantation and gamma sterilisation on degradation and {sup 32}P-fixation behavior has been studied by ion beam and chemical analysis. Irradiation effects due to the applied ion fluence (10{sup 15} ions/cm{sup 2}) and gamma dose (25 kGy) are found to be tolerable.

  9. The materials used in bone tissue engineering

    Energy Technology Data Exchange (ETDEWEB)

    Tereshchenko, V. P., E-mail: tervp@ngs.ru; Kirilova, I. A.; Sadovoy, M. A.; Larionov, P. M. [Novosibirsk Research Institute of Traumatology and Orthopedics n.a. Ya.L. Tsivyan, Novosibirsk (Russian Federation)

    2015-11-17

    Bone tissue engineering looking for an alternative solution to the problem of skeletal injuries. The method is based on the creation of tissue engineered bone tissue equivalent with stem cells, osteogenic factors, and scaffolds - the carriers of these cells. For production of tissue engineered bone equivalent is advisable to create scaffolds similar in composition to natural extracellular matrix of the bone. This will provide optimal conditions for the cells, and produce favorable physico-mechanical properties of the final construction. This review article gives an analysis of the most promising materials for the manufacture of cell scaffolds. Biodegradable synthetic polymers are the basis for the scaffold, but it alone cannot provide adequate physical and mechanical properties of the construction, and favorable conditions for the cells. Addition of natural polymers improves the strength characteristics and bioactivity of constructions. Of the inorganic compounds, to create cell scaffolds the most widely used calcium phosphates, which give the structure adequate stiffness and significantly increase its osteoinductive capacity. Signaling molecules do not affect the physico-mechanical properties of the scaffold, but beneficial effect is on the processes of adhesion, proliferation and differentiation of cells. Biodegradation of the materials will help to fulfill the main task of bone tissue engineering - the ability to replace synthetic construct by natural tissues that will restore the original anatomical integrity of the bone.

  10. Orthopaedic tissue engineering and bone regeneration.

    Science.gov (United States)

    Dickson, Glenn; Buchanan, Fraser; Marsh, David; Harkin-Jones, Eileen; Little, Uel; McCaigue, Mervyn

    2007-01-01

    Orthopaedic tissue engineering combines the application of scaffold materials, cells and the release of growth factors. It has been described as the science of persuading the body to reconstitute or repair tissues that have failed to regenerate or heal spontaneously. In the case of bone regeneration 3-D scaffolds are used as a framework to guide tissue regeneration. Mesenchymal cells obtained from the patient via biopsy are grown on biomaterials in vitro and then implanted at a desired site in the patient's body. Medical implants that encourage natural tissue regeneration are generally considered more desirable than metallic implants that may need to be removed by subsequent intervention. Numerous polymeric materials, from natural and artificial sources, are under investigation as substitutes for skeletal elements such as cartilage and bone. For bone regeneration, cells (obtained mainly from bone marrow aspirate or as primary cell outgrowths from bone biopsies) can be combined with biodegradable polymeric materials and/or ceramics and absorbed growth factors so that osteoinduction is facilitated together with osteoconduction; through the creation of bioactive rather than bioinert scaffold constructs. Relatively rapid biodegradation enables advantageous filling with natural tissue while loss of polymer strength before mass is disadvantageous. Innovative solutions are required to address this and other issues such as the biocompatibility of material surfaces and the use of appropriate scaffold topography and porosity to influence bone cell gene expression.

  11. In Vivo Gait Analysis During Bone Transport.

    Science.gov (United States)

    Mora-Macías, J; Reina-Romo, E; Morgaz, J; Domínguez, J

    2015-09-01

    The load bearing characteristics of the intervened limb over time in vivo are important to know in distraction osteogenesis and bone healing for the characterization of the bone maturation process. Gait analyses were performed for a group of sheep in which bone transport was carried out. The ground reaction force was measured by means of a force platform, and the gait parameters (i.e., the peak, the mean vertical ground reaction force and the impulse) were calculated during the stance phase for each limb. The results showed that these gait parameters decreased in the intervened limb and interestingly increased in the other limbs due to the implantation of the fixator. Additionally, during the process, the gait parameters exponentially approached the values for healthy animals. Corresponding radiographies showed an increasing level of ossification in the callus. This study shows, as a preliminary approach to be confirmed with more experiments, that gait analysis could be used as an alternative method to control distraction osteogenesis or bone healing. For example, these analyses could determine the appropriate time to remove the fixator. Furthermore, gait analysis has advantages over other methods because it provides quantitative data and does not require instrumented fixators.

  12. Implants delivering bisphosphonate locally increase periprosthetic bone density in an osteoporotic sheep model. A pilot study

    Directory of Open Access Journals (Sweden)

    GVA Stadelmann

    2008-07-01

    Full Text Available It is a clinical challenge to obtain a sufficient orthopaedic implant fixation in weak osteoporotic bone. When the primary implant fixation is poor, micromotions occur at the bone-implant interface, activating osteoclasts, which leads to implant loosening. Bisphosphonate can be used to prevent the osteoclastic response, but when administered systemically its bioavailability is low and the time it takes for the drug to reach the periprosthetic bone may be a limiting factor. Recent data has shown that delivering bisphosphonate locally from the implant surface could be an interesting solution. Local bisphosphonate delivery increased periprosthetic bone density, which leads to a stronger implant fixation, as demonstrated in rats by the increased implant pullout force. The aim of the present study was to verify the positive effect on periprosthetic bone remodelling of local bisphosphonate delivery in an osteoporotic sheep model. Four implants coated with zoledronate and two control implants were inserted in the femoral condyle of ovariectomized sheep for 4 weeks. The bone at the implant surface was 50% higher in the zoledronate-group compared to control group. This effect was significant up to a distance of 400µm from the implant surface. The presented results are similar to what was observed in the osteoporotic rat model, which suggest that the concept of releasing zoledronate locally from the implant to increase the implant fixation is not species specific. The results of this trial study support the claim that local zoledronate could increase the fixation of an implant in weak bone.

  13. Only fixation for lumbar canal stenosis: Report of an experience with seven cases

    Directory of Open Access Journals (Sweden)

    Atul Goel

    2014-01-01

    Full Text Available Study Design and Objective: The author reports experience with treatment of degenerative lumbar canal stenosis that involved fixation-arthrodesis of the affected spinal segment using "double insurance" transarticular screws for each joint. No direct bone, ligament or disc resection is done for decompression of the spinal dural tube or root canal. Methods and Summary of Background Data: During the period March 2011-September 2011, seven patients having lumbar canal stenosis were treated with a modification of transarticular method of screw fixation that involved insertion of two or "double insurance" screws at each articular joint. The operation involved section of the spinous process at its base, opening up of the facet joint, denuding of articular cartilage, insertion of intra-articular bone graft and insertion of two transarticular screws at each facet joint. The fixation was done in four levels in two patients, at three levels in four patients and at two levels in one patient. Oswestry disability index and visual analog scale were used to clinically assess the patients before and after the surgery and at follow-up. Results: During the average period of follow-up of 26.9 months (range 24-30 months, there was varying degree of recovery of symptoms. The procedure resulted in firm stabilization and fixation of the spinal segment and provided a ground for arthrodesis. During the period of follow-up, one patient underwent re-exploration and decompressive laminectomy as she continued to have significant pain symptom. Conclusions: Vertical instability and telescoping, listhesis or overriding of the facets on physical activity seems to be the defining phenomenon in the pathogenesis of lumbar canal stenosis. The clinical outcome in our patients suggest that fixation of the spinal segment can be a rationale form of treatment. "Double insurance" transarticular method of treatment is a simple, safe, and effective method of spinal stabilization.

  14. Tibial inlay press-fit fixation versus interference screw in posterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Max Ettinger

    2013-11-01

    Full Text Available Reconstruction of the posterior cruciate ligament (PCL by a tibial press-fit fixation of the patellar tendon with an accessory bone plug is a promising approach because no foreign materials are required. Until today, there is no data about the biomechanical properties of such press-fit fixations. The aim of this study was to compare the biomechanical qualities of a bone plug tibial inlay technique with the commonly applied interference screw of patellar tendon PCL grafts. Twenty patellar tendons including a bone block were harvested from ten human cadavers. The grafts were implanted into twenty legs of adult German country pigs. In group P, the grafts were attached in a press-fit technique with accessory bone plug. In group S, the grafts were fixed with an interference screw. Each group consisted of 10 specimens. The constructs were biomechanically analyzed in cyclic loading between 60 and 250 N for 500 cycles recording elongation. Finally, ultimate failure load and failure mode were analyzed. Ultimate failure load was 598.6±36.3 N in group P and 653.7±39.8 N in group S (not significant, P>0.05. Elongation during cyclic loading between the 1st and the 20th cycle was 3.4±0.9 mm for group P and 3.1±1 mm for group S. Between the 20th and the 500th cycle, elongation was 4.2±2.3 mm in group P and 2.5±0.9 mm in group S (not significant, P>0.05. This is the first study investigating the biomechanical properties of tibial press-fit fixation of the patellar tendon with accessory bone plug in posterior cruciate ligament reconstruction. The implant-free tibial inlay technique shows equal biomechanical characteristics compared to an interference screw fixation. Further in vivo studies are desirable to compare the biological behavior and clinical relevance of this fixation device.

  15. Simultaneous mechanical property and biodegradation improvement of wollastonite bioceramic through magnesium dilute doping.

    Science.gov (United States)

    Xie, Jiajun; Yang, Xianyan; Shao, Huifeng; Ye, Juan; He, Yong; Fu, Jianzhong; Gao, Changyou; Gou, Zhongru

    2016-02-01

    The large-area bone defects in head (including calvarial, orbital, and maxillofacial bone) and segmental bone are attracting increased attention in a wide range of clinical departments. A key requirement for the clinical success of the bioactive ceramics is the match of the mechanical behavior of the implants with the specific bone tissue to be filled. This raises the question as to what design strategy might be the best indicators for the balance between mechanical properties and biological performances. Here we go beyond the traditional approaches that use phase conversion or biphasic hybrid; instead, we achieved a simultaneous enhancement of several mechanical parameters and optimalization of biodegradability by using a dilute doping of Mg in a single-phase wollastonite bioceramic. We show that the wollastonite ceramic can be rationally tuned in phase (α or β), mechanical strength (in compression and bending mode), elastic modulus (18-23GPa), and fracture toughness (>3.2MPam(1/2)) through the usage of Mg dopant introduced at precisely defined dilute concentrations (Mg/Ca molar ratio: 1.2-2.1%). Meanwhile, the dilute Mg-doped wollastonite ceramics are shown to exhibit good bioactivity in vitro in SBF but biodegradation in Tris is inversely proportional to Mg content. Consequently, such new highly bioactive ceramics with appreciable strength and toughness are promising for making specific porous scaffolds for enhancing large segmental bone defect and thin-wall bone defect repair.

  16. Methanotrophy Induces Nitrogen Fixation in Boreal Mosses

    Science.gov (United States)

    Tiirola, M. A.

    2014-12-01

    Many methanotrophic bacterial groups fix nitrogen in laboratory conditions. Furthermore, nitrogen (N) is a limiting nutrient in many environments where methane concentrations are highest. Despite these facts, methane-induced N fixation has previously been overlooked, possibly due to methodological problems. To study the possible link between methanotrophy and diazotrophy in terrestrial and aquatic habitats, we measured the co-occurrence of these two processes in boreal forest, peatland and stream mosses using a stable isotope labeling approach (15 N2 and 13 CH4 double labeling) and sequencing of the nifH gene marker. N fixation associated with forest mosses was dependent on the annual N deposition, whereas methane stimulate N fixation neither in high (>3 kg N ha -1 yr -1) nor low deposition areas, which was in accordance with the nifH gene sequencing showing that forest mosses (Pleurozium schreberi and Hylocomium splendens ) carried mainly cyanobacterial N fixers. On the other extreme, in stream mosses (Fontinalis sp.) methane was actively oxidized throughout the year, whereas N fixation showed seasonal fluctuation. The co-occurrence of the two processes in single cell level was proven by co-localizing both N and methane-carbon fixation with the secondary ion mass spectrometry (SIMS) approach. Methanotrophy and diazotrophy was also studied in peatlands of different primary successional stages in the land-uplift coast of Bothnian Bay, in the Siikajoki chronosequence, where N accumulation rates in peat profiles indicate significant N fixation. Based on experimental evidence it was counted that methane-induced N fixation explained over one-third of the new N input in the younger peatland successional stages, where the highest N fixation rates and highest methane oxidation activities co-occurred in the water-submerged Sphagnum moss vegetation. The linkage between methanotrophic carbon cycling and N fixation may therefore constitute an important mechanism in the rapid

  17. Nitrogen Fixation in Denitrified Marine Waters

    OpenAIRE

    Camila Fernandez; Laura Farías; Osvaldo Ulloa

    2011-01-01

    Nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. Currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria), whereas nitrogen losses occur in oxygen-depleted intermediate wat...

  18. UV photolysis for accelerating pyridine biodegradation.

    Science.gov (United States)

    Zhang, Yongming; Chang, Ling; Yan, Ning; Tang, Yingxia; Liu, Rui; Rittmann, Bruce E

    2014-01-01

    Pyridine, a nitrogen-containing heterocyclic compound, is slowly biodegradable, and coupling biodegradation with UV photolysis is a potential means to accelerate its biotransformation and mineralization. The initial steps of pyridine biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. We employed an internal circulation baffled biofilm reactor for pyridine biodegradation following three protocols: direct biodegradation (B), biodegradation after photolysis (P+B), and biodegradation with succinic acid added (B+S). Succinic acid was the main UV-photolysis product from pyridine, and its catabolic oxidation generates internal electron carriers that may accelerate the initial steps of pyridine biodegradation. Compared with direct biodegradation of pyridine (B), the removal rate for the same concentration of photolyzed pyridine (P+B) was higher by 15 to 43%, depending on the initial pyridine concentrations (increasing through the range of 130 to 310 mg/L). Adding succinic acid alone (B+S) gave results similar to P+B, which supports that succinic acid was the main agent for accelerating the pyridine biodegradation rate. In addition, protocols P+B and B+S were similar in terms of increasing pyridine mineralization over 10 h: 84% and 87%, respectively, which were higher than with protocol B (72%). The positive impact of succinic acid-whether added directly or produced via UV photolysis-confirms that its catabolism, which produced intracellular electron carriers, accelerated the initial steps of pyridine biotransformation.

  19. Prediction of bone density around orthopedic implants delivering bisphosphonate.

    Science.gov (United States)

    Stadelmann, Vincent A; Terrier, Alexandre; Gauthier, O; Bouler, J-M; Pioletti, Dominique P

    2009-06-19

    The fixation of an orthopedic implant depends strongly upon its initial stability. Peri-implant bone may resorb shortly after the surgery. This resorption is directly followed by new bone formation and implants fixation strengthening, the so-called secondary fixation. If the initial stability is not reached, the resorption continues and the implant fixation weakens, which leads to implant loosening. Studies with rats and dogs have shown that a solution to prevent peri-implant resorption is to deliver bisphosphonate from the implant surface. The aims of the study were, first, to develop a model of bone remodeling around an implant delivering bisphosphonate, second, to predict the bisphosphonate dose that would induce the maximal peri-implant bone density, and third to verify in vivo that peri-implant bone density is maximal with the calculated dose. The model consists of a bone remodeling equation and a drug diffusion equation. The change in bone density is driven by a mechanical stimulus and a drug stimulus. The drug stimulus function and the other numerical parameters were identified from experimental data. The model predicted that a dose of 0.3 microg of zoledronate on the implant would induce a maximal bone density. Implants with 0.3 microg of zoledronate were then implanted in rat femurs for 3, 6 and 9 weeks. We measured that peri-implant bone density was 4% greater with the calculated dose compared to the dose empirically described as best. The approach presented in this paper could be used in the design and analysis processes of experiments in local delivery of drug such as bisphosphonate.

  20. Aerobic biodegradation of a nonylphenol polyethoxylate and toxicity of the biodegradation metabolites.

    Science.gov (United States)

    Jurado, Encarnación; Fernández-Serrano, Mercedes; Núñez-Olea, Josefa; Lechuga, Manuela

    2009-09-01

    In this paper a study was made of the biodegradation of a non-ionic surfactant, a nonylphenol polyethoxylate, in biodegradability tests by monitoring the residual surfactant matter. The influence of the concentration on the extent of primary biodegradation, the toxicity of biodegradation metabolites, and the kinetics of degradation were also determined. The primary biodegradation was studied at different initial concentrations: 5, 25 and 50 mg/L, (at sub-and supra-critical micelle concentration). The NPEO used in this study can be considered biodegradable since the primary biodegradation had already taken place (a biodegradation greater than 80% was found for the different initial concentration tested). The initial concentration affected the shape of the resulting curve, the mean biodegradation rate and the percentage of biodegradation reached (99% in less than 8 days at 5 mg/L, 98% in less than 13 days at 25 mg/L and 95% in 14 days at 50 mg/L). The kinetic model of Quiroga and Sales (1991) was applied to predict the biodegradation of the NPEO. The toxicity value was measured as EC(20) and EC(50). In addition, during the biodegradation process of the surfactant a toxicity analysis was made of the evolution of metabolites generated, confirming that the subproducts of the biodegradation process were more toxic than the original.

  1. Fixational eye movements predict visual sensitivity.

    Science.gov (United States)

    Scholes, Chris; McGraw, Paul V; Nyström, Marcus; Roach, Neil W

    2015-10-22

    During steady fixation, observers make small fixational saccades at a rate of around 1-2 per second. Presentation of a visual stimulus triggers a biphasic modulation in fixational saccade rate-an initial inhibition followed by a period of elevated rate and a subsequent return to baseline. Here we show that, during passive viewing, this rate signature is highly sensitive to small changes in stimulus contrast. By training a linear support vector machine to classify trials in which a stimulus is either present or absent, we directly compared the contrast sensitivity of fixational eye movements with individuals' psychophysical judgements. Classification accuracy closely matched psychophysical performance, and predicted individuals' threshold estimates with less bias and overall error than those obtained using specific features of the signature. Performance of the classifier was robust to changes in the training set (novel subjects and/or contrasts) and good prediction accuracy was obtained with a practicable number of trials. Our results indicate a tight coupling between the sensitivity of visual perceptual judgements and fixational eye control mechanisms. This raises the possibility that fixational saccades could provide a novel and objective means of estimating visual contrast sensitivity without the need for observers to make any explicit judgement.

  2. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne

    2012-01-01

    Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

  3. Variable Nitrogen Fixation in Wild Populus.

    Directory of Open Access Journals (Sweden)

    Sharon L Doty

    Full Text Available The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

  4. External fixation in the treatment of open tibial shaft fractures