[Correlative analysis on metatarsalgia and the X-ray measurement indexes under weight-bearing and non-weight-bearing of hallux valgus].

Science.gov (United States)

Gong, Hao; Sang, Zhi-Cheng; Wen, Jian-Min; Sun, Wei-Dong; Hu, Hai-Wei; Zhang, Yong-Chao; Zuo, Jian-Gang; Wang, Hai-Xiong

2014-04-01

To study changes in the radiographic appearance during weight-bearing and non-weigh-bearing in hallux valgus, and to analyse the correlation between the elasticity of plantar soft tissue of hallux valgus and the pain under the metatarsal head. From May 2012 to October 2012, 240 feet of 120 patients with hallux valgus were enrolled in the study. The degrees of the pian under the metatarsal head of all the patients were observed. AP and lateral X-ray films of feet were taken on the condition of weight-bearing and non-weight-bearing. So the hallux valgus angle (HVA), the inter-metatarsal angle between the first and second metatarsals (IM1-2), the inter-metatarsal angle between the first and fifth metatarsals (IM1-5), top angle of the medial longitudinal arch (TAOTMLA),and anterior angle of the medial longitudinal arch (AAOTMLA) were measured on the X-ray films. The differences of HVA, IM1-2, IM1-5, TAOTMLA and AAOTMLA between two groups were compared, and the correlation between the changes of IM1-2, IM 1-5, TAOTMLA, AAOTMLA and the degree of the pain under the metatarsal head were analysed. One hundred and forty-eight feet had the pain under the metatarsal head. The IM1-2, IM1-5 and TAOTMLA increased on weight-bearing position compared with those on non-weight-bearing position, but the HVA and AAOTMLA decreased on weight-bearing position compared with those on non-weight-bearing position. There was a moderate relationship between the changes of IM 1-2,IM1-5 and the degree of the hallux valgus deformity, as well as the relationship between the different of IM1-5 and the degree of the pian under the metatarsal head. The degree of the collapse of the arch of foot with hallux valgus becomes serious with its deformity increasing. The pain under the metatarsal head of hallux valgus increases with the increased changes of IM 1-2,IM 1-5 and TAOTMLA. Analysis of the X-ray observation indexes of hallux valgus on weight-bearing position and non-weight-bearing position has

Weight-bearing radiography in total hip replacement

International Nuclear Information System (INIS)

Turula, K.B.; Haajanen, J.; Friberg, O.; Lindholm, T.S.; Tallroth, K.

1985-01-01

Serial anteroposterior (AP) radiographs of the weight-bearing pelvis and hips were taken of 29 patients with total hip replacement (THR). For constant positioning the patient stands with straight knees on a board with a block between the heels. A U-shaped mercury level strapped to the patient provides a horizontal reference line on the radiograph. On the average, individual variation of pelvic tilt in serial films was 1 0 and pelvic rotation 3.5 0 confirming satisfactory reproducibility. The horizontal reference enables estimation of pre- and postoperative leg length inequality (LLI) and of the angle of the acetabular cup (AA). Reproducibility allows assessment of the exact position of the femoral component and quantitative evaluation of radiolucency and bone resorption around the prosthetic implant in the follow-up of THR. (orig.)

Weight bearing or non-weight bearing after surgically fixed ankle fractures, the WOW! Study: study protocol for a randomized controlled trial.

Science.gov (United States)

Briet, Jan Paul; Houwert, Roderick M; Smeeing, Diederik P J; Pawiroredjo, Janity S; Kelder, Johannes C; Lansink, Koen W; Leenen, Luke P H; van der Zwaal, Peer; van Zutphen, Stephan W A M; Hoogendoorn, Jochem M; van Heijl, Mark; Verleisdonk, Egbert J M M; van Lammeren, Guus W; Segers, Michiel J; Hietbrink, Falco

2015-04-18

The optimal post-operative care regimen after surgically fixed Lauge Hansen supination exorotation injuries remains to be established. This study compares whether unprotected weight bearing as tolerated is superior to protected weight bearing and unprotected non-weight bearing in terms of functional outcome and safety. The WOW! Study is a prospective multicenter clinical trial. Patients between 18 and 65 years of age with a Lauge Hansen supination exorotation type 2, 3 or 4 ankle fractures requiring surgical treatment are eligible for inclusion. An expert panel validates the classification and inclusion eligibility. After surgery, patients are randomized to either the 1) unprotected non-weight-bearing, 2) protected weight-bearing, or 3) unprotected weight-bearing group. The primary outcome measure is ankle-specific disability measured by the Olerud-Molander ankle score. Secondary outcomes are 1) quality of life (e.g., return to work and resumption of sport), 2) complications, 3) range of motion, 4) calf wasting, and 5) maximum pressure load after 3 months and 1 year. This trial is designed to compare the effectiveness and safety of unprotected weight bearing with two commonly used post-operative treatment regimens after internal fixation of specified, intrinsically stable but displaced ankle fractures. An expert panel has been established to evaluate every potential subject, which ensures that every patient is strictly screened according to the inclusion and exclusion criteria and that there is a clear indication for surgical fixation. The WOW! Study is registered in the Dutch Trial Register ( NTR3727 ). Date of registration: 28-11-2012.

Weight loss and bone mineral density.

Science.gov (United States)

Hunter, Gary R; Plaisance, Eric P; Fisher, Gordon

2014-10-01

Despite evidence that energy deficit produces multiple physiological and metabolic benefits, clinicians are often reluctant to prescribe weight loss in older individuals or those with low bone mineral density (BMD), fearing BMD will be decreased. Confusion exists concerning the effects that weight loss has on bone health. Bone density is more closely associated with lean mass than total body mass and fat mass. Although rapid or large weight loss is often associated with loss of bone density, slower or smaller weight loss is much less apt to adversely affect BMD, especially when it is accompanied with high intensity resistance and/or impact loading training. Maintenance of calcium and vitamin D intake seems to positively affect BMD during weight loss. Although dual energy X-ray absorptiometry is normally used to evaluate bone density, it may overestimate BMD loss following massive weight loss. Volumetric quantitative computed tomography may be more accurate for tracking bone density changes following large weight loss. Moderate weight loss does not necessarily compromise bone health, especially when exercise training is involved. Training strategies that include heavy resistance training and high impact loading that occur with jump training may be especially productive in maintaining, or even increasing bone density with weight loss.

Associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact physical activity in later life.

Science.gov (United States)

Elhakeem, Ahmed; Hannam, Kimberly; Deere, Kevin C; Hartley, April; Clark, Emma M; Moss, Charlotte; Edwards, Mark H; Dennison, Elaine; Gaysin, Tim; Kuh, Diana; Wong, Andrew; Fox, Kenneth R; Cooper, Cyrus; Cooper, Rachel; Tobias, Jon H

2017-12-01

High impact physical activity (PA) is thought to benefit bone. We examined associations of lifetime walking and weight bearing exercise with accelerometer-measured high impact and overall PA in later life. Data were from 848 participants (66.2% female, mean age = 72.4 years) from the Cohort for Skeletal Health in Bristol and Avon, Hertfordshire Cohort Study and MRC National Survey of Health and Development. Acceleration peaks from seven-day hip-worn accelerometer recordings were used to derive counts of high impact and overall PA. Walking and weight bearing exercise up to age 18, between 18-29, 30-49 and since age 50 were recalled using questionnaires. Responses in each age category were dichotomised and cumulative scores derived. Linear regression was used for analysis. Greater lifetime walking was related to higher overall, but not high impact PA, whereas greater lifetime weight bearing exercise was related to higher overall and high impact PA. For example, fully-adjusted differences in log-overall and log-high impact PA respectively for highest versus lowest lifetime scores were: walking [0.224 (0.087, 0.362) and 0.239 (- 0.058, 0.536)], and weight bearing exercise [0.754 (0.432, 1.076) and 0.587 (0.270, 0.904)]. For both walking and weight bearing exercise, associations were strongest in the 'since age 50' category. Those reporting the most walking and weight bearing exercise since age 50 had highest overall and high impact PA, e.g. fully-adjusted difference in log-high impact PA versus least walking and weight bearing exercise = 0.588 (0.226, 0.951). Promoting walking and weight bearing exercise from midlife may help increase potentially osteogenic PA levels in later life.

Similar failure rate in immediate post-operative weight bearing versus protected weight bearing following meniscal repair on peripheral, vertical meniscal tears.

Science.gov (United States)

Perkins, Bryan; Gronbeck, Kyle R; Yue, Ruixian Alexander; Tompkins, Marc A

2017-08-16

Post-operative weight bearing after meniscal repair is a point of debate among physicians. This study sought to evaluate whether patients adhering to an immediate WBAT rehabilitation programme have a higher failure rate compared to those adhering to a more traditional, protected, NWB status following meniscal repair. The null hypothesis was that there would be no difference in failure between the two groups. A retrospective review of meniscal repair patients greater than 5 years from surgery was performed for patients receiving meniscal repair treatment. Patients were categorized by post-surgical weight-bearing status, either NWB or WBAT, and then analysed for failure of repair. Failure was defined as re-operation on the torn meniscus. The study controlled for variables including age at surgery, sex, height, weight, and BMI, classification of tear type, acuity of the tear, repair location (medial or lateral), repair location within the meniscus, repair technique, and concomitant procedures. Re-operations were performed in 61 of 157 patients [38.9%]. There was no difference between weight-bearing groups for failure of meniscus repair (n.s.). The tears were acute vertical tears located in the posterior horn and body. For the 61 patients with re-operation, the average time to re-operation was 2.2 years with 10 [16%] > 5 years from surgery, 17 [28%] 2-5 years from surgery, and 34 [56%] bearing groups for rate of re-operation (n.s.). Weight bearing as tolerated after meniscal repair for peripheral, vertical tears does not result in a higher failure rate than traditional, non-weight bearing over a five-year follow-up period. The clinical relevance is that, based on these data, it may be appropriate to allow weight bearing as tolerated following meniscal repair of peripheral, vertical tears. Retrospective cohort study, Level III.

Three dimensional biphasic calcium phosphate nanocomposites for load bearing bioactive bone grafts

Energy Technology Data Exchange (ETDEWEB)

Garai, Subhadra, E-mail: subha@nmlindia.org; Sinha, Arvind

2016-02-01

Mimicking matrix mediated bio-mineralization process, three dimensional blocks of biphasic calcium phosphate (BCP, hydroxyapatite (HA) and β-tricalcium phosphate (TCP)) nanocomposites, having three different stoichiometries have been synthesized for possible application as load bearing synthetic bone graft or scaffolds. Biphasic blocks with three weight ratios of 20:80, 25:75 and 30:70 of HA and TCP respectively have been synthesized. Detailed structural and chemical characterization of the samples revealed a strong dependence of porosity and mechanical properties on the stoichiometry of biphasic blocks. Effect of physiological medium on the microstructure and mechanical properties of the three different blocks has also been studied. Bioactivity of the BCP block, exhibiting highest compressive strength in air as well as in physiological medium, has been evaluated through adhesion, proliferation and differentiation of mesenchymal stem cells using different markers. - Highlights: • Developed a process for the synthesis of load bearing 3d- biphasic nanocomposites. • Synthesized nanocomposites exhibited in vitro osteoconductivity and osteoinductivity for bone marrow mesenchymal cells. • Developed process is a matrix mediated biomimetic one.

Changes in skeletal muscle gene expression consequent to altered weight bearing

Science.gov (United States)

Booth, F. W.; Kirby, C. R.

1992-01-01

Skeletal muscle is a dynamic organ that adapts to alterations in weight bearing. This brief review examines changes in muscle gene expression resulting from the removal of weight bearing by hindlimb suspension and from increased weight bearing due to eccentric exercise. Acute (less than or equal to 2 days) non-weight bearing of adult rat soleus muscle alters only the translational control of muscle gene expression, while chronic (greater than or equal to 7 days) removal of weight bearing appears to influence pretranslational, translational, and posttranslational mechanisms of control. Acute and chronic eccentric exercise are associated with alterations of translational and posttranslational control, while chronic eccentric training also alters the pretranslational control of muscle gene expression. Thus alterations in weight bearing influence multiple sites of gene regulation.

Reconstruction of segmental bone defect of long bones after tumor resection by devitalized tumor-bearing bone.

Science.gov (United States)

Qu, Huayi; Guo, Wei; Yang, Rongli; Li, Dasen; Tang, Shun; Yang, Yi; Dong, Sen; Zang, Jie

2015-09-24

The reconstruction of an intercalary bone defect after a tumor resection of a long bone remains a challenge to orthopedic surgeons. Though several methods have been adopted to enhance the union of long segmental allografts or retrieved segmental autografts to the host bones, still more progresses are required to achieve a better union rate. Several methods have been adopted to devitalize tumor bone for recycling usage, and the results varied. We describe our experiences of using devitalized tumor-bearing bones for the repairing of segmental defects after tumor resection. Twenty-seven eligible patients treated from February 2004 to May 2012 were included. The segmental tumor bone (mean length, 14 cm) was resected, and then devitalized in 20% sterile saline at 65 °C for 30 min after the tumor tissue was removed. The devitalized bone was implanted back into the defect by using nails or plates. Complete healing of 50 osteotomy ends was achieved at a median time of 11 months (interquartile range (IQR) 9-13 months). Major complications included bone nonunion in four bone junctions (7.4%), devitalized bone fracture in one patient (3.7%), deep infection in three patients (11.1%), and fixation failure in two patients (7.4%). The bone union rates at 1 and 2 years were 74.1 and 92.6%, respectively. The average functional score according to the Musculoskeletal Tumor Society (MSTS) 93 scoring system was 93 % (IQR 80-96.7%). Incubation in 20% sterile saline at 65 °C for 30 min is an effective method of devitalization of tumor-bearing bone. The retrieved bone graft may provide as a less expensive alternative for limb salvage. The structural bone and the preserved osteoinductivity of protein may improve bone union.

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

OpenAIRE

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

2007-01-01

Disuse uncouples bone formation from resorption, leading to increased porosity, decreased bone geometrical properties, and decreased bone mineral content which compromises bone mechanical properties and increases fracture risk. However, black bear bone properties are not adversely affected by aging despite annual periods of disuse (i.e., hibernation), which suggests that bears either prevent bone loss during disuse or lose bone and subsequently recover it at a faster rate than other animals. ...

Evaluation of First-Ray Mobility in Patients with Hallux Valgus Using Weight-Bearing CT and a 3-D Analysis System: A Comparison with Normal Feet.

Science.gov (United States)

Kimura, Tadashi; Kubota, Makoto; Taguchi, Tetsuya; Suzuki, Naoki; Hattori, Asaki; Marumo, Keishi

2017-02-01

Some physicians report that patients with hallux valgus have hypermobility at the tarsometatarsal (TMT) joint of the first ray and 3-dimensional (3-D) deformity. With use of non-weight-bearing and weight-bearing computed tomography (CT), we evaluated the 3-D mobility of each joint of the first ray in feet with hallux valgus compared with normal feet. Ten feet of 10 patients with hallux valgus and 10 feet of 10 healthy volunteers with no foot disorders were examined. All participants were women. Weight-bearing (a load equivalent to body weight) and non-weight-bearing CT scans were made with use of a device that we developed. Orthogonal coordinate axes were set and a 3-D model was reconstructed. Each joint of the first ray was aligned with the respective proximal bone, and 3-D displacement of the distal bone relative to the proximal bone under loading was quantified. At the talonavicular joint, significantly greater dorsiflexion of the navicular relative to the talus was observed in the hallux valgus group compared with the control group. At the medial cuneonavicular joint, the hallux valgus group showed significantly greater eversion and abduction of the medial cuneiform relative to the navicular. At the first TMT joint, the hallux valgus group showed significantly greater dorsiflexion, inversion, and adduction of the first metatarsal relative to the medial cuneiform. At the first metatarsophalangeal joint, the hallux valgus group showed significantly greater eversion and abduction of the first proximal phalanx relative to the first metatarsal (all p hallux valgus.

Functional evaluation of bone marrow derived DC of tumor bearing mice after immunotherapy

International Nuclear Information System (INIS)

Li Min; Chen Cheng; Gu Tao; Zhou Huan; Zhang Feng; Zhu Yibei; Yu Gehua; Zhang Xueguang; Gu Zongjiang

2006-01-01

Objective: To evaluate the function of bone marrow derived DC of tumor bearing mice after immunotherapy. Methods: Tumor bearing mice were immunized with DC vaccine plus injection of agonistic anti-4-1BB monoclonal antibody. The proliferation of T cells primed with bone marrow derived DC of tumor bearing mice after immunotherapy was tested by 3 H-TdR incorporation. ELISA was employed to determine the levels of IL-2, IFN-γ and IL-10 secreted by DC primed T cells. Results: Bone marrow derived DC of tumor bearing mice was less efficient in stimulating the proliferation of T cells and IL-2 and IFN-γ secretion made by T cells. After immunotherapy, the proliferation of cells and IL-2 and IFN-γ secretionmade by T cells were enhanced. Conclusion: The function of bone marrow derived DC of tumor bearing mice after immunotherapy was ameliorated. (authors)

The inhibition of subchondral bone lesions significantly reversed the weight-bearing deficit and the overexpression of CGRP in DRG neurons, GFAP and Iba-1 in the spinal dorsal horn in the monosodium iodoacetate induced model of osteoarthritis pain.

Directory of Open Access Journals (Sweden)

Degang Yu

Full Text Available Chronic pain is the most prominent and disabling symptom of osteoarthritis (OA. Clinical data suggest that subchondral bone lesions contribute to the occurrence of joint pain. The present study investigated the effect of the inhibition of subchondral bone lesions on joint pain.Osteoarthritic pain was induced by an injection of monosodium iodoacetate (MIA into the rat knee joint. Zoledronic acid (ZOL, a third generation of bisphosphonate, was used to inhibit subchondral bone lesions. Joint histomorphology was evaluated using X-ray micro computed tomography scanning and hematoxylin-eosin staining. The activity of osteoclast in subchondral bone was evaluated using tartrate-resistant acid phosphatase staining. Joint pain was evaluated using weight-bearing asymmetry, the expression of calcitonin gene-related peptide (CGRP in the dorsal root ganglion (DRG, and spinal glial activation status using glial fibrillary acidic protein (GFAP and ionized calcium binding adaptor molecule-1 (Iba-1 immunofluorescence. Afferent neurons in the DRGs that innervated the joints were identified using retrograde fluorogold labeling.MIA injections induced significant histomorphological alterations and joint pain. The inhibition of subchondral bone lesions by ZOL significantly reduced the MIA-induced weight-bearing deficit and overexpression of CGRP in DRG neurons, GFAP and Iba-1 in the spinal dorsal horn at 3 and 6 weeks after MIA injection; however, joint swelling and synovial reaction were unaffected.The inhibition of subchondral bone lesions alleviated joint pain. Subchondral bone lesions should be a key target in the management of osteoarthritic joint pain.

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults.

Science.gov (United States)

Madeira, Eduardo; Madeira, Miguel; Guedes, Erika Paniago; Mafort, Thiago Thomaz; Moreira, Rodrigo Oliveira; de Mendonça, Laura Maria Carvalho; Lima, Inayá Correa Barbosa; Neto, Leonardo Vieira; de Pinho, Paulo Roberto Alves; Lopes, Agnaldo José; Farias, Maria Lucia Fleiuss

2018-03-21

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolution peripheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect. Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

[Calcium and bone metabolism across women's life stages. Exercise and sport to increase bone strength in accordance with female lifecycle.

Science.gov (United States)

Iwamoto, Jun

Among females who require the strategies for preventing osteoporosis, appropriate exercise and sport through all their life are important to increase or maintain bone mass. However, the type of exercise and sport applied to females is different in accordance with the lifecycle. Jumping exercise increases bone mineral content(BMC)in prepubescent children(premenarcheal girls). Bone mineral density(BMD)is higher in adolescent athletes who are engaged in weight-bearing activities. Jumping exercise, muscle strengthening exercise, and weight-bearing plus muscle strengthening exercises increase BMD in young adults and premenopausal women. Walking, aerobic weight-bearing exercise, muscle strengthening exercise, and weight-bearing plus muscle strengthening exercises maintain or increase BMD in postmenopausal women. Thus, appropriate exercise and sport in accordance with the lifecycle are important strategies for preventing osteoporosis in females.

High Variability of Observed Weight Bearing During Standing Foot and Ankle Radiographs.

Science.gov (United States)

Miller, Christopher P; Ghorbanhoseini, Mohammad; Ehrlichman, Lauren K; Walley, Kempland C; Ghaheri, Azadeh; Kwon, John Y

2017-06-01

Weight-bearing radiographs are a critical component of evaluating foot and ankle pathology. An underlying assumption is that patients are placing 50% of their body weight on the affected foot during image acquisition. The accuracy of weight bearing during radiographs is unknown and, presumably, variable, which may result in uncertain ability of the resultant radiographs to appropriately portray the pathology of interest. Fifty subjects were tested. The percentage body weight through the foot of interest was measured at the moment of radiographic image acquisition. The subject was then instructed to bear "half [their] weight" prior to the next radiograph. The percentage body weight was calculated and compared to ideal 50% weight bearing. The mean percentage body weight in trial 1 and 2 was 45.7% ± 3.2% ( P = .012 compared to the 50% mark) and 49.2% ± 2.4%, respectively ( P = .428 compared to 50%). The mean absolute difference in percentage weight bearing compared to 50% in trials 1 and 2 was 9.3% ± 2.3% and 5.8% ± 1.8%, respectively ( P = .005). For trial 1, 18/50 subjects were within the "ideal" (45%-55%) range for weight bearing compared to 32/50 on trial 2 ( P = .005). In trial 1, 24/50 subjects had "appropriate" (>45%) weight bearing compared to 39/50 on trial 2 ( P = .002). There was substantial variability in the weight applied during radiograph acquisition. This study raises questions regarding the assumptions, reliability, and interpretation when evaluating weight-bearing radiographs. Level III, comparative study.

Skeletal unloading induces selective resistance to the anabolic actions of growth hormone on bone

Science.gov (United States)

Halloran, B. P.; Bikle, D. D.; Harris, J.; Autry, C. P.; Currier, P. A.; Tanner, S.; Patterson-Buckendahl, P.; Morey-Holton, E.

1995-01-01

Loss of skeletal weight bearing or physical unloading of bone in the growing animal inhibits bone formation and induces a bone mineral deficit. To determine whether the inhibition of bone formation induced by skeletal unloading in the growing animal is a consequence of diminished sensitivity to growth hormone (GH) we studied the effects of skeletal unloading in young hypophysectomized rats treated with GH (0, 50, 500 micrograms/100 g body weight/day). Skeletal unloading reduced serum osteocalcin, impaired uptake of 3H-proline into bone, decreased proximal tibial mass, and diminished periosteal bone formation at the tibiofibular junction. When compared with animals receiving excipient alone, GH administration increased bone mass in all animals. The responses in serum osteocalcin, uptake of 3H-proline and 45Ca into the proximal tibia, and proximal tibial mass in non-weight bearing animals were equal to those in weight bearing animals. The responses in trabecular bone volume in the proximal tibia and bone formation at the tibiofibular junction to GH, however, were reduced significantly by skeletal unloading. Bone unloading prevented completely the increase in metaphyseal trabecular bone normally induced by GH and severely dampened the stimulatory effect (158% vs. 313%, p < 0.002) of GH on periosteal bone formation. These results suggest that while GH can stimulate the overall accumulation of bone mineral in both weight bearing and non-weight bearing animals, skeletal unloading selectively impairs the response of trabecular bone and periosteal bone formation to the anabolic actions of GH.

Skeletal unloading induces selective resistance to the anabolic actions of growth hormone on bone

Science.gov (United States)

Halloran, B. P.; Bikle, D. D.; Harris, J.; Autry, C. P.; Currier, P. A.; Tanner, S.; Patterson-Buckendahl, P.; Morey-Holton, E.

1995-01-01

Loss of skeletal weight bearing or physical unloading of bone in the growing animal inhibits bone formation and induces a bone mineral deficit. To determine whether the inhibition of bone formation induced by skeletal unloading in the growing animal is a consequence of diminished sensitivity to growth hormone (GH) we studied the effects of skeletal unloading in young hypophysectomized rats treated with GH (0, 50, 500 micrograms/100 g body weight/day). Skeletal unloading reduced serum osteocalcin, impaired uptake of 3H-proline into bone, decreased proximal tibial mass, and diminished periosteal bone formation at the tibiofibular junction. When compared with animals receiving excipient alone, GH administration increased bone mass in all animals. The responses in serum osteocalcin, uptake of 3H-proline and 45Ca into the proximal tibia, and proximal tibial mass in non-weight bearing animals were equal to those in weight bearing animals. The responses in trabecular bone volume in the proximal tibia and bone formation at the tibiofibular junction to GH, however, were reduced significantly by skeletal unloading. Bone unloading prevented completely the increase in metaphyseal trabecular bone normally induced by GH and severely dampened the stimulatory effect (158% vs. 313%, p bone formation. These results suggest that while GH can stimulate the overall accumulation of bone mineral in both weight bearing and non-weight bearing animals, skeletal unloading selectively impairs the response of trabecular bone and periosteal bone formation to the anabolic actions of GH.

The effect of bone cement particles on the friction of polyethylene and polyurethane knee bearings

International Nuclear Information System (INIS)

Ash, H E; Scholes, S C; Unsworth, A; Jones, E

2004-01-01

Compliant layer knee joints have been considered for use in an attempt to increase the serviceable life of artificial joints. If designed correctly, these joints should operate within the full-fluid film lubrication regime. However, adverse tribological conditions, such as the presence of bone and bone cement particles, may breach the fluid film and cause surface wear. The frictional behaviour of both polyurethane (PU) and conventional polyethylene (PE) tibial components against a metallic femoral component was therefore assessed when bone cement particles were introduced into the lubricant. The bone cement particles caused a large increase in the frictional torque of both the PE and PU bearings; however, the friction produced by the PU bearings was still considerably lower than that produced by the PE bearings. The volume of bone cement particles between each of the bearings and the resultant frictional torque both decreased over time. This occurred more quickly with the PE bearings but greater damage was caused to the surface of the PE bearings than the PU components

Eccentric exercise training as a countermeasure to non-weight-bearing soleus muscle atrophy

Science.gov (United States)

Kirby, Christopher R.; Ryan, Mirelle J.; Booth, Frank W.

1992-01-01

This investigation tested whether eccentric resistance training could prevent soleus muscle atrophy during non-weight bearing. Adult female rats were randomly assigned to either weight bearing +/- intramuscular electrodes or non-weight bearing +/- intramuscular electrodes groups. Electrically stimulated maximal eccentric contractions were performed on anesthetized animals at 48-h intervals during the 10-day experiment. Non-weight bearing significantly reduced soleus muscle wet weight (28-31 percent) and noncollagenous protein content (30-31 percent) compared with controls. Eccentric exercise training during non-weight bearing attenuated but did not prevent the loss of soleus muscle wet weight and noncollagenous protein by 77 and 44 percent, respectively. The potential of eccentric exercise training as an effective and highly efficient counter-measure to non-weight-bearing atrophy is demonstrated in the 44 percent attenuation of soleus muscle noncollagenous protein loss by eccentric exercise during only 0.035 percent of the total non-weight-bearing time period.

Defect nonunion of a metatarsal bone fracture in a cow: successful management with bone plating and autogenous cancellous bone graft.

Science.gov (United States)

Raghunath, M; Singh, N; Singh, T; Gopinathan, A; Mohindroo, J; Atri, K

2013-01-01

A two-and-half-year-old cow was presented with a defect nonunion of the right metatarsal III/IV bone following a severely comminuted open fracture two months previously. The animal underwent open fixation using a 4.5 mm, broad, 10-hole, dynamic compression plate and autogenous cancellous bone graft collected from the contralateral iliac shaft. The animal started partial weight bearing after the third postoperative day and resumed complete weight bearing after the 10th day. Fracture healing was complete and the implants were removed after the 120th postoperative day. Stable fixation by means of a bone plate in conjunction with a cancellous bone graft facilitated complete healing and restoration of the bone column of the defect and the metatarsal fracture. The animal made a complete recovery.

Early Versus Late Weight-Bearing Protocols for Surgically Managed Posterior Wall Acetabular Fractures.

Science.gov (United States)

Heare, Austin; Kramer, Nicholas; Salib, Christopher; Mauffrey, Cyril

2017-07-01

Despite overall improved outcomes with open reduction and internal fixation of acetabular fractures, posterior wall fractures show disproportionately poor results. The effect of weight bearing on outcomes of fracture management has been investigated in many lower extremity fractures, but evidence-based recommendations in posterior wall acetabular fractures are lacking. The authors systematically reviewed the current literature to determine if a difference in outcome exists between early and late postoperative weight-bearing protocols for surgically managed posterior wall acetabular fractures. PubMed and MEDLINE were searched for posterior wall acetabular fracture studies that included weight-bearing protocols and Merle d'Aubigné functional scores. Twelve studies were identified. Each study was classified as either early or late weight bearing. Early weight bearing was defined as full, unrestricted weight bearing at or before 12 weeks postoperatively. Late weight bearing was defined as restricted weight bearing for greater than 12 weeks postoperatively. The 2 categories were then compared by functional score using a 2-tailed t test and by complication rate using chi-square analysis. Six studies (152 fractures) were placed in the early weight-bearing category. Six studies (302 fractures) were placed in the late weight-bearing category. No significant difference in Merle d'Aubigné functional scores was found between the 2 groups. No difference was found regarding heterotopic ossification, avascular necrosis, superficial infections, total infections, or osteoarthritis. This systematic review found no difference in functional outcome scores or complication rates between early and late weight-bearing protocols for surgically treated posterior wall fractures. [Orthopedics. 2017: 40(4):e652-e657.]. Copyright 2017, SLACK Incorporated.

Haptic biofeedback for improving compliance with lower-extremity partial weight bearing.

Science.gov (United States)

Fu, Michael C; DeLuke, Levi; Buerba, Rafael A; Fan, Richard E; Zheng, Ying Jean; Leslie, Michael P; Baumgaertner, Michael R; Grauer, Jonathan N

2014-11-01

After lower-extremity orthopedic trauma and surgery, patients are often advised to restrict weight bearing on the affected limb. Conventional training methods are not effective at enabling patients to comply with recommendations for partial weight bearing. The current study assessed a novel method of using real-time haptic (vibratory/vibrotactile) biofeedback to improve compliance with instructions for partial weight bearing. Thirty healthy, asymptomatic participants were randomized into 1 of 3 groups: verbal instruction, bathroom scale training, and haptic biofeedback. Participants were instructed to restrict lower-extremity weight bearing in a walking boot with crutches to 25 lb, with an acceptable range of 15 to 35 lb. A custom weight bearing sensor and biofeedback system was attached to all participants, but only those in the haptic biofeedback group were given a vibrotactile signal if they exceeded the acceptable range. Weight bearing in all groups was measured with a separate validated commercial system. The verbal instruction group bore an average of 60.3±30.5 lb (mean±standard deviation). The bathroom scale group averaged 43.8±17.2 lb, whereas the haptic biofeedback group averaged 22.4±9.1 lb (Phaptic biofeedback group averaged 14.5±6.3% (Phaptic biofeedback to improve compliance with lower-extremity partial weight bearing, haptic biofeedback was superior to conventional physical therapy methods. Further studies in patients with clinical orthopedic trauma are warranted. Copyright 2014, SLACK Incorporated.

Correlation of psychomotor findings and the ability to partially weight bear

Science.gov (United States)

2012-01-01

Background Partial weight bearing is thought to avoid excessive loading that may interfere with the healing process after surgery of the pelvis or the lower extremity. The object of this study was to investigate the relationship between the ability to partially weight bear and the patient's psychomotor skills and an additional evaluation of the possibility to predict this ability with a standardized psychomotor test. Methods 50 patients with a prescribed partial weight bearing at a target load of 15 kg following surgery were verbally instructed by a physical therapist. After the instruction and sufficient training with the physical therapist vertical ground reaction forces using matrix insoles were measured while walking with forearm crutches. Additionally, psychomotor skills were tested with the Motorische Leistungsserie (MLS). To test for correlations Spearman's Rank correlation was used. For further comparison of the two groups a Mann-Withney test was performed using Bonferroni correction. Results The patient's age and body weight significantly correlated with the ability to partially weight bear at a 15 kg target load. There were significant correlations between several subtests of the MLS and ground reaction forces measured while walking with crutches. Patients that were able to correctly perform partial weight bearing showed significant better psychomotor skills especially for those subtests where both hands had to be coordinated simultaneously. Conclusions The ability to partially weight bear is associated with psychomotor skills. The MLS seems to be a tool that helps predicting the ability to keep within the prescribed load limits. PMID:22330655

Correlation of psychomotor findings and the ability to partially weight bear

Directory of Open Access Journals (Sweden)

Ruckstuhl Thomas

2012-02-01

Full Text Available Abstract Background Partial weight bearing is thought to avoid excessive loading that may interfere with the healing process after surgery of the pelvis or the lower extremity. The object of this study was to investigate the relationship between the ability to partially weight bear and the patient's psychomotor skills and an additional evaluation of the possibility to predict this ability with a standardized psychomotor test. Methods 50 patients with a prescribed partial weight bearing at a target load of 15 kg following surgery were verbally instructed by a physical therapist. After the instruction and sufficient training with the physical therapist vertical ground reaction forces using matrix insoles were measured while walking with forearm crutches. Additionally, psychomotor skills were tested with the Motorische Leistungsserie (MLS. To test for correlations Spearman's Rank correlation was used. For further comparison of the two groups a Mann-Withney test was performed using Bonferroni correction. Results The patient's age and body weight significantly correlated with the ability to partially weight bear at a 15 kg target load. There were significant correlations between several subtests of the MLS and ground reaction forces measured while walking with crutches. Patients that were able to correctly perform partial weight bearing showed significant better psychomotor skills especially for those subtests where both hands had to be coordinated simultaneously. Conclusions The ability to partially weight bear is associated with psychomotor skills. The MLS seems to be a tool that helps predicting the ability to keep within the prescribed load limits.

Weights and hematology of wild black bears during hibernation

Science.gov (United States)

DelGiudice, Glenn D.; Rogers, Lynn L.; Allen, Arthur W.; Seal, U.S.

1991-01-01

We compared weights and hematological profiles of adult (greater than 3-yr-old) female black bears (Ursus americanus) during hibernation (after 8 January). We handled 28 bears one to four times (total of 47) over 4 yr of varying mast and berry production. Mean weight of lactating bears was greater (P less than 0.0001) than that of non-lactating females. White blood cells (P less than 0.05) and mean corpuscular volume (P = 0.005) also differed between lactating and non-lactating bears. Hemoglobin (P = 0.006) and mean corpuscular hemoglobin concentration (P = 0.02) varied among years; values were lowest during 1975, following decreased precipitation and the occurrence of a second year of mast and berry crop shortages in a three-year period. Significant (P less than 0.05) interaction between reproductive status (lactating versus non-lactating) and study year for hemoglobin, red blood cells, and packed cell volume, and increased mean corpuscular volume, suggested a greater nutritional challenge for lactating females compared to non-lactating females during the 1975 denning season. Our data suggest that hematological characteristics of denning bears may be more sensitive than weights as indicators of annual changes in nutritional status; however, other influential factors, in addition to mast and berry crop production, remain to be examined.

Load Bearing Equipment for Bone and Muscle

Science.gov (United States)

Shackelford, Linda; Griffith, Bryan

2015-01-01

Resistance exercise on ISS has proven effective in maintaining bone mineral density and muscle mass. Exploration missions require exercise with similar high loads using equipment with less mass and volume and greater safety and reliability than resistance exercise equipment used on ISS (iRED, ARED, FWED). Load Bearing Equipment (LBE) uses each exercising person to create and control the load to the partner.

Hip arthroscopy protocol: expert opinions on post-operative weight bearing and return to sports guidelines.

Science.gov (United States)

Rath, Ehud; Sharfman, Zachary T; Paret, Matan; Amar, Eyal; Drexler, Michael; Bonin, Nicolas

2017-01-01

The objectives of this study are to survey the weight-bearing limitation practices and delay for returning to running and impact sports of high volume hip arthroscopy orthopedic surgeons. The study was designed in the form of expert survey questionnaire. Evidence-based data are scares regarding hip arthroscopy post-operative weight-bearing protocols. An international cross-sectional anonymous Internet survey of 26 high-volume hip arthroscopy specialized surgeons was conducted to report their weight-bearing limitations and rehabilitation protocols after various arthroscopic hip procedures. The International Society of Hip Arthroscopy invited this study. The results were examined in the context of supporting literature to inform the studies suggestions. Four surgeons always allow immediate weight bearing and five never offer immediate weight bearing. Seventeen surgeons provide weight bearing depending on the procedures performed: 17 surgeons allowed immediate weight bearing after labral resection, 10 after labral repair and 8 after labral reconstruction. Sixteen surgeons allow immediate weight bearing after psoas tenotomy. Twenty-one respondents restrict weight bearing after microfracture procedures for 3-8 weeks post-operatively. Return to running and impact sports were shorter for labral procedures and bony procedures and longer for cartilaginous and capsular procedures. Marked variability exists in the post-operative weight-bearing practices of hip arthroscopy surgeons. This study suggests that most surgeons allow immediate weight bearing as tolerated after labral resection, acetabular osteoplasty, chondroplasty and psoas tenotomy. For cartilage defect procedures, 6 weeks or more non-weight bearing is suggested depending on the area of the defect and lateral central edge angle. Delayed return to sports activities is suggested after microfracture procedures. The level of evidence was Level V expert opinions.

Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures.

Science.gov (United States)

Raaben, Marco; Holtslag, Herman R; Leenen, Luke P H; Augustine, Robin; Blokhuis, Taco J

2018-01-01

Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight bearing in individuals with lower extremity fractures in two conditions: full weight bearing and touch-down weight bearing. 11 participants with full weight bearing and 12 participants with touch-down weight bearing after lower extremity fractures have been measured with an ambulatory biofeedback system. The participants first walked 15m and the biofeedback system was only used to register the weight bearing. The same protocol was then repeated with real-time visual feedback during weight bearing. The participants could thereby adapt their loading to the desired level and improve therapy compliance. In participants with full weight bearing, real-time visual biofeedback resulted in a significant increase in loading from 50.9±7.51% bodyweight (BW) without feedback to 63.2±6.74%BW with feedback (P=0.0016). In participants with touch-down weight bearing, the exerted lower extremity load decreased from 16.7±9.77kg without feedback to 10.27±4.56kg with feedback (P=0.0718). More important, the variance between individual steps significantly decreased after feedback (P=0.018). Ambulatory monitoring weight bearing after lower extremity fractures showed that therapy compliance is low, both in full and touch-down weight bearing. Real-time visual biofeedback resulted in significantly higher peak loads in full weight bearing and increased accuracy of individual steps in touch-down weight bearing. Real-time visual biofeedback therefore results in improved therapy compliance after lower extremity fractures. Copyright © 2017 Elsevier B.V. All rights reserved.

Activation of the hip adductor muscles varies during a simulated weight-bearing task.

Science.gov (United States)

Hides, Julie A; Beall, Paula; Franettovich Smith, Melinda M; Stanton, Warren; Miokovic, Tanja; Richardson, Carolyn

2016-01-01

To investigate the pattern of muscle activation of the individual hip adductor muscles using a standardised simulated unilateral weight-bearing task. A repeated measures design. Laboratory. 20 healthy individuals (11 females, 9 males) participated in the study. Age ranged from 20 to 25 years. Surface electromyography recordings from adductor magnus and adductor longus muscles were taken at levels representing 10-50% of body weight during a simulated weight-bearing task. Electromyography (EMG) data were normalised to maximal voluntary isometric contraction. The adductor magnus was recruited at significantly higher levels than the adductor longus muscle during a simulated weight-bearing task performed across 10-50% of body weight (p bearing task. This information should be considered when selecting exercises for management and prevention of groin strains. Closed chain exercises with weight-bearing through the lower limb are more likely to recruit the adductor magnus muscle over the adductor longus muscle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Is Bone Mineral Composition Disrupted by Organochlorines in East Greenland Polar Bears (Ursus maritimus)?

DEFF Research Database (Denmark)

Sonne, C.; Dietz, R.; Born, E. W.

2004-01-01

We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs.......04) and SigmaCHL (p polar...... bears may have been caused by organochlorine exposure. Udgivelsesdato: 2004-Dec...

Preservation of bone mass and structure in hibernating black bears (Ursus americanus) through elevated expression of anabolic genes.

Science.gov (United States)

Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Chang, Celia; Wang, Haifang; Yan, Jun; Showe, Louise C; Showe, Michael K; Donahue, Seth W; Barnes, Brian M

2012-06-01

Physical inactivity reduces mechanical load on the skeleton, which leads to losses of bone mass and strength in non-hibernating mammalian species. Although bears are largely inactive during hibernation, they show no loss in bone mass and strength. To obtain insight into molecular mechanisms preventing disuse bone loss, we conducted a large-scale screen of transcriptional changes in trabecular bone comparing winter hibernating and summer non-hibernating black bears using a custom 12,800 probe cDNA microarray. A total of 241 genes were differentially expressed (P 1.4) in the ilium bone of bears between winter and summer. The Gene Ontology and Gene Set Enrichment Analysis showed an elevated proportion in hibernating bears of overexpressed genes in six functional sets of genes involved in anabolic processes of tissue morphogenesis and development including skeletal development, cartilage development, and bone biosynthesis. Apoptosis genes demonstrated a tendency for downregulation during hibernation. No coordinated directional changes were detected for genes involved in bone resorption, although some genes responsible for osteoclast formation and differentiation (Ostf1, Rab9a, and c-Fos) were significantly underexpressed in bone of hibernating bears. Elevated expression of multiple anabolic genes without induction of bone resorption genes, and the down regulation of apoptosis-related genes, likely contribute to the adaptive mechanism that preserves bone mass and structure through prolonged periods of immobility during hibernation.

How Does Physical Activity Help Build Healthy Bones?

Science.gov (United States)

... Share Facebook Twitter Pinterest Email Print How does physical activity help build healthy bones? Bones are living tissue. Weight-bearing physical activity causes new bone tissue to form, and this ...

The effects of a 12-week program of static upper extremity weight bearing exercises on weight bearing in children with hemiplegic type of cerebral palsy

Directory of Open Access Journals (Sweden)

P. Jayaraman

2010-01-01

Full Text Available The  major  objective  of  this  study  was  to  quantify  the  effects  of a  12-week  program  of  weight  bearing  exercises  on  weight  borne  through  the hand and grip pressures in children with hemiplegic cerebral palsy. This study also sought to monitor the change in spasticity immediately following weight-bearing  exercises.  A  quasi-experimental,  one  group  pre-test,  post-test  study  was used. Eleven children with hemiplegic type of cerebral palsy from a special school in KwaZulu Natal participated after fully informed written consent. The intervention consisted of a 12-week program of weight bearing. The Tekscan Grip system was used to quantify weight borne through the hand during extended arm prone and quadruped positions and whilst holding a pencil and a tumbler. The modified Ashworth grading of spasticity was used to monitor spasticity. The data was analysed using the random effects GLS model Wald Chi Square test. Significant increases in contact pressure in extended arms prone (p=0,012 and quadruped (p=0,002 and when holding a pencil (p=0,045 was noted post-test compared to pre-test. Significant increases in contact area of the hand was also noted in prone (p=0,000, quadruped (p=0, 03 at assessment 7 and when holding a pencil (p=0,035.  A significant decrease in spasticity during elbow extension (p=0,004, and wrist flexion (p=0,026 and extension (p=0,004 was noted. An overall significant effect of static weight bearing exercises on weight borne through the hands, grip strength and spasticity justifies the use of static weight-bearing in therapy.

Relative contributions of lean and fat mass to bone strength in young Hispanic and non-Hispanic girls.

Science.gov (United States)

Hetherington-Rauth, Megan; Bea, Jennifer W; Blew, Robert M; Funk, Janet L; Hingle, Melanie D; Lee, Vinson R; Roe, Denise J; Wheeler, Mark D; Lohman, Timothy G; Going, Scott B

2018-05-22

With the high prevalence of childhood obesity, especially among Hispanic children, understanding how body weight and its components of lean and fat mass affect bone development is important, given that the amount of bone mineral accrued during childhood can determine osteoporosis risk later in life. The aim of this study was to assess the independent contributions of lean and fat mass on volumetric bone mineral density (vBMD), geometry, and strength in both weight-bearing and non-weight-bearing bones of Hispanic and non-Hispanic girls. Bone vBMD, geometry, and strength were assessed at the 20% distal femur, the 4% and 66% distal tibia, and the 66% distal radius of the non-dominant limb of 326, 9- to 12-year-old girls using peripheral quantitative computed tomography (pQCT). Total body lean and fat mass were measured by dual-energy x-ray absorptiometry (DXA). Multiple linear regression was used to assess the independent relationships of fat and lean mass with pQCT bone measures while adjusting for relevant confounders. Potential interactions between ethnicity and both fat and lean mass were also tested. Lean mass was a significant positive contributor to all bone outcomes (p Lean mass is the main determinant of bone strength for appendicular skeletal sites. Fat mass contributes to bone strength in the weight-bearing skeleton but does not add to bone strength in non-weight-bearing locations and may potentially be detrimental. Bone vBMD, geometry, and strength did not differ between Hispanic and non-Hispanic girls; fat mass may be a stronger contributor to bone strength in weight-bearing bones of Hispanic girls compared to non-Hispanic. Copyright © 2018. Published by Elsevier Inc.

Diffusion-weighted imaging and dynamic contrast-enhanced MRI of experimental breast cancer bone metastases – A correlation study with histology

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Merz, Maximilian [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Department of Hematology, Oncology and Rheumatology, Heidelberg University Hospital, Im Neuenheimer Feld 410, 69120 Heidelberg (Germany); Seyler, Lisa; Bretschi, Maren; Semmler, Wolfhard [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Bäuerle, Tobias, E-mail: tobias.baeuerle@uk-erlangen.de [Department of Medical Physics in Radiology, German Cancer Research Center, Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Institute of Radiology, University Medical Center Erlangen, Palmsanlage 5, 90154 Erlangen (Germany)

2015-04-15

Purpose: To validate imaging parameters from diffusion-weighted imaging and dynamic contrast-enhanced MRI with immunohistology and to non-invasively assess microstructure of experimental breast cancer bone metastases. Materials and methods: Animals bearing breast cancer bone metastases were imaged in a clinical 1.5 T MRI scanner. HASTE sequences were performed to calculate apparent diffusion coefficients. Saturation recovery turbo FLASH sequences were conducted while infusing 0.1 mmol/l Gd–DTPA for dynamic contrast-enhanced MRI to quantify parameters amplitude A and exchange rate constant k{sub ep}. After imaging, bone metastases were analyzed immunohistologically. Results: We found correlations of the apparent diffusion coefficients from diffusion-weighted imaging with tumor cellularity as assessed with cell nuclei staining. Histological vessel maturity was correlated negatively with parameters A and k{sub ep} from dynamic contrast-enhanced MRI. Tumor size correlated inversely with cell density and vessel permeability as well as positively with mean vessel calibers. Parameters from the rim of bone metastases differed significantly from values of the center. Conclusion: In vivo diffusion-weighted imaging and dynamic contrast-enhanced MRI in experimental bone metastases provide information about tumor cellularity and vascularity and correlate well with immunohistology.

Baropodometric technology used to analyze types of weight-bearing during hemiparetic upright position

Directory of Open Access Journals (Sweden)

Lidiane Teles de Menezes

Full Text Available INTRODUCTION: Although baropodometric analysis has been published since the 1990s, only now it is found a considerable number of studies showing different uses in the rehabilitation. OBJECTIVE: To amplify the use of this technology, this research aimed to analyze baropodometric records during upright position of subjects with hemiparesis, describing a way to define weight-bearing profiles in this population. METHOD: 20 healthy subjects were matched by gender and age with 12 subjects with chronic spastic hemiparesis. This control group was formed to establish the limits of symmetry during weight-bearing distribution in the hemiparesis group. Next, hemiparesis group was submitted to procedures to measure baropodometric records used to provide variables related to the weight-bearing distribution, the arch index and the displacements in the center of pressure (CoP. Data were used to compare differences among kinds of weight-bearing distribution (symmetric, asymmetric toward non-paretic or paretic foot and coordination system for CoP displacements. RESULTS: Hemiparesis group was compounded by eight symmetrics, eight asymmetrics toward non-paretic foot and four asymmetric toward paretic foot. Significant differences in the weight-bearing distributions between non-predominantly and predominantly used foot did not promote differences in the other baropodometric records (peak and mean of pressure, and support area. Mainly in the asymmetry toward non-paretic foot it was observed significant modifications of the baropodometric records. CONCLUSION: Baropodometric technology can be used to analyze weight-bearing distribution during upright position of subjects with hemiparesis, detecting different kinds of weight-bearing profiles useful to therapeutic programs and researches involving subjects with this disability.

Gait analysis and weight bearing in pre-clinical joint pain research.

Science.gov (United States)

Ängeby Möller, Kristina; Svärd, Heta; Suominen, Anni; Immonen, Jarmo; Holappa, Johanna; Stenfors, Carina

2018-04-15

There is a need for better joint pain treatment, but development of new medication has not been successful. Pre-clinical models with readouts that better reflect the clinical situation are needed. In patients with joint pain, pain at rest and pain at walking are two major complaints. We describe a new way of calculating results from gait analysis using the CatWalk™ setup. Rats with monoarthritis induced by injection of Complete Freund's Adjuvant (CFA) intra-articularly into the ankle joint of one hind limb were used to assess gait and dynamic weight bearing. The results show that dynamic weight bearing was markedly reduced for the injected paw. Gait parameters such as amount of normal step sequences, walking speed and duration of step placement were also affected. Treatment with naproxen (an NSAID commonly used for inflammatory pain) attenuated the CFA-induced effects. Pregabalin, which is used for neuropathic pain, had no effect. Reduced dynamic weight bearing during locomotion, assessed and calculated in the way we present here, showed a dose-dependent and lasting normalization after naproxen treatment. In contrast, static weight bearing while standing (Incapacitance tester) showed a significant effect for a limited time only. Mechanical sensitivity (von Frey Optihairs) was completely normalized by naproxen, and the window for testing pharmacological effect disappeared. Objective and reproducible effects, with an endpoint showing face validity compared to pain while walking in patients with joint pain, are achieved by a new way of calculating dynamic weight bearing in monoarthritic rats. Copyright © 2017 Elsevier B.V. All rights reserved.

Skeletal unloading induces selective resistance to the anabolic actions of growth hormone on bone

Science.gov (United States)

Halloran, B. P.; Bikle, D. D.; Harris, J.; Autry, C. P.; Currier, P. A.; Tanner, S.; Patterson-Buckendahl, P.; Morey-Holton, E.

1995-01-01

Loss of skeletal weight bearing or physical unloading of bone in the growing animal inhibits bone formation and induces a bone mineral deficit. To determine whether the inhibition of bone formation induced by skeletal unloading in the growing animal is a consequence of diminished sensitivity to growth hormone (GH) we studied the effects of skeletal unloading in young hypophysectomized rats treated with GH (0, 50, 500 micrograms/100 g body weight/day). Skeletal unloading reduced serum osteocalcin, impaired uptake of 3H-proline into bone, decreased proximal tibial mass, and diminished periosteal bone formation at the tibiofibular junction. When compared with animals receiving excipient alone, GH administration increased bone mass in all animals. The responses in serum osteocalcin, uptake of 3H-proline and 45Ca into the proximal tibia, and proximal tibial mass in non-weight bearing animals were equal to those in weight bearing animals. The responses in trabecular bone volume in the proximal tibia and bone formation at the tibiofibular junction to GH, however, were reduced significantly by skeletal unloading. Bone unloading prevented completely the increase in metaphyseal trabecular bone normally induced by GH and severely dampened the stimulatory effect (158% vs. 313%, p anabolic actions of GH.

Is prescribed lower extremity weight-bearing status after geriatric lower extremity trauma associated with increased mortality?

Science.gov (United States)

Gitajn, Ida Leah; Connelly, Daniel; Mascarenhas, Daniel; Breazeale, Stephen; Berger, Peter; Schoonover, Carrie; Martin, Brook; O'Toole, Robert V; Pensy, Raymond; Sciadini, Marcus

2018-02-01

Evaluate whether mortality after discharge is elevated in geriatric fracture patients whose lower extremity weight-bearing is restricted. Retrospective cohort study SETTING: Urban Level 1 trauma center PATIENTS/PARTICIPANTS: 1746 patients >65 years of age INTERVENTION: Post-operative lower extremity weight-bearing status MAIN OUTCOME MEASURE: Mortality, as determined by the Social Security Death Index RESULTS: Univariate analysis demonstrated that patients who were weight-bearing as tolerated on bilateral lower extremities (BLE) had significantly higher 5-year mortality compared to patients with restricted weight-bearing on one lower extremity and restricted weight-bearing on BLE (30%, 21% and 22% respectively, p bearing as tolerated on BLE, restricted weight-bearing on one lower extremity had a hazard ratio (HR) of 0.97 (95% confidence interval 0.78 to 1.20, p = 0.76) and restricted weight-bearing in BLE had a HR of 0.91 (95% confidence interval 0.60 to 1.36, p = 0.73). In geriatric patients, prescribed weight-bearing status did not have a statistically significant association with mortality after discharge, when controlling for age, sex, body mass index, medical comorbidities, Injury Severity Scale (ISS), mechanism of injury, nonoperative treatment and admission GCS. This remained true in when the analysis was restricted to operative injuries only. Copyright © 2017 Elsevier Ltd. All rights reserved.

Myelopotentiating effect of curcumin in tumor-bearing host: Role of bone marrow resident macrophages

Energy Technology Data Exchange (ETDEWEB)

Vishvakarma, Naveen Kumar; Kumar, Anjani; Kumar, Ajay; Kant, Shiva [School of Biotechnology, Banaras Hindu University, Varanasi-221 005, U.P. (India); Bharti, Alok Chandra [Division of Molecular Oncology, Institute of Cytology and Preventive Oncology, Noida, UP (India); Singh, Sukh Mahendra, E-mail: sukhmahendrasingh@yahoo.com [School of Biotechnology, Banaras Hindu University, Varanasi-221 005, U.P. (India)

2012-08-15

The present investigation was undertaken to study if curcumin, which is recognized for its potential as an antineoplastic and immunopotentiating agent, can also influence the process of myelopoiesis in a tumor-bearing host. Administration of curcumin to tumor-bearing host augmented count of bone marrow cell (BMC) accompanied by an up-regulated BMC survival and a declined induction of apoptosis. Curcumin administration modulated expression of cell survival regulatory molecules: Bcl2, p53, caspase-activated DNase (CAD) and p53-upregulated modulator of apoptosis (PUMA) along with enhanced expression of genes of receptors for M-CSF and GM-CSF in BMC. The BMC harvested from curcumin-administered hosts showed an up-regulated colony forming ability with predominant differentiation into bone marrow-derived macrophages (BMDM), responsive for activation to tumoricidal state. The number of F4/80 positive bone marrow resident macrophages (BMM), showing an augmented expression of M-CSF, was also augmented in the bone marrow of curcumin-administered host. In vitro reconstitution experiments indicated that only BMM of curcumin-administered hosts, but not in vitro curcumin-exposed BMM, augmented BMC survival. It suggests that curcumin-dependent modulation of BMM is of indirect nature. Such prosurvival action of curcumin is associated with altered T{sub H1}/T{sub H2} cytokine balance in serum. Augmented level of serum-borne IFN-γ was found to mediate modulation of BMM to produce enhanced amount of monokines (IL-1, IL-6, TNF-α), which are suggested to augment the BMC survival. Taken together the present investigation indicates that curcumin can potentiate myelopoiesis in a tumor-bearing host, which may have implications in its therapeutic utility. Highlights: ► Curcumin augments myelopoiesis in tumor-bearing host. ► Bone marrow resident macrophages mediate curcumin-dependent augmented myelopoiesis. ► Serum borne cytokine are implicated in modulation of bone marrow resident

Myelopotentiating effect of curcumin in tumor-bearing host: Role of bone marrow resident macrophages

International Nuclear Information System (INIS)

Vishvakarma, Naveen Kumar; Kumar, Anjani; Kumar, Ajay; Kant, Shiva; Bharti, Alok Chandra; Singh, Sukh Mahendra

2012-01-01

The present investigation was undertaken to study if curcumin, which is recognized for its potential as an antineoplastic and immunopotentiating agent, can also influence the process of myelopoiesis in a tumor-bearing host. Administration of curcumin to tumor-bearing host augmented count of bone marrow cell (BMC) accompanied by an up-regulated BMC survival and a declined induction of apoptosis. Curcumin administration modulated expression of cell survival regulatory molecules: Bcl2, p53, caspase-activated DNase (CAD) and p53-upregulated modulator of apoptosis (PUMA) along with enhanced expression of genes of receptors for M-CSF and GM-CSF in BMC. The BMC harvested from curcumin-administered hosts showed an up-regulated colony forming ability with predominant differentiation into bone marrow-derived macrophages (BMDM), responsive for activation to tumoricidal state. The number of F4/80 positive bone marrow resident macrophages (BMM), showing an augmented expression of M-CSF, was also augmented in the bone marrow of curcumin-administered host. In vitro reconstitution experiments indicated that only BMM of curcumin-administered hosts, but not in vitro curcumin-exposed BMM, augmented BMC survival. It suggests that curcumin-dependent modulation of BMM is of indirect nature. Such prosurvival action of curcumin is associated with altered T H1 /T H2 cytokine balance in serum. Augmented level of serum-borne IFN-γ was found to mediate modulation of BMM to produce enhanced amount of monokines (IL-1, IL-6, TNF-α), which are suggested to augment the BMC survival. Taken together the present investigation indicates that curcumin can potentiate myelopoiesis in a tumor-bearing host, which may have implications in its therapeutic utility. Highlights: ► Curcumin augments myelopoiesis in tumor-bearing host. ► Bone marrow resident macrophages mediate curcumin-dependent augmented myelopoiesis. ► Serum borne cytokine are implicated in modulation of bone marrow resident

Is weight-bearing asymmetry associated with postural instability after stroke? A systematic review.

NARCIS (Netherlands)

Kamphuis, J.F.; Kam, D.C.J. de; Geurts, A.C.H.; Weerdesteijn, V.G.M.

2013-01-01

Introduction. Improvement of postural stability is an important goal during poststroke rehabilitation. Since weight-bearing asymmetry (WBA) towards the nonparetic leg is common, training of weight-bearing symmetry has been a major focus in post-stroke balance rehabilitation. It is assumed that

Is it correct to always consider weight-bearing asymmetrically distributed in individuals with hemiparesis?

Science.gov (United States)

Martins, Emerson Fachin; de Araujo Barbosa, Paulo Henrique Ferreira; de Menezes, Lidiane Teles; de Sousa, Pedro Henrique Côrtes; Costa, Abraão Souza

2011-11-01

Injuries may cause unilateral deterioration of brain areas related to postural control resulting in lateralized motor disability with abnormal asymmetry in weight-bearing distribution. Although overloading toward the nonaffected limb has been described as the preferred posture among individuals with hemiparesis, characterization of the weight-bearing asymmetry is poorly and indirectly described. Therefore, this study aimed to describe weight-bearing distribution during upright stance, establishing criteria to consider asymmetry in hemiparesis when analyzed within the limits defined by controls matched by age and gender. Forty subjects with (n = 20) or without hemiparesis (n = 20) were included in procedures to record weight-bearing values between hemibodies, and these values were used to calculate a symmetry ratio. Control presented 95% confidence interval (CI) of the mean for symmetry ratio ranging from 0.888 to 1.072, defining limits to symmetry. Four subjects with hemiparesis (20%) had symmetry ratios inside limits defined by controls (i.e., weight-bearing symmetrically distributed), and 11 (55%) subjects without hemiparesis showed symmetry ratios outside the limits, suggesting asymmetrical weight-bearing distribution. It was concluded that asymmetry, when present in a control group, was more frequently overloading nonpredominantly used hemibody (nondominant side), differing from a hemiparesis group commonly forced to assume the nonaffected side as the predominantly used hemibody and where the overload was observed.

Permissive weight bearing in trauma patients with fracture of the lower extremities: prospective multicenter comparative cohort study.

Science.gov (United States)

Kalmet, Pishtiwan H S; Meys, Guido; V Horn, Yvette Y; Evers, Silvia M A A; Seelen, Henk A M; Hustinx, Paul; Janzing, Heinrich; Vd Veen, Alexander; Jaspars, Coen; Sintenie, Jan Bernard; Blokhuis, Taco J; Poeze, Martijn; Brink, Peter R G

2018-02-02

The standard aftercare treatment in surgically treated trauma patients with fractures around or in a joint, known as (peri)- or intra-articular fractures of the lower extremities, is either non-weight bearing or partial weight bearing. We have developed an early permissive weight bearing post-surgery rehabilitation protocol in surgically treated patients with fractures of the lower extremities. In this proposal we want to compare our early permissive weight bearing protocol to the existing current non-weight bearing guidelines in a prospective comparative cohort study. The study is a prospective multicenter comparative cohort study in which two rehabilitation aftercare treatments will be contrasted, i.e. permissive weight bearing and non-weight bearing according to the AO-guideline. The study population consists of patients with a surgically treated fracture of the pelvis/acetabulum or a surgically treated (peri)- or intra-articular fracture of the lower extremities. The inclusion period is 12 months. The duration of follow up is 6 months, with measurements taken at baseline, 2,6,12 and 26 weeks post-surgery. ADL with Lower Extremity Functional Scale. Outcome variables for compliance, as measured with an insole pressure measurement system, encompass peak load and step duration. This study will investigate the (cost-) effectiveness of a permissive weight bearing aftercare protocol. The results will provide evidence whether a permissive weight bearing protocol is more effective than the current non-weight bearing protocol. The study is registered in the Dutch Trial Register ( NTR6077 ). Date of registration: 01-09-2016.

Influence of Body Weight on Bone Mass, Architecture, and Turnover

Science.gov (United States)

Iwaniec, Urszula T.; Turner, Russell T.

2016-01-01

Weight-dependent loading of the skeleton plays an important role in establishing and maintaining bone mass and strength. This review focuses on mechanical signaling induced by body weight as an essential mechanism for maintaining bone health. In addition, the skeletal effects of deviation from normal weight are discussed. The magnitude of mechanical strain experienced by bone during normal activities is remarkably similar among vertebrates, regardless of size, supporting the existence of a conserved regulatory mechanism, or mechanostat, that senses mechanical strain. The mechanostat functions as an adaptive mechanism to optimize bone mass and architecture based on prevailing mechanical strain. Changes in weight, due to altered mass, weightlessness (spaceflight), and hypergravity (modeled by centrifugation), induce an adaptive skeletal response. However, the precise mechanisms governing the skeletal response are incompletely understood. Furthermore, establishing whether the adaptive response maintains the mechanical competence of the skeleton has proven difficult, necessitating development of surrogate measures of bone quality. The mechanostat is influenced by regulatory inputs to facilitate non-mechanical functions of the skeleton, such as mineral homeostasis, as well as hormones and energy/nutrient availability that support bone metabolism. While the skeleton is very capable of adapting to changes in weight, the mechanostat has limits. At the limits, extreme deviations from normal weight and body composition are associated with impaired optimization of bone strength to prevailing body size. PMID:27352896

Is bone mineral composition disrupted by organochlorines in east Greenland polar bears (Ursus maritimus)?

DEFF Research Database (Denmark)

Sonne, Christian; Dietz, Rune; Born, Erik W

2004-01-01

We analyzed bone mineral density (BMD) in skulls of polar bears (Ursus maritimus) (n = 139) from East Greenland sampled during 1892-2002. Our primary goal was to detect possible changes in bone mineral content (osteopenia) due to elevated exposure to organochlorine [polychlorinated biphenyls (PCBs...

Diet and exercise : a match made in bone

NARCIS (Netherlands)

Willems, H.M.E.; van den Heuvel, E.G.H.M.; Schoemaker, R.J.W.; Klein-Nulend, J.; Bakker, A.D.

2017-01-01

Purpose of Review: Multiple dietary components have the potential to positively affect bone mineral density in early life and reduce loss of bone mass with aging. In addition, regular weight-bearing physical activity has a strong positive effect on bone through activation of osteocyte signaling. We

Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs.

Science.gov (United States)

McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Bunnell, Kevin; Auger, Janene; Black, Hal L; Donahue, Seth W

2009-07-22

Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.

Upright Cone CT of the hindfoot: Comparison of the non-weight-bearing with the upright weight-bearing position

Energy Technology Data Exchange (ETDEWEB)

Hirschmann, Anna; Pfirrmann, Christian W.A.; Buck, Florian M. [University of Zurich, Department of Radiology, Orthopaedic University Hospital Balgrist, Zurich (Switzerland); Klammer, Georg; Espinosa, Norman [University of Zurich, Department of Orthopedic Surgery, Orthopaedic University Hospital Balgrist, Zurich (Switzerland)

2014-03-15

To prospectively compare computed tomography (CT) of the hindfoot in the supine non-weight-bearing position (NWBCT) with upright weight-bearing position (WBCT). Institutional review board approval and informed consent of all patients were obtained. NWBCT and WBCT scans of the ankle were obtained in 22 patients (mean age, 46.0 ± 17.1 years; range 19-75 years) using a conventional 64-row CT for NWBCT and a novel cone-beam CT for WBCT. Two musculoskeletal radiologists independently performed the following measurements: the hindfoot alignment angle, fibulocalcaneal and tibiocalcaneal distances, lateral talocalcaneal joint space width, talocalcaneal overlap and naviculocalcaneal distance. Significant changes between NWBCT and WBCT were sought using Wilcoxon signed-rank test. P values <0.05 were considered statistically significant. Significant differences were found for all measurements except the hindfoot alignment angle and tibiocalcaneal distance. Significant measurement results were as follows (NWBCT/WBCT reader 1; NWBCT/WBCT reader 2, mean ± standard deviation): fibulocalcaneal distance 3.6 mm ± 5.2/0.3 mm ± 6.0 (P = 0.006); 1.4 mm ± 6.3/-1.1 mm ± 6.3 (P = 0.002), lateral talocalcaneal joint space width 2.9 mm ± 1.7/2.2 mm ± 1.1 (P = 0.005); 3.4 mm ± 1.9/2.4 mm ± 1.3 (P = 0.001), talocalcaneal overlap 4.1 mm ± 3.9/1.4 mm ± 3.9 (P = 0.001); 4.5 mm ± 4.3/1.4 mm ± 3.7 (P < 0.001) and naviculocalcaneal distance 13.5 mm ± 4.0/15.3 mm ± 4.7 (P = 0.037); 14.0 mm ± 4.4/15.7 mm ± 6.2 (P = 0.100). Interreader agreement was good to excellent (ICC 0.48-0.94). Alignment of the hindfoot significantly changes in the upright weight-bearing CT position. Differences can be visualised and measured using WBCT. (orig.)

Advantage and limitations of a minimally-invasive approach and early weight bearing in the treatment of tibial shaft fractures with locking plates.

Science.gov (United States)

Adam, P; Bonnomet, F; Ehlinger, M

2012-09-01

Intramedullary nailing is a common method of treating tibial shaft fractures. However, precise control of reduction at the proximal and distal quarters is difficult to achieve. The purpose of this study was to assess the results of plating using locking screws and the feasibility of a minimally-invasive approach. All patients with tibial shaft fracture treated by means of locking plates from January 2004 to October 2006. Thirty-two fractures were treated in 32 patients with a mean age of 43.8 years. Internal fixation with a locking plate and screw construct, using a minimally-invasive or standard approach. Surgical approach, time to weight bearing, complications and their type, time to bone union, alignment in the frontal and sagittal planes on anteroposterior and lateral radiographs. The minimally-invasive approach was performed in 28 cases and immediate full weight bearing allowed in 25 cases. At a mean follow-up of 27 months, two patients had died and two patients were lost to follow-up. The mean time to bone union was 9.1 weeks. Four cases had a complicated course: one infection, one compartment syndrome, one hardware breakage and one pseudarthrosis. Six cases ended up with valgus malunion exceeding 5° in the frontal plane, already present at the time of surgery. Where a minimally-invasive approach can be performed, immediate pain-free weight bearing can be allowed without further displacement at follow-up. The observed rate of malunion underlines the need for adequate reduction and shows that the rationale for success does not solely depend on the plate anatomic design but also on the skills of the operating surgeon. Level I university regional hospital Cohort study. Copyright © 2012. Published by Elsevier Masson SAS.

Drug loaded biodegradable load-bearing nanocomposites for damaged bone repair

Science.gov (United States)

Gutmanas, E. Y.; Gotman, I.; Sharipova, A.; Psakhie, S. G.; Swain, S. K.; Unger, R.

2017-09-01

In this paper we present a short review-scientific report on processing and properties, including in vitro degradation, of load bearing biodegradable nanocomposites as well as of macroporous 3D scaffolds for bone ingrowth. Biodegradable implantable devices should slowly degrade over time and disappear with ingrown of natural bone replacing the synthetic graft. Compared to low strength biodegradable polymers, and brittle CaP ceramics, biodegradable CaP-polymer and CaP-metal nanocomposites, mimicking structure of natural bone, as well as strong and ductile metal nanocomposites can provide to implantable devices both strengths and toughness. Nanostructuring of biodegradable β-TCP (tricalcium phosphate)-polymer (PCL and PLA), β-TCP-metal (FeMg and FeAg) and of Fe-Ag composites was achieved employing high energy attrition milling of powder blends. Nanocomposite powders were consolidated to densities close to theoretical by high pressure consolidation at ambient temperature—cold sintering, with retention of nanoscale structure. The strength of developed nanocomposites was significantly higher as compared with microscale composites of the same or similar composition. Heat treatment at moderate temperatures in hydrogen flow resulted in retention of nanoscale structure and higher ductility. Degradation of developed biodegradable β-TCP-polymer, β-TCP-metal and of Fe-Ag nanocomposites was studied in physiological solutions. Immersion tests in Ringer's and saline solution for 4 weeks resulted in 4 to 10% weight loss and less than 50% decrease in compression or bending strength, the remaining strength being significantly higher than the values reported for other biodegradable materials. Nanostructuring of Fe-Ag based materials resulted also in an increase of degradation rate because of creation on galvanic Fe-Ag nanocouples. In cell culture experiments, the developed nanocomposites supported the attachment the human osteoblast cells and exhibited no signs of cytotoxicity

Factors affecting bone mineral mass loss after lower-limb fractures in a pediatric population.

Science.gov (United States)

Ceroni, Dimitri; Martin, Xavier; Kherad, Omar; Salvo, Davide; Dubois-Ferrière, Victor

2015-06-01

The purpose of this study was to assess the effects of the durations of cast immobilization and non-weight-bearing periods, and decreases in vigorous physical activity (VPA) on bone mineral parameters in a pediatric population treated for a lower-limb fracture. Fifty children and teenagers who had undergone a cast-mediated immobilization for a leg or ankle fracture were prospectively recruited. The durations of cast immobilization and non-weight-bearing periods were recorded for each participant. Dual-energy x-ray absorptiometry scans were performed at the time of fracture treatment (baseline) and at cast removal. Physical activity during cast immobilization was assessed using accelerometers. A strong negative correlation was found between the total duration of cast immobilization and decreases in both calcaneal bone mineral density (BMD) (r=-0.497) and total lower-limb bone mineral content (BMC) (r=-0.405). A strong negative correlation was also noted between the durations of the non-weight-bearing periods and alterations in calcaneal BMD (r=-0.420). No apparent correlations were found between lower BMD and BMC and decreased VPA. Bone mineral loss was correlated to the total duration of cast immobilization for all measurement sites on the affected leg, whereas it was only correlated to the durations of non-weight-bearing periods for calcaneal BMD and total lower-limb BMC. However, no correlations were noted between bone mineral loss and decreased VPA.

Measuring polyethylene wear in total knee arthroplasty by RSA: differences between weight-bearing and non-weight-bearing positioning.

Science.gov (United States)

van Ijsseldijk, Emiel A; Valstar, Edward R; Stoel, Berend C; de Ridder, Ruud; Nelissen, Rob G H H; Kaptein, Bart L

2014-04-01

Measuring the minimum-joint-space-width (mJSW) in total knee arthroplasty (TKA) in Roentgen stereophotogrammetric analysis (RSA) provides valuable information on polyethylene wear, a leading cause for TKA failure. Most existing studies use non-weight-bearing (NWB) patient positioning. The latter may compromise mJSW measurements due to knee laxity with subsequent non-contact between the TKA components. We investigated the difference in mJSW between weight-bearing (WB) and NWB images and the association with mediolateral (ML) knee stability. At one-year follow-up, 23 TKAs were included from an ongoing RSA study, and ML stability was evaluated. For each examination, the mJSW and femoral-tibial contact locations were measured. A linear regression model was used to analyze the association between the mJSW difference (NWB-WB) with the ML stability and contact locations. The mean mJSW difference was 0.28 mm medially and 0.20 mm laterally. Four TKAs had medium (5-9°) and 19 TKAs had high (RSA studies are influenced by knee laxity, but may still provide information on wear progression based on TKA with high ML stability. A direct comparison of mJSW measurements from WB and NWB data is not possible. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Foot Loading Characteristics of Different Graduations of Partial Weight Bearing

Science.gov (United States)

Gusinde, Johannes; Pauser, Johannes; Swoboda, Bernd; Gelse, Kolja; Carl, Hans-Dieter

2011-01-01

Limited weight bearing of the lower extremity is a commonly applied procedure in orthopaedic rehabilitation after reconstructive forefoot surgery, trauma surgery and joint replacement. The most frequent limitations are given as percentage of body weight (BW) and represent 10 or 50% BW. The extent of foot loading under these graduations of partial…

Outcomes and weight-bearing status during rehabilitation after arthroplasty for hip fractures.

Science.gov (United States)

Siebens, Hilary C; Sharkey, Phoebe; Aronow, Harriet U; Horn, Susan D; Munin, Michael C; DeJong, Gerben; Smout, Randall J; Radnay, Craig S

2012-08-01

To examine the association of weight-bearing status with patient-related variables and outcomes of inpatient rehabilitation after hip arthroplasty for acute hip fracture. A multi-site prospective observational cohort study. Eighteen skilled nursing and inpatient rehabilitation facilities. Patients with hip fractures (N = 224) treated with hip arthroplasty and admitted to either skilled nursing or inpatient rehabilitation facilities; a subset (N = 84) with telephone follow-up outcomes 8 months after rehabilitation discharge. Measurements included demographic variables, medical severity using the Comprehensive Severity Index, and functional levels using the Functional Independence Measure. MAIN OUTCOMES MEASUREMENT: Cognitive, motor, and total Functional Independence Measure scores at rehabilitation discharge and at 8-month follow-up; living location at discharge and follow-up. Patients on average (standard deviation) were 76.8 ± 11.4 years old, mainly women (78%), and mainly white (87%). In unadjusted analysis, weight bearing as tolerated (WBAT) was associated with less osteoarthritis (P = .025) and lower admission medical severity (ACSI) (P = .014). One participating facility had a significant preponderance of restricted weight-bearing cases. WBAT had no bivariate association with cognitive or motor function at discharge. Therapists cited restricted weight bearing as a barrier to therapy in 11% of cases. In logistic regressions, lower medical admission severity, older age, and one specified site significantly predicted WBAT (c statistic = 0.714). Significant predictors for home discharge included lower maximum severity (P < .001), younger age (P < .001), higher cognition (P = .037), and WBAT (P = .051) (c statistic = 0.863). WBAT is associated with a greater likelihood of home discharge and had similar functional outcomes compared with restricted weight bearing. These findings add support for allowing WBAT after arthroplasty for hip fracture. Copyright © 2012

Bone health in endurance athletes: runners, cyclists, and swimmers.

Science.gov (United States)

Scofield, Kirk L; Hecht, Suzanne

2012-01-01

Weight-bearing exercise has been recognized widely to be beneficial for long-term bone health. However inherent differences in bone-loading characteristics and energy expenditure during participation in endurance sports place many endurance athletes at a relative disadvantage with regard to bone health compared with other athletes. Adolescents and adults who participate in endurance sports, such as running, and non-weight-bearing sports, such as biking and swimming, often have lower bone mineral density (BMD) than athletes participating in ball and power sports, and sometimes their BMD is lower than their inactive peers. Low BMD increases the risk of stress and fragility fractures, both while an athlete is actively competing and later in life. This article reviews the variable effects of distance running, cycling, swimming, and triathlons on bone health; the evaluation of stress and fragility fractures; and the diagnosis, management, and prevention of low BMD in endurance athletes.

Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures

NARCIS (Netherlands)

Raaben, Marco; Holtslag, Herman R.; Leenen, Luke P. H.; Augustine, Robin; Blokhuis, Taco J.

2017-01-01

Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback on weight

Characteristics of postoperative weight bearing and management protocols for tibial plateau fractures: Findings from a scoping review.

Science.gov (United States)

Arnold, John B; Tu, Chen Gang; Phan, Tri M; Rickman, Mark; Varghese, Viju Daniel; Thewlis, Dominic; Solomon, Lucian B

2017-12-01

To identify and describe the characteristics of existing practices for postoperative weight bearing and management of tibial plateau fractures (TPFs), identify gaps in the literature, and inform the design of future research. Seven electronic databases and clinical trial registers were searched from inception until November 17th 2016. Studies were included if they reported on the surgical management of TPFs, had a mean follow-up time of ≥1year and provided data on postoperative management protocols. Data were extracted and synthesized according to study demographics, patient characteristics and postoperative management (weight bearing regimes, immobilisation devices, exercises and complications). 124 studies were included involving 5156 patients with TPFs. The mean age across studies was 45.1 years (range 20.8-72; 60% male), with a mean follow-up of 34.9 months (range 12-264). The most frequent fracture types were AO/OTA classification 41-B3 (29.5%) and C3 (25%). The most commonly reported non-weight bearing time after surgery was 4-6 weeks (39% of studies), with a further 4-6 weeks of partial weight bearing (51% of studies), resulting in 9-12 weeks before full weight bearing status was recommended (55% of studies). Loading recommendations for initial weight bearing were most commonly toe-touch/bearing was positively correlated with the proportion of fractures of AO/OTA type C (r=0.465, p=0.029) and Schatzker type IV-VI (r=0.614, pbearing time before full weight bearing is recommended at 9-12 weeks. Partial weight bearing protocols and brace use were varied. Type of rehabilitation may be an important factor influencing recovery, with future high quality prospective studies required to determine the impact of different protocols on clinical and radiological outcomes. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Functional weight-bearing mobilization after Achilles tendon rupture enhances early healing response: a single-blinded randomized controlled trial.

Science.gov (United States)

Valkering, Kars P; Aufwerber, Susanna; Ranuccio, Francesco; Lunini, Enricomaria; Edman, Gunnar; Ackermann, Paul W

2017-06-01

Functional weight-bearing mobilization may improve repair of Achilles tendon rupture (ATR), but the underlying mechanisms and outcome were unknown. We hypothesized that functional weight-bearing mobilization by means of increased metabolism could improve both early and long-term healing. In this prospective randomized controlled trial, patients with acute ATR were randomized to either direct post-operative functional weight-bearing mobilization (n = 27) in an orthosis or to non-weight-bearing (n = 29) plaster cast immobilization. During the first two post-operative weeks, 15°-30° of plantar flexion was allowed and encouraged in the functional weight-bearing mobilization group. At 2 weeks, patients in the non-weight-bearing cast immobilization group received a stiff orthosis, while the functional weight-bearing mobilization group continued with increased range of motion. At 6 weeks, all patients discontinued immobilization. At 2 weeks, healing metabolites and markers of procollagen type I (PINP) and III (PIIINP) were examined using microdialysis. At 6 and 12 months, functional outcome using heel-rise test was assessed. Healing tendons of both groups exhibited increased levels of metabolites glutamate, lactate, pyruvate, and of PIIINP (all p bearing mobilization group demonstrated significantly higher concentrations of glutamate compared to the non-weight-bearing cast immobilization group (p = 0.045).The upregulated glutamate levels were significantly correlated with the concentrations of PINP (r = 0.5, p = 0.002) as well as with improved functional outcome at 6 months (r = 0.4; p = 0.014). Heel-rise tests at 6 and 12 months did not display any differences between the two groups. Functional weight-bearing mobilization enhanced the early healing response of ATR. In addition, early ankle range of motion was improved without the risk of Achilles tendon elongation and without altering long-term functional outcome. The relationship between

Load Bearing Equipment for Bone and Muscle Project

Science.gov (United States)

Terrier, Douglas; Clayton, Ronald G.; Shackelford, Linda

2015-01-01

Axial skeletal loads coupled with muscle torque forces around joints maintain bone. Astronauts working in pairs to exercise can provide high eccentric loads for each other that are most effective. A prototype of load bearing equipment that will allow astronauts to perform exercises using each other for counter force generation in a controlled fashion and provide eccentric overload is proposed. A frame and attachments that can be rapidly assembled for use and easily stored will demonstrate feasibility of a design that can be adapted for ISS testing and Orion use.

Connectivity strategies to enhance the capacity of weight-bearing networks

International Nuclear Information System (INIS)

Janaki, T.M.; Gupte, Neelima

2003-01-01

The connectivity properties of a weight-bearing network are exploited to enhance its capacity. We study a 2D network of sites where the weight-bearing capacity of a given site depends on the capacities of the sites connected to it in the layers above. The network consists of clusters, viz., a set of sites connected with each other with the largest such collection of sites being denoted as the maximal cluster. New connections are made between sites in successive layers using two distinct strategies. The key element of our strategies consists of adding as many disjoint clusters as possible to the sites on the trunk T of the maximal cluster. In the first strategy the reconnections start from the last layer upwards and stop when no new sites are added. In the second case, the reconnections start from the top layer and go all the way down to the last layer. The new networks can bear much higher weights than the original networks and have much lower failure rates. The first strategy leads to a greater enhancement of stability, whereas the second leads to a greater enhancement of capacity compared to the original networks. The original network used here is a typical example of the branching hierarchical class. However, the application of strategies similar to ours can yield useful results in other types of networks as well

Beneficial impact of aerobic exercises on bone mineral density in obese premenopausal women under caloric restriction.

Science.gov (United States)

Hosny, Iman Abbas; Elghawabi, Hamed Samir; Younan, Wael Bahat Fahmy; Sabbour, Adly Aly; Gobrial, Mona Abdel Messih

2012-04-01

The aim of this study was to assess the impact of caloric restriction diet versus caloric restriction diet combined with aerobic exercises on bone mineral density (BMD) in obese premenopausal women. Forty premenopausal obese women were classified randomly into two groups equal in number. The first group (group A) received caloric restriction diet, while the second (group B) received caloric restriction diet combined with a program of aerobic exercises, over 3 months. The variables measured in this study included age, weight, height, body mass index, fat weight, lean mass, fat percent, basal metabolic rate, and BMD. The comparison between group A and group B showed significantly higher post-treatment lean mass, basal metabolic rate, and BMD in weight-bearing bones (L2-L4 lumbar spine and total hip) in group B compared to group A. In contrast to the BMD of the weight-bearing bones, the BMD of the radius showed significant decrease between the pre- and post-treatment results in groups A and B with no significant differences between the two groups. A greater improvement in the BMD of weight-bearing bones was observed in obese premenopausal women undergoing caloric restriction combined with exercise than in those not undergoing exercise. Anaerobic exercises incorporated into weight loss programs help offset the adverse effects of dietary restriction on bone.

EFFECTS OF TAEKWONDO TRAINING ON BONE MINERAL DENSITY OF HIGH SCHOOL GIRLS IN KOREA

Directory of Open Access Journals (Sweden)

S. Young Ho

2011-09-01

Full Text Available The incidence of bone fractures has increased in the current decade due to osteoporosis. Bone mineral density (BMD, or the amount of mineralized bone, is an important determinant of risk for bone fractures. Bone mineralization is strongly stimulated by weight-bearing exercise during growth and development. Taekwondo, a Korean martial art, is a well-known form of strenuous and weight-bearing physical activity. Therefore, the primary goal of this study was to determine the effects of taekwondo training on the bone health of female high school students in Korea. The secondary goal of this study was to clarify the relationships between body weight and BMD in this sample. Thirty taekwondo players (TKD and 30 sedentary high school girls (CON voluntarily participated in the present study and were split into three groups by weight: light weight (L under 51 kg; middle weight (M between 51 and under 57 kg; and heavy weight (H over 57 kg. BMD was determined from dual-emission X-ray absorptiometry (DEXA, and percent body fat was measured by the skin-fold method. Lumbar spine and femoral BMD were not significantly different between light, middle and heavy body weight groups. However, the average BMD in the TKD group was significantly greater than in the CON group for all lumbar spine regions (P<0.05. The results of this study suggest that taekwondo training during growth significantly improved bone health in all weight groups.

GLP-1 receptor agonist treatment increases bone formation and prevents bone loss in weight-reduced obese women

DEFF Research Database (Denmark)

Iepsen, Eva Pers Winning; Lundgren, Julie Rehné; Hartmann, Bolette

2015-01-01

with or without administration of the GLP-1 RA liraglutide (1.2mg/day) for 52 weeks. In case of weight gain, up to two meals per day could be substituted with a low-calorie diet product in order to maintain the weight loss. MAIN OUTCOME MEASURES: Total, pelvic and arm-leg bone mineral content (BMC) and bone...... markers (CTX-1 and P1NP) were investigated before, after weight loss and after 52 weeks weight maintenance. Primary end points: Change in BMC and bone markers after 52 weeks weight maintenance with or without GLP-1 RA treatment. RESULTS: Total, pelvic and arm-leg BMC decreased during weight maintenance...... in the control group (ptotal and arm-leg BMC loss was 4 times greater in the control group compared to the liraglutide group (estimated difference 27g (95% CI 5-48), p=0.01), although the 12% weight loss was maintained in both groups...

Bone scintigraphy in diabetic osteoarthropathy

International Nuclear Information System (INIS)

Eymontt, M.J.; Alavi, A.; Dalinka, M.K.; Kyle, G.C.

1981-01-01

Bone scans of patients with diabetic osteoarthropathy of the ankle and foot were characterized by a combination of diffuse and focal increased uptake, similar to that seen with hyperemia and reactive new bone formation. Scintigraphy showed more extensive abnormalities than radiography, with the scan abnormalities sometimes preceding the radiographic changes. The clinical and scintigraphic appearance of osteoarthropathy may improve following strict diabetic control and non-weight-bearing

Hybrid scaffold bearing polymer-siloxane Schiff base linkage for bone tissue engineering

Energy Technology Data Exchange (ETDEWEB)

Nair, Bindu P., E-mail: bindumelekkuttu@gmail.com; Gangadharan, Dhanya; Mohan, Neethu; Sumathi, Babitha; Nair, Prabha D., E-mail: pdnair49@gmail.com

2015-07-01

Scaffolds that can provide the requisite biological cues for the fast regeneration of bone are highly relevant to the advances in tissue engineering and regenerative medicine. In the present article, we report the fabrication of a chitosan–gelatin–siloxane scaffold bearing interpolymer-siloxane Schiff base linkage, through a single-step dialdehyde cross-linking and freeze-drying method using 3-aminopropyltriethoxysilane as the siloxane precursor. Swelling of the scaffolds in phosphate buffered saline indicates enhancement with increase in siloxane concentration, whereas compressive moduli of the wet scaffolds reveal inverse dependence, owing to the presence of siloxane, rich in silanol groups. It is suggested that through the strategy of dialdehyde cross-linking, a limiting siloxane loading of 20 wt.% into a chitosan-gelatin matrix should be considered ideal for bone tissue engineering, because the scaffold made with 30 wt.% siloxane loading degrades by 48 wt.%, in 21 days. The hybrid scaffolds bearing Schiff base linkage between the polymer and siloxane, unlike the stable linkages in earlier reports, are expected to give a faster release of siloxanes and enhancement in osteogenesis. This is verified by the in vitro evaluation of the hybrid scaffolds using rabbit adipose mesenchymal stem cells, which revealed osteogenic cell-clusters on a polymer-siloxane scaffold, enhanced alkaline phosphatase activity and the expression of bone-specific genes, whereas the control scaffold without siloxane supported more of cell-proliferation than differentiation. A siloxane concentration dependent enhancement in osteogenic differentiation is also observed. - Highlights: • A hybrid scaffold bearing interpolymer-siloxane Schiff base linkage • A limiting siloxane loading of 20 wt.% into chitosan–gelatin matrix • A siloxane concentration dependent enhancement in osteogenic differentiation.

Real-time visual biofeedback during weight bearing improves therapy compliance in patients following lower extremity fractures

NARCIS (Netherlands)

Raaben, Marco; Holtslag, Herman R; Leenen, Luke P H; Augustine, Robin; Blokhuis, Taco J

BACKGROUND: Individuals with lower extremity fractures are often instructed on how much weight to bear on the affected extremity. Previous studies have shown limited therapy compliance in weight bearing during rehabilitation. In this study we investigated the effect of real-time visual biofeedback

Effect of partial weight bearing program on functional ability and ...

African Journals Online (AJOL)

Lilian A. Zaky

2013-03-17

Mar 17, 2013 ... essence of the importance of partial weight bearing program in rehabilitation of lower limb condi ... and long term physical and psychosocial impairments [11,12]. .... gram for their functional walking using the 6-min walking test,.

Inadequate thickness of the weight-bearing surface of claws in ruminants : clinical review

Directory of Open Access Journals (Sweden)

A.S. Shakespeare

2009-05-01

Full Text Available The term 'thin soles' refers to the suboptimal thickness of the weight-bearing surface of claws in ruminants. These palmar / plantar surfaces of the claws support the weight of the animal and consist of the distal wall horn, the sole proper, the heel and the minute white line area. The sole should normally only bear weight on uneven or undulating surfaces. A decrease in the thickness of the weight-bearing claw surface will decrease the protective function of this structure and may alter the proportion of weight-bearing by each section with possible detrimental effects on hoof function. Horn tissue readily absorbs water and becomes softer which can lead to increased wear rates. Growth rates normally match wear rates but, unlike the latter, time is needed for the growth rate response to adapt to changes in wear rate. Concrete surfaces can be abrasive and dairy cows that spend their lactation cycle on these floors should be let out to pasture in the dry period so that their claws can recoup lost horn. Frictional coefficient is a measure of the 'slipperiness' of hooves on various surfaces. Newly laid or fresh concrete is not only abrasive but the thin surface suspension of calcium hydroxide that forms has a very alkaline pH which causes keratin degradation and is mostly responsible for the excessive claw wear that occurs. Four case studies are used to illustrate the importance of the distal wall horn, the dangers of over-trimming and the effects of disease and concrete on horn growth and wear rates.

Inaccuracy of a physical strain trainer for the monitoring of partial weight bearing.

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Pauser, Johannes; Jendrissek, Andreas; Swoboda, Bernd; Gelse, Kolja; Carl, Hans-Dieter

2011-11-01

To investigate the use of a physical strain trainer for the monitoring of partial weight bearing. Case series with healthy volunteers. Orthopedic clinic. Healthy volunteers (N=10) with no history of foot complaints. Volunteers were taught to limit weight bearing to 10% body weight (BW) and 50% BW, monitored by a physical strain trainer. The parameters peak pressure, maximum force, force-time integral, and pressure-time integral were assessed by dynamic pedobarography when volunteers walked with full BW (condition 1), 50% BW (condition 2), and 10% BW (condition 3). With 10% BW (condition 3), forces with normative gait (condition 1) were statistically significantly reduced under the hindfoot where the physical strain trainer is placed. All pedobarographic parameters were, however, exceeded when the total foot was measured. A limitation to 10% BW with the physical strain trainer (condition 3) was equal to a bisection of peak pressure and maximum force for the total foot with normative gait (condition 1). Halved BW (condition 2) left a remaining mean 82% of peak pressure and mean 59% of maximum force from full BW (condition 1). The concept of controlling partial weight bearing with the hindfoot-addressing device does not represent complete foot loading. Such devices may be preferably applied in cases when the hindfoot in particular must be off-loaded. Other training devices (eg, biofeedback soles) that monitor forces of the total foot have to be used to control partial weight bearing of the lower limb accurately. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Initial non-weight-bearing therapy is important for preventing vertebral body collapse in elderly patients with clinical vertebral fractures

Directory of Open Access Journals (Sweden)

Kishikawa Y

2012-04-01

Full Text Available Yoichi KishikawaKishikawa Orthopaedic Clinic, Saga City, Saga, JapanPurpose: The aim of the present conventional observational study was to compare the clinical outcomes of initial non-weight-bearing therapy and conventional relative rest therapy among elderly patients with clinical vertebral fractures.Methods: In total, 196 consecutive patients with clinical vertebral fractures (mean age: 78 years who were hospitalized for treatment between January 1999 and March 2007 were analyzed. Initial non-weight-bearing therapy consisted of complete bed rest allowing rolling on the bed without any weight-bearing to the spine for 2 weeks, followed by rehabilitation wearing a soft brace. The indications for initial non-weight-bearing therapy were vertebral fracture involving the posterior portion of the vertebral body at the thoraco-lumbar spine, mild neurological deficit, instability of the fracture site, severe pain, multiple vertebral fractures arising from trauma, malalignment at the fracture site, and mild spinal canal stenosis caused by the fracture. Patients who met the indication criteria were treated with initial non-weight-bearing therapy (n = 103, while the other patients were treated with conventional relative rest (n = 93. All the patients were uniformly treated with intramuscular elcatonin to relieve pain. The primary endpoint was progression of the vertebral fracture. The secondary endpoints included bony union and subjective back pain. The follow-up period was 12 weeks.Results: Compared with the conventional relative rest group, the collapse rate of the anterior and posterior portions of the vertebral body was significantly smaller in the initial non-weight-bearing group. The bony union rate was 100% in the initial non-weight-bearing group and 97% in the conventional relative rest group. The number of patients who experienced back pain was significantly lower in the initial non-weight-bearing group than in the conventional relative rest

Do Knee Bracing and Delayed Weight Bearing Affect Mid-Term Functional Outcome after Anterior Cruciate Ligament Reconstruction?

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Di Miceli, Riccardo; Marambio, Carlotta Bustos; Zati, Alessandro; Monesi, Roberta; Benedetti, Maria Grazia

2017-12-01

Purpose  The aim of this study was to assess the effect of knee bracing and timing of full weight bearing after anterior cruciate ligament reconstruction (ACLR) on functional outcomes at mid-term follow-up. Methods  We performed a retrospective study on 41 patients with ACLR. Patients were divided in two groups: ACLR group, who received isolated ACL reconstruction and ACLR-OI group who received ACL reconstruction and adjunctive surgery. Information about age at surgery, bracing, full or progressive weight bearing permission after surgery were collected for the two groups. Subjective IKDC score was obtained at follow-up. Statistical analysis was performed to compare the two groups for IKDC score. Subgroup analysis was performed to assess the effect of postoperative regimen (knee bracing and weight bearing) on functional outcomes. Results  The mean age of patients was 30.8 ± 10.6 years. Mean IKDC score was 87.4 ± 13.9. The mean follow-up was 3.5 ± 1.8 years. Twenty-two (53.7%) patients underwent ACLR only, while 19 (46.3%) also received other interventions, such as meniscal repair and/or collateral ligament suture. Analysis of overall data showed no differences between the groups for IKDC score. Patients in the ACLR group exhibited a significantly better IKDC score when no brace and full weight bearing after 4 weeks from surgery was prescribed in comparison with patients who worn a brace and had delayed full weight bearing. No differences were found with respect to the use of brace and postoperative weight bearing regimen in the ACLR-OI group. Conclusion  Brace and delayed weight bearing after ACLR have a negative influence on long-term functional outcomes. Further research is required to explore possible differences in the patients operated on ACLR and other intervention with respect to the use of a brace and the timing of full weight bearing to identify optimal recovery strategies. Level of Evidence  Level III, retrospective observational

Rap system of stress stimulation can promote bone union after lower tibial bone fracture: a clinical research.

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Yao, Jian-fei; Shen, Jia-zuo; Li, Da-kun; Lin, Da-sheng; Li, Lin; Li, Qiang; Qi, Peng; Lian, Ke-jian; Ding, Zhen-qi

2012-01-01

Lower tibial bone fracture may easily cause bone delayed union or nonunion because of lacking of dynamic mechanical load. Research Group would design a new instrument as Rap System of Stress Stimulation (RSSS) to provide dynamic mechanical load which would promote lower tibial bone union postoperatively. This clinical research was conducted from January 2008 to December 2010, 92 patients(male 61/female 31, age 16-70 years, mean 36.3 years) who suffered lower tibial bone closed fracture were given intramedullary nail fixation and randomly averagely separated into experimental group and control group(according to the successively order when patients went for the admission procedure). Then researchers analysed the clinical healing time, full weight bearing time, VAS (Visual Analogue Scales) score and callus growth score of Lane-Sandhu in 3,6,12 months postoperatively. The delayed union and nonunion rates were compared at 6 and 12 months separately. All the 92 patients had been followed up (mean 14 months). Clinical bone healing time in experimental group was 88.78±8.80 days but control group was 107.91±9.03 days. Full weight bearing time in experimental group was 94.07±9.81 days but control group was 113.24±13.37 days respectively (Ptibial bone union, reduce bone delayed union or nonunion rate. It is an adjuvant therapy for promoting bone union after lower tibial bone fracture.

Weight-bearing recommendations after operative fracture treatment-fact or fiction? Gait results with and feasibility of a dynamic, continuous pedobarography insole.

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Braun, Benedikt J; Veith, Nils T; Rollmann, Mika; Orth, Marcel; Fritz, Tobias; Herath, Steven C; Holstein, Jörg H; Pohlemann, Tim

2017-08-01

Rehabilitation after lower-extremity fractures is based on the physicians' recommendation for non-, partial-, or full weight-bearing. Clinical studies rely on this assumption, but continuous compliance or objective loading rates are unknown. The purpose of this study was to determine the compliance to weight-bearing recommendations by introducing a novel, pedobarography system continuously registering postoperative ground forces into ankle, tibial shaft and proximal femur fracture aftercare and test its feasibility for this purpose. In this prospective, observational study, a continuously measuring pedobarography insole was placed in the patients shoe during the immediate post-operative aftercare after ankle, tibial shaft and intertrochanteric femur fractures. Weight-bearing was ordered as per the institutional standard and controlled by physical therapy. The insole was retrieved after a maximum of six weeks (28 days [range 5-42 days]). Non-compliance was defined as a failure to maintain, or reach the ordered weight-bearing within 30%. Overall 30 patients were included in the study. Fourteen (47%) of the patients were compliant to the weight-bearing recommendations. Within two weeks after surgery patients deviated from the recommendation by over 50%. Sex, age and weight did not influence the performance (p > 0.05). Ankle fracture patients (partial weight-bearing) showed a significantly increased deviation from the recommendation (p = 0.01). Our study results show that, despite physical therapy training, weight-bearing compliance to recommended limits was low. Adherence to the partial weight-bearing task was further decreased over time. Uncontrolled weight-bearing recommendations should thus be viewed with caution and carefully considered as fiction. The presented insole is feasible to determine weight bearing continuously, could immediately help define real-time patient behaviour and establish realistic, individual weight-bearing recommendations.

Effects of microgravity on rat bone, cartlage and connective tissues

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Doty, S.

1990-01-01

The response to hypogravity by the skeletal system was originally thought to be the result of a reduction in weight bearing. Thus a reduced rate of new bone formation in the weight-bearing bones was accepted, when found, as an obvious result of hypogravity. However, data on non-weight-bearing tissues have begun to show that other physiological changes can be expected to occur to animals during spaceflight. This overview of the Cosmos 1887 data discusses these results as they pertain to individual bones or tissues because the response seems to depend on the architecture and metabolism of each tissue under study. Various effects were seen in different tissues from the rats flown on Cosmos 1887. The femur showed a reduced bone mineral content but only in the central region of the diaphysis. This same region in the tibia showed changes in the vascularity of bone as well as some osteocytic cell death. The humerus demonstrated reduced morphometric characteristics plus a decrease in mechanical stiffness. Bone mineral crystals did not mature normally as a result of flight, suggesting a defect in the matrix mineralization process. Note that these changes relate directly to the matrix portion of the bone or some function of bone which slowly responds to changes in the environment. However, most cellular functions of bone are rapid responders. The stimulation of osteoblast precursor cells, the osteoblast function in collagen synthesis, a change in the proliferation rate of cells in the epiphyseal growth plate, the synthesis and secretion of osteocalcin, and the movement of water into or out of tissues, are all processes which respond to environmental change. These rapidly responding events produced results from Cosmos 1887 which were frequently quite different from previous space flight data.

Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs

OpenAIRE

McGee-Lawrence, Meghan E.; Wojda, Samantha J.; Barlow, Lindsay N.; Drummer, Thomas D.; Bunnell, Kevin; Auger, Janene; Black, Hal L.; Donahue, Seth W.

2009-01-01

Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechan...

[Bone homeostasis and Mechano biology.

Science.gov (United States)

Nakashima, Tomoki

The weight-bearing exercises help to build bones and to maintain them strength. Bone is constantly renewed by the balanced action of osteoblastic bone formation and osteoclastic bone resorption both of which mainly occur at the bone surface. This restructuring process called "bone remodeling" is important not only for normal bone mass and strength, but also for mineral homeostasis. Bone remodeling is stringently regulated by communication between bone component cells such as osteoclasts, osteoblasts and osteocytes. An imbalance of this process is often linked to various bone diseases. During bone remodeling, resorption by osteoclasts precedes bone formation by osteoblasts. Based on the osteocyte location within the bone matrix and the cellular morphology, it is proposed that osteocytes potentially contribute to the regulation of bone remodeling in response to mechanical and endocrine stimuli.

Cellular Therapy to Obtain Rapid Endochondral Bone Formation

Science.gov (United States)

2008-02-01

length from the tibial fusion site, and then stop which would be consistent with the resorption being associated with the lack of weight bearing load. In...Defect in the Rat Femur with Use of a Vascularized Periosteal Flap, a Biodegradable Matric, and Bone Morphogenetic Protein. J Bone Joint Surg 87-A(6

Bone Growth, Mechanical Stimulus and IGF-1

National Research Council Canada - National Science Library

Gilsanz, Vicente

2006-01-01

... in the weight bearing skeleton of young adult females with low bone density. Ultimately, this information could be of great benefit to enhance musculoskeletal development and decrease the risk for stress fractures in military recruits...

Blood lead levels and bone turnover with weight reduction in women

OpenAIRE

RIEDT, CLAUDIA S.; BUCKLEY, BRIAN T.; BROLIN, ROBERT E.; AMBIA-SOBHAN, HASINA; RHOADS, GEORGE G.; SHAPSES, SUE A.

2008-01-01

High bone turnover states are known to raise blood lead levels (BPb). Caloric restriction will increase bone turnover, yet it remains unknown if weight reduction increases BPb due to mobilization of skeletal stores. We measured whole blood Pb levels (206Pb) by inductively coupled plasma mass spectrometry in 73 women (age 24–75 years; BMI 23– 61 kg/m2) before and after 6 months of severe weight loss (S-WL), moderate weight loss (M-WL), or weight maintenance (WM). Baseline BPb levels were relat...

Comparison of Findings from Oblique Radiographs of the Raised Limb with Those of the Weight-bearing Limb for Selected Diseases of the Equine Digit

Directory of Open Access Journals (Sweden)

J. Šterc

2007-01-01

Full Text Available In the present study, the radiographic examination of the distal and proximal interphalangeal joints was performed in 43 randomly selected horses. A total of 86 forelimbs were examined. On the forelimbs, dorsolateral-palmaromedial, and dorsomedial-palmarolateral oblique views were performed. The oblique views were performed on raised limbs placed in a navicular block and on weight-bearing limbs placed on a pedestal made at the equine clinic. In total, 688 dorsolateral-palmaromedial and dorsomedial-palmarolateral views were taken. During the evaluation of the radiographs we focused on the detection of signs of degenerative joint disease of the distal and proximal iterphalangeal joints, and the detection of new bone formation in the phalanx regions, not associated with a disease of the distal or proximal interphalangeal joints. Based on the radiographic signs visible on these views, we diagnosed 9 cases of degenerative joint disease of the distal intraphalangeal joint, 13 cases of the degenerative joint disease of the proximal intraphalangeal joint and 21 cases of new bone formation in the phalanx regions. These signs were observed in 253 of 688 oblique views. Positive radiographic findings of the above-mentioned disorders were shown on 127 oblique views of the raised limb placed in the navicular block and 126 oblique views of the weight-bearing limb placed on the pedestal we made. When 128 oblique views of the weight-bearing limb (placed on the pedestal were compared with those of the raised limb (in the navicular block, there were different radiographic findings in three cases only. The differences in detection rates of radiographic signs between different type views showed no statistical significance (p ≥ 0.05. Therefore we assume that the pedestal we made can be routinely used for the radiographic examination of the distal and proximal interphalangeal joints on DL-PM and DM-PL oblique views, as part of pre-purchase examination or diagnosis

Biophotonics and Bone Biology

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Zimmerli, Gregory; Fischer, David; Asipauskas, Marius; Chauhan, Chirag; Compitello, Nicole; Burke, Jamie; Tate, Melissa Knothe

2004-01-01

One of the more-serious side effects of extended space flight is an accelerated bone loss [Bioastronautics Critical Path Roadmap, http://research.hq.nasa.gov/code_u/bcpr/index.cfm]. Rates of bone loss are highest in the weight-bearing bones of the hip and spine regions, and the average rate of bone loss as measured by bone mineral density measurements is around 1.2% per month for persons in a microgravity environment. It shows that an extrapolation of the microgravity induced bone loss rates to longer time scales, such as a 2.5 year round-trip to Mars (6 months out at 0 g, 1.5 year stay on Mars at 0.38 g, 6 months back at 0 g), could severely compromise the skeletal system of such a person.

Characteristics of monolayer culture of bone marrow cells of rats bearing 239Pu-induced osteosarcoma

International Nuclear Information System (INIS)

Bukhtoyarova, Z.M.; Lemberg, V.K.

1984-01-01

The report is concerned with a monolayer culture of bone marrow cells of rats in which optimal blastogenic dose (92.5 kBq/kg) induced osteosarcoma. The cell culture showed an enhanced rate of fibroblast-like cell proliferation (increased number of mitoses and symplasts and larger colonies of cells), apparent signs of radiation in ury (pathologic mitoses, chromosome aberrations and gaps) as well as an increase in ploidy. Diffusion chamber measurements demonstrated osteogenic precursor-cells in osteosarcoma-bearing rats to be highly capable of bone formation. This relatively high ability seems to occur outside bone marrow as well

The longitudinal effects of physical activity and dietary calcium on bone mass accrual across stages of pubertal development.

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Lappe, Joan M; Watson, Patrice; Gilsanz, Vicente; Hangartner, Thomas; Kalkwarf, Heidi J; Oberfield, Sharon; Shepherd, John; Winer, Karen K; Zemel, Babette

2015-01-01

Childhood and adolescence are critical periods of bone mineral content (BMC) accrual that may have long-term consequences for osteoporosis in adulthood. Adequate dietary calcium intake and weight-bearing physical activity are important for maximizing BMC accrual. However, the relative effects of physical activity and dietary calcium on BMC accrual throughout the continuum of pubertal development in childhood remains unclear. The purpose of this study was to determine the effects of self-reported dietary calcium intake and weight-bearing physical activity on bone mass accrual across the five stages of pubertal development in a large, diverse cohort of US children and adolescents. The Bone Mineral Density in Childhood study was a mixed longitudinal study with 7393 observations on 1743 subjects. Annually, we measured BMC by dual-energy X-ray absorptiometry (DXA), physical activity and calcium intake by questionnaire, and pubertal development (Tanner stage) by examination for up to 7 years. Mixed-effects regression models were used to assess physical activity and calcium intake effects on BMC accrual at each Tanner stage. We found that self-reported weight-bearing physical activity contributed to significantly greater BMC accrual in both sexes and racial subgroups (black and nonblack). In nonblack males, the magnitude of the activity effect on total body BMC accrual varied among Tanner stages after adjustment for calcium intake; the greatest difference between high- and low-activity boys was in Tanner stage 3. Calcium intake had a significant effect on bone accrual only in nonblack girls. This effect was not significantly different among Tanner stages. Our findings do not support differential effects of physical activity or calcium intake on bone mass accrual according to maturational stage. The study demonstrated significant longitudinal effects of weight-bearing physical activity on bone mass accrual through all stages of pubertal development. © 2014 American

FUNCTIONAL OUTCOMES OF HIP ARTHROSCOPY IN AN ACTIVE DUTY MILITARY POPULATION UTILIZING A CRITERION-BASED EARLY WEIGHT BEARING PROGRESSION.

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Shaw, K Aaron; Jacobs, Jeremy M; Evanson, J Richard; Pniewski, Josh; Dickston, Michelle L; Mueller, Terry; Bojescul, John A

2017-10-01

Hip arthroscopy allows surgeons to address intra-articular pathology of the hip while avoiding more invasive open surgical dislocation. However the post-operative rehabilitation protocols have varied greatly in the literature, with many having prolonged periods of limited motion and weight bearing. The purpose of this study was to describe a criterion-based early weight bearing protocol following hip arthroscopy and investigate functional outcomes in the subjects who were active duty military. Active duty personnel undergoing hip arthroscopy for symptomatic femoroacetabular impingement were prospectively assessed in a controlled environment for the ability to incorporate early postoperative weight-bearing with the following criteria: no increased pain complaint with weight bearing and normalized gait pattern. Modified Harris Hip (HHS) and Hip Outcome score (HOS) were performed preoperatively and at six months post-op. Participants were progressed with a standard hip arthroscopy protocol. Hip flexion was limited to not exceed 90 degrees for the first three weeks post-op, with progression back to running beginning at three months. Final discharge was dependent upon the ability to run two miles at military specified pace and do a single leg broad jump within six inches of the contralateral leg without an increase in pain. Eleven participants met inclusion criteria over the study period. Crutch use was discontinued at an average of five days following surgery based on established weight bearing criteria. Only one participant required continued crutch use at 15 days. Participants' functional outcome was improved postoperatively, as demonstrated by significant increases in HOS and HHS. At the six month follow up, eight of 11 participants were able to take and complete a full Army Physical Fitness Test. Following completion of the early weight bearing rehabilitation protocol, 81% of participants were able to progress to full weight bearing by four days post

NGF blockade at early times during bone cancer development attenuates bone destruction and increases limb use.

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McCaffrey, Gwen; Thompson, Michelle L; Majuta, Lisa; Fealk, Michelle N; Chartier, Stephane; Longo, Geraldine; Mantyh, Patrick W

2014-12-01

Studies in animals and humans show that blockade of nerve growth factor (NGF) attenuates both malignant and nonmalignant skeletal pain. While reduction of pain is important, a largely unanswered question is what other benefits NGF blockade might confer in patients with bone cancer. Using a mouse graft model of bone sarcoma, we demonstrate that early treatment with an NGF antibody reduced tumor-induced bone destruction, delayed time to bone fracture, and increased the use of the tumor-bearing limb. Consistent with animal studies in osteoarthritis and head and neck cancer, early blockade of NGF reduced weight loss in mice with bone sarcoma. In terms of the extent and time course of pain relief, NGF blockade also reduced pain 40% to 70%, depending on the metric assessed. Importantly, this analgesic effect was maintained even in animals with late-stage disease. Our results suggest that NGF blockade immediately upon detection of tumor metastasis to bone may help preserve the integrity and use, delay the time to tumor-induced bone fracture, and maintain body weight. ©2014 American Association for Cancer Research.

Reconstruction of irradiated bone segmental defects with a biomaterial associating MBCP+(R), microstructured collagen membrane and total bone marrow grafting: an experimental study in rabbits.

Science.gov (United States)

Jégoux, Franck; Goyenvalle, Eric; Cognet, Ronan; Malard, Olivier; Moreau, Francoise; Daculsi, Guy; Aguado, Eric

2009-12-15

The bone tissue engineering models used today are still a long way from any oncologic application as immediate postimplantation irradiation would decrease their osteoinductive potential. The aim of this study was to reconstruct a segmental critical size defect in a weight-bearing bone irradiated after implantation. Six white New Zealand rabbits were immediately implanted with a biomaterial associating resorbable collagen membrane EZ(R) filled and micro-macroporous biphasic calcium phosphate granules (MBCP+(R)). After a daily schedule of radiation delivery, and within 4 weeks, a total autologous bone marrow (BM) graft was injected percutaneously into the center of the implant. All the animals were sacrificed at 16 weeks. Successful osseous colonization was found to have bridged the entire length of the defects. Identical distribution of bone ingrowth and residual ceramics at the different levels of the implant suggests that the BM graft plays an osteoinductive role in the center of the defect. Periosteum-like formation was observed at the periphery, with the collagen membrane most likely playing a role. This model succeeded in bridging a large segmental defect in weight-bearing bone with immediate postimplantation fractionated radiation delivery. This has significant implications for the bone tissue engineering approach to patients with cancer-related bone defects.

Skeletal muscle fat content is inversely associated with bone strength in young girls.

Science.gov (United States)

Farr, Joshua N; Funk, Janet L; Chen, Zhao; Lisse, Jeffrey R; Blew, Robert M; Lee, Vinson R; Laudermilk, Monica; Lohman, Timothy G; Going, Scott B

2011-09-01

Childhood obesity is an established risk factor for metabolic disease. The influence of obesity on bone development, however, remains controversial and may depend on the pattern of regional fat deposition. Therefore, we examined the associations of regional fat compartments of the calf and thigh with weight-bearing bone parameters in girls. Data from 444 girls aged 9 to 12 years from the Jump-In: Building Better Bones study were analyzed. Peripheral quantitative computed tomography (pQCT) was used to assess bone parameters at metaphyseal and diaphyseal sites of the femur and tibia along with subcutaneous adipose tissue (SAT, mm(2) ) and muscle density (mg/cm(3) ), an index of skeletal muscle fat content. As expected, SAT was positively correlated with total-body fat mass (r = 0.87-0.89, p  .05), except the distal tibia (β = 0.09, p = .03). In conclusion, skeletal muscle fat content of the calf and thigh is inversely associated with weight-bearing bone strength in young girls. Copyright © 2011 American Society for Bone and Mineral Research.

Curcumin reduces trabecular and cortical bone in naive and Lewis lung carcinoma-bearing mice

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The present study investigated the effects of dietary supplementation with curcumin on bone microstructural changes in female C57BL/6 mice in the presence or absence of Lewis lung carcinoma. Morphometric analysis showed that in tumor-bearing mice curcumin at 2% and 4% dietary levels (w/w) significa...

Upright CT of the knee: the effect of weight-bearing on joint alignment

Energy Technology Data Exchange (ETDEWEB)

Hirschmann, Anna [Orthopedic University Hospital Balgrist, University of Zurich, Department of Radiology, Zurich (Switzerland); University of Basel Hospital, Clinic of Radiology and Nuclear Medicine, Basel (Switzerland); Buck, Florian M.; Pfirrmann, Christian W.A. [Orthopedic University Hospital Balgrist, University of Zurich, Department of Radiology, Zurich (Switzerland); Fucentese, Sandro F. [Orthopedic University Hospital Balgrist, University of Zurich, Orthopedic Surgery, Zurich (Switzerland)

2015-11-15

To prospectively compare patellofemoral and femorotibial alignment in supine non-weight-bearing computed tomography (NWBCT) and upright weight-bearing CT (WBCT) and assess the differences in joint alignment. NWBCT and WBCT images of the knee were obtained in 26 patients (mean age, 57.0 ± 15.9 years; range, 21-81) using multiple detector CT for NWBCT and cone-beam extremity CT for WBCT. Two musculoskeletal radiologists independently quantified joint alignment by measuring femorotibial rotation, tibial tuberosity-trochlear groove distance (TTTG), lateral patellar tilt angle, lateral patellar shift, and medial and lateral femorotibial joint space widths. Significant differences between NWBCT and WBCT were sought using Wilcoxon signed-rank test (P-value < 0.05). Significant differences were found for femorotibial rotation (the NWBCT mean changed from 2.7 ± 5.1 (reader 1)/2.6 ± 5.6 (reader 2) external rotation to WBCT 0.4 ± 7.7/0.2 ± 7.5 internal rotation; P = 0.009/P = 0.004), TTTG decrease from NWBCT (13.8 mm ± 5.1/13.9 mm ± 3.9) to WBCT (10.5 mm ± 5.0/10.9 mm ± 5.2; P = 0.008/P = 0.002), lateral patellar tilt angle decrease from NWBCT (15.6 ± 6.7/16.9 ± 7.4) to WBCT (12.5 ± 7.7/15.0 ± 6.2; P = 0.011/P = 0.188). The medial femorotibial joint space decreased from NWBCT (3.9 mm ± 1.4/4.5 mm ± 1.3) to WBCT (2.9 mm ± 2.2/3.5 mm ± 2.2; P = 0.003/P = 0.004). Inter-reader agreement ranged from 0.52-0.97. Knee joint alignment changes significantly in the upright weight-bearing position using CT when compared to supine non-weight-bearing CT. (orig.)

Upright CT of the knee: the effect of weight-bearing on joint alignment

International Nuclear Information System (INIS)

Hirschmann, Anna; Buck, Florian M.; Pfirrmann, Christian W.A.; Fucentese, Sandro F.

2015-01-01

To prospectively compare patellofemoral and femorotibial alignment in supine non-weight-bearing computed tomography (NWBCT) and upright weight-bearing CT (WBCT) and assess the differences in joint alignment. NWBCT and WBCT images of the knee were obtained in 26 patients (mean age, 57.0 ± 15.9 years; range, 21-81) using multiple detector CT for NWBCT and cone-beam extremity CT for WBCT. Two musculoskeletal radiologists independently quantified joint alignment by measuring femorotibial rotation, tibial tuberosity-trochlear groove distance (TTTG), lateral patellar tilt angle, lateral patellar shift, and medial and lateral femorotibial joint space widths. Significant differences between NWBCT and WBCT were sought using Wilcoxon signed-rank test (P-value < 0.05). Significant differences were found for femorotibial rotation (the NWBCT mean changed from 2.7 ± 5.1 (reader 1)/2.6 ± 5.6 (reader 2) external rotation to WBCT 0.4 ± 7.7/0.2 ± 7.5 internal rotation; P = 0.009/P = 0.004), TTTG decrease from NWBCT (13.8 mm ± 5.1/13.9 mm ± 3.9) to WBCT (10.5 mm ± 5.0/10.9 mm ± 5.2; P = 0.008/P = 0.002), lateral patellar tilt angle decrease from NWBCT (15.6 ± 6.7/16.9 ± 7.4) to WBCT (12.5 ± 7.7/15.0 ± 6.2; P = 0.011/P = 0.188). The medial femorotibial joint space decreased from NWBCT (3.9 mm ± 1.4/4.5 mm ± 1.3) to WBCT (2.9 mm ± 2.2/3.5 mm ± 2.2; P = 0.003/P = 0.004). Inter-reader agreement ranged from 0.52-0.97. Knee joint alignment changes significantly in the upright weight-bearing position using CT when compared to supine non-weight-bearing CT. (orig.)

Association Between Insulin Resistance and Bone Structure in Nondiabetic Postmenopausal Women

Science.gov (United States)

Finkelstein, Joel S.; Bouxsein, Mary L.; Yu, Elaine W.

2016-01-01

Context: The clinical consequences of insulin resistance and hyperinsulinemia on bone remain largely unknown. Objective: The objective of the study was to evaluate the effect of insulin resistance on peripheral bone geometry, volumetric bone mineral density (vBMD), bone microarchitecture, and estimated bone strength. Design, Setting, and Participants: This cross-sectional study included 146 postmenopausal, nondiabetic Caucasian women (mean age 60.3 ± 2.7 y) who were participating in the Study of Women's Health Across the Nation. Interventions: There were no interventions. Main Outcome Measures: High-resolution peripheral quantitative computed tomography was used to assess bone density and microstructure at the distal radius and tibia. Fasting insulin and glucose were measured and insulin resistance was estimated using homeostasis model assessment of insulin resistance (HOMA-IR), with higher values indicating greater insulin resistance. Results: There was a negative association between HOMA-IR and bone size and a positive association between HOMA-IR and total vBMD, trabecular vBMD, trabecular thickness, and cortical thickness at the radius and tibia. These relationships remained, even after adjusting for body weight and other potential covariates (eg, time since menopause, cigarette smoking, physical activity, prior use of osteoporosis medications or glucocorticoids). Conclusions: In nondiabetic, postmenopausal women, insulin resistance was associated with smaller bone size, greater volumetric bone mineral density, and generally favorable bone microarchitecture at weight-bearing and nonweight-bearing skeletal sites. These associations were independent of body weight and other potential covariates, suggesting that hyperinsulinemia directly affects bone structure independent of obesity and may explain, in part, the higher trabecular bone density and favorable trabecular microarchitecture seen in individuals with type 2 diabetes mellitus. PMID:27243136

Osteogenic protein 1 device increases bone formation and bone graft resorption around cementless implants

DEFF Research Database (Denmark)

Jensen, Thomas B; Overgaard, Søren; Lind, Martin

2002-01-01

In each femoral condyle of 8 Labrador dogs, a non weight-bearing hydroxyapatite-coated implant was inserted surrounded by a 3 mm gap. Each gap was filled with bone allograft or ProOsteon with or without OP-1 delivered in a bovine collagen type I carrier (OP-1 device). 300 microg OP-1 was used...

Effect and safety of early weight-bearing on the outcome after open-wedge high tibial osteotomy: a systematic review and meta-analysis.

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Lee, O-Sung; Ahn, Soyeon; Lee, Yong Seuk

2017-07-01

The purpose of this systematic review and meta-analysis was to evaluate the effectiveness and safety of early weight-bearing by comparing clinical and radiological outcomes between early and traditional delayed weight-bearing after OWHTO. A rigorous and systematic approach was used. The methodological quality was also assessed. Results that are possible to be compared in two or more than two articles were presented as forest plots. A 95% confidence interval was calculated for each effect size, and we calculated the I 2 statistic, which presents the percentage of total variation attributable to the heterogeneity among studies. The random-effects model was used to calculate the effect size. Six articles were included in the final analysis. All case groups were composed of early full weight-bearing within 2 weeks. All control groups were composed of late full weight-bearing between 6 weeks and 2 months. Pooled analysis was possible for the improvement in Lysholm score, but there was no statistically significant difference shown between groups. Other clinical results were also similar between groups. Four studies reported mechanical femorotibial angle (mFTA) and this result showed no statistically significant difference between groups in the pooled analysis. Furthermore, early weight-bearing showed more favorable results in some radiologic results (osseointegration and patellar height) and complications (thrombophlebitis and recurrence). Our analysis supports that early full weight-bearing after OWHTO using a locking plate leads to improvement in outcomes and was comparable to the delayed weight-bearing in terms of clinical and radiological outcomes. On the contrary, early weight-bearing was more favorable with respect to some radiologic parameters and complications compared with delayed weight-bearing.

Pitfalls in comparing modern hair and fossil bone collagen C and N isotopic data to reconstruct ancient diets: a case study with cave bears (Ursus spelaeus).

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Bocherens, Hervé; Grandal-d'Anglade, Aurora; Hobson, Keith A

2014-01-01

Stable isotope analyses provide one of the few means to evaluate diet of extinct taxa. However, interpreting isotope data from bone collagen of extinct animals based on isotopic patterns in different tissues of modern animal proxies is precarious. For example, three corrections are needed before making comparisons of recent hair and ancient bone collagen: calibration of carbon-13 variations in atmospheric CO2, different isotopic discrimination between diet-hair keratin and diet-bone collagen, and time averaging of bone collagen versus short-term record in hair keratin. Recently, Robu et al. [Isotopic evidence for dietary flexibility among European Late Pleistocene cave bears (Ursus spelaeus). Can J Zool. 2013;91:227-234] published an article comparing extant carbon (δ(13)C) and nitrogen (δ(15)N) stable isotopic data of European cave bear bone collagen with those of Yellowstone Park grizzly bear hair in order to test the prevailing assumption of a largely vegetarian diet among cave bears. The authors concluded that cave bears were carnivores. This work is unfortunately unfounded as the authors failed to consider the necessary corrections listed above. When these corrections are applied to the Romanian cave bears, these individuals can be then interpreted without involving consumption of high trophic-level food, and environmental changes are probably the reason for the unusual isotopic composition of these cave bears in comparison with other European cave bears, rather than a change of diet. We caution researchers to pay careful attention to these factors when interpreting feeding ecology of extinct fauna using stable isotope techniques.

Effect of castration age on weight and size of some bones in Piemontese male cattle

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C. Lazzaroni

2010-04-01

Full Text Available Effect of pre- and post-pubertal castration on bone weight and measurements has been studied in 3 groups of Piemontese male cattle (EC - early castrated, LC - late castrated, IM - intact reared in the same environmental conditions and slaughtered at about 18 month of age, at about 550 kg of l.w., and at the same commercial fattening degree. At side commercial dissection all separated bones were weighted, and on the main ones (scapula, humerus, radius, femur, and tibia linear measures were recorded and then some conformation ratios were calculated (weight/length, length/width, and length/circumference. Data were analysed by GLM ANCOVA procedure, correcting data on side weight to avoid bias due to differences in carcass weight. No differences were found in side bone weight (23.58 ± 2.61 kg, so as in single bone weight, measures and ratios.

Bone mineral density and content during weight cycling in female rats: effects of dietary amylase-resistant starch

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Jagpal Sugeet

2008-11-01

Full Text Available Abstract Background Although there is considerable evidence for a loss of bone mass with weight loss, the few human studies on the relationship between weight cycling and bone mass or density have differing results. Further, very few studies assessed the role of dietary composition on bone mass during weight cycling. The primary objective of this study was to determine if a diet high in amylase-resistant starch (RS2, which has been shown to increase absorption and balance of dietary minerals, can prevent or reduce loss of bone mass during weight cycling. Methods Female Sprague-Dawley (SD rats (n = 84, age = 20 weeks were randomly assigned to one of 6 treatment groups with 14 rats per group using a 2 × 3 experimental design with 2 diets and 3 weight cycling protocols. Rats were fed calcium-deficient diets without RS2 (controls or diets high in RS2 (18% by weight throughout the 21-week study. The weight cycling protocols were weight maintenance/gain with no weight cycling, 1 round of weight cycling, or 2 rounds of weight cycling. After the rats were euthanized bone mineral density (BMD and bone mineral content (BMC of femur were measured by dual energy X-ray absorptiometry, and concentrations of calcium, copper, iron, magnesium, manganese, and zinc in femur and lumbar vertebrae were determined by atomic absorption spectrophotometry. Results Rats undergoing weight cycling had lower femur BMC (p 2 had higher femur BMD (p 2-fed rats also had higher femur calcium (p Conclusion Weight cycling reduces bone mass. A diet high in RS2 can minimize loss of bone mass during weight cycling and may increase bone mass in the absence of weight cycling.

Arthrosis of the ankle evaluated on films in weight-bearing position

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Bauer, M.; Bergstroem, B.; Hemborg, A.

1979-01-01

About 7 years after a malleolar fracture 113 patients were examined for development of arthrosis. The addition of films exposed in weight-bearing position with a.p. beam direction to views of the ankle joint exposed in supine position did not contribute to the diagnosis of arthrosis. (Auth.)

Disuse exaggerates the detrimental effects of alcohol on cortical bone

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

2003-01-01

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

Postoperative weight bearing and patient reported outcomes at one year following tibial plateau fractures.

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Thewlis, Dominic; Fraysse, Francois; Callary, Stuart A; Verghese, Viju Daniel; Jones, Claire F; Findlay, David M; Atkins, Gerald J; Rickman, Mark; Solomon, Lucian B

2017-07-01

Tibial plateau fractures are complex and the current evidence for postoperative rehabilitation is weak, especially related to the recommended postoperative weight bearing. The primary aim of this study was to investigate if loading in the first 12 weeks of recovery is associated with patient reported outcome measures at 26 and 52 weeks postoperative. We hypothesized that there would be no association between loading and patient reported outcome measures. Seventeen patients, with a minimum of 52-week follow-up following fragment-specific open reduction and internal fixation for tibial plateau fracture, were selected for this retrospective analysis. Postoperatively, patients were advised to load their limb to a maximum of 20kg during the first 6 weeks. Loading data were collected during walking using force platforms. A ratio of limb loading (affected to unaffected) was calculated at 2, 6 and 12 weeks postoperative. Knee Injury and Osteoarthritis Scores were collected at 6, 12, 26 and 52 weeks postoperative. The association between loading ratios and patient reported outcomes were investigated. Compliance with weight bearing recommendations and changes in the patient reported outcome measures are described. Fracture reduction and migration were assessed on plain radiographs. No fractures demonstrated any measurable postoperative migration at 52 weeks. Significant improvements were seen in all patient reported outcome measures over the first 52 weeks, despite poor adherence to postoperative weight bearing restrictions. There were no associations between weight bearing ratio and patient reported outcomes at 52 weeks postoperative. Significant associations were identified between the loading ratio at 2 weeks and knee-related quality of life at six months (R 2 =0.392), and between the loading ratio at 6 weeks combined with injury severity and knee-related quality of life at 26 weeks (R 2 =0.441). In summary, weight bearing as tolerated does not negatively affect the

Evaluation with fat-suppression fast spin-echo T2-weighted images for bone and soft tissue disorders

International Nuclear Information System (INIS)

Kakitsubata, Yousuke; Watanabe, Katsushi; Kakitsubata, Sachiko; Shimizu, Tokiyoshi.

1997-01-01

One hundred and sixty-four magnetic resonance (MR) studies of bone or soft tissue disorders were evaluated with T2-weighted fast spin echo (FSE) imaging and T2-weighted fat-suppressed FSE (FS-FSE) imaging. Fifty-two patients with bone contusion of the knee were also evaluated with conventional T2-weighted SE imaging and T2-weighted FS-FSE imaging. In 50 of 71 patients (70.4%), areas of high signal intensity in bone marrow were more clearly demonstrated on T2-weighted FS-FSE images than on T2-weighted FSE image. Edema or inflammation of soft tissues were also clearly revealed on T2-weighted FS-FSE images. In 27 of 32 patients (84%), bone contusions were more apparently shown on T2-weighted FS-FSE images than on conventional T2-weighted SE image. T2-weighted FS-FSE imaging is a sensitive method of evaluating the long T2 lesions of bone or soft tissue disorders. (author)

Prospective study of bone metastasis from prostate cancer: comparison between large field diffusion-weighted imaging and bone scintigraphy

International Nuclear Information System (INIS)

Wang Xiaoying; Zhang Chunyan; Jiang Xuexiang

2009-01-01

Objective: To evaluate the large field diffusion weighted imaging (DWI) (from head vertex to lower leg) in detection of bone metastases from prostate cancer. Methods: One hundred and sixty- six consecutive patients who were suspected of prostate cancer received pelvic MRI and large field diffusion weighted imaging examination. Forty-nine of them underwent bone scintigraphy within one month of the examination of large field DWI. The images were double-blindly evaluated without the knowledge of the pathology result. Conventional MR T 1 and fat saturation T 2 weighted images were taken as standard for the diagnosis of bone metastasis. The sensitivity, specificity, and area under curve between large field DWI and bone scintigraphy were compared with McNemar test. Five patients with bone metastases exceeding 10 per patient were excluded in the lesion-by-lesion analysis. Results: Ten of the 49 patients were diagnosed as bone metastases. The diagnosis of bone metastasis were made in 15 patients by large field DWI and in 17 patients by bone scintigraphy. With patient number as study units (n=49), the diagnostic sensitivity of bone metastases with large field DWI and bone metastases were both 100% (10/10), and specificity were 87.2% (34/39) vs. 82.1% (32/39), respectively. ROC study showed the area under curve (AUC) of large field DWI and bone scintigraphy were 0.936 vs. 0.910, respectively. Totally 68 abnormal foci were identified from large field DWI and/or bone scintigraphy in 44 patients (while 5 patients with bone metastases exceeding 10 foci per patient were excluded), 20 of them were diagnosed as foci of bone metastasis. The diagnosis of bone metastases was made in 23 foci by large field DWI and in 34 by bone scintigraphy. With lesion numbers as study units (n=68), the diagnostic sensitivity of large field DWI and bone scintigraphy were both 90.0% (18/20), and specificity were 89.6% (43/48) vs. 66.7% (32/48), respectively. ROC study showed the area under curve of

Birth weight and adult bone metabolism are unrelated

DEFF Research Database (Denmark)

Frost, Morten; Petersen, Inge Lund; Andersen, Thomas Levin

2013-01-01

INTRODUCTION: Low birth weight (BW) has been associated with poor bone health in adulthood. The aim of this study was to investigate the association between BW and bone mass and metabolism in adult BW discordant monozygotic twins (MZ). METHODS: 153 BW extremely discordant MZ twin-pairs were recru......-BMC, and -WB-Area after adjustments. Compared to the co-twin, twins with the highest BW were heavier and taller in adulthood (Mean differences (SD): 3.0 (10.5) kg; 1.6 (2.6) cm, both p ...

The Effect of Weight-Bearing Exercise on the Strength of Femur Bone in Ovariectomized Rats

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GH Sharifi

2011-08-01

Full Text Available Introduction & Objective: Fractures due to osteoporosis after menopause in women is widespread. Osteoporosis may occur in case of inadequate lack of physical activity .The aim of this study was to determine the effect of running training on femur bone strength in ovariectomized rats. Materials & Methods Forty matured Sprague Dawley rats were chosen for this study. A group of 10 were killed randomly to measure their initial femur strength. The remaining rats had ovarian surgery. After three months, in order to reach menopause period, they were randomly divided into 3 groups, including pre test, running training and control groups. The running training program was carried out for one hour a day, five days a week, for eight weeks. Femur bone strength was measured by HOUNSFIELD system. Data was analyzed by using one-way analysis of variance and dependent T- tests by the SPSS software. Results: Results of this study showed that ovariectomy leads to significant decrease of femur bone strength. On the other hand the eight weeks running training lead to significant increase of femur bone strength. Conclusion: The results of this study suggest that life style is important factors in preventing of osteoporosis and running training program had an inhibitory or reversal effect on decrease of menopause-induced femur bone strength.

Forces associated with launch into space do not impact bone fracture healing

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Childress, Paul; Brinker, Alexander; Gong, Cynthia-May S.; Harris, Jonathan; Olivos, David J.; Rytlewski, Jeffrey D.; Scofield, David C.; Choi, Sungshin Y.; Shirazi-Fard, Yasaman; McKinley, Todd O.; Chu, Tien-Min G.; Conley, Carolynn L.; Chakraborty, Nabarun; Hammamieh, Rasha; Kacena, Melissa A.

2018-02-01

Segmental bone defects (SBDs) secondary to trauma invariably result in a prolonged recovery with an extended period of limited weight bearing on the affected limb. Soldiers sustaining blast injuries and civilians sustaining high energy trauma typify such a clinical scenario. These patients frequently sustain composite injuries with SBDs in concert with extensive soft tissue damage. For soft tissue injury resolution and skeletal reconstruction a patient may experience limited weight bearing for upwards of 6 months. Many small animal investigations have evaluated interventions for SBDs. While providing foundational information regarding the treatment of bone defects, these models do not simulate limited weight bearing conditions after injury. For example, mice ambulate immediately following anesthetic recovery, and in most cases are normally ambulating within 1-3 days post-surgery. Thus, investigations that combine disuse with bone healing may better test novel bone healing strategies. To remove weight bearing, we have designed a SBD rodent healing study in microgravity (μG) on the International Space Station (ISS) for the Rodent Research-4 (RR-4) Mission, which launched February 19, 2017 on SpaceX CRS-10 (Commercial Resupply Services). In preparation for this mission, we conducted an end-to-end mission simulation consisting of surgical infliction of SBD followed by launch simulation and hindlimb unloading (HLU) studies. In brief, a 2 mm defect was created in the femur of 10 week-old C57BL6/J male mice (n = 9-10/group). Three days after surgery, 6 groups of mice were treated as follows: 1) Vivarium Control (maintained continuously in standard cages); 2) Launch Negative Control (placed in the same spaceflight-like hardware as the Launch Positive Control group but were not subjected to launch simulation conditions); 3) Launch Positive Control (placed in spaceflight-like hardware and also subjected to vibration followed by centrifugation); 4) Launch Positive

Cranial acetabular retroversion is common in developmental dysplasia of the hip as assessed by the weight bearing position

DEFF Research Database (Denmark)

Troelsen, Anders; Mikkelsen, Lone Rømer; Jacobsen, Steffen

2010-01-01

The appearance of acetabular version differs between the supine and weight bearing positions in developmental dysplasia of the hip. Weight bearing radiographic evaluation has been recommended to ensure the best coherence between symptoms, functional appearance, and hip deformities. Previous...... prevalence estimates of acetabular retroversion in dysplastic hips have been established in radiographs recorded with the patient supine and with inclusion only if pelvic tilt met standardized criteria. We assessed the prevalence and the extent of acetabular retroversion in dysplastic hip joints in weight...

Effects of obesity on weight-bearing versus weight-supported exercise testing in patients with COPD.

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Maatman, Robbert C; Spruit, Martijn A; van Melick, Paula P; Peeters, Jos P I; Rutten, Erica P A; Vanfleteren, Lowie E G W; Wouters, Emiel F M; Franssen, Frits M E

2016-04-01

Obesity is associated with increased dyspnoea and reduced health status in patients with chronic obstructive pulmonary disease (COPD). Studies on the effects of obesity on exercise capacity showed divergent results. The objective of this study is to investigate the impact of obesity on weight-bearing versus weight-supported exercise tolerance in obese and normal weight patients, matched for age, gender and degree of airflow limitation. Retrospective analyses of data obtained during pre-pulmonary rehabilitation assessment in 108 obese COPD patients (OB) (age: 61.2 ± 5.3y, FEV1 : 43.2 ± 7.4%, BMI: 34.1 ± 3.9 kg/m(2) ,) and 108 age and FEV1 -matched normal weight COPD patients (NW) (age: 61.7 ± 3.6y, FEV1 : 41.5 ± 8.4%, BMI: 22.9 ± 1.2 kg/m(2) ,). Cardiopulmonary exercise test (CPET) and 6 min walk test (6MWT) were performed, Borg scores for dyspnoea and leg fatigue were recorded, before and after the tests. Six-minute walk distance differed between OB (398 ± 107 m) and NW patients (446 ± 109 m, P exercise load was comparable (OB: 75 ± 29 W, NW: 70 ± 25 W, ns). Dyspnoea (OB 3.2 ± 2.0 vs NW 3.1 ± 1.7, ns) and leg fatigue (OB 2.4 ± 2.3 vs NW 1.9 ± 1.7, ns) were not significantly different in OB compared with NW after 6MWT, or after CPET (dyspnoea: OB 5.1 ± 2.4 vs NW 5.4 ± 2.2, ns; leg fatigue: OB 4.0 ± 2.3 vs NW 4.0 ± 2.7, ns). In contrast to weight-supported exercise, obesity has a negative impact on weight-bearing exercise capacity, despite comparable exercise-related symptoms. The results of this study enhance the understanding of the impact of obesity on physical performance in COPD. © 2015 Asian Pacific Society of Respirology.

Hindlimb Skeletal Muscle Function and Skeletal Quality and Strength in +/G610C Mice With and Without Weight-Bearing Exercise.

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Jeong, Youngjae; Carleton, Stephanie M; Gentry, Bettina A; Yao, Xiaomei; Ferreira, J Andries; Salamango, Daniel J; Weis, MaryAnn; Oestreich, Arin K; Williams, Ashlee M; McCray, Marcus G; Eyre, David R; Brown, Marybeth; Wang, Yong; Phillips, Charlotte L

2015-10-01

Osteogenesis imperfecta (OI) is a heterogeneous heritable connective tissue disorder associated with reduced bone mineral density and skeletal fragility. Bone is inherently mechanosensitive, with bone strength being proportional to muscle mass and strength. Physically active healthy children accrue more bone than inactive children. Children with type I OI exhibit decreased exercise capacity and muscle strength compared with healthy peers. It is unknown whether this muscle weakness reflects decreased physical activity or a muscle pathology. In this study, we used heterozygous G610C OI model mice (+/G610C), which model both the genotype and phenotype of a large Amish OI kindred, to evaluate hindlimb muscle function and physical activity levels before evaluating the ability of +/G610C mice to undergo a treadmill exercise regimen. We found +/G610C mice hindlimb muscles do not exhibit compromised muscle function, and their activity levels were not reduced relative to wild-type mice. The +/G610C mice were also able to complete an 8-week treadmill regimen. Biomechanical integrity of control and exercised wild-type and +/G610C femora were analyzed by torsional loading to failure. The greatest skeletal gains in response to exercise were observed in stiffness and the shear modulus of elasticity with alterations in collagen content. Analysis of tibial cortical bone by Raman spectroscopy demonstrated similar crystallinity and mineral/matrix ratios regardless of sex, exercise, and genotype. Together, these findings demonstrate +/G610C OI mice have equivalent muscle function, activity levels, and ability to complete a weight-bearing exercise regimen as wild-type mice. The +/G610C mice exhibited increased femoral stiffness and decreased hydroxyproline with exercise, whereas other biomechanical parameters remain unaffected, suggesting a more rigorous exercise regimen or another exercise modality may be required to improve bone quality of OI mice. © 2015 American Society for Bone

The role of lean body mass and physical activity in bone health in children.

Science.gov (United States)

Baptista, Fátima; Barrigas, Carlos; Vieira, Filomena; Santa-Clara, Helena; Homens, Pedro Mil; Fragoso, Isabel; Teixeira, Pedro J; Sardinha, Luís B

2012-01-01

In the context of physical education curricula, markers of physical fitness (e.g., aerobic capacity, muscular strength, flexibility, and body mass index or body fat) are usually evaluated in reference to health standards. Despite their possible mediating role in the relationship between weight-bearing or muscle forces and features of bone tissue, these attributes of fitness may not be the most relevant to predict skeletal health. It is therefore important to analyze the relative contribution of these factors to the variability in bone tissue of different parts of the skeleton, and to analyze it by gender, as sensitivity to mechanical loading can diverge for boys and girls. We compared the effects of habitual physical activity (PA) and lean mass, as surrogates of weight-bearing and muscle forces, and of physical fitness (aerobic and muscle capacity of lower and upper limbs) on bone mineral content (BMC) and size of total body, lumbar spine, femoral neck, and 1/3 radius in 53 girls and 64 boys from 7.9 to 9.7 years of age. After controlling for bone age, body mass, body height, and calcium intake, lean mass was the most important predictor of bone size and/or mineral in both genders (p  608 counts/min/day (~105 min/day of moderate and vigorous intensity) showed 13-20% more BMC than those with less physical activity, and girls with a lean mass >19 kg showed 12-19% more BMC than those with less lean mass. These findings suggest that lean mass was the most important predictor of bone size and/or mineralization in both genders, while habitual weight-bearing PA appears to positively impact on bone mineral in prepubertal boys and that both lean mass and PA need to be considered in physical education curricula and other health-enhancing programs.

Does taurine deficiency cause metabolic bone disease and rickets in polar bear cubs raised in captivity?

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Chesney, Russell W; Hedberg, Gail E; Rogers, Quinton R; Dierenfeld, Ellen S; Hollis, Bruce E; Derocher, Andrew; Andersen, Magnus

2009-01-01

Rickets and fractures have been reported in captive polar bears. Taurine (TAU) is key for the conjugation of ursodeoxycholic acid (UDCA), a bile acid unique to bears. Since TAU-conjugated UDCA optimizes fat and fat-soluble vitamin absorption, we asked if TAU deficiency could cause vitamin D malabsorption and lead to metabolic bone disease in captive polar bears. We measured TAU levels in plasma (P) and whole blood (WB) from captive and free-ranging cubs and adults, and vitamin D3 and TAU concentrations in milk samples from lactating sows. Plasma and WB TAU levels were significantly higher in cubs vs captive and free-ranging adult bears. Vitamin D in polar bear milk was 649.2 +/- 569.2 IU/L, similar to that found in formula. The amount of TAU in polar bear milk is 3166.4 +/- 771 nmol/ml, 26-fold higher than in formula. Levels of vitamin D in bear milk and formula as well as in plasma do not indicate classical nutritional vitamin D deficiency. Higher dietary intake of TAU by free-ranging cubs may influence bile acid conjugation and improve vitamin D absorption.

Effects of body weight and season on serum lipid concentrations in sloth bears (Melursus ursinus ursinus).

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Shanmugam, Arun Attur; Kumar, Jadav Kajal; Selvaraj, Illayaraja; Selvaraj, Vimal

2011-09-01

Serum lipid levels were measured in 66 healthy sloth bears (Melursus ursinus ursinus) living under semicaptive conditions with access to natural food resources in the Bannerghatta Biological Park (Karnataka, India), a portion of their native habitat range in the Indian peninsula. Total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein cholesterol levels were analyzed. The effects of age, body weight, and season on these lipid parameters were statistically evaluated. There were no correlations between age and any of the serum lipid parameters analyzed. Positive correlations of body weight to both triglyceride and HDL cholesterol levels in these bears were identified. In addition, seasonal trends in physiological serum lipid values, potentially due to variations in the sloth bear diet, were identified. Serum triglyceride levels were higher during postmonsoon season and cholesterol levels were higher during winter compared to other seasons. Serum lipid values obtained from sloth bears in this study were also compared to previously published data on other members of the family Ursidae. This is the first report of serum lipid values as a reference for sloth bears. These values can be used as sensitive predictors of overall health and nutritional status to aid in the captive management and feeding of these bears.

Appearance of the weight-bearing lateral radiograph in retrocalcaneal bursitis

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Muller, Bart; Maas, Mario; Sierevelt, Inger N; van Dijk, C Niek

2010-01-01

Background and purpose A retrocalcaneal bursitis is caused by repetitive impingement of the bursa between the Achilles tendon and the posterosuperior calcaneus. The bursa is situated in the posteroinferior corner of Kager's triangle (retrocalcaneal recess), which is a radiolucency with sharp borders on the lateral radiograph of the ankle. If there is inflammation, the fluid-filled bursa is less radiolucent, making it difficult to delineate the retrocalcaneal recess. We assessed whether the radiographic appearance of the retrocalcaneal recess on plain digital (filmless) radiographs could be used in the diagnosis of a retrocalcaneal bursitis. Methods Whether or not there was obliteration of the retrocalcaneal recess (yes/no) on 74 digital weight-bearing lateral radiographs of the ankle was independently assessed by 2 observers. The radiographs were from 24 patients (25 heels) with retrocalcaneal bursitis (confirmed on endoscopic calcaneoplasty); the control group consisted of 50 patients (59 heels). Results The sensitivity of the test was 83% for observer 1 and 79% for observer 2. Specificity was 100% and 98%, respectively. The kappa value of the interobserver reliability test was 0.86. For observer 1, intraobserver reliability was 0.96 and for observer 2 it was 0.92. Interpretation On digital weight-bearing lateral radiographs of a retrocalcaneal bursitis, the retrocalcaneal recess has a typical appearance. PMID:20450438

Radiographic changes and factors associated with subsequent progression of damage in weight-bearing joints of patients with rheumatoid arthritis under TNF-blocking therapies-three-year observational study.

Science.gov (United States)

Matsushita, Isao; Motomura, Hiraku; Seki, Eiko; Kimura, Tomoatsu

2017-07-01

The long-term effects of tumor necrosis factor (TNF)-blocking therapies on weight-bearing joints in patients with rheumatoid arthritis (RA) have not been fully characterized. The purpose of this study was to assess the radiographic changes of weight-bearing joints in patients with RA during 3-year of TNF-blocking therapies and to identify factors related to the progression of joint damage. Changes in clinical variables and radiological findings in 243 weight-bearing joints (63 hips, 54 knees, 71 ankles, and 55 subtalar joints) in 38 consecutive patients were investigated during three years of treatment with TNF-blocking agents. Multivariate logistic regression analysis was used to identify risk factors for the progression of weight-bearing joint damage. Seventeen (14.5%) of proximal weight-bearing joints (hips and knees) showed apparent radiographic progression during three years of treatment, whereas none of the proximal weight-bearing joints showed radiographic evidence of improvement or repair. In contrast, distal weight-bearing joints (ankle and subtalar joints) displayed radiographic progression and improvement in 20 (15.9%) and 8 (6.3%) joints, respectively. Multivariate logistic analysis for proximal weight-bearing joints identified the baseline Larsen grade (p bearing joints identified disease activity at one year after treatment (p bearing joints. Disease activity after treatment was an independent factor for progression of damage in proximal and distal weight-bearing joints. Early treatment with TNF-blocking agents and tight control of disease activity are necessary to prevent the progression of damage of the weight-bearing joints.

Randall Selitto pressure algometry for assessment of bone-related pain in rats.

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Falk, S; Ipsen, D H; Appel, C K; Ugarak, A; Durup, D; Dickenson, A H; Heegaard, A M

2015-03-01

Deep pain is neglected compared with cutaneous sources. Pressure algometry has been validated in the clinic for assessment of bone-related pain in humans. In animal models of bone-related pain, we have validated the Randall Selitto behavioural test for assessment of acute and pathological bone pain and compared the outcome with more traditional pain-related behaviour measures. Randall Selitto pressure algometry was performed over the anteromedial part of the tibia in naïve rats, sham-operated rats, and rats inoculated with MRMT-1 carcinoma cells in the left tibia, and the effect of morphine was investigated. Randall Selitto measures of cancer-induced bone pain were supplemented by von Frey testing, weight-bearing and limb use test. Contribution of cutaneous nociception to Randall Selitto measures were examined by local anaesthesia. Randall Selitto pressure algometry over the tibia resulted in reproducible withdrawal thresholds, which were dose-dependently increased by morphine. Cutaneous nociception did not contribute to Randall Selitto measures. In cancer-bearing animals, compared with sham, significant differences in pain-related behaviours were demonstrated by the Randall Selitto test on day 17 and 21 post-surgery. A difference was also demonstrated by von Frey testing, weight-bearing and limb use tests. Our results indicate that pressure applied by the Randall Selitto algometer on a region, where the bone is close to the skin, may offer a way to measure bone-related pain in animal models and could provide a supplement to the traditional behavioural tests and a means to study deep pain. © 2014 European Pain Federation - EFIC®

Re-evaluation of bone pain in patients with type 1 Gaucher disease suggests that bone crises occur in small bones as well as long bones.

Science.gov (United States)

Baris, Hagit N; Weisz Hubshman, Monika; Bar-Sever, Zvi; Kornreich, Liora; Shkalim Zemer, Vered; Cohen, Ian J

2016-09-01

Bone crises in type 1 Gaucher disease are reported in long bones and occasionally in weight bearing bones and other bones, but rarely in small bones of the hands and feet. We retrospectively examined the incidence of bone pain in patients followed at the Rabin Medical Center, Israel, before and following the initiation of enzyme replacement therapy (ERT) and evaluated them for bone crises. Of 100 type I Gaucher disease patients, 30 (30%) experienced one or more bone crises. Small bone crises represented 31.5% of all bone crises and were always preceded by crises in other bones. While the incidence of long bone crises reduced after the initiation of ERT, small bone crises increased. Almost 60% of patients with bone crises were of the N370S/84GG genotype suggesting a greater susceptibility of N370S/84GG patients to severe bone complications. These patients also underwent the greatest number of splenectomies (70.6% of splenectomised patients). Splenectomised patients showed a trend towards increased long and small bone crises after surgery. Active investigation of acute pain in the hands and feet in patients in our cohort has revealed a high incidence of small bone crises. Physicians should consider imaging studies to investigate unexplained pain in these areas. Copyright © 2015 Elsevier Inc. All rights reserved.

Delay in weight bearing in surgically treated tibial shaft fractures is associated with impaired healing: a cohort analysis of 166 tibial fractures.

Science.gov (United States)

Houben, I B; Raaben, M; Van Basten Batenburg, M; Blokhuis, T J

2018-04-09

The relation between timing of weight bearing after a fracture and the healing outcome is yet to be established, thereby limiting the implementation of a possibly beneficial effect for our patients. The current study was undertaken to determine the effect of timing of weight bearing after a surgically treated tibial shaft fracture. Surgically treated diaphyseal tibial fractures were retrospectively studied between 2007 and 2015. The timing of initial weight bearing (IWB) was analysed as a predictor for impaired healing in a multivariate regression. Totally, 166 diaphyseal tibial fractures were included, 86 cases with impaired healing and 80 with normal healing. The mean age was 38.7 years (range 16-89). The mean time until IWB was significantly shorter in the normal fracture healing group (2.6 vs 7.4 weeks, p bearing is independently associated with impaired fracture healing in surgically treated tibial shaft fractures. Unlike other factors such as fracture type or soft tissue condition, early resumption of weight bearing can be influenced by the treating physician and this factor therefore has a direct clinical relevance. This study indicates that early resumption of weight bearing should be the treatment goal in fracture fixation. 3b.

Trace and macro elements in the femoral bone as indicators of long-term environmental exposure to toxic metals in European brown bear (Ursus arctos) from Croatia.

Science.gov (United States)

Lazarus, Maja; Orct, Tatjana; Reljić, Slaven; Sedak, Marija; Bilandžić, Nina; Jurasović, Jasna; Huber, Đuro

2018-05-21

We explored the long-term accumulation of aluminium, strontium, cadmium and lead in the compact and trabecular bone of the femoral epiphysis, metaphysis and diaphysis in 41 brown bears (Ursus arctos) from Croatia. Also, we assessed their influence on macro and trace elements (sodium, magnesium, phosphorus, potassium, calcium, manganese, iron, cobalt, copper, zinc and barium) in bears' bone. There were no sex differences in element levels in general, while age was associated with bone length and levels of all elements, except for cadmium. Elements had different levels depending on the part of the bone sampled. More pronounced differences were observed between the compact and trabecular regions, with higher levels of majority of elements found in compact bone. Moderate to high associations (Spearman coefficient, r S  = 0.59-0.97) were confirmed between calcium and potassium, magnesium, phosphorus, manganese, cobalt, zinc, strontium and lead. Lead levels in the bone were below those known to cause adverse health effects, but in 4 of 41 animals they exceeded baseline levels for domestic animals. The femoral bone of the brown bear reflected the accumulative nature of lead and strontium well, as it did the impairment of bone-forming essential element levels associated with these two elements. However, the distribution pattern of elements along the bone was not uniform, so additional care should be taken when choosing on the part of the bone sampled.

Joint distraction and movement for repair of articular cartilage in a rabbit model with subsequent weight-bearing.

Science.gov (United States)

Nishino, T; Chang, F; Ishii, T; Yanai, T; Mishima, H; Ochiai, N

2010-07-01

We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.

[Factors affecting bone regeneration in Ilizarov callus distraction].

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Fink, B; Krieger, M; Schneider, T; Menkhaus, S; Fischer, J; Rüther, W

1995-12-01

We evaluated the X-rays of 36 patients who underwent 50 callus distractions. With the aid of a computerized digitalisation system for analogue films, the relative X-ray density of the distraction area was calculated for each X-ray. These relative X-ray densities were figured graphically for the duration of treatment for each patient. In the consolidation phase, the graph of each patient had a logarithmic relationship. The gradients of the logarithmic density curves were considered an indicator of the quantity of new bone formation. These gradients were correlated to the following clinical parameters: age of the patient, beginning of distraction after corticotomy, average speed of distraction, average weight bearing during the distraction and consolidation phase, location of corticotomy (distal femur versus proximal tibia) and diclofenac medication. Except for the location of the corticotomy and diclofenac, all parameters had an influence on osteoneogenesis by callus distraction. The parameters affecting new bone formation the most were the age of the patient and weight bearing. Patients aged under 18 years (p = 0.005), beginning of distraction later than 8 days (p = 0.109), an average distraction speed below 1 mm/day (p = 0.079), and average weight bearing of more than 30 kg (p = 0.068 for the distraction phase and p = 0.089 for the consolidation phase) showed a quantitatively higher rate of new bone formation by callus distraction than the patients in the other groups. Patients with a shorter leg due to poliomyelitis and one patient with an amniotic leg tie showed a slower increase in X-ray density graphs than the other patients.

[Contact characteristics research of acetabular weight-bearing area with different internal fixation methods after compression fracture of acetabular dome].

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Xu, Bowen; Zhang, Qingsong; An, Siqi; Pei, Baorui; Wu, Xiaobo

2017-08-01

To establish the model of compression fracture of acetabular dome, and to measure the contact characteristics of acetabular weight-bearing area of acetabulum after 3 kinds of internal fixation. Sixteen fresh adult half pelvis specimens were randomly divided into 4 groups, 4 specimens each group. Group D was the complete acetabulum (control group), and the remaining 3 groups were prepared acetabular dome compression fracture model. The fractures were fixed with reconstruction plate in group A, antegrade raft screws in group B, and retrograde raft screws in group C. The pressure sensitive films were attached to the femoral head, and the axial compression test was carried out on the inverted single leg standing position. The weight-bearing area, average stress, and peak stress were measured in each group. Under the loading of 500 N, the acetabular weight-bearing area was significantly higher in group D than in other 3 groups ( P area were significantly higher in group B and group C than in group A, and the average stress and peak stress were significantly lower than in group A ( P 0.05). For the compression fracture of the acetabular dome, the contact characteristics of the weight-bearing area can not restore to the normal level, even if the anatomical reduction and rigid internal fixation were performed; compared with the reconstruction plate fixation, antegrade and retrograde raft screws fixations can increase the weight-bearing area, reduce the average stress and peak stress, and reduce the incidence of traumatic arthritis.

The impact of bone development on final carcass weight

DEFF Research Database (Denmark)

Tatara, M.R.; Tygesen, Malin Plumhoff; Sawa-Wojtanowicz, B.

2006-01-01

Proper development and function of the skeleton is crucial for the optimal growth of an organism, with rapid growth rates often resulting in skeletal disorders in farm animals. Yet, despite clear benefits for breed selection and animal welfare (HARRISON et al., 2004), the impact of bone development...... was removed and its parameters correlated with carcass weight. Results suggest that both femur length and femur weight act as good predictors of final carcass weight in lambs. However, no effect of paternal genetics, on the femur to carcass correlations, was noted....

Exercise training, menstrual irregularities and bone development in children and adolescents.

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Eliakim, Alon; Beyth, Yoram

2003-08-01

Weight bearing physical activity plays an important role in bone development. This is particularly important in children and adolescents since bone mineral density reaches about 90% of its peak by the end of the second decade, and because about one quarter of adult bone is accumulated during the two years surrounding the peak bone growth velocity. Recent studies suggested that the exercise-induced increase in bone mineralization is maturity dependent, and that there is a "window of opportunity" and a critical period for bone response to weight bearing exercise during early puberty and premenarchal years. This supports the idea that increase in physical activity during childhood and adolescence can prevent bone disorders (like osteoporosis) later in life. In contrast, strenuous physical activity may affect the female reproductive system and lead to "athletic amenorrhea". The prevalence of "athletic amenorrhea" is 4-20 times higher than the general population. As a consequence, bone demineralization may develop with increased risk of skeletal fragility, fractures, vertebral instability, and curvature. Menstrual abnormalities in the female athlete result from hypothalamic suppression of the spontaneous pulsatile secretion of gonadotropin releasing hormone. Recent studies suggested that reduced energy availability (increased energy expenditure with inadequate caloric intake) is the main cause of the central suppression of the hypothalamic pituitary-gonadal axis. Therefore, effort should be made to optimize the nutritional state of female athletes, and if not successful, to reduce the training load in order to prevent menstrual abnormalities, and deleterious bone effects in particular during the critical period of rapid bone growth.

Relationship between pelvic alignment and weight-bearing asymmetry in community-dwelling chronic stroke survivors

Directory of Open Access Journals (Sweden)

Suruliraj Karthikbabu

2016-01-01

Full Text Available Background and Purpose: Altered pelvic alignment and asymmetrical weight bearing on lower extremities are the most common findings observed in standing and walking after stroke. The purpose of this study was to find the relationship between pelvic alignment and weight-bearing asymmetry (WBA in community-dwelling chronic stroke survivors. Materials and Methods: This cross-sectional study was conducted in tertiary care rehabilitation centers. In standing, the lateral and anterior pelvic tilt angle of chronic stroke survivors was assessed using palpation (PALM™ meter device. The percentage of WBA was measured with two standard weighing scales. Pearson correlation coefficient (r was used to study the correlation between pelvic tilt and WBA. Results: Of 112 study participants, the mean (standard deviation age was 54.7 (11.7 years and the poststroke duration was 14 (11 months. The lateral pelvic tilt on the most affected side and bilateral anterior pelvic tilt were 2.47 (1.8 and 4.4 (1.8 degree, respectively. The percentage of WBA was 23.2 (18.94. There was a high correlation of lateral pelvic tilt with WBA (r = 0.631; P< 0.001 than anterior pelvic tilt (r = 0.44; P< 0.001. Conclusion: Excessive lateral pelvic tilt toward the most affected side in standing may influence the weight-bearing ability of the ipsilateral lower extremity in community-dwelling chronic stroke survivors.

Relationship of total body fat mass to weight-bearing bone volumetric density, geometry, and strength in young girls.

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Farr, Joshua N; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

2010-04-01

Understanding the influence of total body fat mass (TBFM) on bone during the peri-pubertal years is critical for the development of future interventions aimed at improving bone strength and reducing fracture risk. Thus, we evaluated the relationship of TBFM to volumetric bone mineral density (vBMD), geometry, and strength at metaphyseal and diaphyseal sites of the femur and tibia of young girls. Data from 396 girls aged 8-13 years from the "Jump-In: Building Better Bones" study were analyzed. Bone parameters were assessed using peripheral quantitative computed tomography (pQCT) at the 4% and 20% distal femur and 4% and 66% distal tibia of the non-dominant leg. Bone parameters at the 4% sites included trabecular vBMD, periosteal circumference, and bone strength index (BSI), while at the 20% femur and 66% tibia, parameters included cortical vBMD, periosteal circumference, and strength-strain index (SSI). Multiple linear regression analyses were used to assess associations between bone parameters and TBFM, controlling for muscle cross-sectional area (MCSA). Regression analyses were then repeated with maturity, bone length, physical activity, and ethnicity as additional covariates. Analysis of covariance (ANCOVA) was used to compare bone parameters among tertiles of TBFM. In regression models with TBFM and MCSA, associations between TBFM and bone parameters at all sites were not significant. TBFM explained very little variance in all bone parameters (0.2-2.3%). In contrast, MCSA was strongly related (p<0.001) to all bone parameters, except cortical vBMD. The addition of maturity, bone length, physical activity, and ethnicity did not alter the relationship between TBFM and bone parameters. With bone parameters expressed relative to total body mass, ANCOVA showed that all outcomes were significantly (p<0.001) greater in the lowest compared to the middle and highest tertiles of TBFM. Although TBFM is correlated with femur and tibia vBMD, periosteal circumference, and

High Birth Weight Increases the Risk for Bone Tumor: A Systematic Review and Meta-Analysis

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Songfeng Chen

2015-09-01

Full Text Available There have been several epidemiologic studies on the relationship between high birth weight and the risk for bone tumor in the past decades. However, due to the rarity of bone tumors, the sample size of individual studies was generally too small for reliable conclusions. Therefore, we have performed a meta-analysis to pool all published data on electronic databases with the purpose to clarify the potential relationship. According to the inclusion and exclusion criteria, 18 independent studies with more than 2796 cases were included. As a result, high birth weight was found to increase the risk for bone tumor with an Odds Ratio (OR of 1.13, with the 95% confidence interval (95% CI ranging from 1.01 to 1.27. The OR of bone tumor for an increase of 500 gram of birth weight was 1.01 (95% CI 1.00–1.02; p = 0.048 for linear trend. Interestingly, individuals with high birth weight had a greater risk for osteosarcoma (OR = 1.22, 95% CI 1.06–1.40, p = 0.006 than those with normal birth weight. In addition, in the subgroup analysis by geographical region, elevated risk was detected among Europeans (OR = 1.14, 95% CI 1.00–1.29, p = 0.049. The present meta-analysis supported a positive association between high birth weight and bone tumor risk.

Femoral fracture repair using a locking plate technique in an adult captive polar bear (Ursus maritimus).

Science.gov (United States)

Zimmerman, Dawn M; Dew, Terry; Douglass, Michael; Perez, Edward

2010-02-01

To report successful femoral fracture repair in a polar bear. Case report. Female polar bear (Ursus maritimus) 5 years and approximately 250 kg. A closed, complete, comminuted fracture of the distal midshaft femur was successfully reduced and stabilized using a compression plating technique with 2 specialized human femur plates offering axial, rotational, and bending support, and allowing the bone to share loads with the implant. Postoperative radiographs were obtained at 11.5 weeks, 11 months, and 24 months. Bone healing characterized by marked periosteal reaction was evident at 11 months with extensive remodeling evident at 24 months. No complications were noted. Distal mid shaft femoral fracture was reduced, stabilized, and healed in an adult polar bear with a locking plate technique using 2 plates. Previously, femoral fractures in polar bears were considered irreparable. Use of 2 plates applied with a locking plate technique can result in successful fracture repair despite large body weight and inability to restrict postoperative activity.

Postero-anterior radiogram of the knee in weight-bearing and semiflexion. Comparison with MR imaging

International Nuclear Information System (INIS)

Boegaard, T.; Rudling, O.; Sanfridsson, J.; Jonsson, K.; Saxne, T.; Svensson, B.

1997-01-01

Purpose: The purpose was four-fold: to assess the reproducibility of p.a. weight-bearing radiograms of the knee and the minimal joint-space (MJS) width measurements in these radiograms; to compare the MJS with MR-detected cartilage defects; to evaluate the location of these cartilage defects; and to estimate the relation between meniscal abnormalities and joint-space narrowing. Material and Methods: Fifty-nine individuals, aged 41-58 years (mean 50), with chronic knee pain were examined by means of p.a. weight-bearing radiograms in semiflexion with fluoroscopic guidance of the knee joint. The MJS was measured with a standard ruler. On the same day MR imaging was performed with proton-density- and T2-weighted turbo spin-echo on a 1.0 T imager. Meniscal abnormalities and cartilage defects in the tibiofemoral joint (TFJ) were noted. Results and Conclusion: The p.a. view of the knee and the MJS measurements were reproducible. MJS of 3 mm is a limit in diagnosing joint-space narrowing in knees with MR-detected cartilage defects. There was a high proportion (p<0.001) of meniscal abnormality within the narrowed compartments in comparison with those that were not narrowed. A larger number of the cartilage defects (p<0.05) was found in the medial femoral condyle than in any of the other condyles of the TFJ. The defects had a dorsal location (p<0.001) as shown in the weight-bearing radiograms of the knee in semiflexion. (orig.)

Effects of upright weight bearing and the knee flexion angle on patellofemoral indices using magnetic resonance imaging in patients with patellofemoral instability.

Science.gov (United States)

Becher, Christoph; Fleischer, Benjamin; Rase, Marten; Schumacher, Thees; Ettinger, Max; Ostermeier, Sven; Smith, Tomas

2017-08-01

This study analysed the effects of upright weight bearing and the knee flexion angle on patellofemoral indices, determined using magnetic resonance imaging (MRI), in patients with patellofemoral instability (PI). Healthy volunteers (control group, n = 9) and PI patients (PI group, n = 16) were scanned in an open-configuration MRI scanner during upright weight bearing and supine non-weight bearing positions at full extension (0° flexion) and at 15°, 30°, and 45° flexion. Patellofemoral indices included the Insall-Salvati Index, Caton-Deschamp Index, and Patellotrochlear Index (PTI) to determine patellar height and the patellar tilt angle (PTA), bisect offset (BO), and the tibial tubercle-trochlear groove (TT-TG) distance to assess patellar rotation and translation with respect to the femur and alignment of the extensor mechanism. A significant interaction effect of weight bearing by flexion angle was observed for the PTI, PTA, and BO for subjects with PI. At full extension, post hoc pairwise comparisons revealed a significant effect of weight bearing on the indices, with increased patellar height and increased PTA and BO in the PI group. Except for the BO, no such changes were seen in the control group. Independent of weight bearing, flexing the knee caused the PTA, BO, and TT-TG distance to be significantly reduced. Upright weight bearing and the knee flexion angle affected patellofemoral MRI indices in PI patients, with significantly increased values at full extension. The observations of this study provide a caution to be considered by professionals when treating PI patients. These patients should be evaluated clinically and radiographically at full extension and various flexion angles in context with quadriceps engagement. Explorative case-control study, Level III.

Dynamic weight-bearing assessment of pain in knee osteoarthritis

DEFF Research Database (Denmark)

Klokker, Louise; Christensen, Robin; Osborne, Richard

2015-01-01

PURPOSE: To evaluate the reliability, agreement and smallest detectable change in a measurement instrument for pain and function in knee osteoarthritis; the Dynamic weight-bearing Assessment of Pain (DAP). METHODS: The sample size was set to 20 persons, recruited from the outpatient osteoarthritis...... for intra-rater test (1.95). The three knee bend scores all had ICC above 0.50, showing fair-to-good reliability. None of the knee bend scores showed acceptable SEM and SDC. CONCLUSIONS: The reproducibility of the DAP pain score meets the demands for use in clinical practice and research. The total knee...

Weight bearing cone beam CT scan versus gravity stress radiography for analysis of supination external rotation injuries of the ankle.

Science.gov (United States)

Marzo, John M; Kluczynski, Melissa A; Clyde, Corey; Anders, Mark J; Mutty, Christopher E; Ritter, Christopher A

2017-12-01

For AO 44-B2 ankle fractures of uncertain stability, the current diagnostic standard is to obtain a gravity stress radiograph, but some have advocated for the use of weight-bearing radiographs. The primary aim was to compare measures of medial clear space (MCS) on weight-bearing cone beam computed tomography (CBCT) scans versus gravity stress radiographs for determining the state of stability of ankle fractures classified as AO SER 44-B2 or Weber B. The secondary aim was to evaluate the details offered by CBCT scans with respect to other findings that may be relevant to patient care. Nine patients were enrolled in this cross-sectional study between April 2016 and February 2017 if they had an AO SER 44-B2 fracture of uncertain stability, had a gravity stress radiograph, and were able to undergo CT scan within seven days. The width of the MCS was measured at the level of the talar dome on all radiographs and at the mid coronal slice on CT. Wilcoxon signed-ranks tests were used to compare MCS between initial radiographs, gravity stress radiographs and weight-bearing CBCT scans. MCS on weight-bearing CBCT scan (1.41±0.41 mm) was significantly less than standard radiographs (3.28±1.63 mm, P=0.004) and gravity stress radiographs (5.82±1.93 mm, P=0.02). There was no statistically significant difference in MCS measured on standard radiographs versus gravity stress radiographs (P=0.11). Detailed review of the multiplanar CT images revealed less than perfect anatomical reduction of the fractures, with residual fibular shortening, posterior displacement, and fracture fragments in the incisura as typical findings. Similar to weight-bearing radiographs, weight-bearing CBCT scan can predict stability of AO 44-B2 ankle fractures by showing restoration of the MCS, and might be used to indicate patients for non-operative treatment. None of the fractures imaged in this study were perfectly reduced however, and further clinical research is necessary to determine if any of the

Persistent organic pollutants and penile bone mineral density in East Greenland and Canadian polar bears (Ursus maritimus) during 1996-2015.

Science.gov (United States)

Daugaard-Petersen, Tobias; Langebæk, Rikke; Rigét, Frank F; Dyck, Markus; Letcher, Robert J; Hyldstrup, Lars; Jensen, Jens-Erik Bech; Dietz, Rune; Sonne, Christian

2018-05-01

Persistent organic pollutants (POPs) are long-range transported to the Arctic via atmospheric and oceanic currents, where they biomagnify to high concentrations in the tissues of apex predators such as polar bears (Ursus maritimus). A major concern of POP exposure is their physiological effects on vital organ-tissues posing a threat to the health and survival of polar bears. Here we examined the relationship between selected POPs and baculum bone mineral density (BMD) in the East Greenland and seven Canadian subpopulations of polar bears. BMD was examined in 471 bacula collected between years 1996-2015 while POP concentrations in adipose tissue were determined in 67-192 of these individuals collected from 1999 to -2015. A geographical comparison showed that baculum BMD was significantly lowest in polar bears from East Greenland (EG) when compared to Gulf of Boothia (GB), Southern Hudson (SH) and Western Hudson (WH) Bay subpopulations (all p bears as a reference group gave a T-score of -1.44 which indicate risk of osteopenia. Concentrations of ΣPCB 74 (polychlorinated biphenyls), ΣDDT 3 (dichlorodiphenyltrichloroethanes), p,p'-DDE (dichlorodiphenyldichloroethylene), ΣHCH 3 (hexachlorohexane) and α-HCH was significantly highest in EG bears while ΣPBDE (polybrominated diphenyl ethers), BDE-47 and BDE-153 was significantly highest in SH bears (all p polar bears despite the positive statistical correlations of BMD vs. POPs. Other important factors such as nutritional status, body mass and body condition was not available for the statistical modelling. Since on-going environmental changes are known to affect these, future studies need to incorporate nutritional, endocrine and genetic parameters to further understand how POP exposure may disrupt bone homeostasis and affect baculum BMD across polar bear subpopulations. Copyright © 2018 Elsevier Ltd. All rights reserved.

Osteogenic capacity of nanocrystalline bone cement in a weight-bearing defect at the ovine tibial metaphysis.

Science.gov (United States)

Harms, Christoph; Helms, Kai; Taschner, Tibor; Stratos, Ioannis; Ignatius, Anita; Gerber, Thomas; Lenz, Solvig; Rammelt, Stefan; Vollmar, Brigitte; Mittlmeier, Thomas

2012-01-01

The synthetic material Nanobone(®) (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix) was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone(®), while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone(®) showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone(®) appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone(®) also in humans.

Effect of a novel load-bearing trabecular Nitinol scaffold on rabbit radius bone regeneration

Energy Technology Data Exchange (ETDEWEB)

Gotman, Irena, E-mail: gotman@technion.ac.il; Gutmanas, Elazar Y., E-mail: gutmanas@technion.ac.il [Department of Materials Science and Engineering, Techion-Israel Institute of Technology, Haifa, 32000 Israel (Israel); National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Zaretzky, Asaph [The Bruce Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, 31096 Israel (Israel); Psakhie, Sergey G. [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation)

2015-10-27

The research aim was to evaluate the bone regeneration capability of novel load-bearing NiTi alloy (Nitinol) scaffolds in a critical-size defect (CSD) model. High strength “trabecular Nitinol” scaffolds were prepared by PIRAC (Powder Immersion Reaction Assisted Coating) annealing of the highly porous Ni foam in Ti powder at 900°C. This was followed by PIRAC nitriding to mitigate the release of potentially toxic Ni ions. Scaffolds phase composition and microstructure were characterized by X-ray diffraction and scanning electron microscopy (SEM/EDS), and their mechanical properties were tested in compression. New Zealand white rabbits received bone defect in right radius and were divided in four groups randomly. In the control group, nothing was placed in the defect. In other groups, NiTi scaffolds were implanted in the defect: (i) as produced, (ii) loaded with bone marrow aspirate (BMA), and (iii) biomimetically CaP-coated. The animals were sacrificed after 12 weeks. The forelimbs with scaffolds were resected, fixed, sectioned and examined in SEM. New bone formation inside the scaffold was studied by EDS analysis and by the processing of backscattered electron images. Bone ingrowth into the scaffold was observed in all implant groups, mostly next to the ulna. New bone formation was strongly enhanced by BMA loading and biomimeatic CaP coating, the bone penetrating as much as 1–1.5 mm into the scaffold. The results of this preliminary study demonstrate that the newly developed high strength trabecular Nitinol scaffolds can be successfully used for bone regeneration in critical size defects.

Biomimetic nanocomposites of carboxymethyl cellulose-hydroxyapatite: novel three dimensional load bearing bone grafts.

Science.gov (United States)

Garai, Subhadra; Sinha, Arvind

2014-03-01

An innovative biomimetic synthesis of novel three dimensional micro/macro porous carboxymethyl cellulose (CMC)-hydroxyapatite (HA) nanocomposites having four systematically different compositions has been established for its possible application as a load bearing synthetic bone graft. Our process, being in situ, involves a simple and cost effective route akin to a matrix mediated biomineralization process. Developed synthesis route not only controls the size of HA particles in the range of 15-50 nm, embedded in CMC matrix, but also assists in the formation of a mechanically strong three dimensional nanocomposite structures due to physical cross linking of HA impregnated CMC matrix. The process does not involve any toxic cross linker and works at near ambient conditions. The nanocomposites are systematically structurally and mechanically characterized using various techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform IR (FTIR), solid state (13)C nuclear magnetic resonance ((13)C NMR), thermo-gravimetric analysis (TGA) and Universal mechanical test. It reveals that the ionic/polar or electrostatic interactions are the main driving force for formation of load bearing three dimensional nanocomposites via a process similar to matrix mediated biomineralization. Compressive strength and compressive modulus of nanocomposites, being in the range of 1.74-12 MPa and 157-330 MPa, respectively, meet the desired range of compressive strength for the synthetic grafts used in cancellous bone. An increase in the compressive strength with increase in the porosity has been an interesting observation in the present study. In vitro cytotoxicity of the synthesized nanocomposites has been evaluated using bone marrow mesenchymal stem cells (BMSC) isolated from Wistar rat. Copyright © 2013 Elsevier B.V. All rights reserved.

Improvement of Roller Bearing Diagnosis with Unlabeled Data Using Cut Edge Weight Confidence Based Tritraining

Directory of Open Access Journals (Sweden)

Wei-Li Qin

2016-01-01

Full Text Available Roller bearings are one of the most commonly used components in rotational machines. The fault diagnosis of roller bearings thus plays an important role in ensuring the safe functioning of the mechanical systems. However, in most cases of bearing fault diagnosis, there are limited number of labeled data to achieve a proper fault diagnosis. Therefore, exploiting unlabeled data plus few labeled data, this paper proposed a roller bearing fault diagnosis method based on tritraining to improve roller bearing diagnosis performance. To overcome the noise brought by wrong labeling into the classifiers training process, the cut edge weight confidence is introduced into the diagnosis framework. Besides a small trick called suspect principle is adopted to avoid overfitting problem. The proposed method is validated in two independent roller bearing fault experiment vibrational signals that both include three types of faults: inner-ring fault, outer-ring fault, and rolling element fault. The results demonstrate the desirable diagnostic performance improvement by the proposed method in the extreme situation where there is only limited number of labeled data.

Wholebody and pinhole bone scan manifestations of reiter's syndorme: distribution pattern and specific and early signs

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Kim, S. H.; Chung, S. K.; Park, Y. H.; Lee, S. Y.; Sohn, H. S.; Han, B. H.; Bahk, Y. W. [College of Medicine, Catholic Univ., Seoul (Korea, Republic of)

1998-07-01

We wish to describe the characteristics panoramic wholebody bone distribution, and specific and preradiographic pinhole bone scan signs of Reiter's syndrome(RS) featured by pauciarthritis and enthesopathies in and about weight-bearing joints of the lower extremities and axial bones. We analyzed 55 sets of wholebody and pinhole bone scintigraphs of 55 patients with RS. The population was 44 men and 11 women with age ranging from 15 to 52 yr (mean=29.3). The scintigraphy was performed 2-2.5 hr pi of Tc-99m-HDP using a single-head gamma camera with a LEHR collimator and a 4-mm pinhole collimator for the wholebody and pinhole scintigraphy, respectively. We found 223 lesions with increased tracer uptake in total. Wholebody scans showed asymmetric pauciarticular distribution in weight bearing joints and periarticular entheses in the lower extremities in 63.2% (calcaneus=24.2%, ankle=8.1%, tibia=8.1% and others). The sternum, sacroiliac joint and spine were involved in 8.5%, 5.8% and 4.5%, respectively. Pinhole scan portrayed many specific signs including the 'tear-drop' sign of paravertebral ossification. 'whiskers' sign of femoral osteophytes and 'knuckle bone' sign of sausage digit. Twenty-four lesions (10.8%) showed preradiogrpahic signs in symptomatic ehthesopathies mostly in the calcaneus and proximal tibia. Nine cases with calcaneal enthesopathies and four cases with proximal tibial enthesopathy without radiographic bone change showed intense tracer uptake. Wholebody and pinhole magnification scans were useful in studying RS. The asymmetric pauciarticular distribution in the weight-bearing bones with enthesopathies was characteristic. Pinhole scan portrayed many specific signs and was sensitive permitting accurate preradiographic diagnosis in many cases.

Is Weight-Bearing Asymmetry Associated with Postural Instability after Stroke? A Systematic Review

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Jip F. Kamphuis

2013-01-01

Full Text Available Introduction. Improvement of postural stability is an important goal during poststroke rehabilitation. Since weight-bearing asymmetry (WBA towards the nonparetic leg is common, training of weight-bearing symmetry has been a major focus in post-stroke balance rehabilitation. It is assumed that restoration of a more symmetrical weight distribution is associated with improved postural stability. Objective. To determine to what extent WBA is associated with postural instability in people after stroke. Methods. Electronic databases were searched (Cochrane, MEDLINE, EMBASE, and CINAHL until March 2012. Main Eligibility Criteria. (1 Participants were people after stroke. (2 The association between WBA and postural stability was reported. Quality of reporting was assessed with the STROBE checklist and a related tool for reporting of confounding. Results. Nine observational studies met all criteria. Greater spontaneous WBA was associated with higher center of pressure (COP velocity and with poorer synchronization of COP trajectories between the legs (two and one studies, resp.. Evidence for associations between WBA and performance on clinical balance tests or falls was weak. Conclusion. Greater WBA after stroke was associated with increased postural sway, but the current literature does not provide evidence for a causal relationship. Further studies should investigate whether reducing WBA would improve postural stability.

Osteogenic capacity of nanocrystalline bone cement in a weight-bearing defect at the ovine tibial metaphysis

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Mittlmeier T

2012-06-01

Full Text Available Christoph Harms,1 Kai Helms,1 Tibor Taschner,1 Ioannis Stratos,1 Anita Ignatius,5 Thomas Gerber,2 Solvig Lenz,3 Stefan Rammelt,6 Brigitte Vollmar,4 Thomas Mittlmeier11Department of Trauma and Reconstructive Surgery, 2Department for Materials Research and Nanostructures, Institute for Physics, 3Department of Oral and Maxillofacial Plastic Surgery, 4Institute for Experimental Surgery, University of Rostock, Rostock, 5Institute of Orthopaedic Research and Biomechanics, University of Ulm, Ulm, 6Clinic of Trauma and Reconstructive Surgery, University Hospital "Carl Gustav Carus", Dresden, GermanyAbstract: The synthetic material Nanobone® (hydroxyapatite nanocrystallines embedded in a porous silica gel matrix was examined in vivo using a standardized bone defect model in the ovine tibial metaphysis. A standardized 6 × 12 × 24-mm bone defect was created below the articular surface of the medial tibia condyles on both hind legs of 18 adult sheep. The defect on the right side was filled with Nanobone®, while the defect on the contralateral side was left empty. The tibial heads of six sheep were analyzed after 6, 12, and 26 weeks each. The histological and radiological analysis of the defect on the control side did not reveal any bone formation after the total of 26 weeks. In contrast, the microcomputed tomography analysis of the defect filled with Nanobone® showed a 55%, 72%, and 74% volume fraction of structures with bone density after 6, 12, and 26 weeks, respectively. Quantitative histomorphological analysis after 6, and 12 weeks revealed an osteoneogenesis of 22%, and 36%, respectively. Hematoxylin and eosin sections demonstrated multinucleated giant cells on the surface of the biomaterial and resorption lacunae, indicating osteoclastic resorptive activity. Nanobone® appears to be a highly potent bone substitute material with osteoconductive properties in a loaded large animal defect model, supporting the potential use of Nanobone® also in

Intramedullary screw fixation with bone autografting to treat proximal fifth metatarsal metaphyseal-diaphyseal fracture in athletes: a case series

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Tsukada Sachiyuki

2012-07-01

Full Text Available Abstract Background Delayed unions or refractures are not rare following surgical treatment for proximal fifth metatarsal metaphyseal-diaphyseal fractures. Intramedullary screw fixation with bone autografting has the potential to resolve the issue. The purpose of this study was to evaluate the result of the procedure. Methods The authors retrospectively reviewed 15 athletes who underwent surgical treatment for proximal fifth metatarsal metaphyseal-diaphyseal fracture. Surgery involved intramedullary cannulated cancellous screw fixation after curettage of the fracture site, followed by bone autografting. Postoperatively, patients remain non weight-bearing in a splint or cast for two weeks and without immobilization for an additional two weeks. Full weight-bearing was allowed six weeks postoperatively. Running was permitted after radiographic bone union, and return-to-play was approved after gradually increasing the intensity. Results All patients returned to their previous level of athletic competition. Mean times to bone union, initiation of running, and return-to-play were 8.4, 8.8, and 12.1 weeks, respectively. Although no delayed unions or refractures was observed, distal diaphyseal stress fractures at the distal tip of the screw occurred in two patients and a thermal necrosis of skin occurred in one patient. Conclusions There were no delayed unions or refractures among patients after carrying out a procedure in which bone grafts were routinely performed, combined with adequate periods of immobilization and non weight-bearing. These findings suggest that this procedure may be useful option for athletes to assuring return to competition level.

Radial and tibial bone indices in athletes participating in different endurance sports: a pQCT study.

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Oosthuyse, Tanja; McVeigh, Joanne A; Micklesfield, Lisa K; Meiring, Rebecca M

2017-03-01

Low magnitude bone-loading sports may benefit bone structure and strength in the exercised limbs. This study compared peripheral quantitative computed tomography measures of radial and tibial diaphyseal strength (strength-strain index, SSI), structure (total area (ToA) and cortical area (CoA), density (CoD) and thickness (CT), and circumferences), muscle cross-sectional area (MCSA) and strength (one-repetition maximum, 1-RM) in male endurance athletes taking part in (i) non-weight-bearing and non-impact sports: swimmers (SWIM, n = 13) and road cyclists (RC, n = 10), (ii) non-weight-bearing, impact sport: mountain bikers (MB, n = 10), (iii) weight bearing and impact sport: runners (RUN, n = 9). All athlete groups were also compared to sedentary controls (CON, n = 10). Arm MCSA, 1-RM and radial bone size and strength tended to be greater in SWIM than CON and/or RC (ToA, %difference  ± 95%CI, SWIM-CON: 14.6% ± 12.7%; SWIM-RC: 12.9% ± 10.7%) but not different to MB and RUN. RUN had bigger tibial CoA than CON, SWIM and RC (CoA, RUN-CON: 12.1% ± 10.7%; RUN-SWIM: 10.9% ± 9.4%; RUN-RC: 15.8% ± 9.5%) without marked changes in tibial strength indices, lower-limb MCSA or 1-RM. Both MB and RC failed to display any difference in tibial indices, lower-limb MCSA and 1-RM compared to CON. In swimmers, the bone structure and strength of the primary exercised limbs, the arms, is greater than controls and road cyclists. Conversely, although runners experience impact and weight-bearing loading, tibial structure is greater without a substantial difference in tibial strength compared to controls and non-impact sports. Failure to observe a difference in tibial indices in MB and RC compared to controls is unexpected.

Effect of Symmetry Improvement in Weight Bearing on Postural Stability of Hemiparetic Patients

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Hossein Asghar-Hosseini

2008-07-01

Full Text Available Objective: Impaired postural control has been known as the main cause of fall in hemiparesis after stroke. Is Asymmetry of weight bearing on lower limb is one of the prominent characteristics of postural imbalance in these patients. The aim of this study was to evaluate the effect of symmetry improvement in weight bearing through therapeutic interventions on postural stability in hemiparetic patients. Materials & Methods: In this quasi – experimental study which 27 hemiparetic patients were selected through sample of convenience by simple method from men and women who were referred to neurology clinic of Hazrat-e-Rasool hospital. For postural assessment patients stood quietly with open eyes and close eyes on force plates. Primary assessments included evaluation of asymmetry index (AI, RMS COP displacement (Root Mean Square of Center of Pressure and RMS COP velocity in both frontal and sagital planes. Then a 10mm lift was inserted under the unaffected limb and primary assessments were repeated. Data were analyzed by repeated measure ANOVA test. Results: Simple main effect of lift on asymmetry index was significant (P<0/0001. There was no significant interaction between vision and lift. Simple main effect of lift on postural stability variables was also non significant (for RMS COP displacement in frontal and sagital planes P=0.186 and P=0.245, respectively and for RMS COP velocity P=0.259 and P=0.342 respectively. Conclusion: Inserting a lift can improve symmetry by shifting center of gravity to midline. Since symmetry improvement did not decrease postural instability, asymmetric weight bearing can not be the primary cause of postural instability and may not be the principal target of rehabilitation programs aiming at restoring standing balance after stroke.

Assessment of Brown Bear\\'s (Ursus arctos syriacus Winter Habitat Using Geographically Weighted Regression and Generalized Linear Model in South of Iran

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A. A. Zarei

2016-03-01

Full Text Available Winter dens are one of the important components of brown bear's (Ursus arctos syriacus habitat, affecting their reproduction and survival. Therefore identification of factors affecting the habitat selection and suitable denning areas in the conservation of our largest carnivore is necessary. We used Geographically Weighted Logistic Regression (GWLR and Generalized Linear Model (GLM for modeling suitability of denning habitat in Kouhkhom region in Fars province. In the present research, 20 dens (presence locations and 20 caves where signs of bear were not found (absence locations were used as dependent variables and six environmental factors were used for each location as independent variables. The results of GLM showed that variables of distance to settlements, altitude, and distance to water were the most important parameters affecting suitability of the brown bear's denning habitat. The results of GWLR showed the significant local variations in the relationship between occurrence of brown bear dens and the variable of distance to settlements. Based on the results of both models, suitable habitats for denning of the species are impassable areas in the mountains and inaccessible for humans.

Bone Parameters in Anorexia Nervosa and Athletic Amenorrhea: Comparison of Two Hypothalamic Amenorrhea States.

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Kandemir, Nurgun; Slattery, Meghan; Ackerman, Kathryn E; Tulsiani, Shreya; Bose, Amita; Singhal, Vibha; Baskaran, Charumathi; Ebrahimi, Seda; Goldstein, Mark; Eddy, Kamryn; Klibanski, Anne; Misra, Madhusmita

2018-04-05

We have reported low bone mineral density (BMD), impaired bone structure, and increased fracture risk in anorexia nervosa (AN) and normal-weight, oligo-amenorrheic athletes (OA). However, data directly comparing compartment-specific bone parameters in AN, OA and controls are lacking. 426 females 14-21.9 years old were included; 231 AN, 94 OA and 101 normal-weight eumenorrheic controls. Dual energy x-ray absorptiometry was used to assess areal BMD (aBMD) of the whole body less head (WBLH), spine, and hip. High resolution peripheral quantitative CT was used to assess volumetric BMD (vBMD), bone geometry and structure at the non-weight bearing distal radius and weight-bearing distal tibia. AN had lower WBLH and hip aBMD Z-scores than OA and controls (p<0.0001). AN and OA had lower spine aBMD Z-scores than controls (p<0.01). At the radius, total and cortical vBMD, percent cortical area and thickness were lower in AN and OA vs. controls (p≤0.04); trabecular vBMD was lower in AN than controls. At the tibia, AN had lower measures for most parameters vs. OA and controls (p<0.05); OA had lower cortical vBMD than controls (p=0.002). AN and OA had higher fracture rates vs. controls. Stress fracture prevalence was highest in OA (p<0.0001); non-stress fracture prevalence was highest in AN (p<0.05). AN is deleterious to bone at all sites and both bone compartments. A high stress fracture rate in OA, who have comparable WBLH and hip aBMD measures to controls, indicates that BMD in these women may need to be even higher to avoid fractures.

Age, gender, and race/ethnic differences in total body and subregional bone density.

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Looker, A C; Melton, L J; Harris, T; Borrud, L; Shepherd, J; McGowan, J

2009-07-01

Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing. Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton. The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing. Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm. This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.

A comparison between the dimensions of positive transtibial residual limb molds prepared by air pressure casting and weight-bearing casting methods.

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Hajiaghaei, Behnam; Ebrahimi, Ismail; Kamyab, Mojtaba; Saeedi, Hassan; Jalali, Maryam

2016-01-01

Creating a socket with proper fit is an important factor to ensure the comfort and control of prosthetic devices. Several techniques are commonly used to cast transtibial stumps but their effect on stump shape deformation is not well understood. This study compares the dimensions, circumferences and volumes of the positive casts and also the socket comfort between two casting methods. Our hypothesis was that the casts prepared by air pressure method have less volume and are more comfortable than those prepared by weight bearing method. Fifteen transtibial unilateral amputees participated in the study. Two weight bearing and air pressure casting methods were utilized for their residual limbs. The diameters and circumferences of various areas of the residual limbs and positive casts were compared. The volumes of two types of casts were measured by a volumeter and compared. Visual Analogue Scale (VAS) was used to measure the sockets fit comfort. Circumferences at 10 and 15 cm below the patella on the casts were significantly smaller in air pressure casting method compared to the weight bearing method (p=0.00 and 0.01 respectively). The volume of the cast in air pressure method was lower than that of the weight bearing method (p=0.006). The amputees found the fit of the sockets prepared by air pressure method more comfortable than the weight bearing sockets (p=0.015). The air pressure casting reduced the circumferences of the distal portion of residual limbs which has more soft tissue and because of its snug fit it provided more comfort for amputees, according to the VAS measurements.

Polar bear use of a persistent food subsidy: insights from non-invasive genetic sampling in Alaska

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Peacock, Elizabeth; Herreman, Jason

2013-01-01

Remains of bowhead whales (Balaena mysticetus) harvested by Iñupiat whalers are deposited in bone piles along the coast of Alaska and have become persistent and reliable food sources for polar bears (Ursus maritimus). The importance of bone piles to individuals and the population, the patterns of use, and the number, sex, and age of bears using these resources are poorly understood. We implemented barbed-wire hair snaring to obtain genetic identities from bears using the Point Barrow bone pile in winter 2010–11. Eighty-three percent of genotyped samples produced individual and sex identification. We identified 97 bears from 200 samples. Using genetic mark–recapture techniques, we estimated that 228 bears used the bone pile during November to February, which would represent approximately 15% of the Southern Beaufort Sea polar bear subpopulation, if all bears were from this subpopulation. We found that polar bears of all age and sex classes simultaneously used the bone pile. More males than females used the bone pile, and males predominated in February, likely because 1/3 of adult females would be denning during this period. On average, bears spent 10 days at the bone pile (median  =  5 days); the probability that an individual bear remained at the bone pile from week to week was 63% for females and 45% for males. Most bears in the sample were detected visiting the bone pile once or twice. We found some evidence of matrilineal fidelity to the bone pile, but the group of animals visiting the bone pile did not differ genetically from the Southern Beaufort Sea subpopulation, nor did patterns of relatedness. We demonstrate that bowhead whale bone piles may be an influential food subsidy for polar bears in the Barrow region in autumn and winter for all sex and age classes.

Effect of antiresorptive and anabolic bone therapy on development of osteoarthritis in a posttraumatic rat model of OA.

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Bagi, Cedo M; Berryman, Edwin; Zakur, David E; Wilkie, Dean; Andresen, Catharine J

2015-11-06

Osteoarthritis (OA) is a leading cause of disability, but despite the high unmet clinical need and extensive research seeking dependable therapeutic interventions, no proven disease-modifying treatment for OA is currently available. Due to the close interaction and interplay between the articular cartilage and the subchondral bone plate, it has been hypothesized that antiresorptive drugs can also reduce cartilage degradation, inhibit excessive turnover of the subchondral bone plate, prevent osteophyte formation, and/or that bone anabolic drugs might also stimulate cartilage synthesis by chondrocytes and preserve cartilage integrity. The benefit of intensive zoledronate (Zol) and parathyroid hormone (PTH) therapy for bone and cartilage metabolism was evaluated in a rat model of OA. Medial meniscectomy (MM) was used to induce OA in male Lewis rats. Therapy with Zol and human PTH was initiated immediately after surgery. A dynamic weight-bearing (DWB) system was deployed to evaluate the weight-bearing capacity of the front and hind legs. At the end of the 10-week study, the rats were euthanized and the cartilage pathology was evaluated by contrast (Hexabrix)-enhanced μCT imaging and traditional histology. Bone tissue was evaluated at the tibial metaphysis and epiphysis, including the subchondral bone. Histological techniques and dynamic histomorphometry were used to evaluate cartilage morphology and bone mineralization. The results of this study highlight the complex changes in bone metabolism in different bone compartments influenced by local factors, including inflammation, pain and mechanical loads. Surgery caused severe and extensive deterioration of the articular cartilage at the medial tibial plateau, as evidenced by contrast-enhanced μCT and histology. The study results showed the negative impact of MM surgery on the weight-bearing capacity of the operated limb, which was not corrected by treatment. Although both Zol and PTH improved subchondral bone mass and

Lower trabecular volumetric BMD at metaphyseal regions of weight-bearing bones is associated with prior fracture in young girls.

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Farr, Joshua N; Tomás, Rita; Chen, Zhao; Lisse, Jeffrey R; Lohman, Timothy G; Going, Scott B

2011-02-01

Understanding the etiology of skeletal fragility during growth is critical for the development of treatments and prevention strategies aimed at reducing the burden of childhood fractures. Thus we evaluated the relationship between prior fracture and bone parameters in young girls. Data from 465 girls aged 8 to 13 years from the Jump-In: Building Better Bones study were analyzed. Bone parameters were assessed at metaphyseal and diaphyseal sites of the nondominant femur and tibia using peripheral quantitative computed tomography (pQCT). Dual-energy X-ray absorptiometry (DXA) was used to assess femur, tibia, lumbar spine, and total body less head bone mineral content. Binary logistic regression was used to evaluate the relationship between prior fracture and bone parameters, controlling for maturity, body mass, leg length, ethnicity, and physical activity. Associations between prior fracture and all DXA and pQCT bone parameters at diaphyseal sites were nonsignificant. In contrast, lower trabecular volumetric BMD (vBMD) at distal metaphyseal sites of the femur and tibia was significantly associated with prior fracture. After adjustment for covariates, every SD decrease in trabecular vBMD at metaphyseal sites of the distal femur and tibia was associated with 1.4 (1.1-1.9) and 1.3 (1.0-1.7) times higher fracture prevalence, respectively. Prior fracture was not associated with metaphyseal bone size (ie, periosteal circumference). In conclusion, fractures in girls are associated with lower trabecular vBMD, but not bone size, at metaphyseal sites of the femur and tibia. Lower trabecular vBMD at metaphyseal sites of long bones may be an early marker of skeletal fragility in girls. Copyright © 2011 American Society for Bone and Mineral Research.

Disorders of bone-mineral metabolism and their correction with women who have body weight deficiency at pregravid stage and during pregnancy

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L. P. Shelestova

2017-10-01

Full Text Available The processes in bone-mineral metabolism provide normal course of pregnancy, labour and fetus development, women with body weight deficiency are at risk reduction of bone tissue mineral density, progressing of osteopenia and osteoporosis. This shows the necessity of medical and preventive measures that have the aim to correct calcium- phosphorus and bone metabolism with women who have body weight deficiency. Aim. To elaborate and to evaluate medical and preventive measures that have the aim to correct disorders in bone-mineral metabolism with women who have body weight deficiency at pregravid stage and during pregnancy. Materials and methods. The efficiency of adding combined medicine of calcium carbonate and cholecalciferol and dietary nourishment to traditional treatment that affected the state of bone-mineral metabolism with women who have body weight deficiency at pregravid stage and during pregnancy was studied. Results. With women who have body weight deficiency at pregravid stage and during pregnancy it is noted statistically considerable reduction in blood of total calcium and bone tissue markers that grows with the course of gestation. The changes in mineral density of bone tissue can be seen from the existence of osteopenic syndrome at pregravid stage that occurs with every third woman who has body weight deficiency and with every second before labour. The use of elaborated medical and preventive measures including combined medicine of calcium carbonate and cholecalciferol allows to normalize the indexes of bone-mineral metabolism with women who have body weight deficiency. Conclusions. Women with body weight deficiency already at pregravid stage have disorders in bone metabolism and coming of pregnancy lead to aggravation of bone metabolism disorders. The additional use of combined medicine of calcium carbonate and cholecalciferol and dietary nourishment made the indexes of calcium-phosphorus and bone metabolism better and osteopenic

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)

Jensen, T B; Overgaard, S; Lind, M

2007-01-01

Impacted bone allograft is often used in revision joint replacement. Hydroxyapatite granules have been suggested as a substitute or to enhance morcellised bone allograft. We hypothesised that adding osteogenic protein-1 to a composite of bone allograft and non-resorbable hydroxyapatite granules...... (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...

Reconstruction of large diaphyseal bone defect by simplified bone transport over nail technique: A 7-case series.

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Ferchaud, F; Rony, L; Ducellier, F; Cronier, P; Steiger, V; Hubert, L

2017-11-01

Reconstruction of large diaphyseal bone defect is complex and the complications rate is high. This study aimed to assess a simplified technique of segmental bone transport by monorail external fixator over an intramedullary nail.A prospective study included 7 patients: 2 femoral and 5 tibial defects. Mean age was 31years (range: 16-61years). Mean follow-up was 62 months (range: 46-84months). Defects were post-traumatic, with a mean length of 7.2cm (range: 4 to 9.5cm). For 3 patients, reconstruction followed primary failure. In 4 cases, a covering flap was necessary. Transport used an external fixator guided by an intramedullary nail, at a rate of 1mm per day. One pin was implanted on either side of the distraction zone. The external fixator was removed 1 month after bone contact at the docking site. Mean bone transport time was 11 weeks (range: 7-15 weeks). Mean external fixation time was 5.1months (range: 3.5 to 8months). Full weight-bearing was allowed 5.7months (range: 3.5-13months) after initiation of transport. In one patient, a pin had to be repositioned. In 3 patients, the transported segment re-ascended after external fixatorablation, requiring repeat external fixation and resumption of transport. There was just 1 case of superficial pin infection. Reconstruction quality was considered "excellent" on the Paley-Marr criteria in 6 cases. The present technique provided excellent reconstruction quality in 6 of the 7 cases. External fixation time was shorter and resumption of weight-bearing earlier than with other reconstruction techniques, notably including bone autograft, vascularized bone graft or the induced membrane technique. Nailing facilitated control of limb axis and length. The complications rate was 50%, comparable to other techniques. This study raises the question of systematic internal fixation of the docking site, to avoid any mobilization of the transported segment. The bone quality, axial control and rapidity shown by the present technique make

Comparison among T1-weighted magnetic resonance imaging, modified dixon method, and magnetic resonance spectroscopy in measuring bone marrow fat.

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Shen, Wei; Gong, Xiuqun; Weiss, Jessica; Jin, Ye

2013-01-01

An increasing number of studies are utilizing different magnetic resonance (MR) methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI), modified Dixon method (also called fat fraction MRI (FFMRI)), and magnetic resonance spectroscopy (MRS). Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI). Bone marrow adipose tissue (BMAT) of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 (P BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 (P < 0.001) in femoral necks. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

Influence of Ghrelin and Adipocytokines on Bone Mineral Density in Adolescent Female Athletes with Amenorrhea and Eumenorrheic Athletes

OpenAIRE

Russell, Melissa; Misra, Madhusmita

2010-01-01

Adolescent female athletes are at increased risk for low bone mineral density (BMD) secondary to exercise-induced hypogonadism. Of particular concern is that the adolescent years are also a critical time for bone accrual, and deficits incurred during this period could lead to suboptimal peak bone mass acquisition and subsequent fracture risk in later life. Although weight bearing exercise is typically associated with an increase in BMD, amenorrheic athletes have lower BMD than eumenorrheic at...

Exercise-induced rib stress fractures: influence of reduced bone mineral density

DEFF Research Database (Denmark)

Vinther, Anders; Kanstrup, Inge-Lis; Christiansen, Erik

2005-01-01

study investigated BMD in seven Danish national team rowers with previous rib stress fracture (RSF) and 7 controls (C) matched for gender, age, height, weight and training experience. Total body scan and specific scans of the lumbar spine (L2-L4), femoral neck and distal radius were performed using......Exercise-induced rib stress fractures have been reported frequently in elite rowers during the past decade. The etiology of rib stress fractures is unclear, but low bone mineral density (BMD) has been suggested to be a potential risk factor for stress fractures in weight-bearing bones. The present...... density may be a potential risk factor for the development of exercise-induced rib stress fractures in elite rowers....

Comparison of bone density in amenorrheic women due to athletics, weight loss, and premature menopause.

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Jones, K P; Ravnikar, V A; Tulchinsky, D; Schiff, I

1985-07-01

Studied was the peripheral bone density of 39 women (ages 18 to 43) with the diagnosis of secondary amenorrhea in an effort to define the population of amenorrheic women at risk for osteoporosis. Eight women had exercise-induced amenorrhea (athletes), 20 women had amenorrhea associated with weight loss, and 11 women had premature menopause. These diagnoses were made on the basis of history, physical examination, and luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin levels, and failure to have withdrawal bleeding after the administration of progestin. Twenty-five nonathletic, normally menstruating women served as control subjects. The peripheral bone density of the amenorrheic athletes (0.738 g/cm2 +/- 0.047) was not significantly different from that of the controls (0.726 g/cm2 +/- 0.044). The average bone density of the group with weight loss-associated amenorrhea (0.672 g/cm2 +/- 0.066) was significantly less than controls (P less than .005) as was that of the women with premature menopause (0.616 g/cm2 +/- 0.048, P less than .001). There was a significant correlation between months of amenorrhea and decrease in bone density (r = 0.506, P less than .001). From this study it was concluded that women with exercise-associated amenorrhea are not at significant risk for cortical bone loss as measured by direct photon absorptiometry. Women with weight loss-associated amenorrhea and women with premature menopause are at significant risk for bone loss when compared with normal controls.

Impact of marked weight loss induced by bariatric surgery on bone mineral density and remodeling

Directory of Open Access Journals (Sweden)

F.A. Pereira

2007-04-01

Full Text Available Data about the impact of bariatric surgery (BS and subsequent weight loss on bone are limited. The objective of the present study was to determine bone mineral density (BMD, bone remodeling metabolites and hormones that influence bone trophism in premenopausal women submitted to BS 9.8 months, on average, before the study (OGg, N = 16. The data were compared to those obtained for women of normal weight (CG, N = 11 and for obese women (OG, N = 12. Eight patients in each group were monitored for one year, with the determination of BMD, of serum calcium, phosphorus, magnesium, parathyroid hormone, 25-hydroxyvitamin D, insulin-like growth factor-I (IGF-I and osteocalcin, and of urinary calcium and deoxypyridinoline. The biochemical determinations were repeated every three months in the longitudinal study and BMD was measured at the end of the study. Parathyroid hormone levels were similar in the three groups. IGF-I levels (CG = 332 ± 62 vs OG = 230 ± 37 vs OGg = 128 ± 19 ng/mL were significantly lower in the operated patients compared to the non-operated obese women. Only OGg patients presented a significant fall in BMD of 6.2% at L1-L4, of 10.2% in the femoral neck, and of 5.1% in the forearm. These results suggest that the weight loss induced by BS is associated with a significant loss of bone mass even at sites that are not influenced by weight overload, with hormonal factors such as IGF-I being associated with this process.

The anabolic activity of bone tissue, suppressed by disuse, is normalized by brief exposure to extremely low-magnitude mechanical stimuli

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Rubin, C.; Xu, G.; Judex, S.

2001-01-01

It is generally believed that mechanical signals must be large in order to be anabolic to bone tissue. Recent evidence indicates, however, that extremely low-magnitude (bone formation if induced at a high frequency. We examined the ability of extremely low-magnitude, high-frequency mechanical signals to restore anabolic bone cell activity inhibited by disuse. Adult female rats were randomly assigned to six groups: baseline control, age-matched control, mechanically stimulated for 10 min/day, disuse (hind limb suspension), disuse interrupted by 10 min/day of weight bearing, and disuse interrupted by 10 min/day of mechanical stimulation. After a 28 day protocol, bone formation rates (BFR) in the proximal tibia of mechanically stimulated rats increased compared with age-matched control (+97%). Disuse alone reduced BFR (-92%), a suppression only slightly curbed when disuse was interrupted by 10 min of weight bearing (-61%). In contrast, disuse interrupted by 10 min per day of low-level mechanical intervention normalized BFR to values seen in age-matched controls. This work indicates that this noninvasive, extremely low-level stimulus may provide an effective biomechanical intervention for the bone loss that plagues long-term space flight, bed rest, or immobilization caused by paralysis.

Comparison among T1-Weighted Magnetic Resonance Imaging, Modified Dixon Method, and Magnetic Resonance Spectroscopy in Measuring Bone Marrow Fat

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Wei Shen

2013-01-01

Full Text Available Introduction. An increasing number of studies are utilizing different magnetic resonance (MR methods to quantify bone marrow fat due to its potential role in osteoporosis. Our aim is to compare the measurements of bone marrow fat among T1-weighted magnetic resonance imaging (MRI, modified Dixon method (also called fat fraction MRI (FFMRI, and magnetic resonance spectroscopy (MRS. Methods. Contiguous MRI scans were acquired in 27 Caucasian postmenopausal women with a modified Dixon method (i.e., FFMRI. Bone marrow adipose tissue (BMAT of T1-weighted MRI and bone marrow fat fraction of the L3 vertebra and femoral necks were quantified using SliceOmatic and Matlab. MRS was also acquired at the L3 vertebra. Results. Correlation among the three MR methods measured bone marrow fat fraction and BMAT ranges from 0.78 to 0.88 in the L3 vertebra. Correlation between BMAT measured by T1-weighted MRI and bone marrow fat fraction measured by modified FFMRI is 0.86 in femoral necks. Conclusion. There are good correlations among T1-weighted MRI, FFMRI, and MRS for bone marrow fat quantification. The inhomogeneous distribution of bone marrow fat, the threshold segmentation of the T1-weighted MRI, and the ambiguity of the FFMRI may partially explain the difference among the three methods.

Effects of Spaceflight on Bone: The Rat as an Animal Model for Human Bone Loss

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Halloran, B.; Weider, T.; Morey-Holton, E.

1999-01-01

The loss of weight bearing during spaceflight results in osteopenia in humans. Decrements in bone mineral reach 3-10% after as little as 75-184 days in space. Loss of bone mineral during flight decreases bone strength and increases fracture risk. The mechanisms responsible for, and the factors contributing to, the changes in bone induced by spaceflight are poorly understood. The rat has been widely used as an animal model for human bone loss during spaceflight. Despite its potential usefulness, the results of bone studies performed in the rat in space have been inconsistent. In some flights bone formation is decreased and cancellous bone volume reduced, while in others no significant changes in bone occur. In June of 1996 Drs. T. Wronski, S. Miller and myself participated in a flight experiment (STS 78) to examine the effects of glucocorticoids on bone during weightlessness. Technically the 17 day flight experiment was flawless. The results, however, were surprising. Cancellous bone volume and osteoblast surface in the proximal tibial metaphysis were the same in flight and ground-based control rats. Normal levels of cancellous bone mass and bone formation were also detected in the lumbar vertebrae and femoral neck of flight rats. Furthermore, periosteal bone formation rate was found to be identical in flight and ground-based control rats. Spaceflight had little or no effect on bone metabolism! These results prompted us to carefully review the changes in bone observed in, and the flight conditions of previous spaceflight missions.

Differences in bone mineral density between normal-weight children and children with overweight and obesity: a systematic review and meta-analysis.

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van Leeuwen, J; Koes, B W; Paulis, W D; van Middelkoop, M

2017-05-01

This study examines the differences in bone mineral density between normal-weight children and children with overweight or obesity. A systematic review and meta-analysis of observational studies (published up to 22 June 2016) on the differences in bone mineral density between normal-weight children and overweight and obese children was performed. Results were pooled when possible and mean differences (MDs) were calculated between normal-weight and overweight and normal-weight and obese children for bone content and density measures at different body sites. Twenty-seven studies, with a total of 5,958 children, were included. There was moderate and high quality of evidence that overweight (MD 213 g; 95% confidence interval [CI] 166, 261) and obese children (MD 329 g; 95%CI [229, 430]) have a significantly higher whole body bone mineral content than normal-weight children. Similar results were found for whole body bone mineral density. Sensitivity analysis showed that the association was stronger in girls. Overweight and obese children have a significantly higher bone mineral density compared with normal-weight children. Because there was only one study included with a longitudinal design, the long-term impact of childhood overweight and obesity on bone health at adulthood is not clear. © 2017 World Obesity Federation.

Biofeedback in Partial Weight Bearing: Usability of Two Different Devices from a Patient's and Physical Therapist's Perspective.

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van Lieshout, Remko; Pisters, Martijn F; Vanwanseele, Benedicte; de Bie, Rob A; Wouters, Eveline J; Stukstette, Mirelle J

2016-01-01

Partial weight bearing is frequently instructed by physical therapists in patients after lower-limb trauma or surgery. The use of biofeedback devices seems promising to improve the patient's compliance with weight-bearing instructions. SmartStep and OpenGo-Science are biofeedback devices that provide real-time feedback. For a successful implementation, usability of the devices is a critical aspect and should be tested from a user's perspective. To describe the usability from the physical therapists' and a patients' perspective of Smartstep and OpenGo-Science to provide feedback on partial weight bearing during supervised rehabilitation of patients after lower-limb trauma or surgery. In a convergent mixed-methods design, qualitative and quantitative data were collected. Usability was subdivided into user performance, satisfaction and acceptability. Patients prescribed with partial weight bearing and their physical therapists were asked to use SmartStep and OpenGo-Science during supervised rehabilitation. Usability was qualitatively tested by a think-aloud method and a semi-structured interview and quantitatively tested by the System-Usability-Scale (SUS) and closed questions. For the qualitative data thematic content analyses were used. Nine pairs of physical therapists and their patients participated. The mean SUS scores for patients and physical therapists were for SmartStep 70 and 53, and for OpenGo-Science 79 and 81, respectively. Scores were interpreted with the Curved Grading Scale. The qualitative data showed that there were mixed views and perceptions from patients and physical therapists on satisfaction and acceptability. This study gives insight in the usability of two biofeedback devices from the patient's and physical therapist's perspective. The overall usability from both perspectives seemed to be acceptable for OpenGo-Science. For SmartStep, overall usability seemed only acceptable from the patient's perspective. The study findings could help

Mechanical characterization of structurally porous biomaterials built via additive manufacturing: experiments, predictive models, and design maps for load-bearing bone replacement implants.

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Melancon, D; Bagheri, Z S; Johnston, R B; Liu, L; Tanzer, M; Pasini, D

2017-11-01

Porous biomaterials can be additively manufactured with micro-architecture tailored to satisfy the stringent mechano-biological requirements imposed by bone replacement implants. In a previous investigation, we introduced structurally porous biomaterials, featuring strength five times stronger than commercially available porous materials, and confirmed their bone ingrowth capability in an in vivo canine model. While encouraging, the manufactured biomaterials showed geometric mismatches between their internal porous architecture and that of its as-designed counterpart, as well as discrepancies between predicted and tested mechanical properties, issues not fully elucidated. In this work, we propose a systematic approach integrating computed tomography, mechanical testing, and statistical analysis of geometric imperfections to generate statistical based numerical models of high-strength additively manufactured porous biomaterials. The method is used to develop morphology and mechanical maps that illustrate the role played by pore size, porosity, strut thickness, and topology on the relations governing their elastic modulus and compressive yield strength. Overall, there are mismatches between the mechanical properties of ideal-geometry models and as-manufactured porous biomaterials with average errors of 49% and 41% respectively for compressive elastic modulus and yield strength. The proposed methodology gives more accurate predictions for the compressive stiffness and the compressive strength properties with a reduction of the average error to 11% and 7.6%. The implications of the results and the methodology here introduced are discussed in the relevant biomechanical and clinical context, with insight that highlights promises and limitations of additively manufactured porous biomaterials for load-bearing bone replacement implants. In this work, we perform mechanical characterization of load-bearing porous biomaterials for bone replacement over their entire design

The effect of isolating the paretic limb on weight-bearing distribution and EMG activity during squats in hemiplegic and healthy individuals.

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Lee, Dong-Kyu; An, Duk-Hyun; Yoo, Won-Gyu; Hwang, Byong-Yong; Kim, Tae-Ho; Oh, Jae-Seop

2017-05-01

Neural reorganization for movement therapy after a stroke is thought to be an important mechanism that facilitates motor recovery. However, there is a lack of evidence for the effectiveness of exercise programs in improving the lower limbs. We investigated the immediate effect of isolating the paretic limb using different foot positions ((i) foot parallel; both feet parallel, (ii) foot asymmetry; paretic foot backward by 10 cm, and (iii) foot lifting; nonparetic foot lifting by normalization to 25% of knee height) on weight-bearing distribution and electromyography (EMG) of the thigh muscle during squats. In total, 20 patients with hemiplegia and 16 healthy subjects randomly performed three squat conditions in which the knee joint was flexed to 30°. Weight distribution was measured using the BioRescue system. Muscle activity was measured using a surface EMG system. Patients with hemiplegia exhibited significantly decreased weight bearing on the paretic foot at 0° and 30° knee flexion compared with the nondominant foot of a healthy subject. The muscle activity of the quadriceps was significantly lower in patients with hemiplegia compared to healthy subjects. Weight bearing and EMG activity of the quadriceps femoris on the paretic or nondominant side significantly increased during a knee flexion of 30° with under the foot asymmetry and foot lifting positions compared with the parallel foot position. Isolating the paretic limb using the asymmetric foot positions and lifting of the foot during squats might help patients with hemiplegia to improve weight-bearing and achieve greater activation of the quadriceps muscle in the paretic limb.

Three-dimensional quantitative CT of the proximal femur: Relationship to vertebral trabecular bone density

International Nuclear Information System (INIS)

Bhasin, S.; Zlatkin, M.B.; Sartoris, D.J.; Andre, M.; Resnick, D.

1987-01-01

Integrated cancellous, cortical, and total bone density in the femoral neck and inter-trochanteric region was measured bilaterally in 25 women aged 35-90 years (mean age, 65). Contiguous-section (1-cm-thick) data were analyzed using three-dimensional histogram software on a Cemax 1000 image processor. Single-section quantitative CT was used to determine mean mineral equivalent values for vertebral cancellous bone from T-11 to L-3 in each woman. Significant correlation was found between cancellous bone density at the two sites. Cortical and total bone densities in the proximal femur were predicted less well with vertebral cancellous data, suggesting a greater dependence on weight-bearing and activity factors

Cost-effectiveness of bone densitometry among Caucasian women and men without a prior fracture according to age and body weight.

Science.gov (United States)

Schousboe, J T; Gourlay, M; Fink, H A; Taylor, B C; Orwoll, E S; Barrett-Connor, E; Melton, L J; Cummings, S R; Ensrud, K E

2013-01-01

We used a microsimulation model to estimate the threshold body weights at which screening bone densitometry is cost-effective. Among women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to identify those for whom bone densitometry is cost-effective. Bone densitometry may be more cost-effective for those with lower body weight since the prevalence of osteoporosis is higher for those with low body weight. Our purpose was to estimate weight thresholds below which bone densitometry is cost-effective for women and men without a prior clinical fracture at ages 55, 60, 65, 75, and 80 years. We used a microsimulation model to estimate the costs and health benefits of bone densitometry and 5 years of fracture prevention therapy for those without prior fracture but with femoral neck osteoporosis (T-score ≤ -2.5) and a 10-year hip fracture risk of ≥3%. Threshold pre-test probabilities of low BMD warranting drug therapy at which bone densitometry is cost-effective were calculated. Corresponding body weight thresholds were estimated using data from the Study of Osteoporotic Fractures (SOF), the Osteoporotic Fractures in Men (MrOS) study, and the National Health and Nutrition Examination Survey (NHANES) for 2005-2006. Assuming a willingness to pay of $75,000 per quality adjusted life year (QALY) and drug cost of $500/year, body weight thresholds below which bone densitometry is cost-effective for those without a prior fracture were 74, 90, and 100 kg, respectively, for women aged 55, 65, and 80 years; and were 67, 101, and 108 kg, respectively, for men aged 55, 75, and 80 years. For women aged 55-65 years and men aged 55-75 years without a prior fracture, body weight can be used to select those for whom bone densitometry is cost-effective.

Evaluation of Bernese periacetabular osteotomy: prospective studies examining projected load-bearing area, bone density, cartilage thickness and migration.

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Mechlenburg, Inger

2008-06-01

mean thickness of the femoral cartilage was 1.18 mm, SD 0.06. The precision calculated as the error variance was estimated for the thickness of the acetabular cartilage to 0.01 and femoral cartilage 0.02. We suggest that the method can be advantageous for assessing the progression of osteoarthritis in dysplastic hips after periacetabular osteotomy. In study IV, 32 dysplastic hips, 27 females and 5 males were included in the study. Radiostereometric examinations (RSA) were done at one week, four weeks, eight weeks and six months. Data are presented as mean + SD. Six months postoperatively, the acetabular fragment had migrated 0.7 mm + 0.8 medially, and 0.7 mm + 0.5 proximally. Mean rotation in adduction was 0.5 degrees + 1.3. In other directions, mean migration was below 0.5 mm/degrees. There was no statistical difference between migration 8 weeks and 24 weeks postoperatively in translation or rotation. Due to the limited migration, we find our postoperative partial weight-bearing regime safe. In conclusion, the studies in the present PhD thesis indicate that the projected loadbearing area of the hip joint increases considerable in patients undergoing periacetabular osteotomy and a method to estimate this area was described. Bone density increases in the medial quadrants two years postoperative and a method is developed to precisely estimate bone density on CT images. Also a method to precisely estimate cartilage thickness was presented and we suggest that the method can be advantageous for assessing the progression of osteoarthritis in dysplastic hips after periacetabular osteotomy. Due to the very limited migration of the acetabular fragment fixated with two screws, we find our fixation sufficient and the postoperative partial weight-bearing regimen safe.

Influence of muscle strength, physical activity and weight on bone mass in a population-based sample of 1004 elderly women.

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Gerdhem, P; Ringsberg, K A M; Akesson, K; Obrant, K J

2003-09-01

High physical activity level has been associated with high bone mass and low fracture risk and is therefore recommended to reduce fractures in old age. The aim of this study was to estimate the effect of potentially modifiable variables, such as physical activity, muscle strength, muscle mass and weight, on bone mass in elderly women. The influence of isometric thigh muscle strength, self-estimated activity level, body composition and weight on bone mineral density (dual energy X-ray absorptiometry; DXA) in total body, hip and spine was investigated. Subjects were 1004 women, all 75 years old, taking part in the Malmö Osteoporosis Prospective Risk Assessment (OPRA) study. Physical activity and muscle strength accounted for 1-6% of the variability in bone mass, whereas weight, and its closely associated variables lean mass and fat mass, to a much greater extent explained the bone mass variability. We found current body weight to be the variable with the most substantial influence on the total variability in bone mass (15-32% depending on skeletal site) in a forward stepwise regression model. Our findings suggest that in elderly women, the major fracture-preventive effect of physical activity is unlikely to be mediated through increased bone mass. Retaining or even increasing body weight is likely to be beneficial to the skeleton, but an excess body weight increase may have negative effects on health. Nevertheless, training in elderly women may have advantages by improving balance, co-ordination and mobility and therefore decreasing the risk of fractures.

High-strength mineralized collagen artificial bone

Science.gov (United States)

Qiu, Zhi-Ye; Tao, Chun-Sheng; Cui, Helen; Wang, Chang-Ming; Cui, Fu-Zhai

2014-03-01

Mineralized collagen (MC) is a biomimetic material that mimics natural bone matrix in terms of both chemical composition and microstructure. The biomimetic MC possesses good biocompatibility and osteogenic activity, and is capable of guiding bone regeneration as being used for bone defect repair. However, mechanical strength of existing MC artificial bone is too low to provide effective support at human load-bearing sites, so it can only be used for the repair at non-load-bearing sites, such as bone defect filling, bone graft augmentation, and so on. In the present study, a high strength MC artificial bone material was developed by using collagen as the template for the biomimetic mineralization of the calcium phosphate, and then followed by a cold compression molding process with a certain pressure. The appearance and density of the dense MC were similar to those of natural cortical bone, and the phase composition was in conformity with that of animal's cortical bone demonstrated by XRD. Mechanical properties were tested and results showed that the compressive strength was comparable to human cortical bone, while the compressive modulus was as low as human cancellous bone. Such high strength was able to provide effective mechanical support for bone defect repair at human load-bearing sites, and the low compressive modulus can help avoid stress shielding in the application of bone regeneration. Both in vitro cell experiments and in vivo implantation assay demonstrated good biocompatibility of the material, and in vivo stability evaluation indicated that this high-strength MC artificial bone could provide long-term effective mechanical support at human load-bearing sites.

Application of bone scintigraphy

International Nuclear Information System (INIS)

Rondain, J.E.S.

1996-01-01

Bone scanning has varied applications, particularly in the file of oncology. It is used in the diagnosis and follow-up of patients with cancers that metastatize to the bones (breast, prostate CA), also in primary bone cancers, infections of the bones and joints. In early stages of primary breast CA (stage I and II), the incidence of unsuspected bone metastasis is only 1-5%. On the other hand, bone scans serve as a baseline study if bone mets occur at some later stage. In patients with stage II and III breast CA, the conversion from normal to abnormal bone scans is 15% and 17%, respectively, clearly in favor of a baseline bone scan. For prostate CA, bone scanning should be used in conjunction with PSA level determination. In advanced disease, a bone scan will define the extent of the metastases, show problematic lesions in weight-bearing bones, and even allow us to evaluate response to therapy in follow-up bone scans. In patients with lung CA, a positive bone scan will make surgery of the primary lesion inappropriate. For other cancers, a bone scan maybe used if there are other signs, whether clinical or chemical, indicating bone involvement. In patients with GIT, liver, skin, brain or bladder CA, routine bone scanning may be considered superfluous. For patients with suspected infection, a 3-phase bone scan is more desirable. In patients with septic arthritis, the bones of each side of the joint take up the radiopharmaceutical while in patients with cellulitis without bony involvement, only the first two phases (dynamic and bloodpool images) will be abnormal. Bone scanning is also used in avascular lesions such as Legg-calve-Perthes disease where one will see reduced uptake of Tc99m MDP. The advent of SPECT imaging has greatly increased the sensitivity in diagnosing AVN. (author)

Long-distance running, bone density, and osteoarthritis

International Nuclear Information System (INIS)

Lane, N.E.; Bloch, D.A.; Jones, H.H.; Marshall, W.H. Jr.; Wood, P.D.; Fries, J.F.

1986-01-01

Forty-one long-distance runners aged 50 to 72 years were compared with 41 matched community controls to examine associations of repetitive, long-term physical impact (running) with osteoarthritis and osteoporosis. Roentgenograms of hands, lateral lumbar spine, and knees were assessed without knowledge of running status. A computed tomographic scan of the first lumbar vertebra was performed to quantitate bone mineral content. Runners, both male and female, have approximately 40% more bone mineral than matched controls. Female runners, but not male runners, appear to have somewhat more sclerosis and spur formation in spine and weight-bearing knee x-ray films, but not in hand x-ray films. There were no differences between groups in joint space narrowing, crepitation, joint stability, or symptomatic osteoarthritis. Running is associated with increased bone mineral but not, in this cross-sectional study, with clinical osteoarthritis

Glucocorticoid-Induced Avascular Bone Necrosis: Diagnosis and Management

Science.gov (United States)

Chan, KL; Mok, CC

2012-01-01

Glucocorticoid use is one of the most important causes of avascular bone necrosis (AVN). The pathogenesis of glucocorticoid-induced AVN is not fully understood but postulated mechanisms include fat hypertrophy, fat emboli and intravascular coagulation that cause impedance of blood supply to the bones. Data regarding the relationship between AVN and dosage, route of administration and treatment duration of glucocorticoids are conflicting, with some studies demonstrating the cumulative dose of glucocorticoid being the most important determining factor. Early recognition of this complication is essential as the prognosis is affected by the stage of the disease. Currently, there is no consensus on whether universal screening of asymptomatic AVN should be performed for long-term glucocorticoid users. A high index of suspicion should be exhibited for bone and joint pain at typical sites. Magnetic resonance imaging (MRI) or bone scintigraphy is more sensitive than plain radiograph for diagnosing early-stage AVN. Conservative management of AVN includes rest and reduction of weight bearing. Minimization of glucocorticoid dose or a complete withdrawal of the drug should be considered if the underlying conditions allow. The efficacy of bisphosphonates in reducing the rate of collapse of femoral head in AVN is controversial. Surgical therapy of AVN includes core decompression, osteotomy, bone grafting and joint replacement. Recent advances in the treatment of AVN include the use of tantalum rod and the development of more wear resistant bearing surface in hip arthroplasty. PMID:23115605

Glucocorticoid-induced avascular bone necrosis: diagnosis and management.

Science.gov (United States)

Chan, K L; Mok, C C

2012-01-01

Glucocorticoid use is one of the most important causes of avascular bone necrosis (AVN). The pathogenesis of glucocorticoid-induced AVN is not fully understood but postulated mechanisms include fat hypertrophy, fat emboli and intravascular coagulation that cause impedance of blood supply to the bones. Data regarding the relationship between AVN and dosage, route of administration and treatment duration of glucocorticoids are conflicting, with some studies demonstrating the cumulative dose of glucocorticoid being the most important determining factor. Early recognition of this complication is essential as the prognosis is affected by the stage of the disease. Currently, there is no consensus on whether universal screening of asymptomatic AVN should be performed for long-term glucocorticoid users. A high index of suspicion should be exhibited for bone and joint pain at typical sites. Magnetic resonance imaging (MRI) or bone scintigraphy is more sensitive than plain radiograph for diagnosing early-stage AVN. Conservative management of AVN includes rest and reduction of weight bearing. Minimization of glucocorticoid dose or a complete withdrawal of the drug should be considered if the underlying conditions allow. The efficacy of bisphosphonates in reducing the rate of collapse of femoral head in AVN is controversial. Surgical therapy of AVN includes core decompression, osteotomy, bone grafting and joint replacement. Recent advances in the treatment of AVN include the use of tantalum rod and the development of more wear resistant bearing surface in hip arthroplasty.

Electromyographic analysis of the three subdivisions of gluteus medius during weight-bearing exercises

Directory of Open Access Journals (Sweden)

O'Sullivan Kieran

2010-07-01

Full Text Available Abstract Background Gluteus medius (GM dysfunction is associated with many musculoskeletal disorders. Rehabilitation exercises aimed at strengthening GM appear to improve lower limb kinematics and reduce pain. However, there is a lack of evidence to identify which exercises best activate GM. In particular, as GM consists of three distinct subdivisions, it is unclear if GM activation is consistent across these subdivisions during exercise. The aim of this study was to determine the activation of the anterior, middle and posterior subdivisions of GM during weight-bearing exercises. Methods A single session, repeated-measures design. The activity of each GM subdivision was measured in 15 pain-free subjects using surface electromyography (sEMG during three weight-bearing exercises; wall squat (WS, pelvic drop (PD and wall press (WP. Muscle activity was expressed relative to maximum voluntary isometric contraction (MVIC. Differences in muscle activation were determined using one-way repeated measures ANOVA with post-hoc Bonferroni analysis. Results The activation of each GM subdivision during the exercises was significantly different (interaction effect; p Discussion Posterior GM displayed higher activation across all three exercises than both anterior and middle GM. The WP produced the highest %MVIC activation for all GM subdivisions, and this was most pronounced for posterior GM. Clinicians may use these results to effectively progress strengthening exercises for GM in the rehabilitation of lower extremity injuries.

A Canine Non-Weight-Bearing Model with Radial Neurectomy for Rotator Cuff Repair.

Directory of Open Access Journals (Sweden)

Xiaoxi Ji

Full Text Available The major concern of using a large animal model to study rotator cuff repair is the high rate of repair retears. The purpose of this study was to test a non-weight-bearing (NWB canine model for rotator cuff repair research.First, in the in vitro study, 18 shoulders were randomized to 3 groups. 1 Full-width transections repaired with modified Mason-Allen sutures using 3-0 polyglactin suture, 2 Group 1 repaired using number 2 (#2 polyester braid and long-chain polyethylene suture, and 3 Partial-width transections leaving the superior 2 mm infraspinatus tendon intact without repair. In the in vivo study of 6 dogs, the infraspinatus tendon was partially transected as the same as the in vitro group 3. A radial neurectomy was performed to prevent weight bearing. The operated limb was slung in a custom-made jacket for 6 weeks.In the in vitro study, mean ultimate tensile load and stiffness in Group 2 were significantly higher than Group 1 and 3 (p<0.05. In the in vivo study, gross inspection and histology showed that the preserved superior 2-mm portion of the infraspinatus tendon remained intact with normal structure.Based on the biomechanical and histological findings, this canine NWB model may be an appropriate and useful model for studies of rotator cuff repair.

Bone mineral density in anorexia nervosa: Only weight and menses recovery?

Science.gov (United States)

Jáuregui-Lobera, Ignacio; Bolaños-Ríos, Patricia; Sabaté, Juan

2016-11-01

The study objectives were to analyze the presence of reduced bone mass in a sample of patients with anorexia nervosa (AN) and amenorrhea, to assess Bone Mineral Density (BMD) recovery after having a normal weight is reached and regular menses are resumed, and to predict BMD after a treatment period considering different variables (baseline BMD, baseline and final body mass index (BMI), treatment duration). 35 patients with AN (mean age 20.57±5.77) were studied at treatment start (T 0 ) and after they had recovered their normal weight and regular menses (T 1 ) in order to measure their BMD using quantitative computed tomography (QCT) of the lumbar spine (L2-L4). At T 0 , 2.86% of patients had normal BMD, while a reduced bone mass consistent with osteopenia or with osteoporosis was found in 22.86% and 74.28% of patients respectively. At T 1 , the percentages were 20%, 20%, and 60% respectively. No significant differences were seen in L2-L3 and mean BMD (L2-L4). A significant difference was however found for L4 (p11 months, but not when the time period was ≤11 months. This follow-up study of changes not only in BMD but also in BMI and recovery of menses has clinical relevance from the viewpoint of the day-by-day treatment process. Use of QCT makes the study more relevant because this is a more advanced technique that allows for differentiating trabecular and cortical bone. Copyright © 2016 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Changes in bone marrow lesions in response to weight-loss in obese knee osteoarthritis patients

DEFF Research Database (Denmark)

Gudbergsen, Henrik; Boesen, Mikael; Christensen, Robin

2013-01-01

Patients are susceptible for knee osteoarthritis (KOA) with increasing age and obesity and KOA is expected to become a major disabling disease in the future. An important feature of KOA on magnetic resonance imaging (MRI) is changes in the subchondral bone, bone marrow lesions (BMLs), which...... are related to the future degeneration of the knee joint as well as prevalent clinical symptoms. The aim of this study was to investigate the changes in BMLs after a 16-week weight-loss period in obese subjects with KOA and relate changes in BMLs to the effects of weight-loss on clinical symptoms....

The effect of above average weight gains on the incidence of radiographic bone aberrations and epiphysitis in growing horses

International Nuclear Information System (INIS)

Thompson, K.N.; Jackson, S.G.; Rooney, J.R.

1988-01-01

The relationship between body weight gain and the onset of bone aberrations (e.g. epiphysitis) is described. A model was derived which described the increase in transverse epiphyseal width, and the major factor found to affect epiphyseal width was average daily gain in body weight. In addition, a radiographic examination of the epiphyseal areas showed a larger number of bone aberrations in groups gaining weight at an above-average rate. Thus, a rapid increase in body weight can be suggested as a significant factor in the onset of epiphysitis

Lack of Association between Body Weight, Bone Mineral Density and Vitamin D Receptor Gene Polymorphism in Normal and Osteoporotic Women

Directory of Open Access Journals (Sweden)

Massimo Poggi

1999-01-01

Full Text Available In an ethnically homogeneous population of women living in Tuscany, Italy, the relationships between age, body weight, bone mineral density and the vitamin D receptor (VDR gene polymorphism were studied, with the objective of recognizing patients at risk for osteoporosis. In 275 women bone mineral density was measured by Dual Energy X-rays Absorptiometry (DEXA. In 50 of them the individual genetic pattern for VDR was evaluated by DNA extraction followed by PCR amplification of the VDR gene, and digestion with the restriction enzyme BsmI. Age and bone mineral density were inversely related (R2 = 0.298. Body weight was associated with bone mineral density (R2 = 0.059, but not with age. In osteoporotic women, mean (± SD body weight was 59.9 ± 6.5 Kg, lower than that recorded in non osteoporotic women (64.2 ± 9.4 Kg, even though not significantly different (p = 0.18. No association was found between VDR gene polymorphism, bone density or body weight. The performance of anthropometric and genetic components appear to be poor, and, at least for the time being, bone mineral density measurement by means of MOC-DEXA represents the optimal method to detect women at risk for postmenopausal osteoporosis.

Bear maul craniocerebral trauma in Kashmir Valley.

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Bashir, Sheikh Adil; Rasool, Altaf; Zaroo, Mohamad Inam; Wani, Adil Hafeez; Zargar, Haroon Rashid; Darzi, Mohammad Ashraf; Khursheed, Nayil

2013-01-01

Craniocerebral injuries constitute the bulk of the trauma patients in all the tertiary-care hospitals. Bear attacks as a cause of trauma to the brain and its protective covering are rare. This was a hospital-based retrospective (January 1990 to July 2005) and prospective study (August 2005 to December 2010). Craniocerebral trauma was seen in 49 patients of bear maul injuries. Loss of scalp tissue was seen in 17 patients, 13 of whom had exposed pericranium and needed split-thickness skin grafting, while 4 patients with exposed skull bones required scalp transposition flaps as an initial procedure. Skull bone fractures without associated brain injury were observed in 24 cases. Frontal bone was the site of fracture in the majority of cases (95%). Surgical intervention was needed in 18 patients for significantly depressed fractures. Three of these patients had depressed frontal bone fractures with underlying contusions and needed brain debridement and duraplasty. Injury to the brain was observed in 8 patients. Trauma to the brain and its protective coverings as a result of bear attacks is rarely known. Brain injury occurs less commonly as compared to soft tissue and bony injury. Craniocerebral trauma as a result of bear assaults has been a hitherto neglected area of trauma as the past reported incidence has been very low. Of late, the incidence and severity of such attacks has assumed grave proportions in areas adjacent to known bear habitats. An innocuous-looking surface wound might be the only presentation of an underlying severe brain trauma. Public awareness has to be generated to protect the people living in hilly areas.

Bone Mineral Density after Weight Gain in 160 Patients with Anorexia Nervosa

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Najate Achamrah

2017-09-01

Full Text Available Low bone mineral density (BMD is a frequent complication in anorexia nervosa (AN. There are controversial points of views regarding the restoration of bone mineralization after recovery in AN. We aimed to assess changes of BMD at 3 years in patients with AN and to explore the relationships between body composition, physical activity, and BMD. Patients with AN were included from 2009 to 2011 in a first visit (T0 with evaluation of weight, height, body mass index (BMI, body composition [fat mass (FM and fat-free mass], and BMD. Those who had low BMD, either osteoporosis or osteopenia, were admitted in a second visit (T1 to carry out a new bone densitometry examination and body composition; they were also asked for their physical activity. At T0, our study involved 160 patients. Low BMD was observed in 53.6% of them and significant factors associated with demineralization were lower BMIs (16.5 ± 2.1 vs 17.3 ± 2.3 kg/m2, p = 0.01 and higher duration of AN (11.4 ± 10.5 vs 6.4 ± 6.5 years, p = 0.001. At 3 years follow-up (T1, 42 patients were involved and no significant changes in BMD were observed despite body weight increase (3.8 ± 6.1 kg. Interestingly, FM gain was a significant factor associated with BMD improvement at follow-up (8.0 ± 9.1 vs 3.0 ± 3.5 kg, p = 0.02. Our findings suggest that the restoration of normal bone values is not related to the increase of body weight, at least after 3 years. FM seems to play an important role in the pathophysiological mechanism of osteoporosis and osteopenia in AN.

Insights into relationships between body mass, composition and bone: findings in elite rugby players.

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Hind, Karen; Gannon, Lisa; Brightmore, Amy; Beck, Belinda

2015-01-01

Recent reports indicate that bone strength is not proportional to body weight in obese populations. Elite rugby players have a similar body mass index (BMI) to obese individuals but differ markedly with low body fat, high lean mass, and frequent skeletal exposure to loading through weight-bearing exercise. The purpose of this study was to determine relationships between body weight, composition, and bone strength in male rugby players characterized by high BMI and high lean mass. Fifty-two elite male rugby players and 32 nonathletic, age-matched controls differing in BMI (30.2 ± 3.2 vs 24.1 ± 2.1 kg/m²; p = 0.02) received 1 total body and one total hip dual-energy X-ray absorptiometry scan. Hip structural analysis of the proximal femur was used to determine bone mineral density (BMD) and cross-sectional bone geometry. Multiple linear regression was computed to identify independent variables associated with total hip and femoral neck BMD and hip structural analysis-derived bone geometry parameters. Analysis of covariance was used to explore differences between groups. Further comparisons between groups were performed after normalizing parameters to body weight and to lean mass. There was a trend for a positive fat-bone relationship in rugby players, and a negative relationship in controls, although neither reached statistical significance. Correlations with lean mass were stronger for bone geometry (r(2): 0.408-0.520) than for BMD (r(2): 0.267-0.293). Relative to body weight, BMD was 6.7% lower in rugby players than controls (p Rugby players were heavier than controls, with greater lean mass and BMD (p rugby players (p rugby players was reduced in proportion to body weight and lean mass. However, their superior bone geometry suggests that overall bone strength may be adequate for loading demands. Fat-bone interactions in athletes engaged in high-impact sports require further exploration. Copyright © 2015. Published by Elsevier Inc.

Effect of modified constraint induced movement therapy on weight bearing and protective extension in children with hemiplegic cerebral palsy

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Masoud Gharib

2012-01-01

Full Text Available Background: Constraint induced movement therapy is one of the new therapeutic interventions that limits the performance of intact upper limb with increased use of the affected limb. Aim of this study was to investigate the effects of modified constraint induced movement therapy on weight bearing & protective extension in children with hemiplegic cerebral palsy.Methods: 21 hemiplegic children were selected and randomly divided into experimental and control groups. Common Practices of Occupational Therapy applied for 6 weeks in both groups equally and test group received constrain induced movement therapy for three hours every day. Weight-bearing and protective extension was measured based on quality of test skills of upper limbs (QUEST. Data analyzed using appropriated statistical methods. Results: 11 children in the experimental group (7 girls, 4 boys with mean age 47.2 ± 55.5 months and 10 children in the control group (5 girls, 5 boys with mean age 19.2 ± 10.5 months were studied. No significant difference observed before and after six weeks intervention between two groups (P>0.05. There was a significant change before and after six weeks intervention in both subscales (P<0.05.Conclusion: This study showed that modified constraint induced movement therapy may affect weight bearing, but has no effect on the protective extension.

Biofeedback in Partial Weight Bearing: Usability of Two Different Devices from a Patient’s and Physical Therapist’s Perspective

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van Lieshout, Remko; Pisters, Martijn F.; Vanwanseele, Benedicte; de Bie, Rob A.; Wouters, Eveline J.; Stukstette, Mirelle J.

2016-01-01

Background Partial weight bearing is frequently instructed by physical therapists in patients after lower-limb trauma or surgery. The use of biofeedback devices seems promising to improve the patient’s compliance with weight-bearing instructions. SmartStep and OpenGo-Science are biofeedback devices that provide real-time feedback. For a successful implementation, usability of the devices is a critical aspect and should be tested from a user’s perspective. Aim To describe the usability from the physical therapists’ and a patients’ perspective of Smartstep and OpenGo-Science to provide feedback on partial weight bearing during supervised rehabilitation of patients after lower-limb trauma or surgery. Methods In a convergent mixed-methods design, qualitative and quantitative data were collected. Usability was subdivided into user performance, satisfaction and acceptability. Patients prescribed with partial weight bearing and their physical therapists were asked to use SmartStep and OpenGo-Science during supervised rehabilitation. Usability was qualitatively tested by a think-aloud method and a semi-structured interview and quantitatively tested by the System-Usability-Scale (SUS) and closed questions. For the qualitative data thematic content analyses were used. Results Nine pairs of physical therapists and their patients participated. The mean SUS scores for patients and physical therapists were for SmartStep 70 and 53, and for OpenGo-Science 79 and 81, respectively. Scores were interpreted with the Curved Grading Scale. The qualitative data showed that there were mixed views and perceptions from patients and physical therapists on satisfaction and acceptability. Conclusion This study gives insight in the usability of two biofeedback devices from the patient’s and physical therapist’s perspective. The overall usability from both perspectives seemed to be acceptable for OpenGo-Science. For SmartStep, overall usability seemed only acceptable from the

Unusually large solitary unicameral bone cyst: case report.

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Singh, Sandeep; Dhammi, Ish Kumar; Arora, Anil; Kumar, Sudhir

2003-01-01

A 15-year-old boy presented with complaints of pain and swelling of the right leg. Radiography revealed a large lytic lesion involving the proximal half of the tibia. The patient was taken to surgery, where the cavity was curetted and packed with allogeneic bone graft. Tissue was sent for histopathological evaluation. The patient was kept in an above-knee cast for 4 months, after which partial weight-bearing was allowed. The histopathological diagnosis was a unicameral bone cyst. A radiograph at 1 year showed incorporation of the graft, but a small part of the cavity was still visible and there was a persistent discharge. The patient was again subjected to allogeneic bone grafting in the remaining cavity. At 3.5 years of follow-up now, the patient is walking unsupported, there is no pain, and the radiograph shows complete obliteration of the cavity. Unicameral bone cysts are usually a few centimeters in size. To the best of our knowledge, a unicameral bone cyst of such a large size has never been reported in the literature.

Establishment of peak bone mass.

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Mora, Stefano; Gilsanz, Vicente

2003-03-01

Among the main areas of progress in osteoporosis research during the last decade or so are the general recognition that this condition, which is the cause of so much pain in the elderly population, has its antecedents in childhood and the identification of the structural basis accounting for much of the differences in bone strength among humans. Nevertheless, current understanding of the bone mineral accrual process is far from complete. The search for genes that regulate bone mass acquisition is ongoing, and current results are not sufficient to identify subjects at risk. However, there is solid evidence that BMD measurements can be helpful for the selection of subjects that presumably would benefit from preventive interventions. The questions regarding the type of preventive interventions, their magnitude, and duration remain unanswered. Carefully designed controlled trials are needed. Nevertheless, previous experience indicates that weight-bearing activity and possibly calcium supplements are beneficial if they are begun during childhood and preferably before the onset of puberty. Modification of unhealthy lifestyles and increments in exercise or calcium assumption are logical interventions that should be implemented to improve bone mass gains in all children and adolescents who are at risk of failing to achieve an optimal peak bone mass.

The Use of Structural Allograft in Primary and Revision Knee Arthroplasty with Bone Loss

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Raul A. Kuchinad

2011-01-01

Full Text Available Bone loss around the knee in the setting of total knee arthroplasty remains a difficult and challenging problem for orthopaedic surgeons. There are a number of options for dealing with smaller and contained bone loss; however, massive segmental bone loss has fewer options. Small, contained defects can be treated with cement, morselized autograft/allograft or metal augments. Segmental bone loss cannot be dealt with through simple addition of cement, morselized autograft/allograft, or metal augments. For younger or higher demand patients, the use of allograft is a good option as it provides a durable construct with high rates of union while restoring bone stock for future revisions. Older patients, or those who are low demand, may be better candidates for a tumour prosthesis, which provides immediate ability to weight bear and mobilize.

Reconstruction of segmental bone defect of long bones after tumor resection by devitalized tumor-bearing bone

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Qu, Huayi; Guo, Wei; Yang, Rongli; Li, Dasen; Tang, Shun; Yang, Yi; Dong, Sen; Zang, Jie

2015-01-01

Background The reconstruction of an intercalary bone defect after a tumor resection of a long bone remains a challenge to orthopedic surgeons. Though several methods have been adopted to enhance the union of long segmental allografts or retrieved segmental autografts to the host bones, still more progresses are required to achieve a better union rate. Several methods have been adopted to devitalize tumor bone for recycling usage, and the results varied. We describe our experiences of using de...

Impact of intra- and extra-osseous soft tissue composition on changes in bone mineral density with weight loss and regain.

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Bosy-Westphal, Anja; Later, Wiebke; Schautz, Britta; Lagerpusch, Merit; Goele, Kristin; Heller, Martin; Glüer, Claus-C; Müller, Manfred J

2011-07-01

Recent studies report a significant gain in bone mineral density (BMD) after diet-induced weight loss. This might be explained by a measurement artefact. We therefore investigated the impact of intra- and extra-osseous soft tissue composition on bone measurements by dual X-ray absorptiometry (DXA) in a longitudinal study of diet-induced weight loss and regain in 55 women and 17 men (19-46 years, BMI 28.2-46.8 kg/m(2)). Total and regional BMD were measured before and after 12.7 ± 2.2 week diet-induced weight loss and 6 months after significant weight regain (≥30%). Hydration of fat free mass (FFM) was assessed by a 3-compartment model. Skeletal muscle (SM) mass, extra-osseous adipose tissue, and bone marrow were measured by whole body magnetic resonance imaging (MRI). Mean weight loss was -9.2 ± 4.4 kg (P BMAT) were not related to changes in BMD.

Radioprotection of normal tissues in tumor-bearing mice by troxerutin

International Nuclear Information System (INIS)

Maurya, D.K.; Salvi, V.P.; Krishnan Nair, C.K.

2004-01-01

The flavanoid derivative troxerutin, used clinically for treating venous disorders, protected biomembranes and cellular DNA against the deleterious effects of γ-radiation. The peroxidation of lipids (measured as thiobarbituric acid-reacting substances, or TBARS) in rat liver microsomal and mitochondrial membranes resulting from γ-irradiation up to doses of 500 Gy in vitro was prevented by 0.2 mM troxerutin. The administration of troxerutin (175 mg/kg body weight) to tumor-bearing mice by intraperitoneal (ip) one hour prior to 4 Gy whole-body γ-irradiation significantly decreased the radiation-induced peroxidation of lipids in tissues such as liver and spleen, but there was no reduction of lipid peroxidation in tumor. The effect of troxerutin in γ-radiation-induced DNA strand breaks in different tissues of tumor-bearing mice was studied by comet assay. The administration of troxerutin to tumor-bearing animals protected cellular DNA against radiation-induced strand breaks. This was evidenced from decreases in comet tail length, tail moment, and percent of DNA in the tails in cells of normal tissues such as blood leukocytes and bone marrow, and these parameters were not altered in cells of fibrosarcoma tumor. The results revealed that troxerutin could preferentially protect normal tissues against radiation-induced damages in tumor-bearing animals. (author)

The Role of Nutrition in the Changes in Bone and Calcium Metabolism During Space Flight

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Morey-Holton, Emily R.; Arnaud, Sara B.

1995-01-01

On Earth, the primary purpose of the skeleton is provide structural support for the body. In space, the support function of the skeleton is reduced since, without gravity, structures have only mass and no weight. The adaptation to space flight is manifested by shifts in mineral distribution, altered bone turnover, and regional mineral deficits in weight-bearing bones. The shifts in mineral distribution appear to be related to the cephalic fluid shift. The redistribution of mineral from one bone to another or to and from areas in the same bone in response to alterations in gravitational loads is more likely to affect skeletal function than quantitative whole body losses and gains. The changes in bone turnover appear dependent upon changes in body weight with weight loss tending to increase bone resorption as well as decrease bone formation. During bedrest, the bone response to unloading varies depending upon the routine activity level of the subjects with more active subjects showing a greater suppression of bone formation in the iliac crest with inactivity. Changes in body composition during space flight are predicted by bedrest studies on Earth which show loss of lean body mass and increase tn body fat in adult males after one month. In ambulatory studies on Earth, exercising adult males of the same age, height, g weight, body mass index, and shoe size show significantly higher whole body mineral and lean body mass. than non-exercising subjects. Nutritional preference appears to change with activity level. Diet histories in exercisers and nonexercisers who maintain identical body weights show no differences in nutrients except for slightly higher carbohydrate intake in the exercisers. The absence of differences in dietary calcium in men with higher total body calcium is noteworthy. In this situation, the increased bone mineral content was facilitated by the calcium endocrine system. This regulatory system can be by-passed by raising dietary calcium. Increased

Black bears with longer disuse (hibernation) periods have lower femoral osteon population density and greater mineralization and intracortical porosity.

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Wojda, Samantha J; Weyland, David R; Gray, Sarah K; McGee-Lawrence, Meghan E; Drummer, Thomas D; Donahue, Seth W

2013-08-01

Intracortical bone remodeling is persistent throughout life, leading to age related increases in osteon population density (OPD). Intracortical porosity also increases with age in many mammals including humans, contributing to bone fragility and fracture risk. Unbalanced bone resorption and formation during disuse (e.g., physical inactivity) also increases intracortical porosity. In contrast, hibernating bears are a naturally occurring model for the prevention of both age-related and disuse osteoporoses. Intracortical bone remodeling is decreased during hibernation, but resorption and formation remain balanced. Black bears spend 0.25-7 months in hibernation annually depending on climate and food availability. We found longer hibernating bears demonstrate lower OPD and higher cortical bone mineralization than bears with shorter hibernation durations, but we surprisingly found longer hibernating bears had higher intracortical porosity. However, bears from three different latitudes showed age-related decreases in intracortical porosity, indicating that regardless of hibernation duration, black bears do not show the disuse- or age-related increases in intracortical porosity which is typical of other animals. This ability to prevent increases in intracortical porosity likely contributes to their ability to maintain bone strength during prolonged periods of physical inactivity and throughout life. Improving our understanding of the unique bone metabolism in hibernating bears will potentially increase our ability to develop treatments for age- and disuse-related osteoporoses in humans. Copyright © 2013 Wiley Periodicals, Inc.

Proteinase-activated receptor 2 modulates OA-related pain, cartilage and bone pathology.

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Huesa, Carmen; Ortiz, Ana C; Dunning, Lynette; McGavin, Laura; Bennett, Louise; McIntosh, Kathryn; Crilly, Anne; Kurowska-Stolarska, Mariola; Plevin, Robin; van 't Hof, Rob J; Rowan, Andrew D; McInnes, Iain B; Goodyear, Carl S; Lockhart, John C; Ferrell, William R

2016-11-01

Proteinase-activated receptor 2 (PAR2) deficiency protects against cartilage degradation in experimental osteoarthritis (OA). The wider impact of this pathway upon OA-associated pathologies such as osteophyte formation and pain is unknown. Herein, we investigated early temporal bone and cartilage changes in experimental OA in order to further elucidate the role of PAR2 in OA pathogenesis. OA was induced in wild-type (WT) and PAR2-deficient (PAR2 -/- ) mice by destabilisation of the medial meniscus (DMM). Inflammation, cartilage degradation and bone changes were monitored using histology and microCT. In gene rescue experiments, PAR2 -/- mice were intra-articularly injected with human PAR2 (hPAR2)-expressing adenovirus. Dynamic weight bearing was used as a surrogate of OA-related pain. Osteophytes formed within 7 days post-DMM in WT mice but osteosclerosis was only evident from 14 days post induction. Importantly, PAR2 was expressed in the proliferative/hypertrophic chondrocytes present within osteophytes. In PAR2 -/- mice, osteophytes developed significantly less frequently but, when present, were smaller and of greater density; no osteosclerosis was observed in these mice up to day 28. The pattern of weight bearing was altered in PAR2 -/- mice, suggesting reduced pain perception. The expression of hPAR2 in PAR2 -/- mice recapitulated osteophyte formation and cartilage damage similar to that observed in WT mice. However, osteosclerosis was absent, consistent with lack of hPAR2 expression in subchondral bone. This study clearly demonstrates PAR2 plays a critical role, via chondrocytes, in osteophyte development and subchondral bone changes, which occur prior to PAR2-mediated cartilage damage. The latter likely occurs independently of OA-related bone changes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Proteinase-activated receptor 2 modulates OA-related pain, cartilage and bone pathology

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Huesa, Carmen; Ortiz, Ana C; Dunning, Lynette; McGavin, Laura; Bennett, Louise; McIntosh, Kathryn; Crilly, Anne; Kurowska-Stolarska, Mariola; Plevin, Robin; van ‘t Hof, Rob J; Rowan, Andrew D; McInnes, Iain B; Goodyear, Carl S; Lockhart, John C; Ferrell, William R

2016-01-01

Objective Proteinase-activated receptor 2 (PAR2) deficiency protects against cartilage degradation in experimental osteoarthritis (OA). The wider impact of this pathway upon OA-associated pathologies such as osteophyte formation and pain is unknown. Herein, we investigated early temporal bone and cartilage changes in experimental OA in order to further elucidate the role of PAR2 in OA pathogenesis. Methods OA was induced in wild-type (WT) and PAR2-deficient (PAR2−/−) mice by destabilisation of the medial meniscus (DMM). Inflammation, cartilage degradation and bone changes were monitored using histology and microCT. In gene rescue experiments, PAR2−/− mice were intra-articularly injected with human PAR2 (hPAR2)-expressing adenovirus. Dynamic weight bearing was used as a surrogate of OA-related pain. Results Osteophytes formed within 7 days post-DMM in WT mice but osteosclerosis was only evident from 14 days post induction. Importantly, PAR2 was expressed in the proliferative/hypertrophic chondrocytes present within osteophytes. In PAR2−/− mice, osteophytes developed significantly less frequently but, when present, were smaller and of greater density; no osteosclerosis was observed in these mice up to day 28. The pattern of weight bearing was altered in PAR2−/− mice, suggesting reduced pain perception. The expression of hPAR2 in PAR2−/− mice recapitulated osteophyte formation and cartilage damage similar to that observed in WT mice. However, osteosclerosis was absent, consistent with lack of hPAR2 expression in subchondral bone. Conclusions This study clearly demonstrates PAR2 plays a critical role, via chondrocytes, in osteophyte development and subchondral bone changes, which occur prior to PAR2-mediated cartilage damage. The latter likely occurs independently of OA-related bone changes. PMID:26698846

Repair of segmental load-bearing bone defect by autologous mesenchymal stem cells and plasma-derived fibrin impregnated ceramic block results in early recovery of limb function.

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Ng, Min Hwei; Duski, Suryasmi; Tan, Kok Keong; Yusof, Mohd Reusmaazran; Low, Kiat Cheong; Rose, Isa Mohamed; Mohamed, Zahiah; Bin Saim, Aminuddin; Idrus, Ruszymah Bt Hj

2014-01-01

Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB) to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC) and partially demineralized allogeneic bone block (ALLO). Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32), MIC (1.28 ± 0.24), and negative controls (0). Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1%) compared to ALLO (5% ± 2.5%) and MIC (26% ± 5.2%). Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa) compared to those treated with ALLO (15.15 ± 3.57 MPa) and MIC (23.28 ± 6.14 MPa). In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function.

Repair of Segmental Load-Bearing Bone Defect by Autologous Mesenchymal Stem Cells and Plasma-Derived Fibrin Impregnated Ceramic Block Results in Early Recovery of Limb Function

Directory of Open Access Journals (Sweden)

Min Hwei Ng

2014-01-01

Full Text Available Calcium phosphate-based bone substitutes have not been used to repair load-bearing bone defects due to their weak mechanical property. In this study, we reevaluated the functional outcomes of combining ceramic block with osteogenic-induced mesenchymal stem cells and platelet-rich plasma (TEB to repair critical-sized segmental tibial defect. Comparisons were made with fresh marrow-impregnated ceramic block (MIC and partially demineralized allogeneic bone block (ALLO. Six New Zealand White female rabbits were used in each study group and three rabbits with no implants were used as negative controls. By Day 90, 4/6 rabbits in TEB group and 2/6 in ALLO and MIC groups resumed normal gait pattern. Union was achieved significantly faster in TEB group with a radiological score of 4.50 ± 0.78 versus ALLO (1.06 ± 0.32, MIC (1.28 ± 0.24, and negative controls (0. Histologically, TEB group scored the highest percentage of new bone (82% ± 5.1% compared to ALLO (5% ± 2.5% and MIC (26% ± 5.2%. Biomechanically, TEB-treated tibiae achieved the highest compressive strength (43.50 ± 12.72 MPa compared to those treated with ALLO (15.15 ± 3.57 MPa and MIC (23.28 ± 6.14 MPa. In conclusion, TEB can repair critical-sized segmental load-bearing bone defects and restore limb function.

Mice with cancer-induced bone pain show a marked decline in day/night activity.

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Majuta, Lisa A; Guedon, Jean-Marc G; Mitchell, Stefanie A T; Kuskowski, Michael A; Mantyh, Patrick W

2017-09-01

Cancer-induced bone pain (CIBP) is the most common type of pain with cancer. In humans, this pain can be difficult to control and highly disabling. A major problem with CIBP in humans is that it increases on weight-bearing and/or movement of a tumor-bearing bone limiting the activity and functional status of the patient. Currently, there is less data concerning whether similar negative changes in activity occur in rodent models of CIBP. To determine whether there are marked changes in activity in a rodent model of CIBP and compare this to changes in skin hypersensitivity. Osteosarcoma cells were injected and confined to 1 femur of the adult male mouse. Every 7 days, spontaneous horizontal and vertical activities were assessed over a 20-hour day and night period using automated activity boxes. Mechanical hypersensitivity of the hind paw skin was assessed using von Frey testing. As the tumor cells grew within the femur, there was a significant decline in horizontal and vertical activity during the times of the day/night when the mice are normally most active. Mice also developed significant hypersensitivity in the skin of the hind paw in the tumor-bearing limb. Even when the tumor is confined to a single load-bearing bone, CIBP drives a significant loss of activity, which increases with disease progression. Understanding the mechanisms that drive this reduction in activity may allow the development of therapies that allow CIBP patients to better maintain their activity and functional status.

The influence of birth weight and length on bone mineral density and content in adolescence: The Tromsø Study, Fit Futures.

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Christoffersen, Tore; Ahmed, Luai A; Daltveit, Anne Kjersti; Dennison, Elaine M; Evensen, Elin K; Furberg, Anne-Sofie; Gracia-Marco, Luis; Grimnes, Guri; Nilsen, Ole-Andreas; Schei, Berit; Tell, Grethe S; Vlachopoulos, Dimitris; Winther, Anne; Emaus, Nina

2017-12-01

The influence of birth weight and length on bone mineral parameters in adolescence is unclear. We found a positive association between birth size and bone mineral content, attenuated by lifestyle factors. This highlights the impact of environmental stimuli and lifestyle during growth. The influence of birth weight and length on bone mineral density and content later in life is unclear, especially in adolescence. This study evaluated the impact of birth weight and length on bone mineral density and content among adolescents. We included 961 participants from the population-based Fit Futures study (2010-2011). Dual-energy X-ray absorptiometry (DXA) was used to measure bone mineral density (BMD) and bone mineral content (BMC) at femoral neck (FN), total hip (TH) and total body (TB). BMD and BMC measures were linked with birth weight and length ascertained from the Medical Birth Registry of Norway. Linear regression models were used to investigate the influence of birth parameters on BMD and BMC. Birth weight was positively associated with BMD-TB and BMC at all sites among girls; standardized β coefficients [95% CI] were 0.11 [0.01, 0.20] for BMD-TB and 0.15 [0.06, 0.24], 0.18 [0.09, 0.28] and 0.29 [0.20, 0.38] for BMC-FN, TH and TB, respectively. In boys, birth weight was positively associated with BMC at all sites with estimates of 0.10 [0.01, 0.19], 0.12 [0.03, 0.21] and 0.15 [0.07, 0.24] for FN, TH and TB, respectively. Corresponding analyses using birth length as exposure gave significantly positive associations with BMC at all sites in both sexes. The significant positive association between birth weight and BMC-TB in girls, and birth length and BMC-TB in boys remained after multivariable adjustment. We found a positive association between birth size and BMC in adolescence. However, this association was attenuated after adjustment for weight, height and physical activity during adolescence.

Diet and Co-ecology of Pleistocene Short-Faced Bears and Brown Bears in Eastern Beringia

Science.gov (United States)

Matheus, Paul E.

1995-11-01

Carbon and nitrogen stable isotope analysis of fossil bone collagen reveals that Pleistocene short-faced bears ( Arctodus simus) of Beringia were highly carnivorous, while contemporaneous brown bears ( Ursus arctos) had highly variable diets that included varying amounts of terrestrial vegetation, salmon, and small amounts of terrestrial meat. A reconsideration of the short-faced bear's highly derived morphology indicates that they foraged as scavengers of widely dispersed large mammal carcasses and were simultaneously designed both for highly efficient locomotion and for intimidating other large carnivores. This allowed Arctodus to forage economically over a large home range and seek out, procure, and defend carcasses from other large carnivores. The isotope data and this reconstruction of Arctodus' foraging behavior refute the hypothesis that competition from brown bears was a significant factor in the extinction of short-faced bears.

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

NARCIS (Netherlands)

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

2015-01-01

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

Combined oral contraceptives' influence on weight, body composition, height, and bone mineral density in girls younger than 18 years

DEFF Research Database (Denmark)

Warholm, Lina; Petersen, Kresten R; Ravn, Pernille

2012-01-01

Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years.......Combined oral contraceptives (COCs) are increasingly used by adolescents. The aim of this review is to investigate the evidence regarding COCs' influence on weight, height and bone mineral density (BMD) in girls younger than 18 years....

Novel mechanically competent polysaccharide scaffolds for bone tissue engineering

International Nuclear Information System (INIS)

Kumbar, S G; Toti, U S; Deng, M; James, R; Laurencin, C T; Aravamudhan, A; Harmon, M; Ramos, D M

2011-01-01

The success of the scaffold-based bone regeneration approach critically depends on the biomaterial's mechanical and biological properties. Cellulose and its derivatives are inherently associated with exceptional strength and biocompatibility due to their β-glycosidic linkage and extensive hydrogen bonding. This polymer class has a long medical history as a dialysis membrane, wound care system and pharmaceutical excipient. Recently cellulose-based scaffolds have been developed and evaluated for a variety of tissue engineering applications. In general porous polysaccharide scaffolds in spite of many merits lack the necessary mechanical competence needed for load-bearing applications. The present study reports the fabrication and characterization of three-dimensional (3D) porous sintered microsphere scaffolds based on cellulose derivatives using a solvent/non-solvent sintering approach for load-bearing applications. These 3D scaffolds exhibited a compressive modulus and strength in the mid-range of human trabecular bone and underwent degradation resulting in a weight loss of 10–15% after 24 weeks. A typical stress–strain curve for these scaffolds showed an initial elastic region and a less-stiff post-yield region similar to that of native bone. Human osteoblasts cultured on these scaffolds showed progressive growth with time and maintained expression of osteoblast phenotype markers. Further, the elevated expression of alkaline phosphatase and mineralization at early time points as compared to heat-sintered poly(lactic acid–glycolic acid) control scaffolds with identical pore properties affirmed the advantages of polysaccharides and their potential for scaffold-based bone regeneration.

Investigating the mechanism for maintaining eucalcemia despite immobility and anuria in the hibernating American black bear (Ursus americanus).

Science.gov (United States)

Seger, Rita L; Cross, Randal A; Rosen, Clifford J; Causey, Robert C; Gundberg, Caren M; Carpenter, Thomas O; Chen, Tai C; Halteman, William A; Holick, Michael F; Jakubas, Walter J; Keisler, Duane H; Seger, Richard M; Servello, Frederick A

2011-12-01

Ursine hibernation uniquely combines prolonged skeletal unloading, anuria, pregnancy, lactation, protein recycling, and lipolysis. This study presents a radiographic and biochemical picture of bone metabolism in free-ranging, female American black bears (Ursus americanus) that were active (spring bears and autumn bears) or hibernating (hibernating bears). Hibernating bears included lactating and non-lactating individuals. We measured serum calcium, albumin, inorganic phosphate, creatinine, bone specific alkaline phosphatase (BSALP), CTX, parathyroid hormone, insulin-like growth factor-I (IGF-l), leptin, 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and sclerostin from 35 to 50 tranquilized hibernating bears and 14 to 35 tranquilized spring bears. We compared metacarpal cortical indices (MCI), measured by digital X-ray radiogrammetry, from 60 hunter-killed autumn bears and 79 tranquilized, hibernating bears. MCI was greater in autumn than winter in younger bears, but showed no seasonal difference in older bears. During hibernation eucalcemia was maintained, BSALP was suppressed, and CTX was in the range expected for anuria. During hibernation 1,25(OH)(2)D was produced despite anuria. 1,25(OH)(2)D and IGF-I were less in hibernating than spring bears. In a quarter of hibernating bears, sclerostin was elevated. Leptin was greater in hibernating than spring bears. In hibernating bears, leptin correlated positively with BSALP in non-lactating bears and with CTX in lactating bears. Taken together the biochemical and radiographic findings indicate that during hibernation, bone turnover was persistent, balanced, and suppressed; bone resorption was lower than expected for an unloaded skeleton; and there was no unloading-induced bone loss. The skeleton appears to perceive that it was loaded when it was actually unloaded during hibernation. However, at the level of sclerostin, the skeleton recognized that it was unloaded. During hibernation leptin

Recurrence of Hallux Valgus Can Be Predicted from Immediate Postoperative Non-Weight-Bearing Radiographs.

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Park, Chul Hyun; Lee, Woo-Chun

2017-07-19

The aims of this study were to identify risk factors for the recurrence of hallux valgus deformity and to clarify whether recurrence after surgery to treat hallux valgus can be predicted using radiographic parameters assessed on immediate postoperative non-weight-bearing radiographs. A proximal chevron osteotomy combined with a distal soft-tissue procedure was performed by a single surgeon to treat moderate to severe hallux valgus deformity in 93 patients (117 feet). The feet were grouped according to nonrecurrence or recurrence. Changes in the hallux valgus angle, the intermetatarsal angle, and sesamoid position over time were analyzed by comparing values measured during each postoperative period. The relative risks of recurrence as indicated by preoperative and postoperative radiographic parameters were determined. Twenty (17.1%) of the 117 feet showed hallux valgus recurrence at the time of the last follow-up. The hallux valgus angle and the intermetatarsal angle stabilized at 6 months after surgery in the nonrecurrence group. An immediate postoperative hallux valgus angle of ≥8°, an immediate postoperative sesamoid position of grade 4 or greater, a preoperative metatarsus adductus angle of ≥23°, and a preoperative hallux valgus angle of ≥40° were significantly associated with recurrence. Recurrence of hallux valgus after a proximal chevron osteotomy can be reliably predicted from immediate postoperative non-weight-bearing radiographs. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Assessment of diagnosing metastatic bone tumor on T2*-weighted images. Comparison between turbo spin echo (TSE) method and gradient echo (GE) method

International Nuclear Information System (INIS)

Hayashi, Takahiko; Sugiyama, Akira; Katayama, Motoyuki

1996-01-01

We examined the usefulness of T2 * weighted gradient field echo images for diagnosis for metastatic bone tumors in comparison with T2 weighted turbo spin echo (fast spin echo) images. In T2 * weighted gradient field echo sequence to obtain maximum contrast-to-noise ratio (CNR), we experimentally manipulated flip angle (FA) (5deg-90deg), repetition time (TR) (400, 700 msec), and echo time (TE) (10-50 msec). The best CNR was 16.4 in fast low angle shot (FLASH) (TE: 24 msec, TR: 700 msec, FA: 40deg). Magnetic resonance imaging was carried out in 28 patients with metastatic bone tumors. In addition to conventional T1 weighted spin echo images, T2 weighted turbo spin echo (fast spin echo images) and T2 * weighted gradient field echo images were obtained. T2 * weighted gradient field echo images were superior to T2 weighted turbo spin echo (fast spin echo) images in delineating the tumors, adjacent fat tissues, and bone marrow. (author)

Gender differences in tibio-femoral kinematics and quadriceps muscle force during weight-bearing knee flexion in vitro.

Science.gov (United States)

Wünschel, Markus; Wülker, Nikolaus; Müller, Otto

2013-11-01

Females have a higher risk in terms of anterior cruciate ligament injuries during sports than males. Reasons for this fact may be different anatomy and muscle recruitment patterns leading to less protection for the cruciate- and collateral-ligaments. This in vitro study aims to evaluate gender differences in knee joint kinematics and muscle force during weight-bearing knee flexions. Thirty-four human knee specimens (17 females/17 males) were mounted on a dynamic knee simulator. Weight-bearing single-leg knee flexions were performed with different amounts of simulated body weight (BW). Gender-specific kinematics was measured with an ultrasonic motion capture system and different loading conditions were examined. Knee joint kinematics did not show significant differences regarding anteroposterior and medial-lateral movement as well as tibial varus-valgus and internal-external rotation. This applied to all simulated amounts of BW. Simulating 100 N BW in contrast to AF50 led to a significant higher quadriceps overall force in female knees from 45° to 85° of flexion in contrast to BW 50 N. In these female specimens, the quadriceps overall force was about 20 % higher than in male knees being constant in higher flexion angles. It is indicated by our results that in a squatting movement females compared with males produce higher muscle forces, suggesting an increased demand for muscular stabilization, whereas tibio-femoral kinematics was similar for both genders.

Combined aerobic and resistance exercise is effective for achieving weight loss and reducing cardiovascular risk factors without deteriorating bone health in obese young adults

Directory of Open Access Journals (Sweden)

Jung Sub Lim

2013-03-01

Full Text Available PurposeWeight loss reduces cardiovascular risk factors in the obese. However, weight reduction through diet negatively affects long-term bone health. The aim of study was to determine the ability of combined aerobic and resistance exercise (CE to reduce weight and cardiovascular risk without diminishing bone health.MethodsTwenty-five young adults participated in an 8-week weight loss CE program. Subjects were allocated to an obese group or a control group by body mass index (BMI. Body weight, BMI, body composition, and bone mineral density (BMD of the lumbar spine and total hip were measured before and after the CE trial. Serum levels of metabolic markers, including adipokines and bone markers, were also evaluated.ResultsWeight loss was evident in the obese group after the 8 weeks CE trial. Fat mass was significantly reduced in both groups. Fasting insulin, homeostatic model assessment-insulin resistance (HOMA-IR, leptin and aminotransferases level were significantly reduced from baseline only in the obese group. High density lipoprotein cholesterol increased in both groups. Hip BMD increased in the obese group. In all study subjects, BMI changes were correlated with HOMA-IR, leptin, and HDL changes. BMI decreases were correlated with lumbar spine BMD increases, lumbar spine BMD increases were positively correlated with osteocalcin changes, and lumbar spine bone mineral content increases were correlated negatively with C-terminal telopeptide of type 1 collagen changes.ConclusionThese findings suggest that CE provides effective weight loss and improves cardiovascular risk factors without diminishing BMD. Furthermore, they indicate that lumbar spine BMD might be maintained by increasing bone formation and decreasing bone resorption.

49 CFR 229.69 - Side bearings.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Side bearings. 229.69 Section 229.69....69 Side bearings. (a) Friction side bearings with springs designed to carry weight may not have more than 25 percent of the springs in any one nest broken. (b) Friction side bearings may not be run in...

Deproteinized bovine bone functionalized with the slow delivery of BMP-2 for the repair of critical-sized bone defects in sheep.

Science.gov (United States)

Liu, Tie; Wu, Gang; Wismeijer, Daniel; Gu, Zhiyuan; Liu, Yuelian

2013-09-01

As an alternative to an autologous bone graft, deproteinized bovine bone (DBB) is widely used in the clinical dentistry. Although DBB provides an osteoconductive scaffold, it is not capable of enhancing bone regeneration because it is not osteoinductive. In order to render DBB osteoinductive, bone morphogenetic protein 2 (BMP-2) has previously been incorporated into a three dimensional reservoir (a biomimetic calcium phosphate coating) on DBB, which effectively promoted the osteogenic response by the slow delivery of BMP-2. The aim of this study was to investigate the therapeutic effectiveness of such coating on the DBB granules in repairing a large cylindrical bone defect (8 mm diameter, 13 mm depth) in sheep. Eight groups were randomly assigned to the bone defects: (i) no graft material; (ii) autologous bone; (iii) DBB only; (iv) DBB mixed with autologous bone; (v) DBB bearing adsorbed BMP-2; (vi) DBB bearing a coating but no BMP-2; (vii) DBB bearing a coating with adsorbed BMP-2; and (viii) DBB bearing a coating-incorporated depot of BMP-2. 4 and 8 weeks after implantation, samples were withdrawn for a histological and a histomorphometric analysis. Histological results confirmed the excellent biocompatibility and osteoconductivity of all the grafts tested. At 4 weeks, DBB mixed with autologous bone or functionalized with coating-incorporated BMP-2 showed more newly-formed bone than the other groups with DBB. At 8 weeks, the volume of newly-formed bone around DBB that bore a coating-incorporated depot of BMP-2 was greatest among the groups with DBB, and was comparable to the autologous bone group. The use of autologous bone and BMP-2 resulted in more bone marrow formation. Multinucleated giant cells were observed in the resorption process around DBB, whereas histomorphometric analysis revealed no significant degradation of DBB. In conclusion, it was shown that incorporating BMP-2 into the calcium phosphate coating of DBB induced strong bone formation around DBB

Development of model hydroxyapatite bone scaffolds with multiscale porosity for potential load bearing applications

Science.gov (United States)

Dellinger, Jennifer Gwynne

2005-11-01

Model hydroxyapatite (HA) bone scaffolds consisting of a latticed pattern of rods were fabricated by a solid freeform fabrication (SFF) technique based on the robotic deposition of colloidal pastes. An optimal HA paste formulation for this method was developed. Local porosity, i.e. microporosity (1--30 mum) and sintering porosity (less than 1 mum), were produced by including polymer microsphere porogens in the HA pastes and by controlling the sintering of the scaffolds. Scaffolds with and without local porosity were evaluated with and without in vitro accelerated degradation. Percent weight loss of the scaffolds and calcium and phosphorus concentrations in solution increased with degradation time. After degradation, compressive strength and modulus decreased significantly for scaffolds with local porosity, but did not change significantly for scaffolds without local porosity. The compressive strength and modulus of scaffolds without local porosity were comparable to human cortical bone and were significantly greater than the scaffolds with local porosity. Micropores in HA disks caused surface pits that increased the surface roughness as compared to non-microporous HA disks. Mouse mesenchymal stem cells extended their cell processes into these microporous pits on HA disks in vitro. ALP expression was prolonged, cell attachment strength increased, and ECM production appeared greater on microporous HA disks compared to non-microporous HA disks and tissue culture treated polystyrene controls. Scaffolds with and without microporosity were implanted in goats bones. Microporous scaffolds with rhBMP-2 increased the percent of the scaffold filled with bone tissue compared to microporous scaffolds without rhBMP-2. Lamellar bone inside scaffolds was aligned near the rods junctions whereas lamellar bone was aligned in a more random configuration away from the rod junctions. Microporous scaffolds stained darkly with toluidine blue beneath areas of contact with new bone. This

A hippotherapy simulator is effective to shift weight bearing toward the affected side during gait in patients with stroke.

Science.gov (United States)

Sung, Yun-Hee; Kim, Chang-Ju; Yu, Byong-Kyu; Kim, Kyeong-Mi

2013-01-01

We investigated whether a hippotherapy simulator has influence on symmetric body weight bearing during gait in patients with stroke. Stroke patients were divided into a control group (n = 10) that received conventional rehabilitation for 60 min/day, 5 times/week for 4 weeks and an experimental group (n = 10) that used a hippotherapy simulator for 15 min/day, 5 times/week for 4 weeks after conventional rehabilitation for 45 min/day. Temporospatial gait assessed using OptoGait and trunk muscles (abdominis and erector spinae on affected side) activity evaluated using surface electromyography during sit-to-stand and gait. Prior to starting the experiment, pre-testing was performed. At the end of the 4-week intervention, we performed post-testing. Activation of the erector spinae in the experimental group was significantly increased compared to that in the control group (p hippotherapy simulator compared to control group (p hippotherapy simulator to patients with stroke can improve asymmetric weight bearing by influencing trunk muscles.

LIGHT-WEIGHT LOAD-BEARING STRUCTURES REINFORCED BY CORE ELEMENTS MADE OF SEGMENTS AND A METHOD OF CASTING SUCH STRUCTURES

DEFF Research Database (Denmark)

2009-01-01

The invention relates to a light-weight load-bearing structure, reinforced by core elements (2) of a strong material constituting one or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2......), where the core (2) is constructed from segments (1) of core elements (2) assembled by means of one or more prestressing elements (4). The invention further relates to a method of casting of light-weight load-bearing structures, reinforced by core elements (2) of a strong material constituting one...... or more compression or tension zones in the structure to be cast, which core (2) is surrounded by or adjacent to a material of less strength compared to the core (2), where the core (2) is constructed from segments (1) of core elements (2) assembled and hold together by means of one or more prestressing...

Rosai-Dorfman Disease with Epidural and Spinal Bone Marrow Involvement: Magnetic Resonance Imaging and Diffusion-Weighted Imaging Features

International Nuclear Information System (INIS)

Oner, A.Y.; Akpek, S.; Tali, T.

2007-01-01

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is a rare histiocytic disorder that typically presents with chronic, self-limiting cervical lymphadenopathy. Although this disease mainly affects histiocytes, there are a few reports of bone marrow infiltration. Diffusion-weighted imaging (DWI) is a promising technology in differentiating between various bone marrow pathologies. We here present conventional magnetic resonance imaging and DWI features of a patient with SHML and bone marrow involvement

Rosai-Dorfman Disease with Epidural and Spinal Bone Marrow Involvement: Magnetic Resonance Imaging and Diffusion-Weighted Imaging Features

Energy Technology Data Exchange (ETDEWEB)

Oner, A.Y.; Akpek, S.; Tali, T. [Dept. of Radiology, Gazi Univ. School of Medicine. Besevler-Ankara (Turkey)

2007-04-15

Sinus histiocytosis with massive lymphadenopathy (SHML), or Rosai-Dorfman disease, is a rare histiocytic disorder that typically presents with chronic, self-limiting cervical lymphadenopathy. Although this disease mainly affects histiocytes, there are a few reports of bone marrow infiltration. Diffusion-weighted imaging (DWI) is a promising technology in differentiating between various bone marrow pathologies. We here present conventional magnetic resonance imaging and DWI features of a patient with SHML and bone marrow involvement.

Neuropeptide Y knockout mice reveal a central role of NPY in the coordination of bone mass to body weight.

Directory of Open Access Journals (Sweden)

Paul A Baldock

Full Text Available Changes in whole body energy levels are closely linked to alterations in body weight and bone mass. Here, we show that hypothalamic signals contribute to the regulation of bone mass in a manner consistent with the central perception of energy status. Mice lacking neuropeptide Y (NPY, a well-known orexigenic factor whose hypothalamic expression is increased in fasting, have significantly increased bone mass in association with enhanced osteoblast activity and elevated expression of bone osteogenic transcription factors, Runx2 and Osterix. In contrast, wild type and NPY knockout (NPY (-/- mice in which NPY is specifically over expressed in the hypothalamus (AAV-NPY+ show a significant reduction in bone mass despite developing an obese phenotype. The AAV-NPY+ induced loss of bone mass is consistent with models known to mimic the central effects of fasting, which also show increased hypothalamic NPY levels. Thus these data indicate that, in addition to well characterized responses to body mass, skeletal tissue also responds to the perception of nutritional status by the hypothalamus independently of body weight. In addition, the reduction in bone mass by AAV NPY+ administration does not completely correct the high bone mass phenotype of NPY (-/- mice, indicating the possibility that peripheral NPY may also be an important regulator of bone mass. Indeed, we demonstrate the expression of NPY specifically in osteoblasts. In conclusion, these data identifies NPY as a critical integrator of bone homeostatic signals; increasing bone mass during times of obesity when hypothalamic NPY expression levels are low and reducing bone formation to conserve energy under 'starving' conditions, when hypothalamic NPY expression levels are high.

Effects of spine loading in a patient with post-decompression lumbar disc herniation: observations using an open weight-bearing MRI.

Science.gov (United States)

Mahato, Niladri Kumar; Sybert, Daryl; Law, Tim; Clark, Brian

2017-05-01

Our objective was to use an open weight-bearing MRI to identify the effects of different loading conditions on the inter-vertebral anatomy of the lumbar spine in a post-discectomy recurrent lumbar disc herniation patient. A 43-year-old male with a left-sided L5-S1 post-decompression re-herniation underwent MR imaging in three spine-loading conditions: (1) supine, (2) weight-bearing on standing (WB), and (3) WB with 10 % of body mass axial loading (WB + AL) (5 % through each shoulder). A segmentation-based proprietary software was used to calculate and compare linear dimensions, angles and cross sections across the lumbar spine. The L5 vertebrae showed a 4.6 mm posterior shift at L5-S1 in the supine position that changed to an anterior translation >2.0 mm on WB. The spinal canal sagittal thickness at L5-S1 reduced from supine to WB and WB + AL (13.4, 10.6, 9.5 mm) with corresponding increases of 2.4 and 3.5 mm in the L5-S1 disc protrusion with WB and WB + AL, respectively. Change from supine to WB and WB + AL altered the L5-S1 disc heights (10.2, 8.6, 7.0 mm), left L5-S1 foramen heights (12.9, 11.8, 10.9 mm), L5-S1 segmental angles (10.3°, 2.8°, 4.3°), sacral angles (38.5°, 38.3°, 40.3°), L1-L3-L5 angles (161.4°, 157.1°, 155.1°), and the dural sac cross sectional areas (149, 130, 131 mm 2 ). Notably, the adjacent L4-L5 segment demonstrated a retro-listhesis >2.3 mm on WB. We observed that with weight-bearing, measurements indicative of spinal canal narrowing could be detected. These findings suggest that further research is warranted to determine the potential utility of weight-bearing MRI in clinical decision-making.

Optimising diffusion weighted MRI for imaging metastatic and myeloma bone disease and assessing reproducibility

International Nuclear Information System (INIS)

Messiou, C.; Collins, D.J.; Morgan, V.A.; DeSouza, N.M.

2011-01-01

To establish normal bone marrow values of apparent diffusion coefficient (ADC) over an age range, compare them with metastatic and myelomatous involvement, to establish reproducibility and to optimise b values. The ADCs of bone marrow in 7 volunteers (mean age 29.7 years), 34 volunteers (mean age 63.3 years) and 43 patients with metastatic and myelomatous involvement (mean age 65.5 years) were measured. In 9 volunteers diffusion weighted MRI was repeated within 7 days. b values were derived to optimise contrast between normal and pathological marrow. The mean ADC of bone marrow in younger volunteers was significantly higher than that of older volunteers. The coefficient of reproducibility was 14.8%. The ADC mean of metastatic and myeloma bone disease was 1054+/-456 x 10 -6 mm 2 s -1 . An ADC threshold of 655 x 10 -6 mm 2 s -1 separated normal and abnormal marrow with a sensitivity and specificity of 90% and 93% respectively. Contrast between normal and abnormal marrow was optimal at b = 1389 smm -2 . The reproducibility of ADC measurements in bone is equivalent to published data for soft tissue with a high sensitivity and specificity for separating abnormal from age matched normal bone marrow. A b value of around 1,400 smm -2 is optimal for imaging bone marrow. (orig.)

Optimising diffusion weighted MRI for imaging metastatic and myeloma bone disease and assessing reproducibility

Energy Technology Data Exchange (ETDEWEB)

Messiou, C. [Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, Cancer Research UK Clinical Magnetic Resonance Research Group, Surrey (United Kingdom); Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, MRI Department, Surrey (United Kingdom); Collins, D.J.; Morgan, V.A.; DeSouza, N.M. [Institute of Cancer Research and Royal Marsden, NHS Foundation Trust, Cancer Research UK Clinical Magnetic Resonance Research Group, Surrey (United Kingdom)

2011-08-15

To establish normal bone marrow values of apparent diffusion coefficient (ADC) over an age range, compare them with metastatic and myelomatous involvement, to establish reproducibility and to optimise b values. The ADCs of bone marrow in 7 volunteers (mean age 29.7 years), 34 volunteers (mean age 63.3 years) and 43 patients with metastatic and myelomatous involvement (mean age 65.5 years) were measured. In 9 volunteers diffusion weighted MRI was repeated within 7 days. b values were derived to optimise contrast between normal and pathological marrow. The mean ADC of bone marrow in younger volunteers was significantly higher than that of older volunteers. The coefficient of reproducibility was 14.8%. The ADC mean of metastatic and myeloma bone disease was 1054+/-456 x 10{sup -6} mm{sup 2}s{sup -1}. An ADC threshold of 655 x 10{sup -6} mm{sup 2}s{sup -1} separated normal and abnormal marrow with a sensitivity and specificity of 90% and 93% respectively. Contrast between normal and abnormal marrow was optimal at b = 1389 smm{sup -2}. The reproducibility of ADC measurements in bone is equivalent to published data for soft tissue with a high sensitivity and specificity for separating abnormal from age matched normal bone marrow. A b value of around 1,400 smm{sup -2} is optimal for imaging bone marrow. (orig.)

Functional assessment of endoprosthesis in the treatment of bone tumors

Directory of Open Access Journals (Sweden)

Denis Kiyoshi Fukumothi

Full Text Available ABSTRACT OBJECTIVES: Evaluate the functional grade of these patients and to identify the types of complications found that influenced the average life span of endoprostheses the functions of the operated limb. METHODS: We analyzed 14 post-operative cases of endoprosthesis, patients with malignant bone tumors and aggressive benign bone tumors submitted to surgery between 2004 and 2014. The evaluation system used was proposed by Enneking, recommended by the Musculoskeletal Tumor Society (MSTS, in addition to the radiologic evaluation. RESULTS: Endoprosthesis are excellent choices for the treatment of bone tumors with limb preservation in relation to pain, strength, and patient's emotional acceptance. Another factor for good results is the immediate weight-bearing capacity, generating a greater independence. CONCLUSION: The authors conclude that all patients classified the therapy as excellent/good, regardless of the type of prosthesis used, extent of injury, and/or type of tumor resection performed.

Change in body weight of mothers and neonates and in milk composition during denning period in captive Japanese black bears (Ursus thibetanus japonicus).

Science.gov (United States)

Iibuchi, Ruriko; Nakano, Noriko; Nakamura, Tadashi; Urashima, Tadasu; Shimozuru, Michito; Murase, Tetsuma; Tsubota, Toshio

2009-05-01

Japanese black bears, Ursus thibetanus japonicus, have been classified as a vulnerable species so that data on reproduction are needed to maintain and/or extend their population. They are known to have a peculiar style of reproduction, giving birth to their neonates and raising them during denning, a period of complete fasting. In this study, we investigated the metabolic rate and milk composition of mother bears raising neonates, and the changes in body weight of the neonates under captive conditions. Seven female bears kept in dens were weighed once a month, and the amount of energy they used was calculated. From birth, cubs were also weighed and their growth rate was determined. In addition, the milk composition was analyzed to investigate its characteristics. As a result, it was found that mother bears used 34% more energy than did solitary females. There was no significant difference in the energy used for nursing whether they had single or twin cubs. On the other hand, the body weight gain of single cubs was significantly higher than that of twin cubs, suggesting that the growth of the cubs was highly affected by the suppression of mother's energy consumption during the fasting period. The milk had high fat and low sugar concentrations. This indicates that mother bears used the fat accumulated prior to denning for their main energy source when raising cubs. Considering all results together, Japanese black bears showed remarkable efficiency in the use of energy for reproduction during the fasting period.

Bone Turnover Markers and Lean Mass in Pubescent Boys: Comparison Between Elite Soccer Players and Controls.

Science.gov (United States)

Nebigh, Ammar; Abed, Mohamed Elfethi; Borji, Rihab; Sahli, Sonia; Sellami, Slaheddine; Tabka, Zouhair; Rebai, Haithem

2017-11-01

The aim of this study was to examine the relationship between bone mass and bone turnover markers with lean mass (LM) in pubescent soccer players. Two groups participated in this study, which included 65 elite young soccer players who trained for 6-8 hours per week and 60 controls. Bone mineral density; bone mineral content in the whole body, lower limbs, lumbar spine, and femoral neck; biochemical markers of osteocalcin; bone-specific alkaline phosphatase; C-telopeptide type I collagen; and total LM were assessed. Young soccer players showed higher bone mineral density and bone mineral content in the whole body and weight-bearing sites (P soccer players compared with the control group, but no significant difference in C-telopeptide type I collagen was observed between the 2 groups. This study showed a significant positive correlation among bone-specific alkaline phosphatase, osteocalcin, and total LM (r = .29; r = .31; P soccer players. Findings of this study highlight the importance of soccer practice for bone mineral parameters and bone turnover markers during the puberty stage.

Effects of Patellofemoral Taping on Patellofemoral Joint Alignment and Contact Area During Weight Bearing.

Science.gov (United States)

Ho, Kai-Yu; Epstein, Ryan; Garcia, Ron; Riley, Nicole; Lee, Szu-Ping

2017-02-01

Study Design Controlled laboratory study. Background Although it has been theorized that patellofemoral joint (PFJ) taping can correct patellar malalignment, the effects of PFJ taping techniques on patellar alignment and contact area have not yet been studied during weight bearing. Objective To examine the effects of 2 taping approaches (Kinesio and McConnell) on PFJ alignment and contact area. Methods Fourteen female subjects with patellofemoral pain and PFJ malalignment participated. Each subject underwent a pretaping magnetic resonance imaging (MRI) scan session and 2 MRI scan sessions after the application of the 2 taping techniques, which aimed to correct lateral patellar displacement. Subjects were asked to report their pain level prior to each scan session. During MRI assessment, subjects were loaded with 25% of body weight on their involved/more symptomatic leg at 0°, 20°, and 40° of knee flexion. The outcome measures included patellar lateral displacement (bisect-offset [BSO] index), mediolateral patellar tilt angle, patellar height (Insall-Salvati ratio), contact area, and pain. Patellofemoral joint alignment and contact area were compared among the 3 conditions (no tape, Kinesio, and McConnell) at 3 knee angles using a 2-factor, repeated-measures analysis of variance. Pain was compared among the 3 conditions using the Friedman test and post hoc Wilcoxon signed-rank tests. Results Our data did not reveal any significant effects of either McConnell or Kinesio taping on the BSO index, patellar tilt angle, Insall-Salvati ratio, or contact area across the 3 knee angles, whereas knee angle had a significant effect on the BSO index and contact area. A reduction in pain was observed after the application of the Kinesio taping technique. Conclusion In a weight-bearing condition, this preliminary study did not support the use of PFJ taping as a medial correction technique to alter the PFJ contact area or alignment of the patella. J Orthop Sports Phys Ther 2017

Zoledronic acid preserves bone structure and increases survival but does not limit tumour incidence in a prostate cancer bone metastasis model.

Directory of Open Access Journals (Sweden)

Tzong-Tyng Hung

Full Text Available BACKGROUND: The bisphosphonate, zoledronic acid (ZOL, can inhibit osteoclasts leading to decreased osteoclastogenesis and osteoclast activity in bone. Here, we used a mixed osteolytic/osteoblastic murine model of bone-metastatic prostate cancer, RM1(BM, to determine how inhibiting osteolysis with ZOL affects the ability of these cells to establish metastases in bone, the integrity of the tumour-bearing bones and the survival of the tumour-bearing mice. METHODS: The model involves intracardiac injection for arterial dissemination of the RM1(BM cells in C57BL/6 mice. ZOL treatment was given via subcutaneous injections on days 0, 4, 8 and 12, at 20 and 100 µg/kg doses. Bone integrity was assessed by micro-computed tomography and histology with comparison to untreated mice. The osteoclast and osteoblast activity was determined by measuring serum tartrate-resistant acid phosphatase 5b (TRAP 5b and osteocalcin, respectively. Mice were euthanased according to predetermined criteria and survival was assessed using Kaplan Meier plots. FINDINGS: Micro-CT and histological analysis showed that treatment of mice with ZOL from the day of intracardiac injection of RM1(BM cells inhibited tumour-induced bone lysis, maintained bone volume and reduced the calcification of tumour-induced endochondral osteoid material. ZOL treatment also led to a decreased serum osteocalcin and TRAP 5b levels. Additionally, treated mice showed increased survival compared to vehicle treated controls. However, ZOL treatment did not inhibit the cells ability to metastasise to bone as the number of bone-metastases was similar in both treated and untreated mice. CONCLUSIONS: ZOL treatment provided significant benefits for maintaining the integrity of tumour-bearing bones and increased the survival of tumour bearing mice, though it did not prevent establishment of bone-metastases in this model. From the mechanistic view, these observations confirm that tumour-induced bone lysis is not a

Glucocorticoids and inhibition of bone formation induced by skeletal unloading

International Nuclear Information System (INIS)

Halloran, B.P.; Bikle, D.D.; Cone, C.M.; Morey-Holton, E.

1988-01-01

Skeletal unloading or loss of normal weight bearing in the growing animal inhibits bone formation and reduces bone calcium. To determine whether the inhibition of bone formation induced by skeletal unloading is a consequence of an increase in plasma glucocorticoids and/or an increase in bone sensitivity to glucocorticoids, the authors measured plasma corticosterone throughout the day in unloaded and normally loaded rats (hindlimb elevation model) and examined the effect of adrenalectomy on the response of bone to skeletal unloading. Plasma corticosterone levels were similar in normally loaded and unloaded rats at all times. Skeletal unloading in sham-adrenalectomized animals reduced tibial and vertebral calcium by 11.5 and 11.1%, respectively, and in adrenalectomized animals by 15.3 and 20.3%, respectively. Uptake of 45 Ca and [ 3 H]proline in the tibia was reduced by 8 and 14%, respectively, in the sham-adrenalectomized animals and by 13 and 19% in the adrenalectomized animals. Bone formation and apposition rates were reduced to the same level in sham- and adrenalectomized animals. These results suggest that the inhibition of bone formation induced by skeletal unloading is not a consequence of increased plasma glucocorticoids or an increase in bone sensitivity to the glucocorticoids but, rather, point to a local mediator in bone that senses mechanical load and transmits that information to the bone-forming cells directly

Anorexia Nervosa and Bone

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Misra, Madhusmita; Klibanski, Anne

2014-01-01

Anorexia nervosa (AN) is a condition of severe low weight that is associated with low bone mass, impaired bone structure and reduced bone strength, all of which contribute to increased fracture risk., Adolescents with AN have decreased rates of bone accrual compared with normal-weight controls, raising addition concerns of suboptimal peak bone mass and future bone health in this age group. Changes in lean mass and compartmental fat depots, hormonal alterations secondary to nutritional factors contribute to impaired bone metabolism in AN. The best strategy to improve bone density is to regain weight and menstrual function. Oral estrogen-progesterone combinations are not effective in increasing bone density in adults or adolescents with AN, and transdermal testosterone replacement is not effective in increasing bone density in adult women with AN. However, physiologic estrogen replacement as transdermal estradiol with cyclic progesterone does increase bone accrual rates in adolescents with AN to approximate that in normal-weight controls, leading to a maintenance of bone density Z-scores. A recent study has shown that risedronate increases bone density at the spine and hip in adult women with AN. However, bisphosphonates should be used with great caution in women of reproductive age given their long half-life and potential for teratogenicity, and should be considered only in patients with low bone density and clinically significant fractures when non-pharmacological therapies for weight gain are ineffective. Further studies are necessary to determine the best therapeutic strategies for low bone density in AN. PMID:24898127

Penile density and globally used chemicals in Canadian and Greenland polar bears

DEFF Research Database (Denmark)

Sonne, Christian; Dyck, Markus; Rigét, Frank F.

2015-01-01

-range dispersed and to biomagnify to very high concentrations in the tissues of Arctic apex predators such as polar bears (Ursus maritimus). A major concern relating to EDCs is their effects on vital organ-tissues such as bone and it is possible that EDCs represent a more serious challenge to the species......' survival than the more conventionally proposed prey reductions linked to climate change. We therefore analyzed penile bone mineral density (BMD) as a key phenotype for reproductive success in 279 polar bear samples born 1990-2000 representing eight polar bear subpopulations. Since EDC concentrations were...... not available from the same specimens, we compared BMD with published literature information on EDC concentrations. Latitudinal and longitudinal BMD and EDC gradients were clearly observed, with Western Hudson bears having the highest BMD and lowest EDCs, and North East Greenland polar bears carrying the lowest...

Role of apparent diffusion coefficients with diffusion-weighted magnetic resonance imaging in differentiating between benign and malignant bone tumors.

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Wang, Tingting; Wu, Xiangru; Cui, Yanfen; Chu, Caiting; Ren, Gang; Li, Wenhua

2014-11-29

Benign and malignant bone tumors can present similar imaging features. This study aims to evaluate the significance of apparent diffusion coefficients (ADC) in differentiating between benign and malignant bone tumors. A total of 187 patients with 198 bone masses underwent diffusion-weighted (DW) magnetic resonance (MR) imaging. The ADC values in the solid components of the bone masses were assessed. Statistical differences between the mean ADC values in the different tumor types were determined by Student's t-test. Histological analysis showed that 84/198 (42.4%) of the bone masses were benign and 114/198 (57.6%) were malignant. There was a significant difference between the mean ADC values in the benign and malignant bone lesions (Pbenign and malignant bone tumors.

Protecting Bone Health in Pediatric Rheumatic Diseases: Pharmacological Considerations.

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Zhang, Yujuan; Milojevic, Diana

2017-06-01

Bone health in children with rheumatic conditions may be compromised due to several factors related to the inflammatory disease state, delayed puberty, altered life style, including decreased physical activities, sun avoidance, suboptimal calcium and vitamin D intake, and medical treatments, mainly glucocorticoids and possibly some disease-modifying anti-rheumatic drugs. Low bone density or even fragility fractures could be asymptomatic; therefore, children with diseases of high inflammatory load, such as systemic onset juvenile idiopathic arthritis, juvenile dermatomyositis, systemic lupus erythematosus, and those requiring chronic glucocorticoids may benefit from routine screening of bone health. Most commonly used assessment tools are laboratory testing including serum 25-OH-vitamin D measurement and bone mineral density measurement by a variety of methods, dual-energy X-ray absorptiometry as the most widely used. Early disease control, use of steroid-sparing medications such as disease-modifying anti-rheumatic drugs and biologics, supplemental vitamin D and calcium, and promotion of weight-bearing physical activities can help optimize bone health. Additional treatment options for osteoporosis such as bisphosphonates are still controversial in children with chronic rheumatic diseases, especially those with decreased bone density without fragility fractures. This article reviews common risk factors leading to compromised bone health in children with chronic rheumatic diseases and discusses the general approach to prevention and treatment of bone fragility.

Big bearings. Unsung hero; Kyodaina jikuuke. Hitome ni tsukanai hatarakimono

Energy Technology Data Exchange (ETDEWEB)

Nanba, S. [Koyo Seiko Co. Ltd., Osaka (Japan)

1997-03-05

This paper introduces examples of the use of big bearings. Bearings are divided largely into those used for radial load supporting and those used for thrust load supporting, while big bearings are often used for the latter usage. Thrust bearings include a cutter heat supporting bearing for tunnel excavator working underground, in addition to those used for swing motion of parabolic antennas and tower cranes. A bearing used in an excavator has an outer diameter of about half that of the excavator. The outer diameter of a shielding machine practically used in tunnel drilling currently has an outer diameter of 14,140 mm, and the outer diameter of the bearing is 7200 mm (bearing weighing 45 tons). Other big thrust bearings may include a swing tower swinging thrust bearing used in a continuous casting facility. Big radial bearings are used in iron and steel making facilities. This paper describes two examples of bearings used in this application. A spherical roller bearing to support converter trunion should be of an ultra big size to withstand total weight of about 1400 tons composed of a converter weight and weight of steel to be processed. A four-row cylindrical roller bearing to support the backup roll of a thick plate rolling mill is a bearing with durability against large loads to support reduction rolls whose size have become increasingly large. 2 refs., 5 figs.

A simulator study of adverse wear with metal and cement debris contamination in metal-on-metal hip bearings.

Science.gov (United States)

Halim, T; Clarke, I C; Burgett-Moreno, M D; Donaldson, T K; Savisaar, C; Bowsher, J G

2014-03-01

Third-body wear is believed to be one trigger for adverse results with metal-on-metal (MOM) bearings. Impingement and subluxation may release metal particles from MOM replacements. We therefore challenged MOM bearings with relevant debris types of cobalt-chrome alloy (CoCr), titanium alloy (Ti6Al4V) and polymethylmethacrylate bone cement (PMMA). Cement flakes (PMMA), CoCr and Ti6Al4V particles (size range 5 µm to 400 µm) were run in a MOM wear simulation. Debris allotments (5 mg) were inserted at ten intervals during the five million cycle (5 Mc) test. In a clean test phase (0 Mc to 0.8 Mc), lubricants retained their yellow colour. Addition of metal particles at 0.8 Mc turned lubricants black within the first hour of the test and remained so for the duration, while PMMA particles did not change the colour of the lubricant. Rates of wear with PMMA, CoCr and Ti6Al4V debris averaged 0.3 mm(3)/Mc, 4.1 mm(3)/Mc and 6.4 mm(3)/Mc, respectively. Metal particles turned simulator lubricants black with rates of wear of MOM bearings an order of magnitude higher than with control PMMA particles. This appeared to model the findings of black, periarticular joint tissues and high CoCr wear in failed MOM replacements. The amount of wear debris produced during a 500 000-cycle interval of gait was 30 to 50 times greater than the weight of triggering particle allotment, indicating that MOM bearings were extremely sensitive to third-body wear. Cite this article: Bone Joint Res 2015;4:29-37. ©2015 The British Editorial Society of Bone & Joint Surgery.

High-fat-diet-induced weight gain ameliorates bone loss without exacerbating AβPP processing and cognition in female APP/PS1 mice

Directory of Open Access Journals (Sweden)

Yunhua ePeng

2014-08-01

Full Text Available Osteoporosis is negatively correlated with body mass, whereas both osteoporosis and weight loss occur at higher incidence during the progression of Alzheimer’s disease (AD than the age-matched non-dementia individuals. Given that there is no evidence that overweight associated with AD-type cognitive dysfunction, we hypothesized that moderate weight gain might have a protective effect on the bone loss in AD without exacerbating cognitive dysfunction. In the present study, feeding a high-fat-diet (HFD, 45% calorie from fat to female APP/PS1 transgenic mice, an AD animal model, induced weight gain. The bone mineral density, microarchitecture, and biomechanical properties of the femurs were then evaluated. The results showed that the middle-aged female APP/PS1 transgenic mice were susceptible to osteoporosis of the femoral bones and that weight gain significantly enhanced bone mass and mechanical properties. Notably, HFD was not detrimental to brain insulin signaling and AβPP processing, as well as to exploration ability and working, learning and memory performance of the transgenic mice measured by T maze and water maze, compared with the mice fed a normal fat diet (10% calorie from fat. In addition, the circulating levels of leptin but not estradiol were remarkably elevated in HFD-treated mice. These results suggest that a body weight gain induced by the HFD feeding regimen significantly improved bone mass in female APP/PS1 mice with no detriments to exploration ability and spatial memory, most likely via the action of elevated circulating leptin.

Adhesive strength of bone-implant interfaces and in-vivo degradation of PHB composites for load-bearing applications.

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Meischel, M; Eichler, J; Martinelli, E; Karr, U; Weigel, J; Schmöller, G; Tschegg, E K; Fischerauer, S; Weinberg, A M; Stanzl-Tschegg, S E

2016-01-01

Aim of this study was to evaluate the response of bone to novel biodegradable polymeric composite implants in the femora of growing rats. Longitudinal observation of bone reaction at the implant site (BV/TV) as well as resorption of the implanted pins were monitored using in vivo micro-focus computed tomography (µCT). After 12, 24 and 36 weeks femora containing the implants were explanted, scanned with high resolution ex vivo µCT, and the surface roughness of the implants was measured to conclude on the ingrowth capability for bone tissue. Scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to observe changes on the surface of Polyhydroxybutyrate (PHB) during degradation and cell ingrowth. Four different composites with zirconium dioxide (ZrO2) and Herafill(®) were compared. After 36 weeks in vivo, none of the implants did show significant degradation. The PHB composite with ZrO2 and a high percentage (30%) of Herafill® as well as the Mg-alloy WZ21 showed the highest values of bone accumulation (increased BV/TV) around the implant. The lowest value was measured in PHB with 3% ZrO2 containing no Herafill®. Roughness measurements as well as EDX and SEM imaging could not reveal any changes on the PHB composites׳ surfaces. Biomechanical parameters, such as the adhesion strength between bone and implant were determined by measuring the shear strength as well as push-out energy of the bone-implant interface. The results showed that improvement of these mechanical properties of the studied PHBs P3Z, P3Z10H and P3Z30H is necessary in order to obtain appropriate load-bearing material. The moduli of elasticity, tensile strength and strain properties of the PHB composites are close to that of bone and thus promising. Compared to clinically used PLGA, PGA and PLA materials, their additional benefit is an unchanged local pH value during degradation, which makes them well tolerated by cells and immune system. They might be used

3D artificial bones for bone repair prepared by computed tomography-guided fused deposition modeling for bone repair.

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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.

Ideal Timing of Starting Weight-Bearing After Calcaneal Insufficiency Fracture: A Case Report and Review of the Literature

OpenAIRE

Imamura; Mochizuki; Kawakami; Momohara

2016-01-01

Introduction Criteria for starting weight-bearing on the heel with a symptomatic calcaneal insufficiency fracture have not yet been reported. Case Presentation We describe a rare case of a 52-year-old woman with a calcaneal insufficiency fracture who sustained a second ipsilateral calcaneal insufficiency fracture within a short time span. The initial fracture was not evident radiographically, but was detected using magnetic resona...

Bone metabolism in adolescent girls with eating disorders and weight loss: independent effects of weight change, insulin-like growth factor-1 and oestradiol.

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Swenne, Ingemar; Stridsberg, Mats

2015-03-01

Adolescents with eating disorders (ED) are at risk of developing osteoporosis if weight is not recovered. Previous investigations do not separate the effects of weight change per se from those of concomitant hormonal changes. In this investigation serum osteocalcin (OC), C-terminal telopeptide of collagen (CTX), insulin-like growth factor-1 (IGF-1) and oestradiol were measured at assessment of 498 girls with ED and during weight gain of 59 girls. At assessment, OC concentrations were associated independently with weight (change), IGF-1 and oestradiol. Low weight, a high rate of weight loss and the hormone concentrations were associated with low OC. Low weight and high rate of weight loss were associated with high CTX concentrations but there were no associations independent of weight (change) with the hormones. During weight recovery, OC and CTX were independently and positively associated with weight, weight gain, IGF-1 and oestradiol. Bone metabolism markers are related to weight change independently of IGF-1 and oestradiol during both weight loss and weight gain. During weight gain, when pubertal development and growth are resumed there is an additional independent positive association between the markers and IGF-1 and oestradiol. These relationships are strongest in premenarcheal girls.

Experimental Traumatic Brain Injury Induces Bone Loss in Rats.

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Brady, Rhys D; Shultz, Sandy R; Sun, Mujun; Romano, Tania; van der Poel, Chris; Wright, David K; Wark, John D; O'Brien, Terence J; Grills, Brian L; McDonald, Stuart J

2016-12-01

Few studies have investigated the influence of traumatic brain injury (TBI) on bone homeostasis; however, pathophysiological mechanisms involved in TBI have potential to be detrimental to bone. The current study assessed the effect of experimental TBI in rats on the quantity and quality of two different weight-bearing bones, the femur and humerus. Rats were randomly assigned into either sham or lateral fluid percussion injury (FPI) groups. Open-field testing to assess locomotion was conducted at 1, 4, and 12 weeks post-injury, with the rats killed at 1 and 12 weeks post-injury. Bones were analyzed using peripheral quantitative computed tomography (pQCT), histomorphometric analysis, and three-point bending. pQCT analysis revealed that at 1 and 12 weeks post-injury, the distal metaphyseal region of femora from FPI rats had reduced cortical content (10% decrease at 1 week, 8% decrease at 12 weeks; p in trabecular bone volume ratio at 1 week post-injury and a 27% reduction at 12 weeks post-injury in FPI rats compared to sham (p in bone quantity and mechanical properties of the femoral midshaft between sham and TBI animals. There were no differences in locomotor outcomes, which suggested that post-TBI changes in bone were not attributed to immobility. Taken together, these findings indicate that this rat model of TBI was detrimental to bone and suggests a link between TBI and altered bone remodeling.

Sustainable approach for recycling waste lamb and chicken bones for fluoride removal from water followed by reusing fluoride-bearing waste in concrete.

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Ismail, Zainab Z; AbdelKareem, Hala N

2015-11-01

Sustainable management of waste materials is an attractive approach for modern societies. In this study, recycling of raw waste lamb and chicken bones for defluoridation of water has been estimated. The effects of several experimental parameters including contact time, pH, bone dose, fluoride initial concentration, bone grains size, agitation rate, and the effect of co-existing anions in actual samples of wastewater were studied for fluoride removal from aqueous solutions. Results indicated excellent fluoride removal efficiency up to 99.4% and 99.8% using lamb and chicken bones, respectively at fluoride initial concentration of 10 mg F/L and 120 min contact time. Maximum fluoride uptake was obtained at neutral pH range 6-7. Fluoride removal kinetic was well described by the pseudo-second order kinetic model. Both, Langmuir and Freundlich isotherm models could fit the experimental data well with correlation coefficient values >0.99 suggesting favorable conditions of the process. Furthermore, for complete sustainable management of waste bones, the resulted fluoride-bearing sludge was reused in concrete mixes to partially replace sand. Tests of the mechanical properties of fluoride sludge-modified concrete mixes indicated a potential environmentally friendly approach to dispose fluoride sludge in concrete and simultaneously enhance concrete properties. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of cast-mediated immobilization on bone mineral mass at various sites in adolescents with lower-extremity fracture.

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Ceroni, Dimitri; Martin, Xavier; Delhumeau, Cécile; Rizzoli, René; Kaelin, André; Farpour-Lambert, Nathalie

2012-02-01

Leg or ankle fractures occur commonly in the pediatric population and are primarily treated with closed reduction and cast immobilization. The most predictable consequences of immobilization and subsequent weight-bearing restriction are loss of bone mineral mass, substantial muscle atrophy, and functional limitations. The purposes of this study were to determine if lower-limb fractures in adolescents are associated with abnormal bone mineral density or content at the time of fracture, and to quantify bone mineral loss at various sites due to cast-mediated immobilization and limited weight-bearing. We recruited fifty adolescents aged ten to sixteen years who had undergone cast immobilization for a leg or ankle fracture. Dual x-ray absorptiometry scans of the total body, lumbar spine, hip, leg, and calcaneus were performed at the time of fracture and at cast removal. Patients with a fracture were paired with healthy controls according to sex and age. Values at baseline and at cast removal, or at equivalent time intervals in the control group, were compared between groups and between the injured and uninjured legs of the adolescents with the fracture. At the time of fracture, there were no observed differences in the bone mineral density or bone mineral content Z-scores of the total body or the lumbar spine, or in the bone mineral density Z-scores of the calcaneus, between the injured and healthy subjects. At cast removal, bone mineral parameters on the injured side were significantly lower than those on the uninjured side in the injured group. Differences ranged from -5.8% to -31.7% for bone mineral density and from -5.2% to -19.4% for bone mineral content. During the cast period, the injured adolescents had a significant decrease of bone mineral density at the hip, greater trochanter, calcaneus, and total lower limb as compared with the healthy controls. Lower-limb fractures are not related to osteopenia in adolescents at the time of fracture. However, osteopenia

Bone health in children and adolescents with perinatal HIV infection

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Puthanakit, Thanyawee; Siberry, George K

2013-01-01

The long-term impact on bone health of lifelong HIV infection and prolonged ART in growing and developing children is not yet known. Measures of bone health in youth must be interpreted in the context of expected developmental and physiologic changes in bone mass, size, density and strength that occur from fetal through adult life. Low bone mineral density (BMD) appears to be common in perinatally HIV-infected youth, especially outside of high-income settings, but data are limited and interpretation complicated by the need for better pediatric norms. The potential negative effects of tenofovir on BMD and bone mass accrual are of particular concern as this drug may be used more widely in younger children. Emphasizing good nutrition, calcium and vitamin D sufficiency, weight-bearing exercise and avoidance of alcohol and smoking are effective and available approaches to maintain and improve bone health in all settings. More data are needed to inform therapies and monitoring for HIV-infected youth with proven bone fragility. While very limited data suggest lack of marked increase in fracture risk for youth with perinatal HIV infection, the looming concern for these children is that they may fail to attain their expected peak bone mass in early adulthood which could increase their risk for fractures and osteoporosis later in adulthood. PMID:23782476

Electrospun Hydroxyapatite-Containing Chitosan Nanofibers Crosslinked with Genipin for Bone Tissue Engineering

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Frohbergh, Michael E.; Katsman, Anna; Botta, Gregory P.; Lazarovici, Phillip; Schauer, Caroline L.; Wegst, Ulrike G. K.; Lelkes, Peter I.

2012-01-01

Reconstruction of large bone defects remains problematic in orthopedic and craniofacial clinical practice. Autografts are limited in supply and are associated with donor site morbidity while other materials show poor integration with the host’s own bone. This lack of integration is often due to the absence of periosteum, the outer layer of bone that contains osteoprogenitor cells and is critical for the growth and remodeling of bone tissue. In this study we developed a one-step platform to electrospin nanofibrous scaffolds from chitosan, which also contain hydroxyapatite nanoparticles and are crosslinked with genipin. We hypothesized that the resulting composite scaffolds represent a microenvironment that emulates the physical, mineralized structure and mechanical properties of non-weight bearing bone extracellular matrix while promoting osteoblast differentiation and maturation similar to the periosteum. The ultrastructure and physicochemical properties of the scaffolds were studied using scanning electron microscopy and spectroscopic techniques. The average fiber diameters of the electrospun scaffolds were 227±154 nm as spun, and increased to 335±119 nm after crosslinking with genipin. Analysis by X-ray diffraction, Fourier transformed infrared spectroscopy and energy dispersive spectroscopy confirmed the presence of characteristic features of hydroxyapatite in the composite chitosan fibers. The Young’s modulus of the composite fibrous scaffolds was 142±13 MPa, which is similar to that of the natural periosteum. Both pure chitosan scaffolds and composite hydroxyapatite-containing chitosan scaffolds supported adhesion, proliferation and osteogenic differentiation of mouse 7F2 osteoblast-like cells. Expression and enzymatic activity of alkaline phosphatase, an early osteogenic marker, were higher in cells cultured on the composite scaffolds as compared to pure chitosan scaffolds, reaching a significant, 2.4 fold, difference by day 14 (phydroxyapatite

Black bear parathyroid hormone has greater anabolic effects on trabecular bone in dystrophin-deficient mice than in wild type mice.

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Gray, Sarah K; McGee-Lawrence, Meghan E; Sanders, Jennifer L; Condon, Keith W; Tsai, Chung-Jui; Donahue, Seth W

2012-09-01

Duchenne muscular dystrophy (DMD) is an X-linked neuromuscular disease that has deleterious consequences in muscle and bone, leading to decreased mobility, progressive osteoporosis, and premature death. Patients with DMD experience a higher-than-average fracture rate, particularly in the proximal and distal femur and proximal tibia. The dystrophin-deficient mdx mouse is a model of DMD that demonstrates muscle degeneration and fibrosis and osteoporosis. Parathyroid hormone, an effective anabolic agent for post-menopausal and glucocorticoid-induced osteoporosis, has not been explored for DMD. Black bear parathyroid hormone (bbPTH) has been implicated in the maintenance of bone properties during extended periods of disuse (hibernation). We cloned bbPTH and found 9 amino acid residue differences from human PTH. Apoptosis was mitigated and cAMP was activated by bbPTH in osteoblast cultures. We administered 28nmol/kg of bbPTH 1-84 to 4-week old male mdx and wild type mice via daily (5×/week) subcutaneous injection for 6 weeks. Vehicle-treated mdx mice had 44% lower trabecular bone volume fraction than wild type mice. No changes were found in femoral cortical bone geometry or mechanical properties with bbPTH treatment in wild type mice, and only medio-lateral moment of inertia changed with bbPTH treatment in mdx femurs. However, μCT analyses of the trabecular regions of the distal femur and proximal tibia showed marked increases in bone volume fraction with bbPTH treatment, with a greater anabolic response (7-fold increase) in mdx mice than wild type mice (2-fold increase). Trabecular number increased in mdx long bone, but not wild type bone. Additionally, greater osteoblast area and decreased osteoclast area were observed with bbPTH treatment in mdx mice. The heightened response to PTH in mdx bone compared to wild type suggests a link between dystrophin deficiency, altered calcium signaling, and bone. These findings support further investigation of PTH as an anabolic

The role of physical activity in bone health: a new hypothesis to reduce risk of vertebral fracture.

Science.gov (United States)

Sinaki, Mehrsheed

2007-08-01

Locomotion has always been a major criterion for human survival. Thus, it is no surprise that science supports the dependence of bone health on weight-bearing physical activities. The effect of physical activity on bone is site-specific. Determining how to perform osteogenic exercises, especially in individuals who have osteopenia or osteoporosis, without exceeding the biomechanical competence of bone always poses a dilemma and must occur under medical advice. This article presents the hypothesis that back exercises performed in a prone position, rather than a vertical position, may have a greater effect on decreasing the risk for vertebral fractures without resulting in compression fracture. The risk for vertebral fractures can be reduced through improvement in the horizontal trabecular connection of vertebral bodies.

Effects of Zinc Compound on Body Weight and Recovery of Bone Marrow in Mice Treated with Total Body Irradiation

Directory of Open Access Journals (Sweden)

Ming-Yii Huang

2007-09-01

Full Text Available This study aimed to investigate if zinc compound would have effects on body weight loss and bone marrow suppression induced by total body irradiation (TBI. ICR mice were divided randomly into two groups and treated with test or control compounds. The test compound contained zinc (amino acid chelated with bovine prostate extract, and the control was reverse osmosis pure water (RO water. One week after receiving the treatment, mice were unirradiated, or irradiated with 6 or 3 Gy by 6MV photon beams to the total body. Body weight changes were examined at regular intervals. Three and 5 weeks after the radiation, animals were sacrificed to examine the histologic changes in the bone marrow. Lower body weight in the period of 1-5 weeks after radiation and poor survival rate were found after the 6 Gy TBI, as compared with the 3 Gy groups. The median survival time after 6 Gy and 3 Gy TBI for mice given the test compound were 26 and 76 days, respectively, and the corresponding figures were 14 and 70 days, respectively, for mice given the control compound (p < 0.00001. With zinc supplement, the mean body weight in mice which received the same dose of radiation was 7-8 g heavier than in the water-supplement groups during the second and third weeks (p < 0.05. Hence, there was no statistically significant difference in survival rate between zinc and water supplement in mice given the same dose of irradiation. Histopathologically there was less recovery of bone marrow cells in the 6Gy groups compared with the 3Gy groups. In the 3 Gy water-supplement group, the nucleated cells and megakaryocytes were recovered in the fifth week when recovery was still not seen in the 6Gy group. With zinc supplement, these cells were recovered in the third week. In this study, we found that zinc is beneficial to body weight in mice treated with TBI. Histologic examination of bone marrow showed better recovery of bone marrow cells in groups of mice fed with zinc. This study

A semi-analytical bearing model considering outer race flexibility for model based bearing load monitoring

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Kerst, Stijn; Shyrokau, Barys; Holweg, Edward

2018-05-01

This paper proposes a novel semi-analytical bearing model addressing flexibility of the bearing outer race structure. It furthermore presents the application of this model in a bearing load condition monitoring approach. The bearing model is developed as current computational low cost bearing models fail to provide an accurate description of the more and more common flexible size and weight optimized bearing designs due to their assumptions of rigidity. In the proposed bearing model raceway flexibility is described by the use of static deformation shapes. The excitation of the deformation shapes is calculated based on the modelled rolling element loads and a Fourier series based compliance approximation. The resulting model is computational low cost and provides an accurate description of the rolling element loads for flexible outer raceway structures. The latter is validated by a simulation-based comparison study with a well-established bearing simulation software tool. An experimental study finally shows the potential of the proposed model in a bearing load monitoring approach.

EFFECTS OF RUN TRAINING ON BONE DEVELOPMENT AND BONE MINERALIZATION IN GROWING MICE

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B Gönül

2011-06-01

Full Text Available We planned to study the body weights, bone sizes and bone mineral (Ca, Mg, Zn contents of growing mice subjected to treadmill training. Twelve 4-week-old male Swiss Albino mice were divided into sedentary and exercise groups. The mice were trained by running exercise on a flat bed treadmill with 15 m/min, 30 min/day motion, throughout 5 days per week, for 12 weeks. The body weight of animals, and length, fat-free dry weight and Ca, Mg, and Zn contents of bones were measured in both groups. Body weights of animals, and lengths and wet and dry weights of the femur and the tibia were significantly higher in the exercised group. Also, the Zn, Mg and Ca mineral contents of bones in the group that underwent exercise were higher than in the other group. Running exercise with a flat bed treadmill performed by the growing mice is an effective exercise mode, especially for bone morphology.

Spotted hyena and steppe lion predation behaviours on cave bears of Europe - ?Late Quaternary cave bear extinction as result of predator stress

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Diedrich, Cajus G.

2010-05-01

Cave bears hibernated in caves all over Eurasia (e.g. Rabeder et al., 2000) including alpine regions using mainly larger caves for this purpose. Late Quaternary spotted hyenas Crocuta crocuta spelaea instead occupied mainly areas close to the cave entrances as their dens (Diedrich and Žák 2006, Diedrich 2010). The largest predator, the steppe lion Panthera leo spelaea was only a sporadic cave dweller (Diedrich 2007b, 2009b). His presence and its remains from caves all over Europe can be recently explained best as result of imported carcasses after killing by their largest antagonists, the Late Quaternary spotted hyenas. In some cases the kill might have happened in the hyena den cave itself during the theft of prey remains by lions (Diedrich 2009a). Another reason of their remains in caves of Europe is the hunting onto the herbivorous cave bears, especially during hibernation times, when megafauna prey was less available in the open environments (Diedrich 2009c). These lion remains from caves of Europe, nearly all of which were from adult animals, provide evidence of active predation by lions onto cave bears even in medium high alpine regions (Diedrich 2009b, in review). Lion skeletons in European cave bear dens were therefore often found amongst originally articulated cave bear skeletons or scattered cave bear remains and even close to their hibernation nests (Diedrich et al. 2009c, in review). Not only lions fed on cave bears documented mainly by the large quantities of chewed, punctured and crushed cave bear long-bones; even damaged skulls reveal that hyenas scavenged primarily on cave bear carcasses which were mainly responsible for the destruction of their carcasses and bones (Diedrich 2005, 2009d). Predation and scavenging on cave bears by the two largest Late Quaternary predators C. c. spelaea and P. l. spelaea explains well the large quantity of fragmented cave bear bones over all European caves in low to medium high mountainous elevations, whereas in

Development of Composite Scaffolds for Load Bearing Segmental Bone Defects

Science.gov (United States)

2013-07-01

osteoarthritis [24], generic infections, congenital deformity corrections [25], pathological degenerative bone destruction and other degenerative diseases [20...resection and reconstruction), osteoporosis, osteoarthritis , generic infections, congenital deformity corrections, pathological degenerative bone...the construct. Pore size/ Porosity: Quality of a bone scaffold to have pore size and porosity percent similar to established guidelines . Ideal

Primary observation on the effect of APBMV on tumor weight and general physical condition of hepatoma 22-bearing mice after radiotherapy

International Nuclear Information System (INIS)

Kong Tianhan; Wei Ling; Han Xuefei; Dong Weihua

2000-01-01

Objective: To observe the effect of antineoplastic polypeptide from buthus martensii venom (APBMV) combined with radiotherapy on hepatoma-bearing mouse. Methods: Hundreds H22-bearing mice were used in this experiment. The tumor growth inhibiting rate (IR%), WBC count, hemoglobin content, activity of superoxide dismutase (SOD), level of lipid peroxide (LPO) and spleens index (SI) were used as the parameters. After radiotherapy (RT) or after administration of different dosage of APBMV combined with RT, the changes of these parameters were observed. Results: On the 6th and 9th day after radiotherapy, the tumor weights decreased after administrating APBMV combined with RT, in which IR were 78.29% and 70.45%, respectively (comparing with RT and APBMV group, P 0.05) among all groups. SOD activity was the lowest and LPO level was the highest in RT group (comparing with the control group, P 22 -bearing mice, SOD activity increased and LPO level decreased evidently (comparing with RT group, P 22 was stronger than radiation or APBMV alone. APBMV can also antagonize radiation injury on H 22 -bearing mice

Weight-Bearing Exercise and Foot Health in Native Americans.

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Cuaderes, Elena; DeShea, Lise; Lamb, W Lyndon

2014-12-01

Diabetes contributes to sensory peripheral neuropathy, which has been linked to lower limb abnormalities that raise the risk for foot ulcers and amputations. Because amputations are a reason for pain and hospitalization in those with diabetes, it is of critical importance to gain insight about prevention of ulcer development in this population. Although the American Diabetes Association (ADA) now recommends that individuals with neuropathy can engage in moderate-intensity weight-bearing activity (WBA), they must wear appropriate footwear and inspect their feet daily. The physical forces and inflammatory processes from WBA may contribute to plantar characteristics that lead to ulcers. The purpose of this study was to compare neuropathic status and foot characteristics in Native Americans according to WBA classification. The t tests for unequal sample sizes found that exercisers had more difficulty sensing baseline temperature than nonexercisers, except at the right foot (all p values Exercisers demonstrated higher surface skin temperature gradients at the first metatarsal head, a plantar site where wounds tend to form. The more consistently exercisers performed, the higher the plan-tar pressures were at the right second ( r = .24, p = .02) and third metatarsal heads ( r = .26, p = .01). Findings from this investigation do not refute current ADA recommendations and further intervention studies are needed that are longitudinal and measures WBA more accurately.

Early weight-bearing after periacetabular osteotomy leads to a high incidence of postoperative pelvic fractures.

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Ito, Hiroshi; Tanino, Hiromasa; Sato, Tatsuya; Nishida, Yasuhiro; Matsuno, Takeo

2014-07-11

It has not been shown whether accelerated rehabilitation following periacetabular osteotomy (PAO) is effective for early recovery. The purpose of this retrospective study was to compare complication rates in patients with standard and accelerated rehabilitation protocols who underwent PAO. Between January 2002 and August 2011, patients with a lateral center-edge (CE) angle of rehabilitation protocol. In 65 patients (76 hips) with the accelerated rehabilitation protocol, postoperative strengthening of the hip, thigh and core musculature was begun on the day of surgery as tolerated. The exercise program included active hip range of motion, and gentle isometric hamstring and quadriceps muscle sets; these exercises were performed for 30 minutes in the morning and 30 minutes in the afternoon with a physical therapist every weekday for 6 weeks. Full weight-bearing with two axillary crutches started on the day of surgery as tolerated. Complications were evaluated for 2 years. The clinical results at the time of follow-up were similar in the two groups. The average periods between the osteotomy and full-weight-bearing walking without support were 4.2 months and 6.9 months in patients with the accelerated and standard rehabilitation protocols (P rehabilitation protocol could achieve earlier recovery of patients. However, postoperative fractures of the ischial ramus and posterior column of the pelvis were more frequently found in patients with the accelerated rehabilitation protocol (8/76) than in those with the standard rehabilitation protocol (1/80) (P = 0.013). The accelerated rehabilitation protocol seems to have advantages for early muscle recovery in patients undergoing PAO; however, postoperative pelvic fracture rates were unacceptably high in patients with this protocol.

Contrast-enhanced Magnetic Resonance Imaging of Pelvic Bone Metastases at 3.0 T: Comparison Between 3-dimensional T1-weighted CAIPIRINHA-VIBE Sequence and 2-dimensional T1-weighted Turbo Spin-Echo Sequence.

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Yoon, Min A; Hong, Suk-Joo; Lee, Kyu-Chong; Lee, Chang Hee

2018-06-12

This study aimed to compare 3-dimensional T1-weighted gradient-echo sequence (CAIPIRINHA-volumetric interpolated breath-hold examination [VIBE]) with 2-dimensional T1-weighted turbo spin-echo sequence for contrast-enhanced magnetic resonance imaging (MRI) of pelvic bone metastases at 3.0 T. Thirty-one contrast-enhanced MRIs of pelvic bone metastases were included. Two contrast-enhanced sequences were evaluated for the following parameters: overall image quality, sharpness of pelvic bone, iliac vessel clarity, artifact severity, and conspicuity and edge sharpness of the smallest metastases. Quantitative analysis was performed by calculating signal-to-noise ratio and contrast-to-noise ratio of the smallest metastases. Significant differences between the 2 sequences were assessed. CAIPIRINHA-VIBE had higher scores for overall image quality, pelvic bone sharpness, iliac vessel clarity, and edge sharpness of the metastatic lesions, and had less artifacts (all P 0.05). Our results suggest that CAIPIRINHA-VIBE may be superior to turbo spin-echo for contrast-enhanced MRI of pelvic bone metastases at 3.0 T.

Penile density and globally used chemicals in Canadian and Greenland polar bears.

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Sonne, Christian; Dyck, Markus; Rigét, Frank F; Beck Jensen, Jens-Erik; Hyldstrup, Lars; Letcher, Robert J; Gustavson, Kim; Gilbert, M Thomas P; Dietz, Rune

2015-02-01

Industrially produced chemicals have been a major environmental concern across our entire Globe since the onset of rapid industrial development around the early 1900. Many of the substances being used are known to be endocrine disrupting chemicals (EDCs) and are also known to be long-range dispersed and to biomagnify to very high concentrations in the tissues of Arctic apex predators such as polar bears (Ursus maritimus). A major concern relating to EDCs is their effects on vital organ-tissues such as bone and it is possible that EDCs represent a more serious challenge to the species' survival than the more conventionally proposed prey reductions linked to climate change. We therefore analyzed penile bone mineral density (BMD) as a key phenotype for reproductive success in 279 polar bear samples born 1990-2000 representing eight polar bear subpopulations. Since EDC concentrations were not available from the same specimens, we compared BMD with published literature information on EDC concentrations. Latitudinal and longitudinal BMD and EDC gradients were clearly observed, with Western Hudson bears having the highest BMD and lowest EDCs, and North East Greenland polar bears carrying the lowest BMD and highest EDCs. A BMD vs. polychlorinated biphenyls (PCB) regression analysis showed that BMD decreased as a function of the eight subpopulations' PCB concentrations and this relationship was close to being significant (p=0.10, R(2)=0.39). Risk quotient (RQ) estimation demonstrated that PCBs could be in a range that may lead to disruption of normal reproduction and development. It is therefore likely that EDCs directly affect development and bone density in polar bears. Canadian bears had in general the best health and the North East Greenland subpopulation being at the highest risk of having negative health effects. While reductions in BMD is in general unhealthy, reductions in penile BMD could lead to increased risk of species extinction because of mating and subsequent

The Immediate Effect of a Textured Insole in Nonparetic Lower Limb Symmetry of Weight Bearing and Gait Parameters in Patients with Chronic Stroke

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Mehdi Hassan Abadi

2016-04-01

Conclusion The current study showed that obligatory use of affected limb side could improve symmetry of weight bearing in walking and standing position of patients with chronic stroke by overcoming the phenomenon of learned lack of using and correcting the failure of sending sensory signals to centers of movement controls. The results of this study showed that unilateral use of textured insole with shore A-80 in the unaffected side could immediately improve weight bearing symmetry and step length symmetry in patients with hemiparesis, but it has no effect on their walking speed and step length. Using insole with A-60 hardness did not significantly change any variables of tests. Considering the results of this study, these insoles can be used in balance exercises and walking of hemiparetic patients.

Exercise and bone mass in adults.

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Guadalupe-Grau, Amelia; Fuentes, Teresa; Guerra, Borja; Calbet, Jose A L

2009-01-01

decreasing fracture risk. Older men have been less studied than women, and although it seems that men may respond better than their female counterparts, the experimental evidence for a dimorphism based on sex in the osteogenic response to exercise in the elderly is weak. A randomized longitudinal study of the effects of exercise on bone mass in elderly men and women is still lacking. It remains to be determined if elderly females need a different exercise protocol compared with men of similar age. Impact and resistance exercise should be advocated for the prevention of osteoporosis. For those with osteoporosis, weight-bearing exercise in general, and resistance exercise in particular, as tolerated, along with exercise targeted to improve balance, mobility and posture, should be recommended to reduce the likelihood of falling and its associated morbidity and mortality. Additional randomized controlled trials are needed to determine the most efficient training loads depending on age, sex, current bone mass and training history for improvement of bone mass.

BONES WITH BIOCERAMICS

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Wijianto Wijianto

2017-01-01

Full Text Available This paper discuss about ceramics in application as bone implant. Bioceramics for instance Hydroxyapatite, usually is abbreviated with HA or HAp, is a mineral that is very good physical properties as bone replacement in human body. To produce Hydroxyapatite, coating process is used which have good potential as they can exploit the biocompatible and bone bonding properties of the ceramic. There are many advantages and disadvantages of bioceramics as bone implant. Advantages of hydroxyapatite as bone implant are rapidly integrated into the human body, and is most interesting property that will bond to bone forming indistinguishable unions. On contrary, disadvantages of hydroxyapatite as bone implant are poor mechanical properties (in particular fatigue properties mean that hydroxyapatite cannot be used in bulk form for load bearing applications such as orthopaedics and poor adhesion between the calcium phosphate coating and the material implant will occur.

SPECIFIC SITES OF BONE EXPANSION DEPEND ON THE LEVEL OF VOLLEYBALL PRACTICE IN PREPUBESCENT BOYS

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Hamada Chaari

2013-06-01

Full Text Available The purpose of this study was to investigate the effect of 18 months of high and low levels of volleyball practice on bone acquisition. 130 prepubescent boys (mean age 11.4 ± 0.7 were divided into a high-level training group (HLG, low-level training group (LLG, and controls. Bone mineral content (BMC and bone area at the whole body, lumbar spine L2-L4, femoral neck of the dominant leg, and right and left radius were measured using dual-photon X-ray absorptiometry. Enhanced BMC resulted from high-training volleyball activity in all measured sites except the third left and right distal radius, which is not modified by low-level training in prepubescent players but it was accompanied by a bone area expansion in radius and weight-bearing sites for the HLG, and in legs, whole right and left radius for the LLG. Significant improvement of skeletal tissues is associated with the intensity and duration of volleyball training.

Extensive Bone Reaction From Catastrophic Oxidized Zirconium Wear.

Science.gov (United States)

Cassar-Gheiti, Adrian J; Collins, Dennis; McCarthy, Tom

2016-01-01

The use of alternative bearing surfaces for total hip arthroplasty has become popular to minimize wear and increase longevity, especially in young patients. Oxidized zirconium (Oxinium; Smith & Nephew, Memphis, Tennessee) femoral heads were introduced in the past decade for use in total hip arthroplasty. The advantages of oxidized zirconium include less risk of fracture compared with traditional ceramic heads. This case report describes a patient with a history of bilateral avascular necrosis of the femoral head after chemotherapy for acute lymphoblastic leukemia. Nonoperative management of avascular necrosis failed, and the patient was treated with bilateral total hip arthroplasty. The patient was followed at regular intervals and had slow eccentric polyethylene wear during a 10-year period. After 10 years, the patient had accelerated wear, with femoral and acetabular bone changes as a result of Oxinium and ultrahigh-molecular-weight polyethylene wear during a 6-month period. This article highlights the unusual accelerated bone changes that occurred as a result of Oxinium wear particles. Copyright 2016, SLACK Incorporated.

Prolificacy and Its Relationship with Age, Body Weight, Parity, Previous Litter Size and Body Linear Type Traits in Meat-type Goats

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Avijit Haldar

2014-05-01

Full Text Available Data on age and body weight at breeding, parity, previous litter size, days open and some descriptive body linear traits from 389 meat-type, prolific Black Bengal goats in Tripura State of India, were collected for 3 and 1/2 years (2007 to 2010 and analyzed using logistic regression model. The objectives of the study were i to evaluate the effect of age and body weight at breeding, parity, previous litter size and days open on litter size of does; and ii to investigate if body linear type traits influenced litter size in meat-type, prolific goats. The incidence of 68.39% multiple births with a prolificacy rate of 175.07% was recorded. Higher age (>2.69 year, higher parity order (>2.31, more body weight at breeding (>20.5 kg and larger previous litter size (>1.65 showed an increase likelihood of multiple litter size when compared to single litter size. There was a strong, positive relationship between litter size and various body linear type traits like neck length (>22.78 cm, body length (>54.86 cm, withers height (>48.85 cm, croup height (>50.67 cm, distance between tuber coxae bones (>11.38 cm and distance between tuber ischii bones (>4.56 cm for discriminating the goats bearing multiple fetuses from those bearing a single fetus.

Visceral Adipose Tissue Is Associated With Bone Microarchitecture in the Framingham Osteoporosis Study.

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Liu, Ching-Ti; Broe, Kerry E; Zhou, Yanhua; Boyd, Steven K; Cupples, L Adrienne; Hannan, Marian T; Lim, Elise; McLean, Robert R; Samelson, Elizabeth J; Bouxsein, Mary L; Kiel, Douglas P

2017-01-01

Obesity has been traditionally considered to protect the skeleton against osteoporosis and fracture. Recently, body fat, specifically visceral adipose tissue (VAT), has been associated with lower bone mineral density (BMD) and increased risk for some types of fractures. We studied VAT and bone microarchitecture in 710 participants (58% women, age 61.3 ± 7.7 years) from the Framingham Offspring cohort to determine whether cortical and trabecular BMD and microarchitecture differ according to the amount of VAT. VAT was measured from CT imaging of the abdomen. Cortical and trabecular BMD and microarchitecture were measured at the distal tibia and radius using high-resolution peripheral quantitative computed tomography (HR-pQCT). We focused on 10 bone parameters: cortical BMD (Ct.BMD), cortical tissue mineral density (Ct.TMD), cortical porosity (Ct.Po), cortical thickness (Ct.Th), cortical bone area fraction (Ct.A/Tt.A), trabecular density (Tb.BMD), trabecular number (Tb.N), trabecular thickness (Tb.Th), total area (Tt.Ar), and failure load (FL) from micro-finite element analysis. We assessed the association between sex-specific quartiles of VAT and BMD, microarchitecture, and strength in all participants and stratified by sex. All analyses were adjusted for age, sex, and in women, menopausal status, then repeated adjusting for body mass index (BMI) or weight. At the radius and tibia, Ct.Th, Ct.A/Tt.A, Tb.BMD, Tb.N, and FL were positively associated with VAT (all p-trend <0.05), but no other associations were statistically significant except for higher levels of cortical porosity with higher VAT in the radius. Most of these associations were only observed in women, and were no longer significant when adjusting for BMI or weight. Higher amounts of VAT are associated with greater BMD and better microstructure of the peripheral skeleton despite some suggestions of significant deleterious changes in cortical measures in the non-weight bearing radius. Associations were

Orthostatic Tremor and Orthostatic Myoclonus: Weight-bearing Hyperkinetic Disorders: A Systematic Review, New Insights, and Unresolved Questions

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Anhar Hassan

2016-11-01

Full Text Available Background: Orthostatic tremor (OT and orthostatic myoclonus (OM are weight-bearing hyperkinetic movement disorders most commonly affecting older people that induce “shaky legs” upon standing. OT is divided into “classical” and “slow” forms based on tremor frequency. In this paper, the first joint review of OT and OM, we review the literature and compare and contrast their demographic, clinical, electrophysiological, neuroimaging, pathophysiological, and treatment characteristics. Methods: A PubMed search up to July 2016 using the phrases “orthostatic tremor,” “orthostatic myoclonus,” “shaky legs,” and “shaky legs syndrome” was performed. Results: OT and OM should be suspected in older patients reporting unsteadiness with prolonged standing and/or who exhibit cautious, wide-based gaits. Surface electromyography (SEMG is necessary to verify the diagnoses. Functional neuroimaging and electrophysiology suggest the generator of classical OT lies within the cerebellothalamocortical network. For OM, and possibly slow OT, the frontal, subcortical cerebrum is the most likely origin. Clonazepam is the most useful medication for classical OT, and levetiracetam for OM, although results are often disappointing. Deep brain stimulation appears promising for classical OT. Rolling walkers reliably improve gait affected by these disorders, as both OT and OM attenuate when weight is transferred from the legs to the arms. Discussion: Orthostatic hyperkinesias are likely underdiagnosed, as SEMG is often unavailable in clinical practice, and thus may be more frequent than currently recognized. The shared weight-bearing induction of OT and OM may indicate a common pathophysiology. Further research, including use of animal models, is necessary to better define the prevalence and pathophysiology of OT and OM, in order to improve their treatment, and provide additional insights into basic balance and gait mechanisms.

Objectively measured physical activity and bone strength in 9-year-old boys and girls.

Science.gov (United States)

Sardinha, Luís B; Baptista, Fátima; Ekelund, Ulf

2008-09-01

The purpose of this work was to analyze the relationship between intensity and duration of physical activity and composite indices of femoral neck strength and bone-mineral content of the femoral neck, lumbar spine, and total body. Physical activity was assessed by accelerometry in 143 girls and 150 boys (mean age: 9.7 years). Measurement of bone-mineral content, femoral neck bone-mineral density, femoral neck width, hip axis length, and total body fat-free mass was performed with dual-energy radiograph absorptiometry. Compressive [(bone-mineral density x femoral neck width/weight)] and bending strength [(bone-mineral density x femoral neck width(2))/(hip axis length x weight)] express the forces that the femoral neck has to withstand in weight bearing, whereas impact strength [(bone-mineral density x femoral neck width x hip axis length)/(height x weight)] expresses the energy that the femoral neck has to absorb in an impact from standing height. Analysis of covariance (fat-free mass and age adjusted) showed differences between boys and girls of approximately 9% for compressive, 10% for bending, and 9% for impact strength. Stepwise regression analysis using time spent at sedentary, light, moderate, and vigorous physical activity as predictors revealed that vigorous physical activity explained 5% to 9% of femoral neck strength variable variance in both genders, except for bending strength in boys, and approximately 1% to 3% of total body and femoral neck bone-mineral content variance. Vigorous physical activity was then used to categorize boys and girls into quartiles. Pairwise comparison indicated that boys in the third and fourth quartiles (accumulation of >26 minutes/day) demonstrated higher compressive (11%-12%), bending (10%), and impact (14%) strength than boys in the first quartile. In girls, comparison revealed a difference between the fourth (accumulation of >25 minutes/day) and first quartiles for bending strength (11%). We did not observe any

Validity of the Nintendo Wii Balance Board to assess weight bearing asymmetry during sit-to-stand and return-to-sit task.

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Abujaber, Sumayeh; Gillispie, Gregory; Marmon, Adam; Zeni, Joseph

2015-02-01

Weight bearing asymmetry is common in patients with unilateral lower limb musculoskeletal pathologies. The Nintendo Wii Balance Board (WBB) has been suggested as a low-cost and widely-available tool to measure weight bearing asymmetry in a clinical environment; however no study has evaluated the validity of this tool during dynamic tasks. Therefore, the purpose of this study was to determine the concurrent validity of force measurements acquired from the WBB as compared to laboratory force plates. Thirty-five individuals before, or within 1 year of total joint arthroplasty performed a sit-to-stand and return-to-sit task in two conditions. First, subjects performed the task with both feet placed on a single WBB. Second, the task was repeated with each foot placed on an individual laboratory force plate. Peak vertical ground reaction force (VGRF) under each foot and the inter-limb symmetry ratio were calculated. Validity was examined using Intraclass Correlation Coefficients (ICC), regression analysis, 95% limits of agreement and Bland-Altman plots. Force plates and the WBB exhibited excellent agreement for all outcome measurements (ICC=0.83-0.99). Bland-Altman plots showed no obvious relationship between the difference and the mean for the peak VGRF, but there was a consistent trend in which VGRF on the unaffected side was lower and VGRF on the affected side was higher when using the WBB. However, these consistent biases can be adjusted for by utilizing regression equations that estimate the force plate values based on the WBB force. The WBB may serve as a valid, suitable, and low-cost alternative to expensive, laboratory force plates for measuring weight bearing asymmetry in clinical settings. Copyright © 2015 Elsevier B.V. All rights reserved.

Central bone grafting for nonunion of fractures of the tibia: a retrospective series.

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Ryzewicz, M; Morgan, S J; Linford, E; Thwing, J I; de Resende, G V P; Smith, W R

2009-04-01

Nonunion of the tibia associated with bone loss, previous infection, obliteration of the intramedullary canal or located in the distal metaphysis poses a challenge to the surgeon and significant morbidity to patients. We retrospectively reviewed the records of 24 patients who were treated by central bone grafting and compared them to those of 20 who were treated with a traditional posterolateral graft. Central bone grafting entails a lateral approach, anterior to the fibula and interosseous membrane which is used to create a central space filled with cancellous iliac crest autograft. Upon consolidation, a tibiofibular synostosis is formed that is strong enough for weight-bearing. This procedure has advantages over other methods of treatment for selected nonunions. Of the 24 patients with central bone grafting, 23 went on to radiographic and clinical union without further intervention. All healed within a mean of 20 weeks (10 to 48). No further bone grafts were required, and few complications were encountered. These results were comparable to those of the 20 patients who underwent posterolateral bone grafting who united at a mean of 31.3 weeks (16 to 60) but one of whom required below-knee amputation for intractable sepsis. Central bone grafting is a safe and effective treatment for difficult nonunions of the tibia.

Genomic sequencing of Pleistocene cave bears

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Noonan, James P.; Hofreiter, Michael; Smith, Doug; Priest, JamesR.; Rohland, Nadin; Rabeder, Gernot; Krause, Johannes; Detter, J. Chris; Paabo, Svante; Rubin, Edward M.

2005-04-01

Despite the information content of genomic DNA, ancient DNA studies to date have largely been limited to amplification of mitochondrial DNA due to technical hurdles such as contamination and degradation of ancient DNAs. In this study, we describe two metagenomic libraries constructed using unamplified DNA extracted from the bones of two 40,000-year-old extinct cave bears. Analysis of {approx}1 Mb of sequence from each library showed that, despite significant microbial contamination, 5.8 percent and 1.1 percent of clones in the libraries contain cave bear inserts, yielding 26,861 bp of cave bear genome sequence. Alignment of this sequence to the dog genome, the closest sequenced genome to cave bear in terms of evolutionary distance, revealed roughly the expected ratio of cave bear exons, repeats and conserved noncoding sequences. Only 0.04 percent of all clones sequenced were derived from contamination with modern human DNA. Comparison of cave bear with orthologous sequences from several modern bear species revealed the evolutionary relationship of these lineages. Using the metagenomic approach described here, we have recovered substantial quantities of mammalian genomic sequence more than twice as old as any previously reported, establishing the feasibility of ancient DNA genomic sequencing programs.

Effect of gradual weight-bearing on regenerated articular cartilage after joint distraction and motion in a rabbit model.

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Nishino, Tomofumi; Ishii, Tomoo; Chang, Fei; Yanai, Takaji; Watanabe, Arata; Ogawa, Takeshi; Mishima, Hajime; Nakai, Kenjiro; Ochiai, Naoyuki

2010-05-01

The purpose of this study was to clarify the effect of gradual weight bearing (GWB) on regenerating cartilage. We developed a novel external fixation device (EFD) with a controllable weight-bearing system and continuous passive motion (CPM). A full-thickness defect was created by resection of the entire articular surface of the tibial plateau after the EFD was fixed in the rabbit's left knee. In the GWB group (n=6), GWB was started 6 weeks after surgery. In the CPM group (n=6), CPM with EFD was applied in the same manner without GWB. The control group (n=5) received only joint distraction. All rabbits were sacrificed 9 weeks after surgery. The central one-third of the regenerated tissue was assessed and scored blindly using a grading scale modified from the International Cartilage Repair Society visual histological assessment scale. The areas stained by Safranin-O and type II collagen antibody were measured, and the percentage of each area was calculated. There was no significant difference in the histological assessment scale among the groups. The percentage of the type II collagen-positive area was significantly larger in the GWB group than in the CPM group. The present study suggests that optimal mechanical stress, such as GWB, may affect regeneration of cartilage, in vivo. Copyright (c) 2009 Orthopaedic Research Society.

Plantar fascia evaluation with a dedicated magnetic resonance scanner in weight-bearing position: our experience in patients with plantar fasciitis and in healthy volunteers.

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Sutera, R; Iovane, A; Sorrentino, F; Candela, F; Mularo, V; La Tona, G; Midiri, M

2010-03-01

This study assessed the usefulness of upright weight-bearing examination of the ankle/hind foot performed with a dedicated magnetic resonance (MR) imaging scanner in the evaluation of the plantar fascia in healthy volunteers and in patients with clinical evidence of plantar fasciitis. Between January and March 2009, 20 patients with clinical evidence of plantar fasciitis (group A) and a similar number of healthy volunteers (group B) underwent MR imaging of the ankle/hind foot in the upright weight-bearing and conventional supine position. A 0.25-Tesla MR scanner (G-Scan, Esaote SpA, Genoa, Italy) was used with a dedicated receiving coil for the ankle/hind foot. Three radiologists, blinded to patients' history and clinical findings, assessed in consensus morphological and dimensional changes and signal intensity alterations on images acquired in both positions, in different sequences and in different planes. In group A, MR imaging confirmed the diagnosis in 15/20 cases; in 4/15 cases, a partial tear of the plantar fascia was identified in the upright weight-bearing position alone. In the remaining 5/20 cases in group A and in all cases in group B, the plantar fascia showed no abnormal signal intensity. Because of the increased stretching of the plantar fascia, in all cases in group A and B, thickness in the proximal third was significantly reduced (pplantar fascia, which could be overlooked in the supine position.

Silk coating on a bioactive ceramic scaffold for bone regeneration: effective enhancement of mechanical and in vitro osteogenic properties towards load-bearing applications.

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Li, Jiao Jiao; Roohani-Esfahani, Seyed-Iman; Kim, Kyungsook; Kaplan, David L; Zreiqat, Hala

2017-06-01

Bioactive ceramic scaffolds represent competitive choices for clinical bone reconstruction, but their widespread use is restricted by inherent brittleness and weak mechanical performance under load. This study reports the development of strong and tough bioactive scaffolds suitable for use in load-bearing bone reconstruction. A strong and bioactive ceramic scaffold (strontium-hardystonite-gahnite) is combined with single and multiple coating layers of silk fibroin to enhance its toughness, producing composite scaffolds which match the mechanical properties of cancellous bone and show enhanced capacity to promote in vitro osteogenesis. Also reported for the first time is a comparison of the coating effects obtained when a polymeric material is coated on ceramic scaffolds with differing microstructures, namely the strontium-hardystonite-gahnite scaffold with high-density struts as opposed to a conventional ceramic scaffold, such as biphasic calcium phosphate, with low-density struts. The results show that silk coating on a unique ceramic scaffold can lead to simple and effective enhancement of its mechanical and biological properties to suit a wider range of applications in clinical bone reconstruction, and also establish the influence of ceramic microstructure on the effectiveness of silk coating as a method of reinforcement when applied to different types of ceramic bone graft substitutes. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

MR findings of primary bone lymphoma in a 15-year-old girl: emphasis on diffusion-weighted imaging

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Garrett, Kevin M.; Kim, Hee Kyung; Emery, Kathleen H. [Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Stanek, Jerzy [Cincinnati Children' s Hospital Medical Center, Department of Pathology, Cincinnati, OH (United States)

2011-05-15

We report a case of primary bone lymphoma (PBL) in a 15-year-old girl assessed by MR imaging with diffusion-weighted imaging (DWI). DWI has been shown to help characterize the cellularity of solid tumors and this case correlates well with previous data. (orig.)

Weight loss on stimulant medication: how does it affect body composition and bone metabolism? – A prospective longitudinal study

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Poulton Alison

2012-12-01

Full Text Available Abstract Objective Children treated with stimulant medication for attention deficit hyperactivity disorder (ADHD often lose weight. It is important to understand the implications of this during growth. This prospective study was designed to quantify the changes in body composition and markers of bone metabolism on starting treatment. Methods 34 children (29 boys aged 4.7 to 9.1 years newly diagnosed with ADHD were treated with dexamphetamine or methylphenidate, titrating the dose to optimise the therapeutic response. Medication was continued for as long as clinically indicated. Body composition and bone density (dual-energy X-ray absorptiometry were measured at baseline, 6 months and 3 years; changes were analysed in Z-scores based on data from 241 healthy, local children. Markers of bone turnover were measured at baseline, 3 months and 3 years. Results Fat loss of 1.4±0.96kg (total fat 5.7±3.6 to 4.3±3.1kg, p Conclusions Stimulant medication was associated with early fat loss and reduced bone turnover. Lean tissue including bone increased more slowly over 3 years of continuous treatment than would be expected for growth in height. There was long-term improvement in the proportion of central fat for height. This study shows that relatively minor reductions in weight on stimulant medication can be associated with long-term changes in body composition. Further study is required to determine the effects of these changes on adult health.

Volleyball and Basketball Enhanced Bone Mass in Prepubescent Boys.

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Zouch, Mohamed; Chaari, Hamada; Zribi, Anis; Bouajina, Elyès; Vico, Laurence; Alexandre, Christian; Zaouali, Monia; Ben Nasr, Hela; Masmoudi, Liwa; Tabka, Zouhair

2016-01-01

The aim of this study was to examine the effect of volleyball and basketball practice on bone acquisition and to determine which of these 2 high-impact sports is more osteogenic in prepubertal period. We investigated 170 boys (aged 10-12 yr, Tanner stage I): 50 volleyball players (VB), 50 basketball players (BB), and 70 controls. Bone mineral content (BMC, g) and bone area (BA, cm(2)) were measured by dual-energy X-ray absorptiometry at different sites. We found that, both VB and BB have a higher BMC at whole body and most weight-bearing and nonweight-bearing sites than controls, except the BMC in head which was lower in VB and BB than controls. Moreover, only VB exhibited greater BMC in right and left ultra-distal radius than controls. No significant differences were observed between the 3 groups in lumbar spine, femoral neck, and left third D radius BMC. Athletes also exhibited a higher BA in whole body, limbs, lumbar spine, and femoral region than controls. In addition, they have a similar BA in head and left third D radius with controls. The VB exhibited a greater BA in most radius region than controls and a greater femoral neck BA than BB. A significant positive correlation was reported between total lean mass and both BMC and BA in whole body, lumbar spine, total hip, and right whole radius among VB and BB. In summary, we suggest that volleyball and basketball have an osteogenic effect BMC and BA in loaded sites in prepubescent boys. The increased bone mass induced by both volleyball and basketball training in the stressed sites was associated to a decreased skull BMC. Moreover, volleyball practice produces a more sensitive mechanical stress in loaded bones than basketball. This effect seems translated by femoral neck expansion. Copyright © 2016 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Mimicking the effects of spaceflight on bone: Combined effects of disuse and chronic low-dose rate radiation exposure on bone mass in mice

Science.gov (United States)

Yu, Kanglun; Doherty, Alison H.; Genik, Paula C.; Gookin, Sara E.; Roteliuk, Danielle M.; Wojda, Samantha J.; Jiang, Zhi-Sheng; McGee-Lawrence, Meghan E.; Weil, Michael M.; Donahue, Seth W.

2017-11-01

During spaceflight, crewmembers are subjected to biomechanical and biological challenges including microgravity and radiation. In the skeleton, spaceflight leads to bone loss, increasing the risk of fracture. Studies utilizing hindlimb suspension (HLS) as a ground-based model of spaceflight often neglect the concomitant effects of radiation exposure, and even when radiation is accounted for, it is often delivered at a high-dose rate over a very short period of time, which does not faithfully mimic spaceflight conditions. This study was designed to investigate the skeletal effects of low-dose rate gamma irradiation (8.5 cGy gamma radiation per day for 20 days, amounting to a total dose of 1.7 Gy) when administered simultaneously to disuse from HLS. The goal was to determine whether continuous, low-dose rate radiation administered during disuse would exacerbate bone loss in a murine HLS model. Four groups of 16 week old female C57BL/6 mice were studied: weight bearing + no radiation (WB+NR), HLS + NR, WB + radiation exposure (WB+RAD), and HLS+RAD. Surprisingly, although HLS led to cortical and trabecular bone loss, concurrent radiation exposure did not exacerbate these effects. Our results raise the possibility that mechanical unloading has larger effects on the bone loss that occurs during spaceflight than low-dose rate radiation.

Recurrent Migratory Transient Bone Marrow Edema of the Knees Associated with Low Vitamin D and Systemic Low Bone Mineral Density: A Case Report and Literature Review

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Omar Alsaed

2018-01-01

Full Text Available Transient bone marrow edema (TBME is a self-limiting disease characterized by joint pain with localized bone marrow edema by MRI and has been reported in many case series and case reports. It is well known that joints of the lower extremity including hips, knees, ankles, and feet are the classical sites for TBME. Many theories have been proposed for the pathogenesis of TBME. Systemic osteopenia and vitamin D deficiency is one of the theories that have been suggested in the last few years. In this case report, we present a middle-aged male patient, who presented with 4 attacks of TBME in both knees between September 2016 and August 2017. The patient was found to have persistently low vitamin D and osteopenic T score in DXA scan of the lumbar spine and hips. Patients of TBME usually present with joint pain that is provoked by weight-bearing physical activity. The aim of this case report is to raise the awareness that TBME can be the initial presentation of systemic loss of bone mineral density.

[Biomaterials in bone repair].

Science.gov (United States)

Puska, Mervi; Aho, Allan J; Vallittu, Pekka K

2013-01-01

In orthopedics, traumatology, and craniofacial surgery, biomaterials should meet the clinical demands of bone that include shape, size and anatomical location of the defect, as well as the physiological load-bearing stresses. Biomaterials are metals, ceramics, plastics or materials of biological origin. In the treatment of large defects, metallic endoprostheses or bone grafts are employed, whereas ceramics in the case of small defects. Plastics are employed on the artificial joint surfaces, in the treatment of vertebral compression fractures, and as biodegradable screws and plates. Porosity, bioactivity, and identical biomechanics to bone are fundamental for achieving a durable, well-bonded, interface between biomaterial and bone. In the case of severe bone treatments, biomaterials should also imply an option to add biologically active substances.

A Frequency-Weighted Energy Operator and complementary ensemble empirical mode decomposition for bearing fault detection

Science.gov (United States)

Imaouchen, Yacine; Kedadouche, Mourad; Alkama, Rezak; Thomas, Marc

2017-01-01

Signal processing techniques for non-stationary and noisy signals have recently attracted considerable attentions. Among them, the empirical mode decomposition (EMD) which is an adaptive and efficient method for decomposing signals from high to low frequencies into intrinsic mode functions (IMFs). Ensemble EMD (EEMD) is proposed to overcome the mode mixing problem of the EMD. In the present paper, the Complementary EEMD (CEEMD) is used for bearing fault detection. As a noise-improved method, the CEEMD not only overcomes the mode mixing, but also eliminates the residual of added white noise persisting into the IMFs and enhance the calculation efficiency of the EEMD method. Afterward, a selection method is developed to choose relevant IMFs containing information about defects. Subsequently, a signal is reconstructed from the sum of relevant IMFs and a Frequency-Weighted Energy Operator is tailored to extract both the amplitude and frequency modulations from the selected IMFs. This operator outperforms the conventional energy operator and the enveloping methods, especially in the presence of strong noise and multiple vibration interferences. Furthermore, simulation and experimental results showed that the proposed method improves performances for detecting the bearing faults. The method has also high computational efficiency and is able to detect the fault at an early stage of degradation.

Genesis of B lymphocytes in the bone marrow: extravascular and intravascular localization of surface IgM-bearing cells in mouse bone marrow detected by electron-microscope radioautography after in vivo perfusion of 125I anti-IgM antibody

International Nuclear Information System (INIS)

Osmond, D.G.; Batten, S.J.

1984-01-01

The role of mammalian bone marrow in generating surface IgM (sIgM)-bearing B lymphocytes is reviewed. Precursor cells in the marrow give rise to large, rapidly dividing cells bearing free cytoplasmic mu chains (c mu). The progeny of the large c mu+ cells form a population of small, nondividing c mu+ cells that mature into small lymphocytes, progressively expressing sIgM and other B-cell surface membrane components. Newly formed sIgM+ cells soon migrate through the bloodstream to the spleen and other lymphoid tissues, where they may die after a short lifespan or be activated to produce antibody molecules. The large-scale lymphocytopoiesis in the bone marrow thus maintains a population of rapidly renewed virgin B lymphocytes in the peripheral lymphoid tissues. A technique for perfusing radiolabeled anti-IgM antibodies in young mice has now permitted sIgM+ cells to be detected radioautographically in histological preparations of bone marrow under the electron microscope. Small sIgM+ lymphocytes are situated either singly or in small groups throughout the extravascular hemopoietic compartment of the bone marrow, often near sinusoid walls adjacent to late erythroblasts and reticular cells. Some regional concentrations of sIgM+ cells are apparent. sIgM+ cells also appear in transit through the sinusoidal endothelium and are markedly concentrated in the lumen of some sinusoids. Intrasinusoidal sIgM+ small lymphocytes have high densities of sIgM and long microvilli, on which sIgM molecules are concentrated. These studies reveal the localization and cell associations of specifically identified sIgM+ small lymphocytes in the extravascular marrow compartment and suggest that these cells may also undergo a transient intravascular storage and maturation phase. Use of this in vivo immunolabeling technique to detect other cell-surface markers may further elucidate the microenvironmental basis of B lymphocyte genesis in the bone marrow

Telemetry experiments with a hibernating black bear

Science.gov (United States)

Craighead, J. J.; Varney, J. R.; Sumner, J. S.; Craighead, F. C., Jr.

1972-01-01

The objectives of this research were to develop and test telemetry equipment suitable for monitoring physiological parameters and activity of a hibernating bear in its den, to monitor this data and other environmental information with the Nimbus 3 IRLS data collection system, and to refine immobilizing, handling, and other techniques required in future work with wild bears under natural conditions. A temperature-telemetering transmitter was implanted in the abdominal cavity of a captive black bear and body temperature data was recorded continuously during a 3 month hibernation period. Body temperatures ranging between 37.5 and 31.8 C were observed. Body temperature and overall activity were influenced by disturbances and ambient den temperature. Nychthemeral temperature changes were not noticable. A load cell weight recording device was tested for determining weight loss during hibernation. Monitoring of data by satellite was not attempted. The implanted transmitter was removed and the bear was released with a radiolocation collar at the conclusion of the experiment.

Comparison of three different weight maintenance programs on cardiovascular risk, bone, and vitamins in sedentary older adults

DEFF Research Database (Denmark)

Christensen, Pia; Frederiksen, Rikke; Bliddal, Henning

2013-01-01

OBJECTIVE: Obese patients with knee osteoarthritis (OA) are encouraged to lose weight to obtain symptomatic relief. Risk of vascular events is higher in people with OA compared to people without arthritis. Our aim in this randomized trial was to compare changes in cardiovascular disease (CVD) risk......-factors, nutritional health, and body composition after 1-year weight-loss maintenance achieved by [D]diet, [E]knee-exercise, or [C]control, following weight loss by low-energy-diet. DESIGN AND METHODS: Obese individuals (n = 192, >50 years) with knee OA, 63 years (SD 6), weight 103.2 kg (15.0), body-mass index 37......: Dietary support, or control, maintained improvements in cardiovascular risk factors to the same extent and none of the interventions had a detrimental effect on bone....

Structural degradation of acrylic bone cements due to in vivo and simulated aging.

Science.gov (United States)

Hughes, Kerry F; Ries, Michael D; Pruitt, Lisa A

2003-05-01

Acrylic bone cement is the primary load-bearing material used for the attachment of orthopedic devices to adjoining bone. Degradation of acrylic-based cements in vivo results in a loss of structural integrity of the bone-cement-prosthesis interface and limits the longevity of cemented orthopedic implants. The purpose of this study is to investigate the effect of in vivo aging on the structure of the acrylic bone cement and to develop an in vitro artificial aging protocol that mimics the observed degradation. Three sets of retrievals are examined in this study: Palacos brand cement retrieved from hip replacements, and Simplex brand cement retrieved from both hip and knee replacement surgeries. In vitro aging is performed using oxidative and acidic environments on three acrylic-based cements: Palacos, Simplex, and CORE. Gel permeation chromatography (GPC) and Fourier transform infrared spectroscopy (FTIR) are used to examine the evolution of molecular weight and chemical species within the acrylic cements due to both in vivo and simulated aging. GPC analysis indicates that molecular weight is degraded in the hip retrievals but not in the knee retrievals. Artificial aging in an oxidative environment best reproduces this degradation mechanism. FTIR analysis indicates that there exists a chemical evolution within the cement due to in vivo and in vitro aging. These findings are consistent with scission-based degradation schemes in the cement. Based on the results of this study, a pathway for structural degradation of acrylic bone cement is proposed. The findings from this investigation have broad applicability to acrylic-based cements and may provide guidance for the development of new bone cements that resist degradation in the body. Copyright 2003 Wiley Periodicals, Inc.

The Association between Weight Gain/Restoration and Bone Mineral Density in Adolescents with Anorexia Nervosa: A Systematic Review.

Science.gov (United States)

El Ghoch, Marwan; Gatti, Davide; Calugi, Simona; Viapiana, Ombretta; Bazzani, Paola Vittoria; Dalle Grave, Riccardo

2016-11-29

Reduced bone mineral density (BMD) is one of the most frequent medical complications of anorexia nervosa (AN). The purpose of this paper was to conduct a systematic review of the association between weight gain/restoration and BMD in adolescents with AN. Literature searches, study selection, method, and quality appraisal were performed independently by two authors, and data were collated using a narrative approach. Of the 1156 articles retrieved, 19 studies met the inclusion criteria, and their analysis revealed four main findings. First, six studies reported that weight gain and restoration are associated with BMD stabilization after one year of follow-up from baseline. Second, seven studies with longer follow-up periods (≈16 months) reported significant improvements in BMD measures. Third, one study showed that normalization of BMD can be achieved after ≈30-month follow-up of normal-weight maintenance. Fourth, another study showed that male adolescents with AN who achieve weight gain but remain underweight may experience further BMD loss, unlike their weight-restored counterparts (BMI ≥ 19 kg/m²), who show a significant increase in BMD and bone mineral accrual rates that double those of healthy male adolescents. The first two findings can be considered robust, as they are supported by strong evidence. The third and fourth findings, however, derive from single studies and therefore require further confirmation. The literature supports weight gain as an effective strategy for promoting BMD increase in adolescents with AN. However, this process is slow, and improvements do not become detectable until ≈16-month follow-up.

The Association between Weight Gain/Restoration and Bone Mineral Density in Adolescents with Anorexia Nervosa: A Systematic Review

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Marwan El Ghoch

2016-11-01

Full Text Available Background: Reduced bone mineral density (BMD is one of the most frequent medical complications of anorexia nervosa (AN. The purpose of this paper was to conduct a systematic review of the association between weight gain/restoration and BMD in adolescents with AN. Methods: Literature searches, study selection, method, and quality appraisal were performed independently by two authors, and data were collated using a narrative approach. Results: Of the 1156 articles retrieved, 19 studies met the inclusion criteria, and their analysis revealed four main findings. First, six studies reported that weight gain and restoration are associated with BMD stabilization after one year of follow-up from baseline. Second, seven studies with longer follow-up periods (≈16 months reported significant improvements in BMD measures. Third, one study showed that normalization of BMD can be achieved after ≈30-month follow-up of normal-weight maintenance. Fourth, another study showed that male adolescents with AN who achieve weight gain but remain underweight may experience further BMD loss, unlike their weight-restored counterparts (BMI ≥ 19 kg/m2, who show a significant increase in BMD and bone mineral accrual rates that double those of healthy male adolescents. The first two findings can be considered robust, as they are supported by strong evidence. The third and fourth findings, however, derive from single studies and therefore require further confirmation. Conclusion: The literature supports weight gain as an effective strategy for promoting BMD increase in adolescents with AN. However, this process is slow, and improvements do not become detectable until ≈16-month follow-up.

Measurements of Weight Bearing Asymmetry Using the Nintendo Wii Fit Balance Board Are Not Reliable for Older Adults and Individuals With Stroke.

Science.gov (United States)

Liuzzo, Derek M; Peters, Denise M; Middleton, Addie; Lanier, Wes; Chain, Rebecca; Barksdale, Brittany; Fritz, Stacy L

Clinicians and researchers have used bathroom scales, balance performance monitors with feedback, postural scale analysis, and force platforms to evaluate weight bearing asymmetry (WBA). Now video game consoles offer a novel alternative for assessing this construct. By using specialized software, the Nintendo Wii Fit balance board can provide reliable measurements of WBA in healthy, young adults. However, reliability of measurements obtained using only the factory settings to assess WBA in older adults and individuals with stroke has not been established. To determine whether measurements of WBA obtained using the Nintendo Wii Fit balance board and default settings are reliable in older adults and individuals with stroke. Weight bearing asymmetry was assessed using the Nintendo Wii Fit balance board in 2 groups of participants-individuals older than 65 years (n = 41) and individuals with stroke (n = 41). Participants were given a standardized set of instructions and were not provided auditory or visual feedback. Two trials were performed. Intraclass correlation coefficients (ICC), standard error of measure (SEM), and minimal detectable change (MDC) scores were determined for each group. The ICC for the older adults sample was 0.59 (0.35-0.76) with SEM95 = 6.2% and MDC95 = 8.8%. The ICC for the sample including individuals with stroke was 0.60 (0.47-0.70) with SEM95 = 9.6% and MDC95 = 13.6%. Although measurements of WBA obtained using the Nintendo Wii Fit balance board, and its default factory settings, demonstrate moderate reliability in older adults and individuals with stroke, the relatively high associated SEM and MDC values substantially reduce the clinical utility of the Nintendo Wii Fit balance board as an assessment tool for WBA. Weight bearing asymmetry cannot be measured reliably in older adults and individuals with stroke using the Nintendo Wii Fit balance board without the use of specialized software.

Bone X-Ray (Radiography)

Medline Plus

Full Text Available ... taken of the unaffected limb, or of a child's growth plate (where new bone is forming), for ... have special pediatric considerations. The teddy bear denotes child-specific content. Related Articles and Media Radiation Dose ...

Effect of Long-Term Use of Bisphosphonates on Forearm Bone: Atypical Ulna Fractures in Elderly Woman with Osteoporosis

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Yusuf Erdem

2016-01-01

Full Text Available Osteoporosis is a common musculoskeletal disease of the elderly population characterized by decreased bone mineral density and subsequent fractures. Bisphosphonates are a widely accepted drug therapy which act through inhibition of bone resorption and prevent fractures. However, in long-term use, atypical bisphosphonate induced fractures may occur, particularly involving the lower weight bearing extremity. Atypical ulna fracture associated with long-term bisphosphonate use is rarely reported in current literature. We present a 62-year-old woman with atypical ulna due to long-term alendronate therapy without a history of trauma or fall. Clinicians should be aware of stress fracture in a patient who has complaints of upper extremity pain and history of long-term bisphosphonate therapy.

Effects of low dose radiation combined with cyclophosphamide on tumor cell apoptosis, cell cycle and proliferation of bone marrow in tumor-bearing mice

International Nuclear Information System (INIS)

Yu Hongsheng; Fei Conghe; Shen Fangzhen; Liang Jun

2004-01-01

Objective: To study the effect of low dose radiation (LDR) combined with cyclophosphamide on tumor cell apoptosis, cell cycle, and proliferation of bone marrow in mice tumor-bearing mice. Methods: Kunming strain male mice were implanted with S180 sarcoma cells in the left hind leg subcutaneously as an experimental animal model. Five and 8 days after implantation, the mice were given 75 mGy whole-body γ-ray radiation and CTX(300 mg/kg) by intraperitoneal injection 36 hour after LDR. All mice were sacrificed to measure the tumor volume, tumor cell apoptosis, and cell cycle; the proliferation of bone marrow was analyzed by flow cytometry. Results: Tumor growth was significantly slowed down in the treated groups. The apoptosis of tumor cells increased significantly after LDR. The tumor cells were arrested in G 1 phase in CTX and CTX+LDR groups, more significantly in the latter group than in the former group. Concentration of bone marrow cells and proliferation index in CTX + LDR group were higher than those in CTX group, although concentration of bone marrow cells in CTX and CTX+LDR groups were much lower than that in normal mice. Conclusion: Low dose radiation combined with cyclophosphamide causes more significant G 1 -phase arrest than cyclophosphamide alone and enhances anti-tumor effect markedly. At the same time LDR significantly protects hematopoietic function of bone marrow, which is of practical significance as an adjuvant chemotherapy

Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

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Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil [Keimyung Univ., Daegu (Korea, Republic of)

2013-12-15

While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment.

Low-Dose Adefovir-Induced Hypophosphatemic Osteomalacia on Whole-Body Bone Scintigraphy

International Nuclear Information System (INIS)

Kim, Sung Hoon; Won, Kyoung Sook; Song, Bongil; Jo, Il; Zeon, Seok Kil

2013-01-01

While adefovir dipivoxil (ADV) effectively suppresses the hepatitis B virus, it can cause proximal renal tubular dysfunction leading to phosphate wasting. The safety of low-dose ADV (a dose of 10 mg/day), which does not induce clinically significant nephrotoxicity, is well recognized, but a few cases of hypophosphatemic osteomalacia (HO) caused by low-dose ADV therapy have recently been reported. Although HO induced by low-dose ADV therapy is rare, the presence of bone pain in patients treated with ADV should be monitored. Bone scintigraphy can be performed to confirm the occurrence of osteomalacia and to determine the disease extent. Bone scintigraphic and radiological image findings with a brief review of the literature are presented in this article. We report two cases of HO induced by low-dose ADV therapy that showed multifocal increased radiotracer uptakes in the bilateral bony ribs, spines, pelvic bones and lower extremities on whole-body bone scintigraphy. Bone pain gradually improved after phosphate supplementation and by changing the antiviral agent. Whole-body bone scintigraphy is a highly sensitive imaging tool and can show disease extent at once in the setting of the wide range of the clinical spectrum with nonspecific radiological findings. Furthermore, frequent involvement of the lower extremities, as a result of maximum weight bearing, could be an additional scintigraphic clue for the diagnosis of HO. These cases could be helpful for both clinicians prescribing ADV and nuclear physicians to prevent delayed diagnosis and plan further appropriate treatment

Tendon Reattachment to Bone in an Ovine Tendon Defect Model of Retraction Using Allogenic and Xenogenic Demineralised Bone Matrix Incorporated with Mesenchymal Stem Cells.

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Tanujan Thangarajah

Full Text Available Tendon-bone healing following rotator cuff repairs is mainly impaired by poor tissue quality. Demineralised bone matrix promotes healing of the tendon-bone interface but its role in the treatment of tendon tears with retraction has not been investigated. We hypothesized that cortical demineralised bone matrix used with minimally manipulated mesenchymal stem cells will result in improved function and restoration of the tendon-bone interface with no difference between xenogenic and allogenic scaffolds.In an ovine model, the patellar tendon was detached from the tibial tuberosity and a complete distal tendon transverse defect measuring 1 cm was created. Suture anchors were used to reattach the tendon and xenogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5, or allogenic demineralised bone matrix + minimally manipulated mesenchymal stem cells (n = 5 were used to bridge the defect. Graft incorporation into the tendon and its effect on regeneration of the enthesis was assessed using histomorphometry. Force plate analysis was used to assess functional recovery.Compared to the xenograft, the allograft was associated with significantly higher functional weight bearing at 6 (P = 0.047, 9 (P = 0.028, and 12 weeks (P = 0.009. In the allogenic group this was accompanied by greater remodeling of the demineralised bone matrix into tendon-like tissue in the region of the defect (p = 0.015, and a more direct type of enthesis characterized by significantly more fibrocartilage (p = 0.039. No failures of tendon-bone healing were noted in either group.Demineralised bone matrix used with minimally manipulated mesenchymal stem cells promotes healing of the tendon-bone interface in an ovine model of acute tendon retraction, with superior mechanical and histological results associated with use of an allograft.

Bone density and young athletic women. An update.

Science.gov (United States)

Nichols, David L; Sanborn, Charlotte F; Essery, Eve V

2007-01-01

High-school girls and collegiate women have tremendous opportunities to participate in athletic teams. Young girls are also playing in club and select teams at an early age and often, year-round. There are many benefits for participating in sport and physical activity on both the physical and mental health of girls and women. Decreased risk for heart disease and diabetes mellitus, along with improved self-esteem and body-image, were among the first reported benefits of regular physical activity. In addition, sport participation and physical activity is also associated with bone health. Athletes have a greater bone mineral density compared with non-active and physically active females. The increase in bone mass should reduce the risk of fragility fractures in later life. There appears to be a window of opportunity during the development of peak bone mass in which the bone is especially responsive to weight-bearing physical activity. Impact loading sports such as gymnastics, rugby or volleyball tend to produce a better overall osteogenic response than sports without impact loading such as cycling, rowing and swimming. Relatively little is known about the impact of retiring from athletics on bone density. It appears that former athletes continue to have a higher bone density than non-athletes; however, the rate of bone loss appears to be similar in the femoral neck. The positive impact of sports participation on bone mass can be tempered by nutritional and hormonal status. It is not known whether female athletes need additional calcium compared with the general female population. Due to the increased energy expenditure of exercise and/or the pressure to obtain an optimal training bodyweight, some female athletes may develop low energy availability or an eating disorder and subsequently amenorrhoea and a loss of bone mineral density. The three inter-related clinical disorders are referred to as the 'female athlete triad'. This article presents a review of the

Immediate mobilisation with complete weight bearing after uncemented total hip replacement in elderly

Directory of Open Access Journals (Sweden)

Sankarlingam P, Shivraj V, V R Subramaniyam

2014-11-01

Full Text Available This prospective study was analyzed in 23 patients who were allowed to do immediate weight bearing after uncemented total hip arthroplasty. Immediate mobilization shortened the hospital stay and facilitated early rehabilitation of hip. Immediate mobilization was started on postoperative Day 3 rather than Day 7 without any adverse consequences to the patients. A series of 23 elderly patients of age more than 60 years, who were diagnosed with conditions such as avascular necrosis of hip, non union of fracture neck of femur, trochanteric non union and rheumatoid arthritis, underwent uncemented total hip replacement and immediate mobilization was started in our hospital. Patients were evaluated by Harris Hip Scoring Scale. All ambulated patients had painless hip and the mean Harris Hip Score was 85. There were no incidence of stem subsidence, acetabular component loosening, and heterotrophic ossification. This data concluded that early intensive rehabilitation yielded faster attainment of short-term functional milestones in fewer days.

Association of Body Weight and Body Mass Index with Bone Mineral Density in Women and Men from Kosovo.

Science.gov (United States)

Rexhepi, Sylejman; Bahtiri, Elton; Rexhepi, Mjellma; Sahatciu-Meka, Vjollca; Rexhepi, Blerta

2015-08-01

Body weight and body mass index (BMI) are considered potentially modifiable determinants of bone mass. Therefore, the aim of this study was to explore the association between body weight and body mass index (BMI) with total hip and lumbar spine bone mineral density (BMD). This cross-sectional study included a population of 100 women and 32 men from Kosovo into three BMI groups. All the study subjects underwent dual-energy X-ray absorptiometry (DXA) measurements. Total hip BMD levels of obese menopausal and premenopausal women and men were significantly higher compared to overweight or normal weight subjects, while lumbar spine BMD levels of only menopausal women and men were higher among obese subjects. Age-adjusted linear regression analysis showed that BMI is a significant independent associate of lumbar spine and total hip BMD in menopausal women and men. Despite positive association between BMI and lumbar spine and total hip BMD in menopausal women, presence of more obese and osteoporotic subjects among menopausal women represent a population at risk for fractures because of poor balance and frequent falls; therefore, both obesity and osteoporosis prevention efforts should begin early on in life.

Common endocrine control of body weight, reproduction, and bone mass

Science.gov (United States)

Takeda, Shu; Elefteriou, Florent; Karsenty, Gerard

2003-01-01

Bone mass is maintained constant between puberty and menopause by the balance between osteoblast and osteoclast activity. The existence of a hormonal control of osteoblast activity has been speculated for years by analogy to osteoclast biology. Through the search for such humoral signal(s) regulating bone formation, leptin has been identified as a strong inhibitor of bone formation. Furthermore, intracerebroventricular infusion of leptin has shown that the effect of this adipocyte-derived hormone on bone is mediated via a brain relay. Subsequent studies have led to the identification of hypothalamic groups of neurons involved in leptin's antiosteogenic function. In addition, those neurons or neuronal pathways are distinct from neurons responsible for the regulation of energy metabolism. Finally, the peripheral mediator of leptin's antiosteogenic function has been identified as the sympathetic nervous system. Sympathomimetics administered to mice decreased bone formation and bone mass. Conversely, beta-blockers increased bone formation and bone mass and blunted the bone loss induced by ovariectomy.

Reliability of the measures of weight-bearing distribution obtained during quiet stance by digital scales in subjects with and without hemiparesis.

Science.gov (United States)

de Araujo-Barbosa, Paulo Henrique Ferreira; de Menezes, Lidiane Teles; Costa, Abraão Souza; Couto Paz, Clarissa Cardoso Dos Santos; Fachin-Martins, Emerson

2015-05-01

Described as an alternative way of assessing weight-bearing asymmetries, the measures obtained from digital scales have been used as an index to classify weight-bearing distribution. This study aimed to describe the intra-test and the test/retest reliability of measures in subjects with and without hemiparesis during quiet stance. The percentage of body weight borne by one limb was calculated for a sample of subjects with hemiparesis and for a control group that was matched by gender and age. A two-way analysis of variance was used to verify the intra-test reliability. This analysis was calculated using the differences between the averages of the measures obtained during single, double or triple trials. The intra-class correlation coefficient (ICC) was utilized and data plotted using the Bland-Altman method. The intra-test analysis showed significant differences, only observed in the hemiparesis group, between the measures obtained by single and triple trials. Excellent and moderate ICC values (0.69-0.84) between test and retest were observed in the hemiparesis group, while for control groups ICC values (0.41-0.74) were classified as moderate, progressing from almost poor for measures obtained by a single trial to almost excellent for those obtained by triple trials. In conclusion, good reliability ranging from moderate to excellent classifications was found for participants with and without hemiparesis. Moreover, an improvement of the repeatability was observed with fewer trials for participants with hemiparesis, and with more trials for participants without hemiparesis.

Successful correction of tibial bone deformity through multiple surgical procedures, liquid nitrogen-pretreated bone tumor autograft, three-dimensional external fixation, and internal fixation in a patient with primary osteosarcoma: a case report.

Science.gov (United States)

Takeuchi, Akihiko; Yamamoto, Norio; Shirai, Toshiharu; Nishida, Hideji; Hayashi, Katsuhiro; Watanabe, Koji; Miwa, Shinji; Tsuchiya, Hiroyuki

2015-12-07

In a previous report, we described a method of reconstruction using tumor-bearing autograft treated by liquid nitrogen for malignant bone tumor. Here we present the first case of bone deformity correction following a tumor-bearing frozen autograft via three-dimensional computerized reconstruction after multiple surgeries. A 16-year-old female student presented with pain in the left lower leg and was diagnosed with a low-grade central tibial osteosarcoma. Surgical bone reconstruction was performed using a tumor-bearing frozen autograft. Bone union was achieved at 7 months after the first surgical procedure. However, local tumor recurrence and lung metastases occurred 2 years later, at which time a second surgical procedure was performed. Five years later, the patient developed a 19° varus deformity and underwent a third surgical procedure, during which an osteotomy was performed using the Taylor Spatial Frame three-dimensional external fixation technique. A fourth corrective surgical procedure was performed in which internal fixation was achieved with a locking plate. Two years later, and 10 years after the initial diagnosis of tibial osteosarcoma, the bone deformity was completely corrected, and the patient's limb function was good. We present the first report in which a bone deformity due to a primary osteosarcoma was corrected using a tumor-bearing frozen autograft, followed by multiple corrective surgical procedures that included osteotomy, three-dimensional external fixation, and internal fixation.

Bone X-Ray (Radiography)

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Full Text Available ... over time. top of page What are the benefits vs. risks? Benefits Bone x-rays are the fastest and easiest ... bear denotes child-specific content. Related Articles and Media Radiation Dose in X-Ray and CT Exams ...

Ilizarov bone transport versus fibular graft for reconstruction of tibial bone defects in children.

Science.gov (United States)

Abdelkhalek, Mostafa; El-Alfy, Barakat; Ali, Ayman M

2016-11-01

The aim of this study was to compare the results of treatment of segmental tibial defects in the pediatric age group using an Ilizarov external fixator versus a nonvascularized fibular bone graft. This study included 24 patients (age range from 5.5 to 15 years) with tibial bone defects: 13 patients were treated with bone transport (BT) and 11 patients were treated with a nonvascularized fibular graft (FG). The outcome parameters were bone results (union, deformity, infection, leg-length discrepancy) and functional results: external fixation index and external fixation time. In group A (BT), one patient developed refracture at the regenerate site, whereas, in group B (FG), after removal of the external fixator, one of the FGs developed a stress fracture. The external fixator time in group A was 10.7 months (range 8-14.5) versus 7.8 months (range 4-11.5 months) in group B (FG). In group A (BT), one patient had a limb-length discrepancy (LLD), whereas, in group B (FG), three patients had LLD. The functional and bone results of the Ilizarov BT technique were excellent in 23.1 and 30.8%, good in 38.5 and 46.2, fair in 30.8 and 15.4, and poor in 7.6 and 7.6%, respectively. The poor functional result was related to the poor bone result because of prolonged external fixator time resulting in significant pain, limited ankle motion, whereas the functional and bone results of fibular grafting were excellent in 9.1 and 18.2%, good in 63.6 and 45.5%, fair in 18.2 and 27.2%, and poor in 9.1 and 9.1%, respectively. Segmental tibial defects can be effectively treated with both methods. The FG method provides satisfactory results, with early removal of the external fixator. However, it had a limitation in patients with severe infection and those with LLD. Also, it requires a long duration of limb bracing until adequate hypertrophy of the graft. The Ilizarov method has the advantages of early weight bearing, treatment of postinfection bone defect in a one-stage surgery, and the

Variance of [sup 99m]Tc-MDP bone imaging among the repairing process after experimental femoral head necrosis

Energy Technology Data Exchange (ETDEWEB)

Shibiao, Sang; Yimin, Jiang; Jinxi, Wang [Suzhou Medical Coll., Suzhou, JS (China). First Affiliated Hospital

1993-05-01

Six of 26 adult mongrel dogs were used as controls. Avascular necrosis of the left femoral head was induced by freezing method with liquid nitrogen and the right side being used as a self-control. The 20 dogs were divided into four groups, 5 dogs each which was sacrificed successively at 1/2, 2,2 and 6 months after operation. All of the femoral heads were studied by radionuclide bone imaging, radiological, histological and biochemical examinations. The results were as follows: [sup 99m]Tc-MDP bone imaging showed a decreased uptake at the early stage, and was gradually increased later, and reached its peak values at precollape stage at four months. Hypermetabolism state was still maintained at collapsed stage. Above changes was in coincidence with the bone imaging. As for the repairing process after necrosis, the hypermetabolic reaction in bone imaging of the femoral head correlates well with the proliferation of vessels and bone marrow cells and also the activity of tissue collagenase. Therefore, a poor bony reconstruction in the weight-bearing portion could be an important cause for late segmental collapse.

The TiltMeter app is a novel and accurate measurement tool for the weight bearing lunge test.

Science.gov (United States)

Williams, Cylie M; Caserta, Antoni J; Haines, Terry P

2013-09-01

The weight bearing lunge test is increasing being used by health care clinicians who treat lower limb and foot pathology. This measure is commonly established accurately and reliably with the use of expensive equipment. This study aims to compare the digital inclinometer with a free app, TiltMeter on an Apple iPhone. This was an intra-rater and inter-rater reliability study. Two raters (novice and experienced) conducted the measurements in both a bent knee and straight leg position to determine the intra-rater and inter-rater reliability. Concurrent validity was also established. Allied health practitioners were recruited as participants from the workplace. A preconditioning stretch was conducted and the ankle range of motion was established with the weight bearing lunge test position with firstly the leg straight and secondly with the knee bent. The measurement device and each participant were randomised during measurement. The intra-rater reliability and inter-rater reliability for the devices and in both positions were all over ICC 0.8 except for one intra-rater measure (Digital inclinometer, novice, ICC 0.65). The inter-rater reliability between the digital inclinometer and the tilmeter was near perfect, ICC 0.96 (CI: 0.898-0.983); Concurrent validity ICC between the two devices was 0.83 (CI: -0.740 to 0.445). The use of the Tiltmeter app on the iPhone is a reliable and inexpensive tool to measure the available ankle range of motion. Health practitioners should use caution in applying these findings to other smart phone equipment if surface areas are not comparable. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

A two-year program of aerobics and weight training enhances bone mineral density of young women

Science.gov (United States)

Friedlander, A. L.; Genant, H. K.; Sadowsky, S.; Byl, N. N.; Gluer, C. C.

1995-01-01

Previous research suggests that physical activity may have a beneficial effect on bone mineral density (BMD) in women. This relationship was explored in a 2-year, randomized, intervention trial investigating the efficacy of exercise and calcium supplementation on increasing peak bone mass in young women. One hundred and twenty-seven subjects (ages of 20-35 years) were randomly assigned either to an exercise program that contained both aerobics and weight training components or to a stretching program. Calcium supplementation (up to 1500 mg/day including dietary intake) or placebo was given in a double-blinded design to all subjects. Spinal trabecular BMD was determined using quantitative computed tomography (QCT). Spinal integral, femoral neck, and trochanteric BMD were measured by dual X-ray absorptiometry (DXA) and calcaneal BMD by single photon absorptiometry (SPA). Fitness variables included maximal aerobic capacity (VO2max), and isokinetic muscle performance of the trunk and thigh. Measurements were made at baseline, 1 year, and 2 years. Sixty-three subjects (32 exercise, 31 stretching) completed the study, and all the measured bone parameters indicated a positive influence of the exercise intervention. There were significant positive differences in BMD between the exercise and stretching groups for spinal trabecular (2.5%), femoral neck (2.4%), femoral trochanteric (2.3%), and calcaneal (6.4%) measurements. The exercise group demonstrated a significant gain in BMD for spinal integral (1.3 +/- 2.8%, p weight training has beneficial effects on BMD and fitness parameters in young women. However, the addition of daily calcium supplementation does not add significant benefit to the intervention.

The difference between actual and prescribed weight bearing of total hip patients with a trochanteric osteotomy: long-term vertical force measurements inside and outside the hospital

NARCIS (Netherlands)

H.L.P. Hurkmans (Henri); J.B.J. Bussmann (Hans); R.W. Selles (Ruud); E. Benda (Eric); H.J. Stam (Henk); J.A.N. Verhaar (Jan)

2007-01-01

textabstractOBJECTIVE: To determine whether patients load the operated leg at a prescribed weight-bearing target load during postoperative recovery. DESIGN: A descriptive prospective study. SETTING: Orthopedic clinic and patients' homes. PARTICIPANTS: Fifty patients who had undergone total hip

A tissue engineering solution for segmental defect regeneration in load-bearing long bones.

Science.gov (United States)

Reichert, Johannes C; Cipitria, Amaia; Epari, Devakara R; Saifzadeh, Siamak; Krishnakanth, Pushpanjali; Berner, Arne; Woodruff, Maria A; Schell, Hanna; Mehta, Manav; Schuetz, Michael A; Duda, Georg N; Hutmacher, Dietmar W

2012-07-04

The reconstruction of large defects (>10 mm) in humans usually relies on bone graft transplantation. Limiting factors include availability of graft material, comorbidity, and insufficient integration into the damaged bone. We compare the gold standard autograft with biodegradable composite scaffolds consisting of medical-grade polycaprolactone and tricalcium phosphate combined with autologous bone marrow-derived mesenchymal stem cells (MSCs) or recombinant human bone morphogenetic protein 7 (rhBMP-7). Critical-sized defects in sheep--a model closely resembling human bone formation and structure--were treated with autograft, rhBMP-7, or MSCs. Bridging was observed within 3 months for both the autograft and the rhBMP-7 treatment. After 12 months, biomechanical analysis and microcomputed tomography imaging showed significantly greater bone formation and superior strength for the biomaterial scaffolds loaded with rhBMP-7 compared to the autograft. Axial bone distribution was greater at the interfaces. With rhBMP-7, at 3 months, the radial bone distribution within the scaffolds was homogeneous. At 12 months, however, significantly more bone was found in the scaffold architecture, indicating bone remodeling. Scaffolds alone or with MSC inclusion did not induce levels of bone formation comparable to those of the autograft and rhBMP-7 groups. Applied clinically, this approach using rhBMP-7 could overcome autograft-associated limitations.

Doxorubicin-mediated bone loss in breast cancer bone metastases is driven by an interplay between oxidative stress and induction of TGFβ.

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Tapasi Rana

Full Text Available Breast cancer patients, who are already at increased risk of developing bone metastases and osteolytic bone damage, are often treated with doxorubicin. Unfortunately, doxorubicin has been reported to induce damage to bone. Moreover, we have previously reported that doxorubicin treatment increases circulating levels of TGFβ in murine pre-clinical models. TGFβ has been implicated in promoting osteolytic bone damage, a consequence of increased osteoclast-mediated resorption and suppression of osteoblast differentiation. Therefore, we hypothesized that in a preclinical breast cancer bone metastasis model, administration of doxorubicin would accelerate bone loss in a TGFβ-mediated manner. Administration of doxorubicin to 4T1 tumor-bearing mice produced an eightfold increase in osteolytic lesion areas compared untreated tumor-bearing mice (P = 0.002 and an almost 50% decrease in trabecular bone volume expressed in BV/TV (P = 0.0005, both of which were rescued by anti-TGFβ antibody (1D11. Doxorubicin, which is a known inducer of oxidative stress, decreased osteoblast survival and differentiation, which was rescued by N-acetyl cysteine (NAC. Furthermore, doxorubicin treatment decreased Cu-ZnSOD (SOD1 expression and enzyme activity in vitro, and treatment with anti-TGFβ antibody was able to rescue both. In conclusion, a combination therapy using doxorubicin and anti-TGFβ antibody might be beneficial for preventing therapy-related bone loss in cancer patients.

Bone-Inspired Spatially Specific Piezoelectricity Induces Bone Regeneration.

Science.gov (United States)

Yu, Peng; Ning, Chengyun; Zhang, Yu; Tan, Guoxin; Lin, Zefeng; Liu, Shaoxiang; Wang, Xiaolan; Yang, Haoqi; Li, Kang; Yi, Xin; Zhu, Ye; Mao, Chuanbin

2017-01-01

The extracellular matrix of bone can be pictured as a material made of parallel interspersed domains of fibrous piezoelectric collagenous materials and non-piezoelectric non-collagenous materials. To mimic this feature for enhanced bone regeneration, a material made of two parallel interspersed domains, with higher and lower piezoelectricity, respectively, is constructed to form microscale piezoelectric zones (MPZs). The MPZs are produced using a versatile and effective laser-irradiation technique in which K 0.5 Na 0.5 NbO 3 (KNN) ceramics are selectively irradiated to achieve microzone phase transitions. The phase structure of the laser-irradiated microzones is changed from a mixture of orthorhombic and tetragonal phases (with higher piezoelectricity) to a tetragonal dominant phase (with lower piezoelectricity). The microzoned piezoelectricity distribution results in spatially specific surface charge distribution, enabling the MPZs to bear bone-like microscale electric cues. Hence, the MPZs induce osteogenic differentiation of stem cells in vitro and bone regeneration in vivo even without being seeded with stem cells. The concept of mimicking the spatially specific piezoelectricity in bone will facilitate future research on the rational design of tissue regenerative materials.

Weight-making strategies in professional jockeys: implications for physical and mental health and well-being.

Science.gov (United States)

Wilson, George; Drust, Barry; Morton, James P; Close, Graeme L

2014-06-01

fractures), future research should specifically target strategies to improve bone health through the use of structured weight-bearing exercise and correcting nutritional deficiencies.

The observation about the change of the body weight for tumor patients and the bearing tumor mice in radiotherapy

International Nuclear Information System (INIS)

Wu Dijun; Ju Yongjian; Ning Liyan; Wu Hong; Wang Gaoren; Gao Xuan; Tang Yahong

2010-01-01

Objective: To observe the change of the body weight for tumor patients and the bearing tumor mice in radiotherapy. Methods: For 63 tumor patients, the body weight (BW) were measured before and after radiotherapy respectively, and then the change of BW were compared and analyzed with that of 23 healthy volunteers at the median treatment period. Also 45 mice bearing human galactophore tumor cells SK-BR-3 were divided into irradiation and non-irradiation groups, and the change of BW for these two groups were measured and analyzed. Results: The average BW decreases in the irradiation groups' mice but increase in the non-irradiation groups' mice, and the change of BW in these two groups has the statistical significance respectively, also the difference between these two groups has the statistical significance. For the four groups' tumor patients including 63 tumor patients as a whole, the nasopharynx cancer, esophagus cancer and lung cancer, the average BW decreases, but only in nasopharynx cancer and lung cancer groups the statistical significance are found. And at the same period, the BW of healthy volunteers are maintained. Compared change of BW in the four tumor groups with that in the healthy volunteers respectively, except the esophagus cancer group, the statistical significance are found in the other three groups. Conclusion: For tumor patients,perhaps the BW will lose in the period of radiotherapy, so the effect of lose of BW must be cared about. (authors)

FEASIBILITY STUDY OF AIR BEARING ROCKET SLED SLIPPERS

Science.gov (United States)

a simple self-acting type of bearing can support a typical monorail rocket sled, without contact between the slipper and the rail, at speeds between...slipper bearing is capable of preventing slipper-rail contact over the entire speed range of typical monorail and dual rail sleds. However, the weight and

Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging of focal vertebral bone marrow lesions: initial experience of the differentiation of nodular hyperplastic hematopoietic bone marrow from malignant lesions

Energy Technology Data Exchange (ETDEWEB)

Park, Sunghoon; Kwack, Kyu-Sung; Kim, Jae Ho [Ajou University School of Medicine, Division of Musculoskeletal Radiology, Department of Radiology, Suwon, Gyeonggi-do (Korea, Republic of); Ajou University Medical Center, Musculoskeletal Imaging Laboratory, Suwon (Korea, Republic of); Chung, Nam-Su [Ajou University School of Medicine, Department of Orthopaedic Surgery, Suwon (Korea, Republic of); Hwang, Jinwoo [Philips Healthcare, Department of Clinical Science, Seoul (Korea, Republic of); Lee, Hyun Young [Ajou University Medical Center, Regional Clinical Trial Center, Suwon (Korea, Republic of); Yonsei University College of Medicine, Department of Biostatistics, Seoul (Korea, Republic of)

2017-05-15

To evaluate the ability of intravoxel incoherent motion (IVIM) diffusion-weighted magnetic resonance imaging (MRI) parameters to differentiate nodular hyperplastic hematopoietic bone marrow (HHBM) from malignant vertebral bone marrow lesions (VBMLs). A total of 33 patients with 58 VBMLs, including 9 nodular HHBM lesions, 39 bone metastases, and 10 myelomas, were retrospectively assessed. All diagnoses were confirmed either pathologically or via image assessment. IVIM diffusion-weighted MRI with 11 b values (from 0 to 800 s/mm{sup 2}) were obtained using a 3.0-T MR imager. The apparent diffusion coefficient (ADC), pure diffusion coefficient (D), perfusion fraction (f), and pseudodiffusion coefficient (D*) were calculated. ADC and IVIM parameters were compared using the Mann-Whitney U test. Receiver operating characteristic (ROC) curve analysis was performed to assess the diagnostic performances of ADC, D, f, and D* in terms of VBML characterization. The diagnostic performance of morphological MR sequences was also assessed for comparison. The ADC and D values of nodular HHBM were significantly lower than those of malignant VBML (both p values < 0.001), whereas the f value was significantly higher (p < 0.001). However, there were no significant differences in D* between the two groups (p = 0.688). On ROC analysis, the area under the curve (AUC) for D was 1.000, which was significantly larger than that for ADC (AUC = 0.902). Intravoxel incoherent motion diffusion-weighted MRI can be used to differentiate between nodular HHBM and malignant VBML. The D value was significantly lower for nodular HHBM, and afforded a better diagnostic performance than the ADC, f, and D* values in terms of such differentiation. (orig.)

Bone-remodeling transcript levels are independent of perching in end-of-lay white leghorn chickens.

Science.gov (United States)

Dale, Maurice D; Mortimer, Erin M; Kolli, Santharam; Achramowicz, Erik; Borchert, Glenn; Juliano, Steven A; Halkyard, Scott; Sietz, Nick; Gatto, Craig; Hester, Patricia Y; Rubin, David A

2015-01-23

Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks) with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1), RANKL (receptor activator of nuclear factor kappa-B ligand), OPG (osteoprotegerin), PTHLH (PTH-like hormone), PTH1R (PTH/PTHLH type-1 receptor), PTH3R (PTH/PTHLH type-3 receptor), and SOX9 (Sry-related high mobility group box)) in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur > phalange). Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model.

Vascularized fibular graft in infected tibial bone loss

Directory of Open Access Journals (Sweden)

C Cheriyan Kovoor

2011-01-01

union occurred in all patients in a mean time of 3.3 months, at both ends. At a minimum followup of 24 months the mean hypertrophy noted was 63.6% (30 - 136% in the vascularized fibular graft. Ten stress fractures occurred in seven patients. The mean duration of the occurrence of a stress fracture in the graft was 11.1 months (2.5 - 18 months postoperatively. The highest incidence of stress fractures was when the graft hypertrophy was less than 20%. The incidence of stress fractures reduced significantly after the graft hypertrophy exceeded 20%. Conclusion : In most cases hypertrophy of the vascularized fibular graft occurs in response to mechanical loading by protected weight bearing, and the amount of hypertrophy is variable. The presence or absence of an intact fibula has no bearing on the hypertrophy or incidence of stress fracture. The length of the fibular graft has no bearing on the hypertrophy or stress fracture.

Validity of clinical outcome measures to evaluate ankle range of motion during the weight-bearing lunge test.

Science.gov (United States)

Hall, Emily A; Docherty, Carrie L

2017-07-01

To determine the concurrent validity of standard clinical outcome measures compared to laboratory outcome measure while performing the weight-bearing lunge test (WBLT). Cross-sectional study. Fifty participants performed the WBLT to determine dorsiflexion ROM using four different measurement techniques: dorsiflexion angle with digital inclinometer at 15cm distal to the tibial tuberosity (°), dorsiflexion angle with inclinometer at tibial tuberosity (°), maximum lunge distance (cm), and dorsiflexion angle using a 2D motion capture system (°). Outcome measures were recorded concurrently during each trial. To establish concurrent validity, Pearson product-moment correlation coefficients (r) were conducted, comparing each dependent variable to the 2D motion capture analysis (identified as the reference standard). A higher correlation indicates strong concurrent validity. There was a high correlation between each measurement technique and the reference standard. Specifically the correlation between the inclinometer placement at 15cm below the tibial tuberosity (44.9°±5.5°) and the motion capture angle (27.0°±6.0°) was r=0.76 (p=0.001), between the inclinometer placement at the tibial tuberosity angle (39.0°±4.6°) and the motion capture angle was r=0.71 (p=0.001), and between the distance from the wall clinical measure (10.3±3.0cm) to the motion capture angle was r=0.74 (p=0.001). This study determined that the clinical measures used during the WBLT have a high correlation with the reference standard for assessing dorsiflexion range of motion. Therefore, obtaining maximum lunge distance and inclinometer angles are both valid assessments during the weight-bearing lunge test. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Management of infected non-union tibia by intercalary bone transport

International Nuclear Information System (INIS)

Pirwani, M.A.; Siddiqui, A.; Soomro, Y.H.

2008-01-01

To evaluate the efficacy of ilizarov ring fixator in treating infected non-union tibia by intercalary bone transport. Sixteen patients, all males, aged 20-60 years (mean 32 years), with infected non-union tibia (Lax/Cierney Type IV Osteomyelitis); the commonest cause being open fracture and the commonest site being lower 1/3rd. In infected non-union of tibia with draining sinus, wound swab was sent for culture and sensitivity, and sinogram done. Debridement and sequestrectomy was done, leaving behind a gap ranging from 2-8 cms (mean 4.5 cms) and ilizarov ring fixator, a transport assembly, applied. A navigation wire was passed through medial malleolus, irrigation system set up and the wound closed in a single layer. Proximal metaphyseal corticotomy was done. Irrigation with 2-3 litres of normal saline with appropriate antibiotic was continued for five days. On the 5th day irrigation system was removed and the transport started. Patients remained on partial weight bearing till soft tissue healing occured. Transport took place over the navigation wire at the rate of 1mm/day till docking achieved. Full weight bearing was allowed after soft tissue healing; knee and ankle physiotherapy was started from day one. Navigation wire was removed after 2-3 weeks of docking. Follow up ranged from 12-27 months (mean 16 months). Union was achieved at the docking site in all the cases at the time of frame removal i.e. 8-13 months. The duration of union at docking site ranged from 3.5 months to 6 months (mean 4.5 months). Two patients needed bone graft at the docking site. The regenerate was broken in one case due to fall which was treated in cast. All the patients were satisfied except a 60 years old who had severe osteoarthritis of knee. Pin tract infection occurred on and off in all the patients; appropriate antibiotic was given. The infection subsided in all the cases except two in whom debridement was followed by application of a local flap. Intercalary bone transport by

Bone mineral density measurement over the shoulder region

DEFF Research Database (Denmark)

Doetsch, A M; Faber, J; Lynnerup, N

2002-01-01

values decreased with age (P shoulder BMD levels increased significantly with increased body mass index (BMI) (P positive relationship between the increased hip/shoulder BMD differential with BMI supports the conclusion that the shoulder is subject......The purpose of this study was to (1). establish a method for measuring bone mineral density (BMD) over the shoulder region; (2). compare the relationship between shoulder BMD levels with hip BMD and body mass index (BMI); and (3). discuss the relevance of the shoulder scan as an early indicator...... of osteoporosis compared with hip scans, the latter representing a weight-bearing part of the skeleton. We developed a scanning procedure, including a shoulder fixation device, and determined the most appropriate software in order to establish a reference material with the highest possible precision. Duplicate...

MR imaging of normal bone marrow

International Nuclear Information System (INIS)

Stajgis, M.; Paprzycki, W.

1994-01-01

Principles of MR bone marrow imaging on the basis of retrospective analysis of MR examinations of bone marrow in different anatomic sites in 200 patients have been discussed. Significance of different physiologic factors and processes such as age, steatosis, osteoporosis, conversion and reconversion, which influence on MR bone marrow images, have been emphasized. T1-weighted images obtained with spin-echo sequences give the most of information about bone marrow structure in MR. Thorough knowledge of bone marrow physiology and clinical status of the patient is indispensable in correct interpretation of hypointensive lesions on T1-weighted images. When presence of disseminated bone marrow disease is suspected, authors propose routine imaging of lumbar vertebral column, pelvis and proximal parts of femoral bones. (author)

Accuracy of DXA scanning of the thoracic spine: cadaveric studies comparing BMC, areal BMD and geometric estimates of volumetric BMD against ash weight and CT measures of bone volume.

Science.gov (United States)

Sran, Meena M; Khan, Karim M; Keiver, Kathy; Chew, Jason B; McKay, Heather A; Oxland, Thomas R

2005-12-01

Biomechanical studies of the thoracic spine often scan cadaveric segments by dual energy X-ray absorptiometry (DXA) to obtain measures of bone mass. Only one study has reported the accuracy of lateral scans of thoracic vertebral bodies. The accuracy of DXA scans of thoracic spine segments and of anterior-posterior (AP) thoracic scans has not been investigated. We have examined the accuracy of AP and lateral thoracic DXA scans by comparison with ash weight, the gold-standard for measuring bone mineral content (BMC). We have also compared three methods of estimating volumetric bone mineral density (vBMD) with a novel standard-ash weight (g)/bone volume (cm3) as measured by computed tomography (CT). Twelve T5-T8 spine segments were scanned with DXA (AP and lateral) and CT. The T6 vertebrae were excised, the posterior elements removed and then the vertebral bodies were ashed in a muffle furnace. We proposed a new method of estimating vBMD and compared it with two previously published methods. BMC values from lateral DXA scans displayed the strongest correlation with ash weight (r=0.99) and were on average 12.8% higher (pBMC (AP or lateral) was more strongly correlated with ash weight than areal bone mineral density (aBMD; AP: r=0.54, or lateral: r=0.71) or estimated vBMD. Estimates of vBMD with either of the three methods were strongly and similarly correlated with volumetric BMD calculated by dividing ash weight by CT-derived volume. These data suggest that readily available DXA scanning is an appropriate surrogate measure for thoracic spine bone mineral and that the lateral scan might be the scan method of choice.

Effect of Quercetin on Bone Mineral Status and Markers of Bone Turnover in Retinoic Acid-Induced Osteoporosis

Directory of Open Access Journals (Sweden)

Oršolić Nada

2018-06-01

Full Text Available Retinoic acid-induced osteoporosis (RBM is one of the most common causes of secondary osteoporosis. This study tested the anti-osteoporetic effect of quercetin in RBM-induced bone loss model (RBM. After 14-day supplementation of 13cRA to induce RBM, rats were administered with quercetin (100 mg/kg or alendronate (40 mg/kg. We analysed changes in body and uterine weight of animals, femoral geometric characteristics, calcium and phosphorus content, bone weight index, bone hystology, bone mineral density (BMD, markers of bone turnover, lipid peroxidation, glutathione levels and SOD, CAT activity of liver, kidney spleen, and ovary as well as biochemical and haematological variables. In comparison to the control RBM rats, the treatment with quercetin increased bone weight index, BMD, osteocalcin level, femoral geometric characteristics, calcium and phosphorus content in the 13cRA-induced bone loss model. Histological results showed its protective action through promotion of bone formation. According to the results, quercetin could be an effective substitution for alendronate in 13cRA-induced osteoporosis. Good therapeutic potential of quercetin on rat skeletal system is based partly on its antioxidant capacity and estrogenic activity.

Impact of obesity on bone metabolism.

Science.gov (United States)

López-Gómez, Juan J; Pérez Castrillón, José L; de Luis Román, Daniel A

2016-12-01

High weight is a protective factor against osteoporosis and risk of fracture. In obesity, however, where overweight is associated to excess fat, this relationship does not appear to be so clear, excess weight has sometimes been associated to decreased bone mass. Obesity interferes with bone metabolism through mechanical, hormonal, and inflammatory factors. These factors are closely related to weight, body composition, and dietary patterns of these patients. The net beneficial or harmful effect on bone mass or risk of fracture of the different components of this condition is not well known. We need to recognize patients at a greater risk of bone disease related to obesity to start an adequate intervention. Copyright © 2016. Publicado por Elsevier España, S.L.U.

An expression relating breaking stress and density of trabecular bone

DEFF Research Database (Denmark)

Rajapakse, C.S.; Thomsen, J.S.; Ortiz, J.S.E.

2004-01-01

Bone mineral density (BMD) is the principal diagnostic tool used in clinical settings to diagnose and monitor osteoporosis. Experimental studies on ex vivo bone samples from multiple skeletal locations have been used to propose that their breaking stress bears a power-law relationship to volumetric...

A Three-Dimensional Foil Bearing Performance Map Applied to Oil-Free Turbomachinery

Science.gov (United States)

2009-04-01

stress brought on by excessive viscous power loss; therefore a map that graphically relates component and system-level parameters (bearing size, applied...Introduction Foil bearings are self-acting, hydrodynamic gas bearings that use air as their working fluid . Their use in rotating systems eliminates the...weight, maintenance requirements, speed, and temperature limitations associated with conventional oil-lubricated rotor supports (i.e., bearings, dampers

Weight-bearing computed tomography findings in varus ankle osteoarthritis: abnormal internal rotation of the talus in the axial plane.

Science.gov (United States)

Kim, Ji-Beom; Yi, Young; Kim, Jae-Young; Cho, Jae-Ho; Kwon, Min-Soo; Choi, Seung-Hyuk; Lee, Woo-Chun

2017-08-01

To assess the incidence of abnormal internal rotation of the talus in the axial plane in patients with varus ankle osteoarthritis, and to determine whether this incidence differs from the severity of varus ankle osteoarthritis (moderate versus severe). We retrospectively evaluated weight-bearing computed tomography (CT) and plain radiographs of 52 ankles with no abnormalities (control group) and 96 ankles with varus osteoarthritis (varus-OA group), which were further stratified into a moderate-OA subgroup (50 ankles) and a severe-OA subgroup (46 ankles). A new radiographic parameter on weight-bearing CT, the talus rotation ratio, was used to assess the rotation of the talus in the axial plane. The normal range of the talus rotation ratio was defined as the 95% prediction interval for talus rotation ratio values in the control group. Abnormal internal rotation of the talus was defined for talus rotation ratio values above the normal range. We determined the incidence of abnormal internal rotation of the talus in the varus-OA group, moderate-OA subgroup, and severe-OA subgroup. In the varus-OA group, the incidence of abnormal internal rotation of the talus was 45% (43 ankles), which corresponded to an incidence of 32% (16 ankles) in the moderate-OA subgroup and 59% (27 ankles) in the severe-OA subgroup (p = 0.013). Our study demonstrates that abnormal internal rotation of the talus occurs in patients with varus ankle osteoarthritis, and is more frequently noted in severe than in moderate varus ankle osteoarthritis.

Weight-bearing computed tomography findings in varus ankle osteoarthritis: abnormal internal rotation of the talus in the axial plane

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji-Beom; Yi, Young; Lee, Woo-Chun [Seoul Foot and Ankle Center, Dubalo Orthopaedic Clinic, Seochogu, Seoul (Korea, Republic of); Kim, Jae-Young; Kwon, Min-Soo; Choi, Seung-Hyuk [Inje University Seoul Paik Hospital, Department of Orthopaedic Surgery, Jung-gu, Seoul (Korea, Republic of); Cho, Jae-Ho [Hallym University, ChunCheon Sacred Heart Hospital, Department of Orthopaedic Surgery, Chuncheon, GangWon-do (Korea, Republic of)

2017-08-15

To assess the incidence of abnormal internal rotation of the talus in the axial plane in patients with varus ankle osteoarthritis, and to determine whether this incidence differs from the severity of varus ankle osteoarthritis (moderate versus severe). We retrospectively evaluated weight-bearing computed tomography (CT) and plain radiographs of 52 ankles with no abnormalities (control group) and 96 ankles with varus osteoarthritis (varus-OA group), which were further stratified into a moderate-OA subgroup (50 ankles) and a severe-OA subgroup (46 ankles). A new radiographic parameter on weight-bearing CT, the talus rotation ratio, was used to assess the rotation of the talus in the axial plane. The normal range of the talus rotation ratio was defined as the 95% prediction interval for talus rotation ratio values in the control group. Abnormal internal rotation of the talus was defined for talus rotation ratio values above the normal range. We determined the incidence of abnormal internal rotation of the talus in the varus-OA group, moderate-OA subgroup, and severe-OA subgroup. In the varus-OA group, the incidence of abnormal internal rotation of the talus was 45% (43 ankles), which corresponded to an incidence of 32% (16 ankles) in the moderate-OA subgroup and 59% (27 ankles) in the severe-OA subgroup (p = 0.013). Our study demonstrates that abnormal internal rotation of the talus occurs in patients with varus ankle osteoarthritis, and is more frequently noted in severe than in moderate varus ankle osteoarthritis. (orig.)

Weight-bearing computed tomography findings in varus ankle osteoarthritis: abnormal internal rotation of the talus in the axial plane

International Nuclear Information System (INIS)

Kim, Ji-Beom; Yi, Young; Lee, Woo-Chun; Kim, Jae-Young; Kwon, Min-Soo; Choi, Seung-Hyuk; Cho, Jae-Ho

2017-01-01

To assess the incidence of abnormal internal rotation of the talus in the axial plane in patients with varus ankle osteoarthritis, and to determine whether this incidence differs from the severity of varus ankle osteoarthritis (moderate versus severe). We retrospectively evaluated weight-bearing computed tomography (CT) and plain radiographs of 52 ankles with no abnormalities (control group) and 96 ankles with varus osteoarthritis (varus-OA group), which were further stratified into a moderate-OA subgroup (50 ankles) and a severe-OA subgroup (46 ankles). A new radiographic parameter on weight-bearing CT, the talus rotation ratio, was used to assess the rotation of the talus in the axial plane. The normal range of the talus rotation ratio was defined as the 95% prediction interval for talus rotation ratio values in the control group. Abnormal internal rotation of the talus was defined for talus rotation ratio values above the normal range. We determined the incidence of abnormal internal rotation of the talus in the varus-OA group, moderate-OA subgroup, and severe-OA subgroup. In the varus-OA group, the incidence of abnormal internal rotation of the talus was 45% (43 ankles), which corresponded to an incidence of 32% (16 ankles) in the moderate-OA subgroup and 59% (27 ankles) in the severe-OA subgroup (p = 0.013). Our study demonstrates that abnormal internal rotation of the talus occurs in patients with varus ankle osteoarthritis, and is more frequently noted in severe than in moderate varus ankle osteoarthritis. (orig.)

Should risk of bone fragility restrict weight control for other health reasons in postmenopausal women?--A ten year prospective study.

Science.gov (United States)

Sirola, Joonas; Rikkonen, Toni; Tuppurainen, Marjo; Honkanen, Risto; Kröger, Heikki

2012-02-01

The aim of the present study was to investigate the health risks of excess body weight in the light of its protective effects on bone fragility. Femoral neck and lumbar spine dual X-ray absorptiometry was performed for 1970 Finnish women with a mean baseline age of 58.8 years (range 53.1-65.7 years) in 1994 and 2004. Women were categorized according to baseline BMI into normal obese ≥30 kg/m(2). Weight change (kg) was categorized into tertiles. Co-morbidities, not allowed to be present at baseline, was based on self-reports. Osteoporosis was defined as femoral neck or spinal (L2-L4) T-score Obesity (Ob) and overweight (Ow) were related with higher 10-year risk of hypertension (OR=2.6 (Ob)/OR=1.7 (Ow), posteoporosis (OR=0.13/OR=0.28, pobese women the absolute risk increase of hypertension was 17%, of diabetes 12%, and absolute risk reduction of osteoporosis 14% in comparison to BMI <25 kg/m(2). Health related risks of high BMI outweigh its protective effects on bone. Weight gain increases the risk hypertension and breast cancer. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Flexible intramedullary nailing for unicameral cysts in children's long bones : Level of evidence: lV, case series.

Science.gov (United States)

Glanzmann, Michael C; Campos, Lautaro

2007-07-01

The purpose of this study was to evaluate the outcome of flexible intramedullary nailing for unicameral bone cysts in terms of function and osseous consolidation. Twenty-two unicameral bone cysts in children's long bones were treated by flexible intramedullary nailing. In 13 cases the bone cyst was diagnosed in a traumatic event leading to a pathologic fracture. Fifteen patients were referred to our clinic after failed conservative treatment. In 16 patients the cyst was located in the humerus, and in 6 patients in the femur. Mean duration of follow-up after surgery was 24 months. According to Capanna's criteria healing was obtained in 20 cases with a mean time of 16 months. Sixteen cysts healed completely. Four lesions were classified as grade 2, meaning that residual radiolucencies were radiographically visible at the latest follow-up. Two recurrences of humeral cysts were seen at 16 and 18 months postoperatively. The complication rate was minimal. Due to the immediate stabilization of the lesion aftercare becomes facile. This method allows prompt mobilization and early weight bearing without the necessity of a plaster cast. Further it prevents effectively the most common complication, a re-fracture or a pathologic fracture. Therefore we propose this surgical procedure as the treatment of choice for unicameral bone cysts in children's long bones.

Unsuspected pregnancy during bone scintigraphy

International Nuclear Information System (INIS)

Oates, E.; Ramberg, K.; Becker, J.L.

1990-01-01

Despite careful screening efforts to avoid it, nuclear medicine studies are unintentionally performed on pregnant patients. Three-phase bone scanning is a common procedure performed in women of child-bearing age. Unsuspected pregnancies have been discovered on the flow and early view of the pelvis. The authors present a case of a pregnant girl, aged 15, who had a bone scan. They explain how this occurred and how they plan to prevent a recurrence. Dosimetry for the fetus also is considered

Potential effects of a low-molecular-weight fucoidan extracted from brown algae on bone biomaterial osteoconductive properties.

Science.gov (United States)

Changotade, S Igondjo Tchen; Korb, G; Bassil, J; Barroukh, B; Willig, C; Colliec-Jouault, S; Durand, P; Godeau, G; Senni, K

2008-12-01

In this work, we first tested the influence of low-molecular-weight (LMW) fucoidan extracted from pheophicae cell wall on bidimensional cultured normal human osteoblasts' behaviors. Second, by impregnation procedure with LMW fucoidan of bone biomaterial (Lubboc), we explored in this bone extracellular matrix context its capabilities to support human osteoblastic behavior in 3D culture. In bidimensionnal cultures, we evidenced that LMW fucoidan promotes human osteoblast proliferation and collagen type I expression and favors precocious alkaline phosphatase activity. Furthermore, with LMW fucoidan, von Kossa's staining was positive at 30 days and positive only at 45 days in the absence of LMW fucoidan. In our three-dimensional culture models with the biomaterial pretreated with LMW fucoidan, osteoblasts promptly overgrew the pretreated biomaterial. We also evidenced that osteoblasts increased proliferation with pretreated biomaterial when compared with untreated biomaterial. Osteoblasts secreted osteocalcin and expressed BMP2 receptor on control material as well as with LMW fucoidan impregnated biomaterial. In conclusion, in our experimental conditions, LMW fucoidan stimulated expression of osteoblastic markers differentiation such as alkaline phosphatase activity, collagen type I expression, and mineral deposition; furthermore, cell proliferation was favored. These findings suggest that fucoidan could be clinically useful for bone regeneration and bone substitute design. (c) 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2008.

Hydrogel/bioactive glass composites for bone regeneration applications: Synthesis and characterisation

International Nuclear Information System (INIS)

Killion, John A.; Kehoe, Sharon; Geever, Luke M.; Devine, Declan M.; Sheehan, Eoin; Boyd, Daniel; Higginbotham, Clement L.

2013-01-01

Due to the deficiencies of current commercially available biological bone grafts, alternative bone graft substitutes have come to the forefront of tissue engineering in recent times. The main challenge for scientists in manufacturing bone graft substitutes is to obtain a scaffold that has sufficient mechanical strength and bioactive properties to promote formation of new tissue. The ability to synthesise hydrogel based composite scaffolds using photopolymerisation has been demonstrated in this study. The prepared hydrogel based composites were characterised using techniques including Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy-dispersive X-ray spectrometry (EDX), rheological studies and compression testing. In addition, gel fraction, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), porosity and swelling studies of the composites were carried out. It was found that these novel hydrogel bioglass composite formulations did not display the inherent brittleness that is typically associated with bioactive glass based bone graft materials and exhibited enhanced biomechanical properties compared to the polyethylene glycol hydrogel scaffolds along. Together, the combination of enhanced mechanical properties and the deposition of apatite on the surface of these hydrogel based composites make them an ideal candidate as bone graft substitutes in cancellous bone defects or low load bearing applications. Highlights: • Young's modulus increases with the addition of bioactive glasses. • Hydrogel based composites formed an apatite layer in simulated body fluid. • Storage modulus increases with addition of bioactive glasses. • Compressive strength is dependent on molecular weight and bioactive glass loading

Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. II. Experiment

International Nuclear Information System (INIS)

Choi, Jang-Hwan; Maier, Andreas; Keil, Andreas; McWalter, Emily J.; Gold, Garry E.; Fahrig, Rebecca; Pal, Saikat; Beaupré, Gary S.

2014-01-01

Purpose: A C-arm CT system has been shown to be capable of scanning a single cadaver leg under loaded conditions by virtue of its highly flexible acquisition trajectories. In Part I of this study, using the 4D XCAT-based numerical simulation, the authors predicted that the involuntary motion in the lower body of subjects in weight-bearing positions would seriously degrade image quality and the authors suggested three motion compensation methods by which the reconstructions could be corrected to provide diagnostic image quality. Here, the authors demonstrate that a flat-panel angiography system is appropriate for scanning both legs of subjectsin vivo under weight-bearing conditions and further evaluate the three motion-correction algorithms using in vivo data. Methods: The geometry of a C-arm CT system for a horizontal scan trajectory was calibrated using the PDS-2 phantom. The authors acquired images of two healthy volunteers while lying supine on a table, standing, and squatting at several knee flexion angles. In order to identify the involuntary motion of the lower body, nine 1-mm-diameter tantalum fiducial markers were attached around the knee. The static mean marker position in 3D, a reference for motion compensation, was estimated by back-projecting detected markers in multiple projections using calibrated projection matrices and identifying the intersection points in 3D of the back-projected rays. Motion was corrected using three different methods (described in detail previously): (1) 2D projection shifting, (2) 2D deformable projection warping, and (3) 3D rigid body warping. For quantitative image quality analysis, SSIM indices for the three methods were compared using the supine data as a ground truth. Results: A 2D Euclidean distance-based metric of subjects’ motion ranged from 0.85 mm (±0.49 mm) to 3.82 mm (±2.91 mm) (corresponding to 2.76 to 12.41 pixels) resulting in severe motion artifacts in 3D reconstructions. Shifting in 2D, 2D warping, and 3D

Engineering bone grafts with enhanced bone marrow and native scaffolds.

Science.gov (United States)

Hung, Ben P; Salter, Erin K; Temple, Josh; Mundinger, Gerhard S; Brown, Emile N; Brazio, Philip; Rodriguez, Eduardo D; Grayson, Warren L

2013-01-01

The translation of tissue engineering approaches to the clinic has been hampered by the inability to find suitable multipotent cell sources requiring minimal in vitro expansion. Enhanced bone marrow (eBM), which is obtained by reaming long bone medullary canals and isolating the solid marrow putty, has large quantities of stem cells and demonstrates significant potential to regenerate bone tissues. eBM, however, cannot impart immediate load-bearing mechanical integrity or maintain the gross anatomical structure to guide bone healing. Yet, its putty-like consistency creates a challenge for obtaining the uniform seeding necessary to effectively combine it with porous scaffolds. In this study, we examined the potential for combining eBM with mechanically strong, osteoinductive trabecular bone scaffolds for bone regeneration by creating channels into scaffolds for seeding the eBM. eBM was extracted from the femurs of adult Yorkshire pigs using a Synthes reamer-irrigator-aspirator device, analyzed histologically, and digested to extract cells and characterize their differentiation potential. To evaluate bone tissue formation, eBM was seeded into the channels in collagen-coated or noncoated scaffolds, cultured in osteogenic conditions for 4 weeks, harvested and assessed for tissue distribution and bone formation. Our data demonstrates that eBM is a heterogenous tissue containing multipotent cell populations. Furthermore, coating scaffolds with a collagen hydrogel significantly enhanced cellular migration, promoted uniform tissue development and increased bone mineral deposition. These findings suggest the potential for generating customized autologous bone grafts for treating critical-sized bone defects by combining a readily available eBM cell source with decellularized trabecular bone scaffolds. © 2013 S. Karger AG, Basel

Wayside Bearing Fault Diagnosis Based on Envelope Analysis Paved with Time-Domain Interpolation Resampling and Weighted-Correlation-Coefficient-Guided Stochastic Resonance

Directory of Open Access Journals (Sweden)

Yongbin Liu

2017-01-01

Full Text Available Envelope spectrum analysis is a simple, effective, and classic method for bearing fault identification. However, in the wayside acoustic health monitoring system, owing to the high relative moving speed between the railway vehicle and the wayside mounted microphone, the recorded signal is embedded with Doppler effect, which brings in shift and expansion of the bearing fault characteristic frequency (FCF. What is more, the background noise is relatively heavy, which makes it difficult to identify the FCF. To solve the two problems, this study introduces solutions for the wayside acoustic fault diagnosis of train bearing based on Doppler effect reduction using the improved time-domain interpolation resampling (TIR method and diagnosis-relevant information enhancement using Weighted-Correlation-Coefficient-Guided Stochastic Resonance (WCCSR method. First, the traditional TIR method is improved by incorporating the original method with kinematic parameter estimation based on time-frequency analysis and curve fitting. Based on the estimated parameters, the Doppler effect is removed using the TIR easily. Second, WCCSR is employed to enhance the diagnosis-relevant period signal component in the obtained Doppler-free signal. Finally, paved with the above two procedures, the local fault is identified using envelope spectrum analysis. Simulated and experimental cases have verified the effectiveness of the proposed method.

Impact of low-weight severity and menstrual status on bone in adolescent girls with anorexia nervosa.

Science.gov (United States)

Kandemir, Nurgun; Becker, Kendra; Slattery, Meghan; Tulsiani, Shreya; Singhal, Vibha; Thomas, Jennifer J; Coniglio, Kathryn; Lee, Hang; Miller, Karen K; Eddy, Kamryn T; Klibanski, Anne; Misra, Madhusmita

2017-04-01

Clinicians currently use different low-weight cut-offs both to diagnose anorexia nervosa (AN) and to determine AN severity in adolescent girls. The purpose of this study was to evaluate the clinical utility of existing cut-offs and severity criteria by determining which are most strongly associated with risk for low bone mineral density (BMD). Height adjusted BMD Z scores were calculated for 352 females: 262 with AN and 90 healthy controls (controls) (12-20.5 years), using data from the BMD in Childhood Study, for the lumbar spine, whole body less head, and total hip. For most cut-offs used to define low weight (5th or 10th BMI percentile, BMI of 17.5 or 18.5, and 85 or 90% of median BMI), AN had lower BMD Z scores than controls. AN at >85 or >90% expected body weight for height (EBW-Ht) did not differ in BMD Z scores from controls, but differed significantly from AN at ≤85 or ≤90% EBW-Ht. Among AN, any amenorrhea was associated with lower BMD. AN had lower BMD than controls across DSM-5 and The Society for Adolescent Health and Medicine (SAHM) severity categories. The SAHM moderate severity classification was differentiated from the mildly malnourished classification by lower BMD at hip and spine sites. Amenorrhea and %EBW-Ht ≤ 85 or ≤ 90% are markers of severity of bone loss within AN. Among severity categories, BMI Z scores (SAHM) may have the greatest utility in assessing the degree of malnutrition in adolescent girls that corresponds to lower BMD. © 2017 Wiley Periodicals, Inc.

Fixation of Hydroxyapatite-Coated Revision Implants Is Improved by the Surgical Technique of Cracking the Sclerotic Bone Rim

Science.gov (United States)

Elmengaard, Brian; Bechtold, Joan E.; Chen, Xinqian; Søballe, Kjeld

2013-01-01

Revision joint replacement has poorer outcomes that have been associated with poorer mechanical fixation. We investigate a new bone-sparing surgical technique that locally cracks the sclerotic bone rim formed during aseptic loosening. We inserted 16 hydroxyapatite-coated implants bilaterally in the distal femur of eight dogs, using a controlled weight-bearing experimental model that replicates important features of a typical revision setting. At 8 weeks, a control revision procedure and a crack revision procedure were performed on contralateral implants. The crack procedure used a splined tool to perform a systematic local perforation of the sclerotic bone rim of the revision cavity. After 4 weeks, the hydroxyapatite-coated implants were evaluated for mechanical fixation by a push-out test and for tissue distribution by histomorphometry. The cracking revision procedure resulted in significantly improved mechanical fixation, significantly more bone ongrowth and bone volume in the gap, and reduced fibrous tissue compared to the control revision procedure. The study demonstrates that the sclerotic bone rim prevents bone ingrowth and promotes fixation by fibrous tissue. The effect of the cracking technique may be due to improved access to the vascular compartment of the bone. The cracking technique is a simple surgical method that potentially can improve the fixation of revision implants in sclerotic regions important for obtaining the fixation critical for overall implant stability. PMID:19148940

Granuloma debridement and the use of an injectable calcium phosphate bone cement in the treatment of osteolysis in an uncemented total knee replacement

Directory of Open Access Journals (Sweden)

Ranawat Vijai S

2010-04-01

Full Text Available Abstract Polyethylene particulate debris-induced periprosthetic osteolysis is a known complication of knee arthroplasty surgery, and may result in the need for revision surgery. The management of these bony defects can be surgically challenging, and full revisions of well-fixed total knee components can lead to substantial bone loss. We present the case of a 71 year old man who developed knee pain and osteolysis around an uncemented total knee replacement. Due to significant medical comorbidies he was treated by percutaneous cyst granuloma debridement and grafting using an injectable calcium phosphate bone substitute. There were no wound complications, and the patient was allowed to fully weight-bear post-operatively. Histopathology and microbiology of the cyst material confirmed polyethylene granulomata without any evidence of infection. At 6 weeks post-operatively the patient's previous knee pain had resolved, he was able to comfortably fully weight-bear. Preoperative scores (Knee Society Score (KSS 41, WOMAC score 46.2, and Oxford Knee Score 39 had all improved at the 12-month post-operative review KSS 76, WOMAC 81.7 and Oxford Knee score 21. This is a safe and effective technique with minimal morbidity and may be an appropriate treatment modality when more extensive revision surgery is not possible. The case is discussed with reference to the literature.

Low bone mineral density in ambulatory persons with cerebral palsy? A systematic review.

Science.gov (United States)

Mus-Peters, Cindy T R; Huisstede, Bionka M A; Noten, Suzie; Hitters, Minou W M G C; van der Slot, Wilma M A; van den Berg-Emons, Rita J G

2018-05-22

Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I-III) was studied. Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score ≤ -2.0. In addition, we focused on Z-score ≤ -1.0 because this may indicate a tendency towards low bone mineral density. We included 16 studies, comprising 465 patients aged 1-65 years. Moderate and conflicting evidence for low bone mineral density (Z-score ≤ -2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score ≤ -1.0) for several body parts. Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy. Implications for Rehabilitation Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP. Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view. If indicated, medication and fall prevention training should be prescribed.

Relationship between strains of tumor-bearing animals and the tumor affinity of /sup 169/Yb and /sup 67/Ga

Energy Technology Data Exchange (ETDEWEB)

Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K; Ando, I; Ugiie, T

1975-02-01

It is well a well-known fact that ytterbium-169 is a strong bone seeking element. We have already reported that this element was concentrated in nonosseous tumor tissues and that its tumor affinity was stronger than that of gallium-67 in our previous experiment using Yoshida sarcoma-bearing rats. Ytterbium-169 citrate and gallium-67 citrate were compared in four strains of tumor-bearing rats and mice. The uptake rate of ytterbium-169 in tumor tissues was much larger than that of gallium-67 in Ehrlich cancer-bearing mice, but these values of ytterbium-169 were slightly smaller than those of gallium-67 in Yoshida sarcoma-bearing rats, Walker carcinosarcoma 256-bearing rats and sarcoma 180-bearing mice. Tumor to organ ratios of ytterbium-169, which were most important for tumor scanning agents, were much larger than those of gallium-67 in all four strains except for the tumor to bone ratio of ytterbium-169. From the above-described facts, it was shown that ytterbium-169 citrate had a stronger tumor affinity than did gallium-67 citrate and that the tumor affinity of ytterbium-169 citrate was similar in each of these four strains of tumor-bearing animals.

Balancing the Rates of New Bone Formation and Polymer Degradation Enhances Healing of Weight-Bearing Allograft/Polyurethane Composites in Rabbit Femoral Defects

Science.gov (United States)

2014-10-03

Hofwegen, C., Marsh, J.L., and Brown, T.D. Is elevated contact stress predictive of post traumatic osteoarthritis for imprecisely reduced tibial plafond...Boyd, S.K., Christiansen, B.A., Guldberg, R.E., Jepsen, K.J., and Muller, R. Guidelines for assessment of bone microstructure in rodents using micro

Bone-Remodeling Transcript Levels Are Independent of Perching in End-of-Lay White Leghorn Chickens

Directory of Open Access Journals (Sweden)

Maurice D. Dale

2015-01-01

Full Text Available Osteoporosis is a bone disease that commonly results in a 30% incidence of fracture in hens used to produce eggs for human consumption. One of the causes of osteoporosis is the lack of mechanical strain placed on weight-bearing bones. In conventionally-caged hens, there is inadequate space for chickens to exercise and induce mechanical strain on their bones. One approach is to encourage mechanical stress on bones by the addition of perches to conventional cages. Our study focuses on the molecular mechanism of bone remodeling in end-of-lay hens (71 weeks with access to perches. We examined bone-specific transcripts that are actively involved during development and remodeling. Using real-time quantitative PCR, we examined seven transcripts (COL2A1 (collagen, type II, alpha 1, RANKL (receptor activator of nuclear factor kappa-B ligand, OPG (osteoprotegerin, PTHLH (PTH-like hormone, PTH1R (PTH/PTHLH type-1 receptor, PTH3R (PTH/PTHLH type-3 receptor, and SOX9 (Sry-related high mobility group box in phalange, tibia and femur. Our results indicate that the only significant effect was a difference among bones for COL2A1 (femur > phalange. Therefore, we conclude that access to a perch did not alter transcript expression. Furthermore, because hens have been used as a model for human bone metabolism and osteoporosis, the results indicate that bone remodeling due to mechanical loading in chickens may be a product of different pathways than those involved in the mammalian model.

Local administration of calcitriol positively influences bone remodeling and maturation during restoration of mandibular bone defects in rats

International Nuclear Information System (INIS)

Liu, Hongrui; Cui, Jian; Feng, Wei; Lv, Shengyu; Du, Juan; Sun, Jing; Han, Xiuchun; Wang, Zhenming; Lu, Xiong; Yimin; Oda, Kimimitsu; Amizuka, Norio; Li, Minqi

2015-01-01

The aim of this study was to investigate the influence of calcitriol on osteoinduction following local administration into mandibular bone defects. Calcitriol-loaded absorbable collagen membrane scaffolds were prepared using the polydopamine coating method and characterized by scanning electron microscopy. Composite scaffolds were implanted into rat mandibular bone defects in the following groups: no graft material (control), bare collagen membrane (CM group), collagen membrane bearing polydopamine coating (DOP/CM group), and collagen membrane bearing polydopamine coating absorbed with calcitriol (CAL/DOP/CM group). At 1, 2, 4 and 8 weeks post-surgery, the osteogenic potential of calcitriol was examined by histological and immunohistochemical methods. Following in vivo implantation, calcitriol-loaded composite scaffolds underwent rapid degradation with pronounced replacement by new bone and induced reunion of the bone marrow cavity. Calcitriol showed strong potential in inhibiting osteoclastogenesis and promotion of osteogenic differentiation at weeks 1, and 2. Furthermore, statistical analysis revealed that the newly formed bone volume in the CAL/DOP/CM group was significantly higher than other groups at weeks 1, and 2. At weeks 4, and 8, the CAL/DOP/CM group showed more mineralized bone and uniform collagen structure. These data suggest that local administration of calcitriol is promising in promoting osteogenesis and mineralization for restoration of mandibular bone defects. - Highlights: • More information on collagen material was added in the revised manuscript. • Masson–Goldner trichrome stain was performed for histomorphometry. • More specific information on calcitriol was supplemented in the Discussion section. • The MOD of ALP and Runx2 was explained in more detail. • The inhibition of osteoclastogenesis was described more accurately in the second paragraph of the discussion

Local administration of calcitriol positively influences bone remodeling and maturation during restoration of mandibular bone defects in rats

Energy Technology Data Exchange (ETDEWEB)

Liu, Hongrui; Cui, Jian; Feng, Wei; Lv, Shengyu; Du, Juan; Sun, Jing; Han, Xiuchun [Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan (China); Wang, Zhenming; Lu, Xiong [Key Lab of Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu, Sichuan (China); Yimin [Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Sapporo (Japan); Oda, Kimimitsu [Division of Biochemistry, Niigata University Graduate School of Medical and Dental Sciences, Niigata (Japan); Amizuka, Norio [Department of Developmental Biology of Hard Tissue, Graduate School of Dental Medicine, Hokkaido University, Sapporo (Japan); Li, Minqi, E-mail: liminqi@sdu.edu.cn [Department of Bone Metabolism, School of Stomatology Shandong University, Shandong Provincial Key Laboratory of Oral Biomedicine, Jinan (China)

2015-04-01

The aim of this study was to investigate the influence of calcitriol on osteoinduction following local administration into mandibular bone defects. Calcitriol-loaded absorbable collagen membrane scaffolds were prepared using the polydopamine coating method and characterized by scanning electron microscopy. Composite scaffolds were implanted into rat mandibular bone defects in the following groups: no graft material (control), bare collagen membrane (CM group), collagen membrane bearing polydopamine coating (DOP/CM group), and collagen membrane bearing polydopamine coating absorbed with calcitriol (CAL/DOP/CM group). At 1, 2, 4 and 8 weeks post-surgery, the osteogenic potential of calcitriol was examined by histological and immunohistochemical methods. Following in vivo implantation, calcitriol-loaded composite scaffolds underwent rapid degradation with pronounced replacement by new bone and induced reunion of the bone marrow cavity. Calcitriol showed strong potential in inhibiting osteoclastogenesis and promotion of osteogenic differentiation at weeks 1, and 2. Furthermore, statistical analysis revealed that the newly formed bone volume in the CAL/DOP/CM group was significantly higher than other groups at weeks 1, and 2. At weeks 4, and 8, the CAL/DOP/CM group showed more mineralized bone and uniform collagen structure. These data suggest that local administration of calcitriol is promising in promoting osteogenesis and mineralization for restoration of mandibular bone defects. - Highlights: • More information on collagen material was added in the revised manuscript. • Masson–Goldner trichrome stain was performed for histomorphometry. • More specific information on calcitriol was supplemented in the Discussion section. • The MOD of ALP and Runx2 was explained in more detail. • The inhibition of osteoclastogenesis was described more accurately in the second paragraph of the discussion.

Uranium-series dating of fossil bones from alpine caves

International Nuclear Information System (INIS)

Leitner-Wild, E.; Steffan, I.

1993-01-01

During the course of an investigation of fossil cave bear populations the uranium-series method for absolute age determination has been applied to bone material. The applicability of the method to bone samples from alpine caves is demonstrated by the concordance of U/Th and U/Pa ages and cross-checks with the radiocarbon method. Stratigraphic agreement between bone ages and carbonate speleothem ages also indicates the potential of the uranium-series method as a suitable tool for the age determination of fossil bones from alpine cave environments. (Author)

Hormone replacement therapy dissociates fat mass and bone mass, and tends to reduce weight gain in early postmenopausal women

DEFF Research Database (Denmark)

Jensen, L B; Vestergaard, P; Hermann, A P

2003-01-01

in women randomized to HRT (1.94 +/- 4.86 kg) than in women randomized to no HRT (2.57 +/- 4.63, p = 0.046). A similar pattern was seen in the group receiving HRT or not by their own choice. The smaller weight gain in women on HRT was almost entirely caused by a lesser gain in fat. The main determinant...... of the weight gain was a decline in physical fitness. Women opting for HRT had a significantly lower body weight at inclusion than the other participants, but the results in the self-selected part of the study followed the pattern found in the randomized part. The change in fat mass was the strongest predictor...... of bone changes in untreated women, whereas the change in lean body mass was the strongest predictor when HRT was given. Body weight increases after the menopause. The gain in weight is related to a decrease in working capacity. HRT is associated with a smaller increase in fat mass after menopause. Fat...

Evaluation of bone marrow by opposed phase T1-weighted images and enhanced MR imaging

International Nuclear Information System (INIS)

Amano, Yasuo; Tanabe, Yoshihiro; Miyashita, Tsuguhiro; Hayashi, Hiromitsu; Horiuchi, Junichi; Nomura, Takeo; Kumazaki, Tatsuo

1994-01-01

We investigated bone marrow in a control group, cases of aplastic anemia and post-irradiation patients by examining T1-weighted (T1W1), short T1 inversion recovery (STIR), opposed phase T1W1 (op-T1W1) and Gd-DTPA enhanced op-T1W1 images obtained by 0.5 T MRI. Bone marrow was classified into four types based on MR findings. Normal marrow showed low intensity on op-T1W1 and STIR images without enhancement (I). Fatty marrow, which showed high intensity on T1W1 and op-T1W1 images was observed in aplastic anemia and post-irradiation patients (II). Hematopoietic marrow (III) showed low intensity on op-T1W1 and enhanced, while active hematopoietic marrow (IV) revealed high intensity on both STIR and op-T1W1 images and was enhanced following Gd-DTPA infusion. Aplastic anemia of moderate grade included types II, III and IV. Enhanced MR was needed to differentiate between types I and III since both types showed low intensity on op-T1W1 images. Furthermore, type IV was considered as hyperplastic compared with type III. Enhanced MR and op-T1W1 images were useful in evaluating hematopoiesis of bone marrow. (author)

Evaluation of bone marrow by opposed phase T1-weighted images and enhanced MR imaging

Energy Technology Data Exchange (ETDEWEB)

Amano, Yasuo; Tanabe, Yoshihiro; Miyashita, Tsuguhiro; Hayashi, Hiromitsu; Horiuchi, Junichi; Nomura, Takeo; Kumazaki, Tatsuo (Nippon Medical School, Tokyo (Japan))

1994-09-01

We investigated bone marrow in a control group, cases of aplastic anemia and post-irradiation patients by examining T1-weighted (T1W1), short T1 inversion recovery (STIR), opposed phase T1W1 (op-T1W1) and Gd-DTPA enhanced op-T1W1 images obtained by 0.5 T MRI. Bone marrow was classified into four types based on MR findings. Normal marrow showed low intensity on op-T1W1 and STIR images without enhancement (I). Fatty marrow, which showed high intensity on T1W1 and op-T1W1 images was observed in aplastic anemia and post-irradiation patients (II). Hematopoietic marrow (III) showed low intensity on op-T1W1 and enhanced, while active hematopoietic marrow (IV) revealed high intensity on both STIR and op-T1W1 images and was enhanced following Gd-DTPA infusion. Aplastic anemia of moderate grade included types II, III and IV. Enhanced MR was needed to differentiate between types I and III since both types showed low intensity on op-T1W1 images. Furthermore, type IV was considered as hyperplastic compared with type III. Enhanced MR and op-T1W1 images were useful in evaluating hematopoiesis of bone marrow. (author).

Structure of Clavicle In Relation to Weight Transmission

Science.gov (United States)

Routatal, Rohini V

2015-01-01

Aims and Objectives It is a known fact that weight of upper limb is transmitted to the axial skeleton through clavicle. The present study is an attempt to correlate pattern of compact and trabecular bone of clavicle as a weight transmitting bone. Materials and Methods Sixty clavicles were studied from right and left sides of 30 cadavers donated to the Anatomy department, Pramukhswami Medical College, Karamsad, India. The study was focused on the thickness of compact bone of clavicle and trabecular pattern of this bone. Results Cancellous bone: Cancellous bone near both ends of clavicle presented meshwork of thin bony plates. Between the conoid tubercle and area for attachment of costo-clavicular ligament, cancellous bone showed a definite pattern. Thickness of compact bone The compact bone was thicker between conoid tubercle and area for attachment of costo-clavicular ligament. At midshaft point thickness of compact bone was maximum. Conclusion The structure of clavicle between conoid tubercle and area for costoclavicular ligament showed thick compact bone and definite pattern of cancellous bone. This structure of clavicle between conoid tubercle and area for attachment of costo-clavicular ligament transmits weight from lateral to medial direction and this knowledge of clavicular structure will also be useful to orthopedic surgeons to deal with clavicular fractures and other abnormalities. PMID:26393112

Effects of growth hormone and low dose estrogen on bone growth and turnover in long bones of hypophysectomized rats

Science.gov (United States)

Kidder, L. S.; Schmidt, I. U.; Evans, G. L.; Turner, R. T.

1997-01-01

Pituitary hormones are recognized as critical to longitudinal growth, but their role in the radial growth of bone and in maintaining cancellous bone balance are less clear. This investigation examines the histomorphometric effects of hypophysectomy (Hx) and ovariectomy (OVX) and the subsequent replacement of growth hormone (GH) and estrogen (E), in order to determine the effects and possible interactions between these two hormones on cortical and cancellous bone growth and turnover. The replacement of estrogen is of interest since Hx results in both pituitary and gonadal hormone insufficiencies, with the latter being caused by the Hx-associated reduction in follicle stimulating hormone (FSH). All hypophysectomized animals received daily supplements of hydrocortisone (500 microg/kg) and L-thyroxine (10 microg/kg), whereas intact animals received daily saline injections. One week following surgery, hypophysectomized animals received either daily injections of low-dose 17 beta-estradiol (4.8 microg/kg s.c.), 3 X/d recombinant human GH (2 U/kg s.c.), both, or saline for a period of two weeks. Flurochromes were administered at weekly intervals to label bone matrix undergoing mineralization. Whereas Hx resulted in reductions in body weight, uterine weight, and tibial length, OVX significantly increased body weight and tibial length, while reducing uterine weight. The combination of OVX and Hx resulted in values similar to Hx alone. Treatment with GH normalized body weight and bone length, while not affecting uterine weight in hypophysectomized animals. Estrogen increased uterine weight, while not impacting longitudinal bone growth and reduced body weight. Hypophysectomy diminished tibial cortical bone area through reductions in both mineral appositional rate (MAR) and bone formation rate (BFR). While E had no effect, GH increased both MAR and BFR, though not to sham-operated (control) levels. Hypophysectomy reduced proximal tibial trabecular number and cancellous bone

Optimization of Bone Health in Children before and after Renal Transplantation: Current Perspectives and Future Directions

Science.gov (United States)

Sgambat, Kristen; Moudgil, Asha

2014-01-01

The accrual of healthy bone during the critical period of childhood and adolescence sets the stage for lifelong skeletal health. However, in children with chronic kidney disease (CKD), disturbances in mineral metabolism and endocrine homeostasis begin early on, leading to alterations in bone turnover, mineralization, and volume, and impairing growth. Risk factors for CKD–mineral and bone disorder (CKD–MBD) include nutritional vitamin D deficiency, secondary hyperparathyroidism, increased fibroblast growth factor 23 (FGF-23), altered growth hormone and insulin-like growth factor-1 axis, delayed puberty, malnutrition, and metabolic acidosis. After kidney transplantation, nutritional vitamin D deficiency, persistent hyperparathyroidism, tertiary FGF-23 excess, hypophosphatemia, hypomagnesemia, immunosuppressive therapy, and alteration of sex hormones continue to impair bone health and growth. As function of the renal allograft declines over time, CKD–MBD associated changes are reactivated, further impairing bone health. Strategies to optimize bone health post-transplant include healthy diet, weight-bearing exercise, correction of vitamin D deficiency and acidosis, electrolyte abnormalities, steroid avoidance, and consideration of recombinant human growth hormone therapy. Other drug therapies have been used in adult transplant recipients, but there is insufficient evidence for use in the pediatric population at the present time. Future therapies to be explored include anti-FGF-23 antibodies, FGF-23 receptor blockers, and treatments targeting the colonic microbiota by reduction of generation of bacterial toxins and adsorption of toxic end products that affect bone mineralization. PMID:24605319

A Flexible Method for Producing F.E.M. Analysis of Bone Using Open-Source Software

Science.gov (United States)

Boppana, Abhishektha; Sefcik, Ryan; Myers, Jerry G.; Lewandowski, Beth

2016-01-01

Individuals who experience decreases in load-bearing bone densities can be subject to a higher risk of bone fracture during daily activity. Astronauts may lose up to nine percent of their load-bearing bone density for every month they spend in space [1]. Because of this, specialized countermeasures reduce percent loss in bone density and reduce fracture risk upon returning to Earth. Astronauts will typically not be at risk for fracture during spaceflight, because of the lesser loads experienced in microgravity conditions. However, once back on Earth, astronauts have an increased risk for bone fracture as a result of weakened bone and return to 1G conditions [2]. It is therefore important to understand the significance of any bone density loss in addition to developing exercises in an attempt to limit losses in bone strength. NASA seeks to develop a deeper understanding of fracture risk through the development of a computational bone strength model to assess the bone fracture risk of astronauts pre-flight and post-flight. This study addresses the several key processes needed to develop such strength analyses using medical image processing and finite element modeling.

Lead-free bearing alloys for engine applications

Science.gov (United States)

Ratke, Lorenz; Ågren, John; Ludwig, Andreas; Tonn, Babette; Gránásy, László; Mathiesen, Ragnvald; Arnberg, Lars; Anger, Gerd; Reifenhäuser, Bernd; Lauer, Michael; Garen, Rune; Gust, Edgar

2005-10-01

Recent developments to reduce the fuel consumption, emission and air pollution, size and weight of engines for automotive, truck, ship propulsion and electrical power generation lead to temperature and load conditions within the engines that cannot be borne by conventional bearings. Presently, only costly multilayer bearings with electroplated or sputtered surface coatings can cope with the load/speed combinations required. Ecological considerations in recent years led to a ban by the European Commission on the use of lead in cars a problem for the standard bronze-lead bearing material. This MAP project is therefore developing an aluminium-based lead-free bearing material with sufficient hardness, wear and friction properties and good corrosion resistance. Only alloys made of components immiscible in the molten state can meet the demanding requirements. Space experimentation plays a crucial role in optimising the cast microstructure for such applications.

Functionalization of deproteinized bovine bone with a coating-incorporated depot of BMP-2 renders the material efficiently osteoinductive and suppresses foreign-body reactivity.

Science.gov (United States)

Wu, Gang; Hunziker, Ernst B; Zheng, Yuanna; Wismeijer, Daniel; Liu, Yuelian

2011-12-01

The repair of critical-sized bony defects remains a challenge in the fields of implantology, maxillofacial surgery and orthopaedics. As an alternative bone-defect filler to autologous bone grafts, deproteinized bovine bone (DBB) is highly osteoconductive and clinically now widely used. However, this product suffers from the disadvantage of not being intrinsically osteoinductive. In the present study, this property was conferred by coating DBB with a layer of calcium phosphate into which bone morphogenetic protein 2 (BMP-2) was incorporated. Granules of DBB bearing a coating-incorporated depot of BMP-2--together with the appropriate controls (DBB bearing a coating but no BMP-2; uncoated DBB bearing adsorbed BMP-2; uncoated DBB bearing no BMP-2)--were implanted subcutaneously in rats. Five weeks later, the implants were withdrawn for a histomorphometric analysis of the volume densities of (i) bone, (ii) bone marrow, (iii) foreign-body giant cells and (iv) fibrous capsular tissue. Parameters (i) and (ii) were highest, whilst parameters (iii) and (iv) were lowest in association with DBB bearing a coating-incorporated depot of BMP-2. Hence, this mode of functionalization not only confers DBB with the property of osteoinductivity but also improves its biocompatibility--thus dually enhancing its clinical potential in the repair of bony defects. Copyright © 2011 Elsevier Inc. All rights reserved.

Surface Engineering for Bone Implants: A Trend from Passive to Active Surfaces

Directory of Open Access Journals (Sweden)

John Jansen

2012-07-01

Full Text Available The mechanical and biological properties of bone implants need to be optimal to form a quick and firm connection with the surrounding environment in load bearing applications. Bone is a connective tissue composed of an organic collagenous matrix, a fine dispersion of reinforcing inorganic (calcium phosphate nanocrystals, and bone-forming and -degrading cells. These different components have a synergistic and hierarchical structure that renders bone tissue properties unique in terms of hardness, flexibility and regenerative capacity. Metallic and polymeric materials offer mechanical strength and/or resilience that are required to simulate bone tissue in load-bearing applications in terms of maximum load, bending and fatigue strength. Nevertheless, the interaction between devices and the surrounding tissue at the implant interface is essential for success or failure of implants. In that respect, coatings can be applied to facilitate the process of bone healing and obtain a continuous transition from living tissue to the synthetic implant. Compounds that are inspired by inorganic (e.g., hydroxyapatite crystals or organic (e.g., collagen, extracellular matrix components, enzymes components of bone tissue, are the most obvious candidates for application as implant coating to improve the performance of bone implants. This review provides an overview of recent trends and strategies in surface engineering that are currently investigated to improve the biological performance of bone implants in terms of functionality and biological efficacy.

Bioactive lipid coating of bone allografts directs engraftment and fate determination of bone marrow-derived cells in rat GFP chimeras.

Science.gov (United States)

Das, Anusuya; Segar, Claire E; Chu, Yihsuan; Wang, Tiffany W; Lin, Yong; Yang, Chunxi; Du, Xeujun; Ogle, Roy C; Cui, Quanjun; Botchwey, Edward A

2015-09-01

Bone grafting procedures are performed to treat wounds incurred during wartime trauma, accidents, and tumor resections. Endogenous mechanisms of repair are often insufficient to ensure integration between host and donor bone and subsequent restoration of function. We investigated the role that bone marrow-derived cells play in bone regeneration and sought to increase their contributions by functionalizing bone allografts with bioactive lipid coatings. Polymer-coated allografts were used to locally deliver the immunomodulatory small molecule FTY720 in tibial defects created in rat bone marrow chimeras containing genetically-labeled bone marrow for monitoring cell origin and fate. Donor bone marrow contributed significantly to both myeloid and osteogenic cells in remodeling tissue surrounding allografts. FTY720 coatings altered the phenotype of immune cells two weeks post-injury, which was associated with increased vascularization and bone formation surrounding allografts. Consequently, degradable polymer coating strategies that deliver small molecule growth factors such as FTY720 represent a novel therapeutic strategy for harnessing endogenous bone marrow-derived progenitors and enhancing healing in load-bearing bone defects. Copyright © 2015 Elsevier Ltd. All rights reserved.

Behavioral, medical imaging and histopathological features of a new rat model of bone cancer pain.

Directory of Open Access Journals (Sweden)

Louis Doré-Savard

2010-10-01

Full Text Available Pre-clinical bone cancer pain models mimicking the human condition are required to respond to clinical realities. Breast or prostate cancer patients coping with bone metastases experience intractable pain, which affects their quality of life. Advanced monitoring is thus required to clarify bone cancer pain mechanisms and refine treatments. In our model of rat femoral mammary carcinoma MRMT-1 cell implantation, pain onset and tumor growth were monitored for 21 days. The surgical procedure performed without arthrotomy allowed recording of incidental pain in free-moving rats. Along with the gradual development of mechanical allodynia and hyperalgesia, behavioral signs of ambulatory pain were detected at day 14 by using a dynamic weight-bearing apparatus. Osteopenia was revealed from day 14 concomitantly with disorganization of the trabecular architecture (µCT. Bone metastases were visualized as early as day 8 by MRI (T(1-Gd-DTPA before pain detection. PET (Na(18F co-registration revealed intra-osseous activity, as determined by anatomical superimposition over MRI in accordance with osteoclastic hyperactivity (TRAP staining. Pain and bone destruction were aggravated with time. Bone remodeling was accompanied by c-Fos (spinal and ATF3 (DRG neuronal activation, sustained by astrocyte (GFAP and microglia (Iba1 reactivity in lumbar spinal cord. Our animal model demonstrates the importance of simultaneously recording pain and tumor progression and will allow us to better characterize therapeutic strategies in the future.

The effects of orbital spaceflight on bone histomorphometry and messenger ribonucleic acid levels for bone matrix proteins and skeletal signaling peptides in ovariectomized growing rats

Science.gov (United States)

Cavolina, J. M.; Evans, G. L.; Harris, S. A.; Zhang, M.; Westerlind, K. C.; Turner, R. T.

1997-01-01

A 14-day orbital spaceflight was performed using ovariectomized Fisher 344 rats to determine the combined effects of estrogen deficiency and near weightlessness on tibia radial bone growth and cancellous bone turnover. Twelve ovariectomized rats with established cancellous osteopenia were flown aboard the space shuttle Columbia (STS-62). Thirty ovariectomized rats were housed on earth as ground controls: 12 in animal enclosure modules, 12 in vivarium cages, and 6 killed the day of launch for baseline measurements. An additional 18 ovary-intact rats were housed in vivarium cages as ground controls: 8 rats were killed as baseline controls and the remaining 10 rats were killed 14 days later. Ovariectomy increased periosteal bone formation at the tibia-fibula synostosis; cancellous bone resorption and formation in the secondary spongiosa of the proximal tibial metaphysis; and messenger RNA (mRNA) levels for the prepro-alpha2(1) subunit of type 1 collagen, osteocalcin, transforming growth factor-beta, and insulin-like growth factor I in the contralateral proximal tibial metaphysis and for the collagen subunit in periosteum pooled from tibiae and femora and decreased cancellous bone area. Compared to ovariectomized weight-bearing rats, the flight group experienced decreases in periosteal bone formation, collagen subunit mRNA levels, and cancellous bone area. The flight rats had a small decrease in the cancellous mineral apposition rate, but no change in the calculated bone formation rate. Also, spaceflight had no effect on cancellous osteoblast and osteoclast perimeters or on mRNA levels for bone matrix proteins and signaling peptides. On the other hand, spaceflight resulted in an increase in bone resorption, as ascertained from the diminished retention of a preflight fluorochrome label. This latter finding suggests that osteoclast activity was increased. In a follow-up ground-based experiment, unilateral sciatic neurotomy of ovariectomized rats resulted in cancellous

Development of a biodegradable bone cement

International Nuclear Information System (INIS)

Yusof Abdullah; Nurhaslinda Ee Abdullah; Wee Pee Chai; Norita Mohd Zain

2002-01-01

Biodegradable bone cement is a newly developed bone repair material, which is able to give immediate support to the implant area, and does not obstruct the bone repairing and regeneration process through appropriate biodegradation rate, which is synchronized with the mechanical load it should bear. The purpose of this study is to locally produce biodegradable bone cement using HA as absorbable filler. The cement is composed of an absorbable filler and unsaturated polyester for 100% degradation. Cross-linking effect is achieved through the action of poly (vinyl pyrrol lidone) (PVP) and an initiator. On the other hand, PPF was synthesized using direct esterification method. Characteristics of the bone cement were studied; these included the curing time, cross-linking effect and curing temperature. The products were characterized using X-Ray diffraction (XRD) to perform phase analysis and Scanning Electrons Microscopes to determine the morphology. The physical and mechanical properties of the bone cement were also investigated. The biocompatibility of the bone cement was tested using simulated body physiological solution. (Author)

Silk as a biocohesive sacrificial binder in the fabrication of hydroxyapatite load bearing scaffolds.

Science.gov (United States)

McNamara, Stephanie L; Rnjak-Kovacina, Jelena; Schmidt, Daniel F; Lo, Tim J; Kaplan, David L

2014-08-01

Limitations of current clinical methods for bone repair continue to fuel the demand for a high strength, bioactive bone replacement material. Recent attempts to produce porous scaffolds for bone regeneration have been limited by the intrinsic weakness associated with high porosity materials. In this study, ceramic scaffold fabrication techniques for potential use in load-bearing bone repairs have been developed using naturally derived silk from Bombyx mori. Silk was first employed for ceramic grain consolidation during green body formation, and later as a sacrificial polymer to impart porosity during sintering. These techniques allowed preparation of hydroxyapatite (HA) scaffolds that exhibited a wide range of mechanical and porosity profiles, with some displaying unusually high compressive strength up to 152.4 ± 9.1 MPa. Results showed that the scaffolds exhibited a wide range of compressive strengths and moduli (8.7 ± 2.7 MPa to 152.4 ± 9.1 MPa and 0.3 ± 0.1 GPa to 8.6 ± 0.3 GPa) with total porosities of up to 62.9 ± 2.7% depending on the parameters used for fabrication. Moreover, HA-silk scaffolds could be molded into large, complex shapes, and further machined post-sinter to generate specific three-dimensional geometries. Scaffolds supported bone marrow-derived mesenchymal stem cell attachment and proliferation, with no signs of cytotoxicity. Therefore, silk-fabricated HA scaffolds show promise for load bearing bone repair and regeneration needs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of swimming exercise on three-dimensional trabecular bone microarchitecture in ovariectomized rats.

Science.gov (United States)

Ju, Yong-In; Sone, Teruki; Ohnaru, Kazuhiro; Tanaka, Kensuke; Fukunaga, Masao

2015-11-01

Swimming is generally considered ineffective for increasing bone mass in humans, at least compared with weight-bearing sports. However, swimming exercise has sometimes been shown to have a strong positive effect on bone mass in small animals. This study investigated the effects of swimming on bone mass, strength, and microarchitecture in ovariectomized (OVX) rats. OVX or sham operations were performed on 18-wk-old female Fisher 344 rats. Rats were randomly divided into four groups: sham sedentary (Sham-CON), sham swimming exercised (Sham-SWI), OVX sedentary (OVX-CON), and OVX swimming exercised (OVX-SWI). Rats in exercise groups performed swimming in a water bath for 60 min/day, 5 days/wk, for 12 wk. Bone mineral density (BMD) in right femurs was analyzed using dual-energy X-ray absorptiometry. Three-dimensional trabecular architecture at the distal femoral metaphysis was analyzed using microcomputed tomography (μCT). Geometrical properties of diaphyseal cortical bone were evaluated in the midfemoral region using μCT. The biomechanical properties of femurs were analyzed using three-point bending. Femoral BMD was significantly decreased following ovariectomy. This change was suppressed by swimming. Trabecular bone thickness, number, and connectivity were decreased by ovariectomy, whereas structure model index (i.e., ratio of rod-like to plate-like trabeculae) increased. These changes were also suppressed by swimming exercise. Femurs displayed greater cortical width and maximum load in SWI groups than in CON groups. Together, these results demonstrate that swimming exercise drastically alleviated both OVX-induced decreases in bone mass and mechanical strength and the deterioration of trabecular microarchitecture in rat models of osteoporosis. Copyright © 2015 the American Physiological Society.

Idaho Nuclear Technology and Engineering Center Sodium-Bearing Waste Treatment Research and Development FY-2002 Status Report

Energy Technology Data Exchange (ETDEWEB)

Herbst, Alan Keith; Deldebbio, John Anthony; Mc Cray, John Alan; Kirkham, Robert John; Olson, Lonnie Gene; Scholes, Bradley Adams

2002-09-01

The Idaho National Engineering and Environmental Laboratory (INEEL) is considering several optional processes for disposal of liquid sodium-bearing waste. During fiscal year 2002, immobilization-related research included of grout formulation development for sodium-bearing waste, absorption of the waste on silica gel, and off-gas system mercury collection and breakthrough using activated carbon. Experimental results indicate that sodium-bearing waste can be immobilized in grout at 70 weight percent and onto silica gel at 74 weight percent. Furthermore, a loading of 11 weight percent mercury in sulfur-impregnated activated carbon was achieved with 99.8% off-gas mercury removal efficiency.

Geology and preliminary dating of the hominid-bearing sedimentary fill of the Sima de los Huesos Chamber, Cueva Mayor of the Sierra de Atapuerca, Burgos, Spain.

Science.gov (United States)

Bischoff, J L; Fitzpatrick, J A; León, L; Arsuagà, J L; Falgueres, C; Bahain, J J; Bullen, T

1997-01-01

Sediments of the Sima de los Huesos vary greatly over distances of a few meters. This is typical of interior cave facies, and caused by cycles of cut and fill. Mud breccias containing human bones, grading upwards to mud containing bear bones, fill an irregular surface cut into basal marks and sands. The lack of Bedding and the chaotic abundance of fragile speleothem clasts in the fossiliferous muds suggests that the deposit was originally a subterranean pond facies, and that after emplacement of the human remains, underwent vigorous post-depositional rotation and collapse and brecciation, caused by underlying bedrock dissolution and undermining. The fossiliferous deposits are capped by flowstone and guano-bearing muds which lack large-mammal fossils. U-series and radiocarbon dating indicates the capping flowstones formed from about 68 ka to about 25 ka. U-series analyses of speleothem clasts among the human fossils indicate that all are at, or close to, isotopic equilibrium (> 350 ka). The distribution of U-series dates for 25 bear bones (154 +/- 66 ka) and for 16 human bones (148 +/- 34 ka) is similar and rather broad. Because the human bones seem to be stratigraphically older than chose of the bears, the results would indicate that most of the bones have been accumulating uranium irregularly with time. Electron spin resonance (ESR) analyses of six selected bear bones indicates dates of 189 +/- 28 ka, for which each is cordant with their corresponding U-series date (181 +/- 41 ka). Combined ESR and U-series dates for these samples yielded 200 +/- 4 ka. Such agreement is highly suggestive that uranium uptake in these bones was close to the early-uptake (EU) model, and the dates are essentially correct. Another three selected samples yielded combined ESR U-series dates of 320 +/- 4 ka with a modeled intermediate-mode of uranium uptake. The dating results, therefore, seem to provide a firm minimum age of about 200 ka for the human entry: and suggestive evidence of

Graphene-reinforced calcium silicate coatings for load-bearing implants.

Science.gov (United States)

Xie, Youtao; Li, Hongqing; Zhang, Chi; Gu, Xin; Zheng, Xuebin; Huang, Liping

2014-04-01

Owing to the superior mechanical properties and low coefficient of thermal expansion, graphene has been widely used in the reinforcement of ceramics. In the present study, various ratios of graphene (0.5 wt%, 1.5 wt% and 4 wt%) were reinforced into calcium silicate (CS) coatings for load-bearing implant surface modification. Surface characteristics of the graphene/calcium silicate (GC) composite coatings were characterized by scanning electron microscopy. Results show that the graphene plates (less than 4 wt% in the coatings) were embedded in the CS matrix homogeneously. The surfaces of the coatings showed a hierarchical hybrid nano-/microstructure, which is believed to be beneficial to the behaviors of the cell and early bone fixation of the implants. Wear resistance measured by a pin-on-disc model exhibited an obvious enhancement with the adoption of graphene plates. The weight losses of the GC coatings decreased with the increase of graphene content. However, too high graphene content (4 wt% or more) made the composite coatings porous and the wear resistance decreased dramatically. The weight loss was only 1.3 ± 0.2 mg for the GC coating containing 1.5 wt% graphene (denoted as GC1.5) with a load of 10 N and sliding distance of 500 m, while that of the pure CS coating reached up to 28.6 ± 0.5 mg. In vitro cytocompatibility of the GC1.5 coating was evaluated using a human marrow stem cell (hMSC) culture system. The proliferation and alkaline phosphatase, osteopontin and osteocalcin (OC) osteogenesis-related gene expression of the cells on the GC1.5 coating did not deteriorate with the adoption of graphene. Conversely, even better adhesion of the hMSCs was observed on the GC1.5 coating than on the pure CS coating. All of the results indicate that the GC1.5 coating is a good candidate for load-bearing implants.

EARLY WEIGHT-BEARING AFTER ANKLE FRACTURE FIXATION ...