Bone
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The MEDOS study was a prospective, multicentre study of the incidence of hip fractures, carried out in six Mediterranean countries over a 12-month period (1988-1989). The majority of hip fractures recorded were extra-capsular and usually required a stable internal fixation to avoid instability and deformation or pseudoarthrosis. Surgery was performed in the majority of cases (85% of extra-capsular fractures and 84% of intra-capsular fractures), although this proportion also varied between centres. ⋯ During the period of hospitalisation, 26% of patients experienced minor complications, but only 2.4% experienced serious complications, with further surgery required in 2%. Mortality during hospitalisation was 5.1% overall (4.8% and 5.7% in intra- and extra-capsular fracture cases, respectively). The average duration of hospital stay was 24 days, but this varied between centres, with a tendency for shorter stays to be associated with a greater proportion of cases treated surgically.
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Apparent density, yield stress and yield energy were measured in transiliac cores of trabecular bone from iliac crest and craniocaudal cores of L5 vertebra from 26 cadavers. In the iliac crest, bone from the anterior superior spine region had significantly greater apparent density and had greater yield energy than bone from the center of the crest. Yield stress was greater at the anterior superior spine than either the center or at the posterior spine. ⋯ Yield stress in iliac crest paired for density in subjects less than 40 years and greater than 60 years was 40.7% lower in the older subjects (p = 0.03), suggesting a specific mechanical defect in old age. The yield stress advantage accruing to orientated lumbar bone was more marked at lower values of yield stress in the iliac crest when cores from the same cadaver were matched for apparent density. Mechanical properties of iliac crest bone are very dependent upon site and at no one site in the iliac crest do the physical properties satisfactorily predict those in the lumbar spine.
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A 57 year old white male with oncogenous osteomalacia due to a mixed mesenchymal tumor was evaluated by sequential histologic and metabolic studies over a period of 33 mos prior to identifying the location of the tumor. On the basis of these studies we conclude: (i) disorders of the enterohepatic circulation and/or acceleration of metabolism of calcitriol are not responsible for its diminished level in oncogenous osteomalacia, (ii) the Von Kossa stain is preferred to the modified Masson in evaluating osteomalacia, (iii) avascular necrosis of the femoral head may be part of the syndrome, (iv) heterogeneity may be the hallmark of the responsible mesenchymal tumor and account for the different histological interpretations in the literature, (v) in compliant patients with oncogenous osteomalacia, calcitriol and Pi therapy may be effective.
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Histomorphometric changes in the trabecular structure of the principal compressive stress region in the femur in patients with osteoarthritis and fracture of the femoral neck are described. Femoral heads were obtained from patients who had surgery for the treatment of femoral neck fracture or total hip replacement for advanced osteoarthritis. Blocks from the principal compressive region of a coronal slice were sampled systematically to prepare 10 microns sections for automated analysis. ⋯ The trabeculae in OA were significantly thicker than in FNOF, and spacing in OA was significantly greater than in FNOF. The regression of trabecular thickness and spacing on age was not significant for either OA or FNOF. For OA, thickness and spacing showed a significant regression on the mineralized bone volume, positive and negative, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)