Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research
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J. Bone Miner. Res. · Mar 2014
Assessment of incident spine and hip fractures in women and men using finite element analysis of CT scans.
Finite element analysis of computed tomography (CT) scans provides noninvasive estimates of bone strength at the spine and hip. To further validate such estimates clinically, we performed a 5-year case-control study of 1110 women and men over age 65 years from the AGES-Reykjavik cohort (case = incident spine or hip fracture; control = no incident spine or hip fracture). From the baseline CT scans, we measured femoral and vertebral strength, as well as bone mineral density (BMD) at the hip (areal BMD only) and lumbar spine (trabecular volumetric BMD only). ⋯ For incident hip fractures (n = 171), the age-adjusted odds ratio for femoral strength was significant for women (4.2, 95% CI 2.6 to 6.9) and men (3.5, 95% CI 2.3 to 5.3) and remained significant after adjusting for femoral neck areal BMD in women and for total hip areal BMD in both sexes; fracture classification improved for women by combining femoral strength with femoral neck areal BMD (p = 0.002). For both sexes, the probabilities of spine and hip fractures were similarly high at the BMD-based interventional thresholds for osteoporosis and at corresponding preestablished thresholds for "fragile bone strength" (spine: women ≤ 4500 N, men ≤ 6500 N; hip: women ≤ 3000 N, men ≤ 3500 N). Because it is well established that individuals over age 65 years who have osteoporosis at the hip or spine by BMD criteria should be considered at high risk of fracture, these results indicate that individuals who have fragile bone strength at the hip or spine should also be considered at high risk of fracture.
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J. Bone Miner. Res. · Mar 2014
The impact of acute kidney injury with temporary dialysis on the risk of fracture.
Acute kidney injury (AKI) has a negative impact on long-term renal function and prognosis. However, the association between acute renal dysfunction and long-term effects on bone disorders has not yet been characterized. Using a population-based cohort study, we aimed to evaluate associations between AKI and long-term effects on bone fractures. ⋯ Both AKI recovery status (HR = 2.31; p < 0.001) and time varying factor of bone fracture (HR = 1.43; p < 0.001) were independent predictors of mortality compared with controls. In conclusion, AKI requiring temporary dialysis independently increases long-term risk of bone fracture, regardless of subsequent progression to ESRD. Long-term bone fractures may negatively impact patient mortality.
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J. Bone Miner. Res. · Mar 2014
Atypical femoral fractures: transverse morphology at lateral cortex is a critical feature.
In 2010, the American Society for Bone and Mineral Research (ASBMR) task force defined major and minor features to assist in the case finding and reporting of atypical femoral fractures (AFFs). One major feature that was proposed was a "transverse or short oblique configuration." Our primary aim was to compare the conventional overall fracture morphology (OFM) with its associated angle (OFMA) and our proposed lateral cortical fracture angle (LCFA) in the assessment of fracture configuration in suspected AFFs and non-AFFs. The radiographs of 79 patients with AFFs and 39 patients with non-AFFs were each analyzed by two blinded reviewers to obtain the OFM, OFMA, and LCFA. ⋯ Fracture angles were significantly different in AFFs versus non-AFFs regardless of whether the OFMA or LCFA methodology was employed, but the greater difference associated with LCFA suggests its greater discriminating power. When LCFA was used in conjunction with 0° to 30° as the criteria for transverse morphology, all the AFFs and non-AFFs were correctly classified. By using a standardized and precise method in measuring the fracture angle, specifically using only the component of the lateral cortex and limiting to truly transverse fractures, ie, between 0° and 30°, the LCFA is a robust and accurate method to assess the fracture morphology in suspected AFFs.
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J. Bone Miner. Res. · Feb 2014
Multicenter Study Clinical TrialMortality after lower extremity fractures in men with spinal cord injury.
In the United States, there are over 200,000 men with spinal cord injuries (SCIs) who are at risk for lower limb fractures. The risk of mortality after fractures in SCI is unknown. This was a population-based, cohort study of all male veterans (mean age 54.1; range, 20.3-100.5 years) with a traumatic SCI of at least 2 years' duration enrolled in the Veterans Affairs (VA) Spinal Cord Dysfunction Registry from FY2002 to FY2010 to determine the association between lower extremity fractures and mortality. ⋯ In fully-adjusted models, the association of incident lower extremity fracture with increased mortality was substantially greater in older men (age ≥50 years) for the entire cohort (HR, 3.42; 95% CI, 2.75-4.25) and for those with complete SCI (HR, 3.13; 95% CI, 2.19-4.45), compared to younger men (age <50 years) (entire cohort: HR, 1.42; 95% CI, 0.94-2.14; complete SCI: HR, 1.71; 95% CI, 0.98-3.01). Every additional point in the Charlson comorbidity index was associated with a 10% increase in the hazard of death in models involving the entire cohort (HR, 1.11; 95% CI, 1.09-1.13) and also in models limited to men with complete SCI (HR, 1.10; 95% CI, 1.06-1.15). These data support the concept that both the fracture itself and underlying comorbidities are drivers of death in men with SCI.
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J. Bone Miner. Res. · Feb 2014
Delayed bone regeneration is linked to chronic inflammation in murine muscular dystrophy.
Duchenne muscular dystrophy (DMD) patients exhibit skeletal muscle weakness with continuous cycles of muscle fiber degeneration/regeneration, chronic inflammation, low bone mineral density, and increased risks of fracture. Fragility fractures and associated complications are considered as a consequence of the osteoporotic condition in these patients. Here, we aimed to establish the relationship between muscular dystrophy and fracture healing by assessing bone regeneration in mdx mice, a model of DMD with absence of osteoporosis. ⋯ In addition, PLX3397 treatment of mdx mice, a cFMS (colony stimulating factor receptor 1) inhibitor in monocytes, partially rescued the bone repair defect through increasing cartilage deposition and decreasing the number of macrophages. In conclusion, chronic inflammation in mdx mice contributes to the fracture healing delay and is associated with a decrease in angiogenesis and a transient delay in osteoclast recruitment. By revealing the role of dystrophic muscle in regulating the inflammatory response during bone repair, our results emphasize the implication of muscle in the normal bone repair process and may lead to improved treatment of fragility fractures in DMD patients.