Bone strength measured by peripheral quantitative computed tomography and the risk of nonvertebral fractures: The osteoporotic fractures in men (MrOS) study

Abstract

Many fractures occur in individuals without osteoporosis defined by areal bone mineral density (aBMD). Inclusion of other aspects of skeletal strength may be useful in identifying at-risk subjects. We used surrogate measures of bone strength at the radius and tibia measured by peripheral quantitative computed tomography (pQCT) to evaluate their relationships with nonvertebral fracture risk. Femoral neck (FN) aBMD, measured by dual-energy X-ray absorptiometry (DXA), also was included. The study population consisted of 1143 white men aged 69+ years with pQCT measures at the radius and tibia from the Minneapolis and Pittsburgh centers of the Osteoporotic Fractures in Men (MrOS) study. Principal-components analysis and Cox proportional-hazards modeling were used to identify 21 of 58 pQCT variables with a major contribution to nonvertebral incident fractures. After a mean 2.9 years of follow-up, 39 fractures occurred. Men without incident fractures had significantly greater bone mineral content, cross-sectional area, and indices of bone strength than those with fractures by pQCT. Every SD decrease in the 18 of 21 pQCT parameters was significantly associated with increased fracture risk (hazard ration ranged from 1.4 to 2.2) independent of age, study site, body mass index (BMI), and FN aBMD. Using area under the receiver operation characteristics curve (AUC), the combination of FN aBMD and three radius strength parameters individually increased fracture prediction over FN aBMD alone (AUC increased from 0.73 to 0.80). Peripheral bone strength measures are associated with fracture risk and may improve our ability to identify older men at high risk of fracture. © 2011 American Society for Bone and Mineral Research.

Cross-sectional analysis of the association between fragility fractures and bone microarchitecture in older men: The STRAMBO study

“…Men with peripheral fractures had lower D.cort and D.trab, in line with previous data. (7)(8)(9)(10)(11) In addtion, we show that lower D.trab in these men can be due to the lower number of more heterogeneously distributed trabeculae. However, only men with multiple peripheral fractures had poor bone microarchitecture after adjustment for aBMD.…”

An evaluation of the muscle-bone unit theory among individuals with chronic spinal cord injury

“…A relationship has been shown between bone-strength-derived geometry parameters assessed with pQCT and bone fractures in chronic SCI. 14,15 A measure of the distribution of bone material around a given axis from a pQCT scan, such as cross-sectional moment of inertia or polar area moment of inertia, can indicate the bone's resistance to an imposed bending load or imposed torsion; therefore, these measures are important parameters of bone strength. 14 Section modulus is derived from the polar area moment of inertia and the maximum distance between the center of the identified area and its outer boundary; section modulus has been associated with nonvertebral fractures in older men.…”

“…14 Section modulus is derived from the polar area moment of inertia and the maximum distance between the center of the identified area and its outer boundary; section modulus has been associated with nonvertebral fractures in older men. 15 Further, pQCT provides a measure of muscle CSA, which is reported to be an acceptable surrogate of muscle strength for the purpose of exploring associations between muscle and bone, 10,16 and is a beneficial measure among individuals with SCI due to neuromuscular deficits. A surrogate of torque exerted by a muscle can be determined from the product of muscle CSA and bone length (muscle-bending moment, MBM), and may be important to consider since bones are loaded by compression as well as bending.…”

Association of Jumping Mechanography-Derived Indices of Muscle Function with Tibial Cortical Bone Geometry

“…Clearly, further research is needed to elucidate to what extent interventions addressing peak voluntary muscle force influence cortical bone geometry and fracture risk, as this would have an impact on rehabilitation programs or other interventions for patients with suspected bone deficits. Given the fact that fracture risk seems to be mainly predicted by cortical rather than overall bone size [43][44][45][46][47][48], we speculate that increasing peak voluntary muscle force would benefit bone health and fracture risk more than increasing (leg) lean mass.…”