In vivo measurement of apparent trabecular bone structure of the radius in women with low bone density discriminates patients with recent wrist fracture from those without fracture.

The purpose of this cross-sectional case-control study was to determine whether indices of bone structure at the 4% site of the radius discriminate women who have sustained a recent low-energy fracture of the contralateral distal radius (n = 21) from women with similar bone density and no history of fracture (n = 21). Images of the distal forearm were acquired using peripheral quantitative computed tomography (pQCT) and were analyzed using in-house-developed software to determine indices of trabecular bone structure (average hole size [H(A)], maximum hole size, and connectivity index). The same images were analyzed using commercial software to determine bone density, mass, geometry, and torsional strength. The fracture group had significantly larger H(A) (p = 0.03). No other bone variable differed between groups. Individual H(A) values were compared to the mean value for young adult women (n = 42). The odds ratio (95% confidence interval) associated with an H(A) >2 SDs above the young adult mean was 5.4 (1.2-24.3). Thus, estimation of in vivo trabecular bone porosity by measuring the average diameter of the pQCT-imaged marrow spaces in the ultradistal radius identifies individuals with low bone mass most at risk for osteoporotic fracture.