Bone density distribution and gender dominate femoral neck fracture risk predictors.

OBJECTIVE: To determine whether regional characteristics of the proximal femur could discriminate between a group of patients who had just sustained a first low-trauma femoral neck fracture (n=50) from a group of healthy volunteers (n=123). DESIGN: The application of an integral bone measurement (dual-energy X-ray absorptiometry) in conjunction with a volumetric cancellous bone density measurement (quantitative computed tomography) to the proximal femur in vivo provided an estimate of the contribution of the spatial distribution of bone density to hip fracture risk prediction. RESULTS: The primary finding of this study was a significant difference between male and female hip fracture risk predictor variables. In men with femoral neck fracture, a significant decrease in bone density throughout the proximal femur was observed. In women with femoral neck fracture, a combination of local bone deficits (significant decrease in cancellous bone at the site of fracture, and a decrease in cortical bone at the site of impact) and significantly larger proximal femur dimensions (femoral neck and head widths) was evident. CONCLUSIONS: These results imply that effective hip fracture prevention strategies may require separate approaches for men and women. Screening programs for diminished bone density at the proximal femur have proved effective in previous studies. An approach which includes examining these local bone characteristics may further improve our ability to accurately determine hip fracture risk in vivo.