Radiologic morphometry in patients with femoral neck fractures and elderly control subjects. Comparison with histomorphometric parameters.

Radiologic morphometry was performed in 125 patients with femoral neck fractures and 74 elderly control subjects to evaluate simple parameters for screening of the population at risk. Reproducibility of metacarpal cortical thickness was high when measured in six metacarpals. Values of this parameter were similar in patients and control subjects. Reproducibility of the Singh index was poor. The patients with femoral neck fractures had a higher vertebral index, more vertebral crush fractures, and a lower Singh index than the control subjects. There was no significant difference in these radiologic indices between cervical and intertrochanteric fractures. The radiologic indices correlated poorly with each other and with histomorphometric data from transilial bone biopsies of the patients. Stepwise discriminant analysis allowed correct classification as patient or control subject in only 69.8% of the cases, with the Singh index having the highest predictive value. The reported observations indicate a need for a more accurate technique for local assessment of the bone mass in the femoral neck.