Cortical thickness and trabecular pattern of the femoral neck as a measure of osteopenia.

The pelvic radiographs of 312 patients aged 18 to 92 years were reviewed to determine if the Singh index was valid or not. The cortical thickness of the lower part of the femoral calcar, the stress index (body weight, physical activity, and femoral neck angle), and the Singh Index (trabecular pattern of the femoral neck) were measured in each patient and correlated with each other and with the patient's age, sex, and dominant side. It was found that the Singh index correlates well with age but not with the cortical thickness or stress index. Thus, the Singh index is an unreliable measure of osteopenia, and we conclude that other methods should be used for screening patients with osteoporosis.