Osteopenia in patients with above knee amputation.

Using dual energy x-ray absorptiometry, we studied 16 male patients with unilateral above knee amputations (AKA) with a mean age of 48 years (range, 23 to 66 years) who were full-time prosthetic users for more than 5 years. All prostheses were ischial weight bearing. All 16 subjects were found to have normal bone density in their spines and in the normal femurs when compared to nonamputation controls. However, a significant decrease of mean femoral neck bone density was found on the amputated side (0.68g/cm2, range, 0.52 to 1.01) when compared to the normal side (1.01g/cm2, range, 0.75 to 1.20) (p < .05). The mean bone density percentage difference between the two sides was 28% (range, 4% to 48%). There was a significantly negative correlation between the patient's age at the time of amputation and the severity of osteopenia (-0.73; p < 0.05).