Study of bone mass with dual energy x-ray absorptiometry in a population of 99 lower limb amputees

Osteopenia in lower extremity amputation is described with an increased risk of fracture and it seems to be interesting to study bone mass in a population of 99 amputees of limb. We studied the bone mass with Dual Energy Xray Absorptiometry in patients with limb amputation, above and under knee and who have been treated in the rehabilitation department of Mulhouse's hospital and more specifically the percentage of the difference of the mesure between amputed and non amputed side and the influence on this mesure of several factors like sexe; age; diabetes mellitus; delay of amputation; aetiology and use of prosthesis. For all the population, we find lower values of BMD (Bone mineral density) for femoral neck -10.4% +/- 12.2 (P < 0,001) and trochanter -14.9% +/- 14.5 (P < 0,001) between amputated and non amputated side, and also comparing with normal population -19.9% +/- 18.8 (P < 0,001) for femoral neck and -8.8% +/- 22 (P < 0,001) for trochanter.There is no influence of sexe, age, and time since amputation on BMD. The study of sub-groupes shows that the loss of bone mass is depending on traumatic amputation, the level of amputation (above knee) and when prothetis doesn't fit. Arteritis or diabetis are not pejoratif factors. This work confirms the mechanical factors as an important parameter of bone loss in the limb amputation.