Amyotrophie et déminéralisation chez les amputés de membre inférieur

Abstract

Objective To evaluate the degree of both muscular atrophy and demineralization in patients that underwent a lower limb amputation due to vascular disease. Material and method All patients were fitted with a prosthesis, CAT-CAM sockets for Above-Knee(AK) (33 patients) and KBM for Below-Knee (BK) (14 patients), and dynamic feet. CT-Scan of lower limb muscles and Dual Photonic Absorptiometry (DPA) of Ward's triangle, femoral neck, and big trocanter, were performed in both types of amputees. DPA of the tibial plateau was restricted to the BK subset of patients. Values of the involved limb were compared to those of the contralateral one. Muscular atrophy degrees between both subsets (AK and BK) of amputated extremities were also compared. Results The following muscles showed a statistically significant higher degree of atrophy in the injured extremity when compared to the uninjured one: gluteus maximus, gluteus médius, gluteus minimus, rectus femoris, tensor fascia latae and sartorius in AK amputees, and in gluteus maximus, gluteus medius and rectus femoris in BK amputees. In both AK and BK amputees, we objectivized a statistically significant loss of bone mineral density of the injured extremity at all sites. We could not find any correlation between the loss of muscular density and time elapsed from the amputation to definitive fitting for a prosthesis except for AK amputees, where loss of mineral density was related to time elapsed from amputation. When comparing muscles only of the amputated extremity, there were no differences in the muscular density between AK and BK amputees, except for the rectus femoris ( P < 0.05) and tensor fascia latae ( P < 0.05). Conclusions Our results suggest that quadrilateral and CAT-CAM sockets in AK amputees, as well as PTB, PTS and KBM in BK amputees, may increase the risk of muscular atrophy and bone demineralization. In contrast, the use of total contact sockets, practice of routine osteomioplasty and closing bone marrow cavity may decrease the demineralization process.