BONE AND MUSCLE MASS AFTER HIP REARTHROPLASTY - CONTROLLED CT STUDY OF 12 PATIENTS

The cortical bone mineral density (BMD), bone volume, bone mass and mu scle volume of the thigh and the cancellous BMD of the distal femur an d proximal tibia were quantified by computed tomography (QCT) in 12 pa tients after hip rearthroplasty due to prosthetic loosening following arthroplasty for arthrosis. Both legs were scanned and the operated si de was compared with the healthy side. A control group, 12 patients, h ad had unilateral hip arthroplasty without subsequent rearthroplasty. There was a 19 percent decrease in bone mass and 13 percent decrease i n muscle volume in the middle femur, compared to the contralateral sid e, in the patients who had undergone rearthroplasty, and a reduction o f 9 percent for the same variables in the control group. There was als o a more marked osteopenia in the reoperated extremity in the distal f emur and proximal tibia compared to the unoperated side.