Osteonecrosis in renal transplant recipients. Early radiological detection and course

Early radiologic signs and the radiologic course were examined retrospectively in 20 renal transplant patients who developed osteonecrosis after transplantation. Osteonecrosis appeared in 25 hips, 8 knees, 9 shoulders and 1 elbow. In most patients who developed osteonecrosis of the hip the early radiologic signs of osteonecrosis, with areas of lucencies and increased densities, were preceded by a thin fracture line in the immediate subchondral bone, parallel to the articular surface, appearing within a mean of 14 months after renal transplantation. This change seems to be a specific and very early finding in patients who subsequently develop osteonecrosis after renal transplantation. The initiation of collapsing phenomena of the articular surface was preceded by architectural changes near the articular surface wtih areas of lucencies and sclerosis. At the time of this investigation 26 per cent of the bones showed signs of regression of the changes with rebuilding of the former shape; 32 per cent showed progression and in 42 per cent the condition was stationary.