Osteonecrosis and fractures following renal transplantation.

Skeletal radiological surveys in 161 renal transplant recipients identified 36 patients with 115 lesions of osteonecrosis. A further two patients with osteonecrosis found at autopsy had had no radiographic abnormality. The total incidence of osteonecrosis was, therefore, 38 (24%) out of 161. The lesions were frequently multiple and bilateral with structural failure being the most common initial abnormality and the femoral head the most frequent site. Lesions also occurred in the femoral condyles, the talus, the humeral heads and the metatarsals, many being symptom-free. Calcification was demonstrated in the femoral and tibial shafts. The initial radiological abnormality appeared at a mean interval of 19 months after transplant but could occur as late as 75 months. Significantly fewer patients, three (7%) out of 41, developed osteonecrosis following a low-dose prednisolone regimen (0.8 g) compared with a high-dose group (2.8 g) where 35 (29%) out of 120 were affected. More females than males developed osteonecrosis, but no correlation could be demonstrated with regard to age, primary renal disease, number and type of transplant and duration of dialysis prior to transplant. Osteonecrosis is a complication which can be reduced with a low-dose prednisolone regimen. Most lesions will be demonstrated by radiological survey undertaken during the second and fourth years after transplantation.