Osteonecrosis following renal allotransplantation. A quantitative histological study of iliac bone.

Morphometric and dynamic studies of bone obtained by biopsy from a standard locality on the iliac crest were carried out in 10 patients with and 7 patients without radiological signs of osteonecrosis. All the patients had normally functioning kidney transplants. The results obtained in the two groups were compared and both groups were compared with a series of noraml subjects where the age and sex distribution was the same. In the group of patients with osteonecrosis, the reduction in the amount of cancellous bone was found to be highly significant as compared with that in normal subjects and with that in the other group of patients. Apart from the reduction in bone, changes in all patients were characterized by an increased amount of osteoid and a low rate of mineralization, determined by double labelling with tetracycline. As there were no changes in the width of osteoid seams indicating osteomalacia, it is suggested that these patients suffered from a severe corticosteroid osteopenia.