Aseptic necrosis of bone following renal transplantation. Clinical and biochemical aspects and bone morphometry.

Aseptic necrosis of bone has developed 5--48 months (mean 23) after renal transplantation in 22 (11%) of 195 patients with graft function for more than 6 months. The bone lesions were mainly localized to weight-bearing cancellous bone areas, most often the femoral heads. The mean duration of hemodialysis was significantly longer in recipients with aspetic necrosis than in those without. The serum concentration of phosphate was reduced and the serum concentration of parathyroid hormone increased in both groups of recipients. Quantitative histological examination of iliac crest biopsies showed a pronounced reduction of spongy bone (osteopenia) in recipients with aseptic necrosis compared with both normals and recipients without aseptic necrosis. Both patient groups showed similar changes in bone remodelling, indicating decreased bone formation. These findings suggest that osteopenia is an important contributory factor in the development of aseptic necrosis of bone after transplantation. The osteopenia may be a consequence of both the uremic bone disease before transplantation and the immunosuppressive treatment after transplantation.