We perfused 16 human femora with a 50% barium sulphate suspension and studied the intra-osseous vessels by microfocal radiography and histology. There were few anastomoses between the vessels of the greater trochanter and those of the adjacent cancellous bone of the shaft. Ischaemia of the trochanter may contribute to nonunion after trochanteric osteotomy.

We report the results of conservative treatment of stage III and stage IV avascular necrosis of bone (AVN) affecting the hip or knee in renal transplant patients. Twenty-nine patients were followed for a mean period of five years. Conservative management was successful in controlling symptoms in 40% of those with AVN of the hip and in 70% of those with AVN of the knee. Knowledge of the natural history of AVN is important because of the long survival times after renal transplantation.