¹⁸F Scintigraphy in the early diagnosis of osteonecrosis of the femoral head in chronic hemodialysis and transplantation

Osteonecrosis of the femoral head results in an increased uptake of ¹⁸F due to a reparative reaction in the necrotic area and its surroundings. Twenty hemodialysis and twenty-seven post-transplant patients were studied serially. In the hemodialysis group, nine patients had positive scintigraphs and eleven had negative studies. All were asymptomatic. In the transplant group, twelve were positive and fifteen were negative. Four patients with positive scans later developed unequivocal clinical and radiographic evidence of osteonecrosis. Patients with negative scans have been asymptomatic and without radiological abnormalities. Age, sex, duration of dialysis, bone mineral densitometry, total steroid dose, duration of hospitalization after transplantation, and serum chemistries were not different in positive and negative patients. All patients on alternate-day steroids have negative scans. A positive ¹⁸F scintigraph antedates the occurrence of clinical and radiologic findings of osteonecrosis.