[Role of triphasic bone scintigraphy in the diagnosis of osteonecrosis of the femur head].

Twelve patients affected by idiopathic osteonecrosis of the femoral head underwent X-ray, triphasic bone scintigraphic (TBS) and CT tests on the femoral head on both sides. TBS revealed arterial hypoperfusion and an area of hypocaptation in the caput femoris in 3 coxofemoral joints which were radiologically "negative" (and of which one was also CT negative); these are scintigraphical signs which are typical of aseptic necrosis. In line with published data, TBS was found to be a more sensitive test in comparison with traditional X-ray techniques and CT, and in the early stages of disease it is more specific in recognising aseptic necrosis of the femoral head. Lastly, it is underlined that magnetic resonance is currently considered to be most sensitive (88%) and most specific (100%) imaging technique in the diagnosis of osteonecrosis of the femoral head.