Vascularity of the femoral head. Tc diphosphonate scintigraphy validated with tetracycline labeling.

99MTc diphosphonate scintigraphy and tetracycline labeling were performed on 22 hips in 20 patients in whom the femoral heads were subsequently removed. Twelve of the hips had acute neck fractures, and 10 hips had roentgenographic evidence of avascular necrosis. This technique is of greater value for recent fractures, for once revascularization begins to occur, increased radioactivity is usually found by scintiscan. There was good correlation between roentgenogram, scintiscan and tetracycline fluorescence. 99mTe diphosphonate scintigraphy, which can be performed outside the operating theater with little discomfort to the patient, proved to be a reliable, noninvasive method of assessing the blood flow to the femoral head. 99mTc diphosphonate scintigraphy is not a quantitative technique; it detects the presence or absence of femoral head blood flow, not the adequacy of that blood supply.