Natural history of nontraumatic avascular necrosis of the femoral head. ³

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Á Ohzono K. Saito M. Takaoka K. Ono K. Saito S. Nishina T. Kadowaki T. Journal of Bone & Joint Surgery - British Volume. 73(1):68-72, 1991 Jan. We studied the natural history of nontraumatic avascular necrosis of the femoral head (ANFH) in 115 hips in 87 patients, 69 steroid-induced, 21 related to misuse of alcohol and 25 idiopathic. The average length of * follow-up was over five years. Collapse occurred most often when the focus of bone necrosis occupied the weight-bearing surface of the femoral head. Flatness of the head due to subchondral fracture was an early manifestation of collapse. Classification into six types based upon the Á radiographic findings provided an accurate prognosis for individual cases of ANFH which is useful in planning treatment and in assessing its outcome. *