NATURAL COURSE AND PREDICTION OF PROGNOSIS OF FEMORAL HEAD OSTEONECROSIS

Collapsed Nontraumatic Osteonecrosis of the Femoral Head under Observation without Specific Treatment
HJ Kim, WS Song, JJ Yoo, KH Koo, YM Kim
Department of Orthopaedic Surgery, Seoul National University College of Medicine, Seoul, Korea

Introduction: Some patients with collapsed osteonecrosis of the femoral head do not need any specific treatment because of mild symptom or disability. The general features of those patients were evaluated.

Patients and Methods: 45 cases of collapsed osteonecrosis of the femoral head in 38 patients were included in this study. These patients visited outpatient clinic for the first time from January, 1996 to December, 2002. In all cases, pain developed at least 3 years before the last follow-up, but no specific treatment was necessary. There were 27 men and 11 women. The mean age at the onset of pain was 41 years (range, 17 to 72 years). The duration from the onset of pain to the last follow-up was 36~167 months (mean, 73 months). The general and radiological features were evaluated.

Results: Risk factors included steroid therapy in 18, alcoholism in 16, idiopathic in 10 and others in 1 case. In 29 patients, both femoral heads were involved. Extent of the necrosis was 37~89 percent (mean, 62 percent). The amount of depression was 0.5 ~17 mm (mean, 2.2 mm).

Conclusions: Steroid therapy was a more frequent risk factor in this patient population. In most cases, the amount of depression was less than 3 mm. Most patients remembered that the pain was most severe at its onset and improved in next several months.