Differences in age, laterality, and Steinberg stage at initial presentation in patients with steroid-induced, alcohol-induced, and idiopathic femoral head osteonecrosis.

Comparisons between treatments and studies with regard to femoral head osteonecrosis (ON) are difficult because the demographic characteristics of the patients composing the samples vary greatly. The purpose of this investigation was to determine whether ON initiation and progression were specific for a causative agent. A group of 172 patients (245 hips) was subdivided by causative agent. Patients with alcohol-induced ON were significantly older (average age, 49 years; P = .0001), were men (97%), and presented with collapsed femoral heads (90%). Patients with steroid-induced ON averaged 39 years of age, 49% had bilateral disease, and 62% presented with a collapsed femoral head. Patients with idiopathic ON averaged 40 years of age, 35% had bilateral disease, and 55% presented with a collapsed femoral head. Given the different distributions of ON risk factors at initial presentation, it is likely that successful or unsuccessful outcomes may depend most on the sample receiving the intervention. We therefore recommend stratification of patients by causative agent, Steinberg stage at initial presentation, and presence of unilateral or bilateral disease to help clarify the effects of the various treatments for ON of the femoral head.