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

Comparisons between treatments and studies with regard to femoral head oste onecrosis (ON) are difficult because the demographic characteristics of the patients composing the samples vary greatly. The purpose of this investiga tion was to determine whether ON initiation and progression were specific f or 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 coll apsed femoral heads (90%). Patients with steroid-induced ON averaged 39 yea rs of age, 49% had bilateral disease, and 62% presented with a collapsed fe moral head. Patients with idiopathic ON averaged 40 year of age, 35% had bi lateral 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 samp le receiving the intervention. We therefore recommend stratification of pat ients by causative agent, Steinberg stage at initial presentation, and pres ence of unilateral or bilateral disease to help clarify the effects of the various treatments for ON of the femoral head.