Objective To explore the safety and efficacy of one-stage simultaneous bilateral THA for the treat-ment of advanced avascular necrosis of femoral head.Method From Aug 2004 to May 2006.6 Patients(12hips) were treated will one-stage simultaneous bilateral THA.4 of them were male and 2 female with average ages 34.5years(31-55years).4 Cemented prostheses were used in 2 cases(4hips) and 8 non Cemented prostheses were used in 4 cases(8ships).Result The Harris Hip score improved from 31.5± 5.5.preoperatively to 94...