Objective To explore the long-term effect of open reduction and internal fixation for the treatment of displaced acetabular fracture,and analyze the influence of risk factors.Methods The clinical data of 62 patients with acetabular fracture from August 2005 to February 2009 was analyzed retrospectively.All the cases were treated with open reduction and internal fixation.The long-term effect and related risk factors were analyzed.Results All the cases were followed up for 24-52(38.8 ± 2.6) months.According to the Matta standard of replacement of fracture,there were 43 cases with anatomic reduction,14 eases with satisfactory reduction,5 cases with unsatisfactory reduction.Fracture union was obtained in all the patients.Based on the modified Merled' Aubigne -Postel clinical grading system,the result was excellent and good in 50 patients,fair and poor in 12 patients,with excellent rate of 80.65％ (50/62).Postoperative complications including traumatic arthritis were seen in 7 patients,heterotopic ossification in 3 patients and femoral head avascular necrosis in 1 patient.The related risk factors of clinical results of displaced acetabular fracture were age,Letournel-Judet fracture type,operation time,cartilage surface damage of the femoral head and quality of reduction (P ＜ 0.05 ).However,gender,AO fracture type,surgical approach and hip dislocation were not affecting factors of the acetabular fracture(P ＞ 0.05 ).Conclusions Open reduction and internal fixation can result in a satisfactory clinical outcome.Age,Letournel-Judet fracture type,operation time,cartilage surface damage of the femoral head and quality of reduction are independent risk factors affecting postoperative long-term functional outcomes.