Objective To investigate the operative methods in treatment of Tile type B and C old pelvis fracture.Methods The study enrolled 19 cases (13 males and 6 females) with a mean age of 53.4 years (range,25-66 years) treated from July 2009 to July 2014.Injury resulted from traffic accidents in 14 cases,high falls in 3 cases and hit by heavy objects in 2 cases.Time from injury to operation was 1.5-10.3 months.According to the Tile classification,the type of fracture was 5 B2,5 B3,3 C1,4 C2 and 2 C3.Four cases of type B and two cases of type C were combined with acetabulum fracture.Type B fracture deformity was operated through the anterior letournel approach,during which the malunion had osteotomy and reconstruction plate fixation.When posterior wall or column acetabular fracture existed,additional posterior Kocher-Langenbeck incision was used to achieve fracture reduction and stabilization through bilateral fenestration in the floating position.Type C fracture undergone osteotomy through anterior letournel approach and posterior sacral osteotomy or ilio-lumbar fixation following sacroiliac osteotomy.With regard to the combined posterior wall or column acetabular fracture in type C fracture,the surgical method was the same as type B.Radiological and functional results were respectively evaluated using the Mears-Velyvis system and Majeed criteria.Results Mean duration of follow-up was 11.4 months (range,3-24 months).All fracture united in the one-stage,with mean union time of 5.2 months (range,3-7 months).According to the Mears and Velyvis system,10 cases obtained anatomical reduction,6 were satisfied,and 3 were unsatisfied.According to the Majeed criteria,the results were excellent in 6 cases,good in 10 and fair in 3.After operation,2 cases sustained poor control of urination caused by sacral nerve injury;l case still had hip pain caused by old acetabular fracture,but the symptom could be controlled by non-steroidal anti-inflammatory drugs;2 cases had sacroiliac joint pain.There was no fixation failure.Conclusion Through the combined approach,osteotomy and fixation of malunion in anterior and posterior rings of pelvis that restores the pelvic ring is an effective method to improve the quality of fracture reduction and rectify limb shortening.