ABSTRACT
Objective To discuss the feasibility of positioning the acetabular center,fixing acetabular implant correctly and reconstructing hip rotation center according to Harris fossa and the remaining anatomical markers of acetabular notch in revision hip arthroplasty.Methods Twenty-eight patients underwent revision hip arthroplasty from April 2007 to June 2009.Based on Paprosky type,3 cases with type Ⅰ were treated with biological fixed acetabular component;8 cases with ⅡA and ⅡB were reconstructed with using of morselized bone grafting and large diameter cemented acetabular prosthesis;17 cases with type ⅡC,ⅢA and ⅢB were treated with using of morselized bone grafting and fixation of acetabular reinforcement ring.Among them,5 patients with massive bone loss in acetabular wall were reconstructed with the use of the structural and morselized bone grafting.The center of the original acetabulum was believed to be in the lunate cartilage surface which was closed to Harris fossa.During the operation,the center was located in the site which was 25-28 mm above in line with perpendicular bisector of acetabular notch connecting line.The acetabular center was the point of positioning acetabular prosthesis (Ⅰ type) or making new acetabulum by impaction bone grafting.Acetabular reinforcement ring (Ⅱ,Ⅲ type) was fixed in accordance with proper transverse angle and anteversion angle.The vertical distance from hip rotation center to teardrop connection and the horizontal distance from hip rotation center to teardrop were measured on preoperative and postoperative radiograph.And the outcomes of reconstruction of rotation center were evaluated.Results The vertical distance was changed from (14.22±3.39) mm preoperatively to (32.64±4.51) mm postoperatively.The difference was statistically significant (t=3.65,P＜ 0.05).The horizontal distance was changed from (25.13±3.46)mm preoperatively to (32.87±4.73) mm postoperatively.The difference was statistically significant (t=2.72,P＜0.05).Conclusion Using residual Harris fossa and acetabular notch as the anatomical markers in revision hip arthroplasty,the restoration of the anatomical hip center has shown to be favorable.