Predictors affecting the results of impaction grafting for revision hip surgery

Twenty eight consecutive hips in 28 patients were evaluated at an average 47 months [range 30-75 months] after revision hip surgery reconstructed with impaction grafting. The principle revision procedure was the first revision in 20 hips [71.4%], the second revision in 4 [14.3%] hips, and the third revision in 4 hips. A collarless double tapered polished stem [CPT; Zimmer, Warsaw, Indiana] was used in 24 femora [85.8%]. Harris hip score was used to evaluate the function of the hip postoperatively. Implant migration was measured using Oswestry Roentgen Monophotogrammetric analysis software [ORMA]. By the time offollowup three hips [10.7%] had been re-revised. Two hips because of periprosthetic fracture femur and one because of recurrent dislocations. On the femora side significant correlations were found between stem tilt and two predictors: the number of previous revisions [p = 0.03] and the degree of femoral bone loss [P = 0.04]. Significant correlation was found between post operative pain and three predictors: vertical cup migration [p = 0.05], graft incorporation [p = 0.05] and the degree of pre-operative acetabular bone deficiency. [p = 0.024]. This study shows durable results using impaction grafting and identified the degree of bone loss, number of re-revision, and cup migration as important predictors in impaction grafting