Bone removed in two different concepts of Hip bone conservative arthroplasty

Bone saving remains a priority in hip arthroplasty. Birmingham hip resurfacing [BHR] and thrust plate arthroplasty [TPA] are two different designs aiming at bone conservation. By measuring bone removed intraoperatively during 11 BHR, eight TPA and a control group of 15 hybrid hip arthroplasty it was found that BHR and TPA saved significant amount of bone if compared to hybrid hip arthroplasty [ANOVA p < 0.001]. Comparing BHR with TPA; BHR saved a significant amount of bone on the femoral side [ANOVA p < 0.001] while TPA saved a significant amount of bone on the acetabular side [ANOVA p = 0.03]. Preference between the two designs will depend on the long-term results and the degree of bone loss resulted from loosening and osteolysis at revision operation

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