Bone sparing surgical options for total hip replacement

Between 4/5/99 and 5/20/2002, our university performed 31 total hip arthroplasties in 27 young patients utilizing a conservative hip prosthesis developed at the Mayo Clinic. Eleven patients underwent Bipolar replacement, while the remaining twenty required an acetabular component. The patients ranged in age from 25 to 50 (mean of 39.9). The mean follow up was 12.4 months (range 4.5-27). Twenty-eight hips were treated for AVN secondary to RA, HIV, ETOH abuse, and SLE; while two underwent THA for OA secondary to trauma, and one for JRA. Three patients were lost to follow up at less than 6 months and were excluded from the study. The patients were followed for a minimum of 6 months utilizing the Harris hip score, the Charnley hip score, and radiographic evaluation including subsidence, radiolucency, and calcar resorption. Four patients (13%) had subsidence ranging from 1 to 3 mm at the most recent visit. One patients (3.2%) had radiographic evidence of radiolucency measuring 2 mm. Nine patients (29%) developed 1-3 mm of calcar resorption. No hips required revision. Thirty patients had improvement in their Harris hip score and Charnley hip score. The one patient who decreased his score had developed AVN secondary to ETOH abuse. Three hips had an intra-operative complication of lateral cortex penetration and required circlage wiring. Comparisons were made utilizing Multiple Logistic Regression to determine if preoperative BMI, Dorr score, and gender had an impact on the postoperative hip scores or degree of osteolysis, subsidence, and calcar resorption. Although the Harris hip score and Charnley hip scores significantly improved postoperatively, the preoperative BMI, Dorr score, and gender did not correlate with patient outcome. Our patients improved clinically in pain level, function and ROM. Further follow up will reveal if this component truly preserves bone stock for ease of future revision.