Total hip arthroplasty in patients with deficient bone stock and small femoral canals.

Total hip arthroplasty in patients requiring very small femoral stems is a challenge because frequently deformity and inadequate bone stock, especially of the acetabulum, are also present. An analysis of 34 consecutive cases managed with a 9-mm distal diameter noncemented stem was performed. The mean patient age was 42.6 years and mean follow-up time was 7.8 years. Two patients were lost to follow-up at 4 and 6 years, and 1 patient had a fracture below the stem immediately after surgery, necessitating revision. These patients were excluded from analysis. Of the remaining 31 patients, 1 underwent revision for distal osteolysis leading to fracture. The Harris hip ratings for these patients were 58.1% excellent, 22.6% good, 16.1% fair, and 3.2% poor. Complications experienced included 1 femoral component that fractured but remains asymptomatic. Polyethylene wear of the very small acetabular components in 31% of cases is a cause for concern; 2 of these patients have required revision for this reason. The acetabular component was subsequently modified to allow thicker polyethylene.