Total hip arthroplasty utilizing an uncemented, flat, tapered stem with a reduced distal profile.

Abstract

The aim of this study was to report the midterm results of an uncemented, flat, and tapered femoral stem with a reduced distal profile.219 total hip arthroplasties were performed using this stem between March 2007 and October 2012. Survival, radiographs, and modified Harris Hip Scores were analyzed.Twenty-two (11.1%) patients died from comorbidities but retained their hips; 18 (9.1%) patients were lost to follow-up. Of the remaining 179 hips, all stems remained in situ at a median follow-up of 8.4 (7.0-9.3) years. There was 97.5% (95% CI: 95.1-99.9) survival for all-cause revision with 4 hips revised for instability. Early stem subsidence was identified in 2 patients within 3 months postoperative measured at 4 mm in patient 1 and 3 mm in patient 2. Long-term radiographic follow-up showed 2 hips with incomplete radiolucencies but no evidence of stress shielding, osteolysis, or subsidence among examined hips (n = 93). Spot welding and cortical hypertrophy were present in 58 (62.4%) and 50 (53.8%) hips, respectively. Femoral component position did not change from early postoperative imaging relative to long-term follow-up at ≥5 years ( = .097). Median modified Harris Hip Scores improved from 58.3 (49.5-64.9) points preoperative to 95.7 (88.0-100) points at follow-up ( < .0001).The reduced distal profile stem studied showed no stem revisions at long-term follow-up with an all-cause survivorship of 97.5% at a median follow-up of 8.4 (7.0-9.3) years. The stem showed good bone integration and stability at midterm follow-up in most patients reviewed.