Varus stem positioning does not affect long-term functional outcome in cementless anatomical total hip arthroplasty.

Introduction: Varus positioning is the most common femoral malposition in total hip arthroplasty (THA). We compared the long-term outcomes of an anatomical cementless femoral stem positioned in varus versus neutral alignment. Materials and methods: Data were retrospectively reviewed for all patients receiving a cementless anatomical femoral stem in THA for osteoarthritis between 1998 and 2008. Exclusion criteria were complex cases, incomplete data or follow-up < 1 year. Primary outcome was survival rate with complications and secondary outcomes were clinical scores, thigh pain, radiological score, cortical hypertrophy and filling rate. Results: Of the 283 included patients, 127 stems were classified as varus and 156 neutral. Mean follow-up was 10 years. Femoral stem size was smaller in the varus group (4.1 vs. 4.4, p = 0.047). A stem-filling rate < 80% was more frequent in the varus group (p < 0.001). The long-term survival rate without any revision procedure was 94.8% ± 2.3% (95%CI 88.4–98.7) in the varus group and 94.1% ± 2.0% (95%CI 91.3–99.1) in the neutral group (p = 0.55). There was no difference in clinical scores, thigh pain or complication occurrence between groups. The Engh–Massin score was lower in the varus group (p < 0.01) and cortical hypertrophy was higher (p < 0.001). Conclusions: A varus alignment of a cementless anatomic femoral stem does not affect survivorship, clinical outcomes or complication rate on an average follow-up of 10 years, despite increasing stress-shielding rates. [ABSTRACT FROM AUTHOR]