Sex and Risk of Hip Implant Failure: Assessing Total Hip Arthroplasty Outcomes in the United States

Importance: The role of sex in relationship to implant failure after total hip arthroplasty (THA) is important for patient management and device innovation. Objective: To evaluate the association of sex with short-term risk of THA revision after adjusting for patient, implant, surgery, surgeon, and hospital confounders. Design and Setting: A prospective cohort of patients enrolled in a total joint replacement registry from April 1, 2001, through December 31, 2010. Participants: Patients undergoing primary, elective, unilateral THA. Main Outcome Measures: Failure of THA, defined as revision procedure for (1) any reason, (2) septic reason, or (3) aseptic reason after the index procedure. Results: A total of 35 140 THAs with 3.0 years of median follow-up were identified. Women constituted 57.5% of the study sample, and the mean (SD) patient age was 65.7 (11.6) years. A higher proportion of women received 28-mm femoral heads (28.2% vs 13.1%) and had metal on highly cross-linked polyethylene-bearing surfaces (60.6% vs 53.7%) than men. Men had a higher proportion of 36-mm or larger heads (55.4% vs 32.8%) and metal on metal-bearing surfaces (19.4% vs 9.6%). At 5-year follow-up, implant survival was 97.4% (95% CI, 97.2%-97.6%). Device survival for men (97.7%; 95% CI, 97.4%-98.0%) vs women (97.1%; 95% CI, 96.8%-97.4%) was significantly different (P=.01). After adjustments, the hazards ratios for women were 1.29 (95% CI, 1.11-1.51) for allcause revision, 1.32 (95% CI, 1.10-1.58) for aseptic revision, and 1.17 (95% CI, 0.81-1.68) for septic revision. Conclusions: After considering patient-, surgery-, surgeon-, volume-, and implant-specific risk factors, women had a 29% higher risk of implant failure than men after THA in this community-based sample.