Sex-Specific Postoperative Outcomes of Primary Total Hip Replacements: The Performance of Total Hip Replacement Procedures Leads to Worse Outcomes in Men.

Introduction: The demand for primary total hip arthroplasty (THA) is expected to increase significantly in the coming years, and women are expected to account for the greatest proportion of this increased demand. The purpose of this study was to determine, using a national database, the effect of sex on 90-day outcomes in primary THA patients while matching for confounding variables. Specifically, we evaluated: (1) in-hospital lengths of stay; (2) 90-day readmission rates; (3) 90-day medical complications; (4) and total global 90-day episode-of-care (EOC) costs in men and women.

Materials and methods: Using the 100% Medicare Standard Analytical Files (SAF), a query from January 1, 2005 to March 31, 2014 from a nationwide database was performed to analyze patients who received a primary THA. The series was divided into two cohorts: men (n=436,737) and women (n=436,737). Male and female patients were matched according to age and Elixhauser-Comorbidity Index (ECI). Uni- and multi-variable regression analyses were performed to analyze the effects of sex on in-hospital lengths of stay, 90-day readmission rates, 90-day medical complications, and total global 90-day EOC costs.

Results: Men had greater overall 90-day medical complications compared to women following primary THA (1.28 vs. 1.19%, p<0.001). Men were found to have higher rates of acute kidney failure (0.12 vs 0.05%, p<0.0001), acute pancreatitis (0.02 vs. 0.01%, p<0.0001), cerebrovascular accidents (0.03 vs. 0.01%, p<0.0001), deep vein thromboses (0.06 vs. 0.04%, p<0.0001), and myocardial infarctions (0.02 vs. 0.01%, p<0.0001). Women were found to have higher rates of acute post-hemorrhagic anemiae (0.31 vs. 0.30%, p<0.001) and urinary tract infections (UTI; 0.40 vs. 0.28%, p<0.0001) compared to men. Men had shorter in-hospital lengths of stay (LOS) (3.42 vs. 3.54 days, p<0.001) but greater 90-day readmission rates (7.67 vs. 6.39% p<0.0001). Both cohorts had similar total global 90-day EOC costs ($14,869.85 ± $12,333.50 vs. $14,957.34 ± $10,915.61, p=0.36).

Conclusion: Men undergoing THA have a greater number of overall 90-day medical complications and readmission rates while women have higher incidence of UTI, post-hemorrhagic anemia, and longer LOS. Understanding sex-based differences in complication rates and outcomes can help surgeons with preoperative counseling and targeted preoperative optimization.