Sex differences in complications following total hip arthroplasty: a population-based study

Background — The relationship between sex and outcomes, especially complications, after total hip arthroplasty (THA) has not been well established. This study aimed to identify if patient biological sex significantly impacted complications after THA in Ontario, Canada.

Methods — A population-based retrospective cohort study of patients undergoing primary THA in Ontario from April 1, 2015, to March 31, 2020 was conducted. The primary outcome was major surgical complications within a year post-surgery (a composite of revision, deep infection requiring surgery, and dislocation). Secondary outcomes included the individual component of the composite primary outcome and major medical complications within 30 days. Proportional hazards regression calculated the adjusted hazards ratio (aHR) for major surgical complications in men relative to women, adjusting for age, co-morbidities, neighborhood income quintile, surgeon and hospital volume, and year of surgery.

Results — A total of 67,077 patients (median age 68 years; 54.1% women) from 61 hospitals were included; women were older with a higher prevalence of frailty. Women had a higher rate of major surgical complications within one year of surgery compared to men (2.9 versus 2.5%, adjusted OR [odds ratio] 1.19, 95%CI [confidence interval] 1.08 to 1.33, P = 0.0009). Conversely, men had a higher risk for medical complications within 30 days (6.3 versus 2.7%, P < 0.001).

Conclusion — Observable sex disparities exist in post-THA complications; women face surgical complications predominantly, while medical complications are more prevalent in men. These insights can shape preoperative patient consultations.