Association Between Surgical Approach and Major Surgical Complications in Patients Undergoing Total Hip Arthroplasty.

Importance: Controversy exists about the preferred surgical approach for total hip arthroplasty (THA). Objective: To determine whether an anterior approach is associated with lower risk of complications than either a lateral or posterior approach. Design, Setting, and Participants: Population-based retrospective cohort study of all adults in Ontario, Canada, who had undergone primary THA for osteoarthritis between April 1, 2015, and March 31, 2018. All patients were followed up over a 1-year period (study end date, March 31, 2019). Exposures: Surgical approach (anterior vs lateral/posterior) for THA. Main Outcomes and Measures: Major surgical complications within 1 year (composite of deep infection requiring surgery, dislocation requiring closed or open reduction, or revision surgery). Outcomes were compared among propensity-score matched groups using Cox proportional hazards regression. Results: Of the 30 098 patients (mean [SD] age, 67 years [10.7 years]; 16 079 women [53.4%]) who underwent THA, 2995 (10%) underwent the anterior approach; 21 248 (70%), the lateral approach; and 5855 (20%) the posterior approach performed at 1 of 73 hospitals by 1 of 298 surgeons. All patients were followed up for 1 year. Compared with those undergoing the lateral or posterior approach, patients undergoing an anterior approach were younger (mean age, 65 vs 67 years; standardized difference, 0.17); had lower rates of morbid obesity (4.8% vs 7.6%; standardized difference, 0.12), diabetes (14.2% vs 19.9%; standardized difference, 0.15), and hypertension (53.4% vs 62.9%; standardized difference, 0.19); and were treated by higher-volume surgeons (median range, 111 procedures; interquartile range, 69-172 vs 77 procedures, interquartile range, 50-119 in the prior year; standardized difference, 0.55). Compared with 2993 propensity-score matched patients undergoing a lateral or posterior approach, the 2993 matched patients undergoing anterior approaches had a significantly greater risk of a major surgical complication (61 patients [2%] vs 29 patients [1%]; absolute risk difference, 1.07%; 95% CI, 0.46%-1.69%; hazard ratio, 2.07; 95% CI, 1.48 to 2.88). Conclusions and Relevance: Among patients undergoing total hip arthroplasty, an anterior surgical approach compared with a posterior or lateral surgical approach was associated with a small but statistically significant increased risk of major surgical complications. The findings may help inform decisions about surgical approach for hip arthroplasty, although further research is needed to understand pain and functional outcomes.