Influence of surgical approach on complication risk in primary total hip arthroplasty Systematic review and meta-analysis

Background and purpose - Systematic comparisons of anterior approach (A) versus posterior approach (P) in primary total hip arthroplasty (THA) have largely focused on perioperative outcomes. In this systematic review with meta-analysis, we compared complication risk of A versus P in studies of primary THA with at least 1-year mean follow-up. Patients and methods - We performed a systematic review of prospective and retrospective studies with at least 1-year mean follow-up that reported complications of A and P primary THA. Complications included infection, dislocation, reoperation, thromboembolic event, heterotopic ossification, wound complication, fracture, and nerve injury. Random effects meta-analysis was used for all outcomes. Complication risk was reported as rate ratio (RR) to account for differential follow-up durations; values > 1 indicated higher complication risk with A and values < 1 indicated lower risk with A. Results - 19 studies were included; 15 single-center comparative studies with 6,620 patients (2,278 A; 4,342 P) and 4 multi-center registries with 157,687 patients (18,735 A; 138,952 P). Median follow-up was 16 (12-64) months) with A and 18 (12- 110) months with P. Anterior approach was associated with lower rate of infection (RR = 0.55, p = 0.002), dislocation (RR = 0.65, p = 0.03), and reoperation (RR = 0.84, p < 0.001). No statistically significant differences were observed in rate of thromboembolic event (RR = 0.59, p = 0.5), heterotopic ossification (RR = 0.63, p = 0.1), wound complication (RR = 0.93, p = 0.8), or fracture (RR = 1.0, p = 0.9). There was a higher rate of patient-reported nerve injury with A (RR = 2.3, p = 0.01). Interpretation - Comparing A with P in primary THA, A was associated with lower risk of reoperation, dislocation, and infection, but higher risk of patient-reported nerve injury.