To investigate the influence of preserving the piriformis muscle during surgery on postoperative hip joint function recovery and the incidence of dislocation following total hip arthroplasty (THA). This retrospective multicenter study collected clinical data and follow-up information from patients with hip osteoarthritis or femoral head necrosis who underwent primary unilateral total hip arthroplasty at Ningde Municipal Hospital and Fujian Provincial Hospital between 2019 and 2024. A minimum follow-up of 12 months was required for inclusion. Patients were followed at 1 week, 1 month, 3 months, and 12 months after surgery. The choice of surgical approach was made by the attending surgeon according to preoperative planning, surgeon familiarity with the technique, and intraoperative exposure feasibility; it was not assigned by a study protocol. Patients were categorized into the posterolateral piriformis-sparing approach (Mis-PLA) group and the traditional posterolateral approach (PLA) group. A total of 420 patients were finally included, among whom 208 were in the Mis-PLA group and 212 were in the PLA group. All patients completed at least 12 months of follow-up. The preoperative Harris Hip Score was comparable between groups (PLA: 42.7 ± 7.9 vs Mis-PLA: 41.3 ± 8.2; P = .075). At 12 months, the Harris Hip Score remained similar between groups (PLA: 94.98 ± 2.12 vs Mis-PLA: 95.26 ± 1.85; P = .150). In repeated-measures analysis adjusted for age, sex, and body mass index, the group-by-time interaction was significant (Wald χ 2 = 66.39, P < .001), and the Mis-PLA group remained associated with higher Harris Hip Scores at 1 week (β = 5.38, 95% CI: 3.61–7.15; P < .001) and 1 month (β = 3.22, 95% CI: 1.26–5.18; P = .001). In multivariable linear regression, Mis-PLA was independently associated with a higher 1-month Harris Hip Score (β = 2.12, 95% CI: 0.85–3.40; P = .001). The incidence of early postoperative hip dislocation was significantly lower in the Mis-PLA group than in the PLA group (0% vs 2.8%, P = .042). In this retrospective multicenter cohort, preservation of the piriformis muscle during the posterolateral approach was associated with reduced early dislocation and improved early functional recovery, without compromising 12-month functional outcomes. Preservation of the piriformis muscle during the posterolateral approach may be considered a feasible option to reduce early dislocation without compromising functional recovery.
Zheng et al. (Fri,) studied this question.