EP8.31 Longitudinal Pain Trajectory After Hip Arthroscopy for Femoroacetabular Impingement According to Intraoperative Factors and Baseline Patient Characteristics: A Digital Patient-Reported Outcome Studya

Abstract

Abstract Background Hip arthroscopy is widely used for the treatment of femoroacetabular impingement (FAI). Although its effectiveness in improving pain and function is well established, the longitudinal evolution of postoperative pain according to intraoperative procedures and baseline patient characteristics remains insufficiently described. Understanding these trajectories may improve patient counselling and expectation management. Methods A retrospective analysis of prospectively collected patient-reported outcomes was conducted in a single-center cohort of 302 hips undergoing hip arthroscopy for FAI. Pain was recorded using a digital platform preoperatively and at postoperative days 1, 7, 30, 90, 180, and 365. Functional outcomes (iHOT-12, mHHS, NAHS, and HAGOS) were recorded at 6 months and 1 year. Univariate analyses evaluated associations between intraoperative variables (traction time, acetabuloplasty, femoroplasty, capsular management, labral treatment) and postoperative pain. Multivariable regression was used to evaluate independent predictors of pain at 1 year. Longitudinal mixed-effects modeling was used to assess the relationship between traction duration and pain over time. Pain trajectories were also analyzed according to tertiles of preoperative VAS. Results Pain decreased significantly over time, with the greatest improvement during the first six months. Traction time was not associated with postoperative pain in cross-sectional analyses after correction for multiple testing. In longitudinal mixed-effects modeling, a weak association was observed at day 1 (β = +0.027 pain points/mn of traction, p = 0.030), but not after. Differences across intraoperative factors were not maintained after multivariable adjustment. Preoperative pain strongly predicted the magnitude of postoperative pain reduction (β ≈ −0.65, p < 0.001) and was the only independent predictor of residual pain at 1 year (β = 0.361, p < 0.001). Patients with higher baseline pain experienced the greatest absolute improvements but remained slightly more symptomatic throughout follow-up, with trajectories progressively converging toward a common postoperative pain range. Functional outcomes improved significantly regardless of procedures performed. Preoperative pain showed limited predictive value for functional outcomes. In contrast, early postoperative pain (days 1–90) was consistently associated with PROM scores at 6 months and 1 year, with moderate correlations. Conclusion Postoperative pain after hip arthroscopy followed a predictable trajectory with early improvement and later stabilization. Intraoperative procedures, including traction duration, had minimal influence on long-term pain evolution. Instead, baseline pain strongly shaped recovery trajectories, with more symptomatic patients achieving larger absolute improvements while maintaining higher residual pain levels. Early postoperative pain influenced functional outcomes at 6 monts and 1 year. Recovery was primarily driven by baseline patient characteristics rather than intraoperative factors.