Background: Patients with hip pain ≥2 years before hip arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) have been shown to achieve inferior short-term and midterm outcomes compared with patients with a shorter pain duration, although there is limited literature that has evaluated the time to achieve clinically significant outcomes (CSOs) in this population. Purpose: To compare the time to achieve CSOs after hip arthroscopic surgery for FAIS in patients with and without prolonged hip pain and to identify independent predictors of the delayed achievement of CSOs. Study Design: Cohort study; Level of evidence, 3. Methods: Patients who underwent primary hip arthroscopic surgery for FAIS between January 2012 and July 2019 with 6-month, 1-year, and 2-year Hip Outcome Score–Activities of Daily Living (HOS-ADL) and Hip Outcome Score–Sports Subscale (HOS-SS) scores were identified. Patients with prolonged hip pain (preoperative duration ≥2 years) were propensity score matched to a control group (preoperative duration <2 years), controlling for age, sex, and body mass index (BMI). The times to achieve the minimal clinically important difference and Patient Acceptable Symptom State were compared between groups using Kaplan-Meier survival analysis. Multivariate Cox regression considering age, sex, BMI, pain duration, activity level, and chondral status was used to identify independent predictors of the delayed achievement of CSOs. Results: A total of 179 patients with prolonged hip pain were matched to 179 control patients (mean pain duration, 60.5 ± 51.2 vs 9.7 ± 5.1 months, respectively; P < .001) of a similar age, sex, and BMI ( P≥ .488) with similar baseline HOS-ADL and HOS-SS scores ( P≥ .971). The prolonged hip pain group showed delayed achievement of the minimal clinically important difference and Patient Acceptable Symptom State for both the HOS-ADL and HOS-SS on Kaplan-Meier analysis ( P≤ .020). On multivariate Cox regression, hip pain duration ≥2 years was shown to be an independent predictor of the delayed achievement of CSOs, with hazard ratios ranging from 1.32 to 1.65 ( P≤ .029). Additional independent predictors of the delayed achievement of CSOs included increasing age, increasing BMI, female sex, self-endorsed weekly participation in physical activity, and high-grade chondral defects (hazard ratio range, 1.01-4.89; P≤ .045). Conclusion: Findings from this study demonstrate that preoperative hip pain duration ≥2 years was an independent predictor of the delayed achievement of CSOs after primary hip arthroscopic surgery for FAIS.
