Patients Undergoing Revision Hip Arthroscopy Demonstrate Comparable Survivability and Improvement but Worse Postoperative Outcomes Compared to Patients Undergoing Primary Hip Arthroscopy: A Propensity Matched Study at Five-Year Follow-Up

Purpose: To compare mid-term clinical outcomes between patients undergoing primary hip arthroscopy (HA) versus revision hip arthroscopy (RHA) for femoroacetabular impingement syndrome (FAIS). Methods: A retrospective cohort study was conducted on 1,862 patients who underwent hip arthroscopy for FAIS from January 2012 to April 2017. Patients who underwent RHA were propensity matched in a 1:4 ratio by age, sex, body mass index (BMI), and exercise status to patients who underwent primary HA. Preoperative and postoperative radiographs were assessed. Patientreported outcomes before and at 5 years after surgery, including the Hip Outcome Score Activities of Daily Living subscale (HOS-ADL) and Sports subscale (HOS -SS), modified Harris Hip Score (mHHS), international Hip Outcome Tool (iHOT-12), and Visual Analog Scale (VAS) for Pain and Satisfaction, were compared between groups. Minimally clinically important difference and patient -acceptable symptomatic state (PASS) achievement rates were compared using previously published thresholds. Results: Fifty-one patients who underwent RHA (35 female, 16 male; age 36.2 +/- 10.2 years; BMI 26.5 +/- 5.9) were followed up for 63.9 +/- 9.2 months and then propensity matched in a 1:4 ratio by sex, age, and BMI to 204 control patients who underwent primary HA. At midterm follow-up, patients in the RHA cohort had significantly lower scores for HOS -SS (RHA 64.9 +/- 32.5 vs HA 75.3 +/- 26.2, P = .044), mHHS (RHA 72.2 +/- 22.4 vs HA 80.1 +/- 18.1, P = .039), and iHOT-12 (RHA 61.4 +/- 29.3 vs HA 71 +/- 27.6, P = .043) compared to primary HA patients. Rates of achieving PASS were significantly decreased for HOS -SS (RHA 38.3% vs HA 55.4%, P = .039) and iHOT-12 (RHA 41.9% vs HA 59.9%, P = .035) in the RHA cohort. There were no significant differences in rates of conversion to THA or subsequent reoperation on the index hip between groups. Conclusions: Patients undergoing revision hip arthroscopy demonstrate comparable survivability and magnitude of improvement but may experience worse overall outcome scores and meet thresholds for clinically significant outcomes less often when compared to primary hip arthroscopy patients. Level of Evidence: Level III; retrospective comparative study.