Minimum 5-Year Outcomes for Revision Hip Arthroscopy With a Prospective Subanalysis Against a Propensity-Matched Control Primary Group

Background: There is a paucity of midterm outcome data on hip revision arthroscopic surgery. Purpose: (1) To report minimum 5-year patient-reported outcome measurement scores (PROMSs) in patients who underwent revision hip arthroscopy, (2) to compare minimum 5-year PROMSs with a propensity-matched control group that underwent primary hip arthroscopy, and (3) to compare the rate of achieving the minimal clinically important difference (MCID) at minimum 5-year follow-up between the revision group and the propensity-matched control primary group. Study Design: Cohort study; Level of evidence, 3. Methods: Data were prospectively collected between June 2008 and April 2014. Patients were included who underwent revision hip arthroscopy with preoperative and minimum 5-year follow-up scores for the modified Harris Hip Score (mHHS), Non-arthritic Hip Score (NAHS), Hip Outcome Score-Sports Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. Patients with Tonnis grade >1 or with hip conditions such as avascular necrosis, Legg-Calve-Perthes disease, Ehlers-Danlos syndrome, and pigmented villonodular synovitis were excluded. A subanalysis was performed against a propensity-matched control group that underwent primary surgery. Groups were propensity matched in a 1:2 ratio for sex, age, body mass index, and follow-up time. Results: A total of 127 revision arthroscopies (113 patients) were included, and the mean +/- SD follow-up time was 72.8 +/- 23.3 months. The revision group was 74.0% female, and the average age and body mass index were 34.9 +/- 12.4 years and 24.8 +/- 4.2, respectively. The revision group demonstrated improvement for all PROMSs and reached the MCID for the mHHS (66.1%), HOS-SSS (68.4%), NAHS (66.9%), and VAS (80.0%). All revision cases were propensity matched to 254 primary arthroscopy cases. PROMSs in the revision group were lower than those of the control group before and after surgery. Delta values were similar between groups for all PROMSs. There were no differences in rates of achieving the MCID. The relative risk of arthroplasty conversion was 2.6 (95% CI, 1.5-4.6) for the revision group as compared with the primary group. Conclusion: Significant improvement in all PROMSs, including the VAS, and high patient satisfaction at minimum 5-year follow-up were reported after revision hip arthroscopy. A high proportion of patients in the revision cohort reached the MCID for the mHHS, HOS-SSS, NAHS, and VAS, with similar rates and magnitudes of improvement relative to the control group. As expected, these data indicate that patients undergoing primary hip arthroscopy have higher PROMSs before and after surgery and lower rates of conversion to arthroplasty.