Clinical Outcomes of Hip Arthroscopy: A Prospective Survival Analysis of Primary and Revision Surgeries in a Large Mixed Cohort

Abstract

Recent hip arthroscopy literature has focused on revision hip arthroscopies and conversion to total hip arthroplasty (THA) or hip resurfacing (HR). This study reports a survival analysis at minimum two-year follow-up after hip arthroscopy and compares clinical outcomes of primary versus revision hip arthroscopy. From February 2008 to June 2012, data were prospectively collected on all primary and revision hip arthroscopies. Patients were assessed pre- and post-operatively with four patient-reported outcome (PRO) measures: modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Activities of Daily Living (HOS-ADL), and Hip Outcome Score-Sport Specific Subscales (HOS-SSS). Pain was estimated on the visual analog scale (VAS). Patient satisfaction was measured on a scale from 0 to 10. Secondary procedures were recorded. Of 1000 primary arthroscopy patients and 117 revision arthroscopy patients treated, 931 (93.1%) and 107 (91.5%), respectively, were available for follow-up and included in our study. At two-year follow-up, mHHS, HOS-ADL, HOS-SSS, NAHS, and VAS were 79.4, 82.2, 65.6, 79.9, and 2.9, respectively for primary arthroscopy patients and 71.0, 73.0, 54.5, 71.4, and 3.8, respectively for revision arthroscopy patients. All scores improved significantly compared to pre-operatively (p<0.001) and were higher for the primary subgroup compared to the revision subgroup (p<0.05). Satisfaction was 7.6 and 7.0 for primary and revision subgroups, respectively. Of primary and revision arthroscopy patients, 5.8% and 11.2% converted to THA/HR, respectively. The relative risk of a THA/HR was 1.93 after revision arthroscopy compared to primary arthroscopy. The overall complication rate was 5.3%. Hip arthroscopy showed significant improvement in all PRO, VAS, and satisfaction scores at two years postoperatively. Primary arthroscopy patients showed significantly improved PRO scores and a trend towards improved VAS compared to the revision subgroup. Primary arthroscopy patients had a lower conversion rate to THA/HR of 5.8% compared to 11.2% of revision patients.