Defining the Percent Thresholds for Achieving the Maximum Outcome Improvement of the Modified Harris Hip Score, the Non-Arthritic Hip Score, the Hip Outcome Score-Sports Subscale, the Visual Analog Scale for Pain, and the International Hip Outcome Tool-12 in Revision Hip Arthroscopy at Minimum 2-Year Follow-Up
Abstract
Purpose: To determine the respective percent thresholds for achieving the maximal outcome improvement (MOI) for the modified Harris Hip Score (mHHS), the Non-Arthritic Hip Score (NAHS), the Hip Outcome Score-Sports Subscale (HOS-SSS), the visual analog scale (VAS) for pain, and the International Hip Outcome Tool-12 (iHOT-12) that were associated with satisfaction following revision hip arthroscopy, and to identify predictors for achieving the MOI.
Methods: An anchor question was provided to patients who underwent revision hip arthroscopy between April 2017 and July 2020. Patients were included for the final analysis if they answered the anchor question and had minimum 2-year follow-up. Receiver operating characteristic analysis was used to determine the thresholds for the percentage of the MOI predictive of satisfaction. A P-value of < .05 was considered significant.
Results: In total, 318 patients underwent revision hip arthroscopy. Of those patients, 292 (91.8%) had minimum 2-year follow-up. Of this cohort, 68 answered the anchor question, with 49 (72.1%) female and 19 (27.9%) male patients. The mean age, and body mass index time were 32.9 ± 13 years and 25.4 ± 5.1, respectively. It was determined that 42.1%, 50%, 48.1%, 50%, and 50% of MOI were the thresholds for maximal predictability of satisfaction for mHHS, NAHS, HOS-SS, VAS for pain, and the iHOT-12, respectively. The presence of unaddressed subspine impingement was a significant predictor for achieving the MOI threshold for the VAS (odds ratio 1.40; 95% confidence interval 1.00-1.95; P = 0.0273).
Conclusions: Following revision hip arthroscopy, the percent thresholds for achieving the MOI at a minimum 2-year follow-up for the mHHS, NAHS, HOS-SS, VAS for pain, and iHOT-12 were 42.1%, 50%, 48.1%, 50%, and 50.9%, respectively. Addressing residual subspine impingement was identified as significant positive predictor for achieving the MOI.