Staged Bilateral Hip Arthroscopy for Femoroacetabular Impingement Syndrome: Index Surgery Patient Reported Outcome Measures Predict Contralateral Surgery Results at 2 Years.

ABSTRACT

PURPOSE: To determine whether (1) patient-reported outcome (PRO) scores after index hip arthroscopy correlate with PRO scores for the contralateral hip in patients undergoing staged bilateral hip arthroscopy and (2) patients who achieved minimal clinically important difference (MCID) or patient-acceptable symptom state (PASS) for the index hip were more likely to achieve MCID or PASS for the contralateral hip. METHODS: Patients who underwent staged bilateral hip arthroscopy for femoroacetabular impingement syndrome were retrospectively reviewed. PRO scores were prospectively collected at preoperative and 1- and 2-year timepoints. Odds ratios for achievement of MCID and PASS for the contralateral hip given achievement for the index hip were calculated. Improvements from before surgery to 2 years after surgery were correlated between both hips. RESULTS: A total of 143 patients (286 hips) were included in the final analysis. Average time between surgeries was 8.5 months (range, 0.7-57.2). Both hips demonstrated significant improvement (P < .05 for all) in all PROs at 2 years. Achievement of MCID in Hip Outcome Score Activities of Daily Living (HOS-ADL) at the 1-year timepoint for the index hip was predictive of achievement of MCID in HOS-ADL at 2 years for the contralateral hip. Achievement of PASS in all PROs at the 1-year timepoint for the index hip were predictive of achievement of PASS in the equivalent outcome score at the 2-year mark for the contralateral hip. Achievement of MCID or PASS at the 2-year timepoint for the index hip was predictive of achievement of the equivalent outcome at the 2-year timepoint for the contralateral hip. The strongest correlation between improvement in PRO scores for the index and contralateral hips was noted in patients who underwent staged hip arthroscopy within less than 3 months. CONCLUSION: Patients experience significant clinical benefit in both hips after staged bilateral hip arthroscopy. Results from the initial hip arthroscopy at either 1- or 2-year follow-up can be used to predict outcomes on the contralateral side; however, there is a higher degree of predictive value using 2-year results. Average correlations between 2-year PROs on the index and contralateral hips were moderate to strong, regardless of the time between surgeries. LEVEL OF EVIDENCE Level III, retrospective cohort study.