Lower body mass index and age are predictive of improved pain and health utility scores following arthroscopic management of femoroacetabular impingement

PURPOSE: To identify patient factors associated with improved pain scores, functional hip scores, health-related quality of life, and re-operation rates after arthroscopic management of femoroacetabular impingement (FAI). METHODS: Using the comprehensive dataset from the multinational Femoroacetabular Impingement Randomized Controlled Trial (FIRST), a total of 13 prognostic factors that were chosen a priori were identified that would be expected to predict post-surgical outcomes. The primary outcome was pain assessed using a Visual Analogue Scale (VAS) and secondary outcomes included hip function (Hip Outcome Score [HOS] and International Hip Outcome Tool [iHOT-12]), health-related quality of life (Short Form-12 [SF-12] and Euro-Qol 5 Dimensions [EQ-5D]), and re-operation rate. A multivariable linear regression was used to analyse the change questionnaire scores from baseline to 12 months post-surgery including all 13 prognostic factors as independent variables. A total of 27 re-operation events were analysed at 24 months using a multivariable logistic regression including only the treatment group variable. RESULTS: Of the 154 patients that had VAS scores completed at 12 months, a lower BMI (adjusted mean difference [aMD], 4.48 for a 5-unit decrease in BMI; 95% confidence interval [CI] 0.33-8.63; p = 0.035) was significantly associated with less pain. There was a significant negative association between increasing age and 1-year EQ-5D scores (aMD, - 0.04 for every 10-year increase in age; 95% CI - 0.07 to - 0.006; p = 0.020). The degree of impingement, severity of osteoarthritis, type of procedure, and adjudicated quality of surgery were not significantly associated with improvement across all outcomes at 12 months. Furthermore, there was no significant association between the treatment variable and the incidence of re-operation at 24 months. CONCLUSION: This study identified that lower BMI and age are predictive of improved pain and health utility scores, respectively, following arthroscopic management of FAI at 12 months post-surgery. These results may be a helpful adjunct in clinical decisions for this patient population when determining candidacy for surgical intervention. LEVEL OF EVIDENCE: I.