John Charnley Award: Preoperative Patient-reported Outcome Measures Predict Clinically Meaningful Improvement in Function After THA

Background Despite the overall effectiveness of total hip arthroplasty (THA), a subset of patients remain dissatisfied with their results because of persistent pain or functional limitations. It is therefore important to develop predictive tools capable of identifying patients at risk for poor outcomes before surgery. Questions/purposes The purpose of this study was to use preoperative patient-reported outcome measure (PROM) scores to predict which patients undergoing THA are most likely to experience a clinically meaningful change in functional outcome 1 year after surgery. Methods A retrospective cohort study design was used to evaluate preoperative and 1-year postoperative SF-12 version 2 (SF12v2) and Hip Disability and Osteoarthritis Outcome Score (HOOS) scores from 537 selected patients who underwent primary unilateral THA. Minimum clinically important differences (MCIDs) were calculated using a distribution-based method. A receiver operating characteristic analysis was used to calculate threshold values, defined as the levels at which substantial changes occurred, and their predictive ability. MCID values for HOOS and SF12v2 physical component summary (PCS) scores were calculated to be 9.1 and 4.6, respectively. We analyzed the effect of SF12v2 mental component summary (MCS) scores, which measure mental and emotional health, on SF12v2 PCS and HOOS threshold values. Results Threshold values for preoperative HOOS and PCS scores were a maximum of 51.0 (area under the curve [AUC], 0.74; p