Does Failure to Meet Threshold mHHS & iHOT-12 Scores Correlate to Reoperations After Hip Arthroscopy?

Abstract

To determine (a) if failing to achieve a patient reported outcome (PRO) threshold at 1-year is associated with reoperations at minimum 2-year follow up and (b) the outcome threshold with the highest association with future surgeries Patients undergoing primary hip arthroscopy between July 2014 and December 2016 with pre-operative and 1-year post-operative modified Harris Hip Score (mHHS) and international Hip Outcome Tool – 12 item (iHOT-12) scores were identified. The rate of reoperation was compared for patients who achieved minimal clinical important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptom state (PASS) for each PRO against the rate of those who did not. The sensitivity, specificity, accuracy, relative risk, positive predictive, and negative predictive value for these thresholds were calculated. Of 369 of 425 cases (86.8%) were included. A total of 28 patients underwent reoperations (7.59%), with 14 undergoing revision arthroscopies (3.79%) and 14 converting to THA (3.79%). For mHHS, 267 (72.4%), 173 (46.9%), and 277 (75.1%) hips met MCID, SCB, and PASS respectively. For iHOT-12, 234 (63.4%), 218 (59.1%), and 280 (75.9%) hips met the respective thresholds. The highest sensitivity, specificity, and accuracy were identified as iHOT-12 MCID (0.786), iHOT-12 PASS (0.786), and iHOT-12 MCID (0.77) respectively. The iHOT-12 PASS (RR = 6.36 CI95% = 5.883-6.866) was identified as having the highest RR and negative predictive value (0.974). The positive predictive value of not achieving thresholds for reoperations was low across all thresholds. In a novel approach of PRO threshold score utilization, this study identified patients at increased risk of reoperations following primary hip arthroscopy, notably those who do not achieve MCID or PASS for either mHHS or iHOT-12