Time Required to Achieve Clinically Significant Outcomes After Arthroscopic Rotator Cuff Repair

OBJECTIVES: To define the time-dependent nature of the minimally clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) after arthroscopic rotator cuff repair (RCR). METHODS: A prospectively maintained institutional registry was queried for all patients undergoing arthroscopic RCR from 2014-2017 with completed pre-operative, 6 month, 1 and 2 year patient-reported outcome measure (PROM) surveys. MCID, SCB and PASS were calculated for the American Shoulder and Elbow Surgeons Score (ASES) using anchor-based methodology with receiver operating curve/area under curve analysis. Time to MCID, SCB and PASS was calculated using Kaplan-Meier analysis. A Cox multivariate regression model was used to calculate hazard ratios with respect to preoperative factors and intraoperative pathology. RESULTS: 95 patients were included. Average age was 56.9 ± 9.5 years, average BMI was 30.8 ± 7.0 kg/m2. Mean symptom duration was 8.5 ± 7.8 months. Established MCID, SCB, PASS for the ASES were 11.1, 17.5, and 86.7 respectively. A total of 94.8% achieved MCID, 84.4% achieved SCB, and 54.6% achieved thresholds for PASS. Median achievement of MCID, SCB, and PASS occurred at 161, 166, and 347 days, respectively. Older patients had an increased likelihood of achieving MCID and SCB (HR: 1.036, 95% CI: 1.009, 1.064, p=0.009 and HR: 1.026, 95% CI: 1.000, 1.051, p=0.045, respectively). Lower preoperative score increased the likelihood of achieving SCB (HR: 0.976, 95% CI: 0.964, 0.989, p<0.001). Sustaining a dominant sided injury reduced the likelihood of achieving PASS (HR: 0.692, 95% CI: 0.513, 0.932, p=0.015). CONCLUSION: This study established the timeline to reach MCID, SCB and PASS in patients undergoing primary arthroscopic RCR. 80% of patients can expect to achieve MCID and SCB within one year, while 50% achieve PASS at this time point. Future studies should account for this trend in improvement when determining appropriate follow-up.