Establishing Clinically Significant Improvement for Patients After Arthroscopic Surgery for Shoulder Instability With Large Labral Tears

Background: Patients with large labral tears represent a subset of traumatic shoulder instability cases. Outcomes after arthroscopic stabilization in these patients have been studied less compared with other tears. Purpose: To establish minimal clinically important difference (MCID), Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) thresholds for patients after arthroscopic repair of labral tears >= 270 degrees. Patient-reported outcome measures (PROMs) included the Rowe instability score, American Shoulder and Elbow Surgeons (ASES) score, Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) for pain. Study Design: Case-control study; Level of evidence, 3. Methods: A total of 52 arthroscopic large labral repairs (52 patients, mean age 28.7 years) performed in male active-duty military patients with a mean follow-up of 79.2 months (range, 24-117 months) met inclusion criteria and were included in the final analysis. All included patients completed the Rowe, ASES, SANE, and VAS pain preoperatively and at final follow-up, and the MCID, PASS, and SCB were calculated for each PROM score. Factors associated with achieving clinically relevant improvement were also calculated. Results: The MCID, PASS, and SCB, respectively, for each PROM were as follows: 10.4 points, 90, and 35 points for the Rowe; 9.7 points, 80, and 43 points for the ASES; 9.9 points, 87, and 65 points for the SANE; and 1.1 points, 3, and 6 points for VAS pain. More than 90% of patients improved according to the MCID for each PROM, while >75% achieved the PASS threshold for each score. The percentage of patients who improved according to the SCB ranged from 9.6% for the ASES to 75% for the SANE. Maintenance of active-duty status was associated with achieving the MCID for the ASES and SANE, while recurrent instability was associated with lower rates of Rowe MCID achievement and SANE PASS achievement. Higher preoperative scores were also associated with lower rates of achieving clinical improvement. Conclusion: Thresholds found for the MCID, PASS, and SCB in active-duty patients undergoing surgery for shoulder instability with labral tears >= 270 degrees were similar to those for all-comers with anterior instability. Factors associated with achieving success or lack thereof on PROMs included maintenance of active-duty status and lower preoperative PROM scores.