Defining the Minimal Clinically Important Difference and Patient Acceptable Symptom State for Arthroscopic Anterior Shoulder Stabilization at 2-Year Follow-up.

Background: There is a paucity of literature on the short-term clinical significance and patient-reported outcome measures (PROMs) after arthroscopic stabilization for anterior shoulder instability. Purpose: (1) To define the minimal clinically important difference (MCID) and patient acceptable symptom state (PASS) thresholds for arthroscopic anterior shoulder stabilization at a minimum 2-year follow-up. (2) To investigate predictive factors, including preoperative, demographic, and intraoperative variables, for achieving MCID and PASS. Study Design: Case-control study. Methods: Patients who underwent primary arthroscopic stabilization for anterior-inferior labral tears from March 2018 to December 2021 with a minimum of 2-year follow-up were retrospectively identified through a prospectively maintained institutional database. MCID thresholds were determined by a distribution-based method, while PASS thresholds were established using an anchor-based method. The PROMs analyzed included the Western Ontario Shoulder Instability Index (WOSI), Single Assessment Numeric Evaluation (SANE), Patient-Reported Outcomes Measurement Information System Upper Extremity (PROMIS UE), and the Veterans Rand-12 (VR-12) score. Multivariate logistic regression was performed to identify factors associated with achieving MCID and PASS. Results: A total of 65 patients were included. The thresholds for MCID achievement and achievement rates were as follows: WOSI, 12.8 (84.6%); SANE, 14.4 (81.5%); PROMIS UE 4.4 (90.8%); VR-12 Physical, 3.9 (76.9%). The thresholds for PASS achievement and achievement rates were as follows: WOSI, 40.2 (80%); SANE, 74.9 (86.2%); PROMIS UE 40.5 (84.8%); VR-12 Physical, 49.9 (83.1%). Symptom duration >6 months was predictive of failing to achieve MCID for the WOSI and PASS for the WOSI and SANE. Preoperative hyperlaxity was predictive of failing to achieve PASS for the WOSI and PROMIS UE. A lower body mass index (BMI) was predictive of achieving PASS for the WOSI, PROMIS UE, and VR-12. The presence of an anterior labroligamentous periosteal sleeve avulsion (ALPSA) lesion was predictive of failing to achieve PASS for the WOSI and failing to achieve MCID and PASS for the WOSI, PROMIS UE, and VR-12 simultaneously. Conclusion: This study defines thresholds for MCID and PASS achievement at a minimum 2-year follow-up for patients undergoing arthroscopic anterior shoulder stabilization. Factors including symptom duration, hyperlaxity, BMI, and ALPSA lesions were found to be predictive of MCID and PASS achievement on multiple PROMs at short-term follow-up.