Defining the minimal clinically important difference and patient acceptable symptom state following reverse shoulder arthroplasty for glenohumeral arthritis or cuff tear arthropathy at minimum 5-year follow-up

Abstract

Background: While prior studies have assessed the minimal clinically important difference (MCID) and patient acceptable symptomatic state (PASS) following reverse shoulder arthroplasty (rTSA) at 2-year follow-up, data on clinically significant outcomes at mid-term follow-up remain limited.

Purpose: (1) To establish the MCID and PASS thresholds for rTSA with a minimum follow-up period of 5 years. (2) To examine factors that are predictive of MCID and PASS achievement for rTSA, including preoperative, demographic, and intraoperative variables.

Methods: All patients who underwent rTSA for rotator cuff arthropathy or glenohumeral arthritis from January 2016 to December 2018 were retrospectively identified through a prospectively-collected institutional database. MCID thresholds were determined by a distribution-based method while PASS thresholds were established using an anchor-based method. The patient reported outcome measures (PROMs) analyzed included American Shoulder and Elbow Surgeons (ASES) score and Single Assessment Numeric Evaluation (SANE) score and Veterans Rand (VR) 12. Multivariate logistic regressions were performed to determine factors associated with the achievement of MCID and PASS.

Results: Eighty patients were included. The thresholds for MCID achievement and percentages that reached achievement were as follows: ASES, 11.4 (88.8%); SANE, 14.8 (85.0%); VR 12 Physical, 4.9 (66.3%). The thresholds for PASS achievement and percentages that reached achievement were as follows: ASES, 80.8 (65.0%); SANE, 75.9 (66.3%); VR 12 Physical, 44.4 (57.5%). Lower preoperative score was predictive of achieving MCID for all PROMs. Worker's compensation designation was predictive of failing to achieve MCID for ASES and MCID and PASS for SANE. A prior ipsilateral shoulder procedure was predictive of failing to achieve MCID for ASES, SANE, and VR 12 Physical. Tobacco use was predictive of failing to achieve MCID for VR 12 Physical.

Conclusion: This study defines the thresholds for MCID and PASS achievement at minimum 5-year follow-up in a cohort of patients undergoing rTSA for rotator cuff arthropathy or glenohumeral arthritis. More patients achieved MCID than PASS for all PROMs, and lower preoperative scores were predictive of the achievement of MCID. Additionally, factors such as worker's compensation designation, prior surgical history of the ipsilateral shoulder, and tobacco use were found to be predictive of failing to achieve MCID and PASS at mid-term follow-up.

Keywords: MCID; PASS; Reverse shoulder arthroplasty; clinically significant outcome measures; minimum clinically important difference; patient acceptable symptomatic state; rTSA.