Defining Clinically Significant Outcomes Following Superior Capsular Reconstruction with Acellular Dermal Allograft

Abstract Purpose To define clinically significant outcomes (CSO) thresholds for minimal clinically important difference (MCID), substantial clinical benefit (SCB) and patient acceptable symptomatic state (PASS) in patients undergoing superior capsular reconstruction (SCR) with an acellular dermal allograft. We also evaluated patient specific variables predictive of achieving CSO thresholds. Methods The American Shoulder and Elbow Surgeons Standardized Shoulder Assessment Form (ASES), Single Assessment Numeric Evaluation (SANE), and subjective Constant-Murley (Constant) scores were collected pre-operatively and at the most recent follow up for patients undergoing SCR from 2010-2019. A distribution-based approach was used to calculate MCID, and an anchor-based approach was used to calculate SCB and PASS. Logistic regression was used to determine factors associated with CSO achievement. Results Fifty-eight patients were identified (n=39 males; n=19 females) with a mean age of 53.4 ± 14.1 years at surgery and an average follow-up of 23 months. The MCID, SCB, and PASS were, 11.2, 18.02, and 68.82 for ASES, 14.5, 23.13, and 69.9 for SANE, and 3.6, 10, and 18 for Constant, respectively. Subscapularis tear, female sex, and workers compensation (WC) status reduced odds of achieving MCID. Reduced odds of achieving Constant SCB were associated with older age, female sex, and WC status, while concomitant distal clavicle excision during SCR and lower preoperative ASESincreased odds of achieving ASES SCB. Reduced odds for achieving ASES PASS were associated with female sex and WC status, while reduced odds for achieving SANE PASS were associated with subscapularis tearing preoperatively. Conclusion Based on calculated values for MCID, SCB, and PASS, subscapularis tearing, WC status, age, and sex are associated with failure to achieve clinically significant outcomes following SCR. Concomitant distal clavicle excision during SCR and lower preoperative ASES was predictive for achievement of MCID and SCB. By defining the thresholds and variables predictive of achieving CSOs following SCR, surgeons may better counsel patients prior to SCR.