Defining A Successful Total Shoulder Arthroplasty: A Systematic Review of Clinically Relevant Outcome Metrics

Patient-reported outcome measures (PROMs) are increasingly used to evaluate outcomes following total shoulder arthroplasty (TSA). However, there remains no consensus regarding which PROMs and clinically meaningful thresholds best define surgical success. The purpose of this systematic review was to identify the most commonly reported PROMs in the TSA literature, characterize the use of clinically important outcome thresholds, and evaluate the methods used for their derivation.

A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was conducted to identify publications examining primary TSA and included PROM-based quantitative metrics for assessment of clinically significant improvement, including the minimal clinically important difference (MCID), patient acceptable symptom state (PASS), and substantial clinical benefit (SCB). Relevant information including year of study, study design, number of patients, PROMs reported, and methods of derivation were collated from included studies.

A total of 39 studies were identified with a total of 19,674 patients. The American Shoulder and Elbow Surgeons (ASES) score was the most commonly reported PROM in 66.7% of studies, followed by the Simple Shoulder Test, Constant-Murley score, and visual analog scale (VAS) each used in 33.3% of studies. The MCID was the most frequently reported threshold, identified in 82.1% of studies. The SCB was used in 33.3% of studies, and the PASS was used in 28.2% of studies. MCID thresholds were predominantly derived using anchor-based methods in 87.5% of studies, SCB thresholds were predominantly derived using anchor-based methods in 92.3% of studies, and PASS thresholds were predominantly derived using anchor-based methods in 90.9% of studies.

Widespread variability exists in how commonly used metrics to assess change in PROMs, including, MCID, SCB and PASS, are derived and applied in outcomes studies pertaining to TSA. Further standardization of analytic techniques, including prospective derivation of TSA-specific MCID, SCB, and PASS threshold values using anchor-based methods and with stratification by procedure type, baseline severity, preoperative diagnosis, and patient demographics may allow for more rigorous outcomes reporting and pooling across studies.

Basic Science Study, Research Methodology, Systematic Review.