Establishing thresholds for achievement of clinically significant satisfaction at two years following shoulder arthroplasty: the patient acceptable symptomatic state

Background The patient acceptable symptomatic state (PASS) represents clinical improvement following surgery that patients deem as satisfactory; however, thresholds for achieving this clinical benchmark have not yet been established beyond 1 year following primary and reverse shoulder arthroplasty. Methods A prospectively maintained registry was retrospectively queried for patients undergoing either a primary TSA or RTSA at a single institution between November, 2015 and October, 2017. All patients completed the ASES, SANE, and Constant patient-reported outcome (PRO) scores at the 2-year time point. PASS threshold scores were calculated using anchor-based methodology with subsequent calculation of achievement rates. Multivariate logistic regression was used to identify demographic and clinical variables associated with the likelihood of PASS achievement. Results A total of 93 TSA (mean age 61.4 ± 8.5 years, 32.3% female) and 111 RTSA (mean age 70.0 ± 8.1 years, 51.4% female) patients met final inclusion criteria. One-hundred sixty-five patients (80.8%) responded to the binary anchor question as “satisfied” regarding their surgical outcome. The PASS cutoffs for ASES, SANE, and Constant were 81.7, 85.7, and 24.0, respectively (AUC > 80%), with PASS achievement rates ranging from 50.7% to 59.9% for the entire study population and 66.7% to 83.3% for a risk-stratified subgroup. Patients undergoing TSA had a significantly higher PASS achievement rate relative to RTSA (P = .010) for ASES. Independent risk factors for decreased PASS achievement included lower preoperative PRO score, prior shoulder surgery, sedentary lifestyle, smoking, workers’ compensation status, and diabetes mellitus (DM). Conclusion The majority of patients reach the PASS benchmark by 2 years after shoulder arthroplasty, with an optimal subgroup of risk-stratified patients achieving PASS at a rate greater than 80% for ASES. Patients undergoing TSA have a higher likelihood of reaching the PASS than patients undergoing RTSA, independent of other variables. Lower baseline outcome scores, prior shoulder surgery, smoking, and sedentary lifestyle are associated with lower PASS rates after TSA. Worker's compensation status and comorbid DM are predictive of reduced PASS rates after RTSA. Primary diagnosis and glenoid morphology did not have a significant impact on the rate of achieving the PASS. This information is valuable for patient selection and counseling prior to shoulder arthroplasty. Level of Evidence Level III; Prognostic Study; Retrospective Case Series.