Potential of early American Shoulder and Elbow Surgeons score changes to predict postoperative outcomes after total shoulder arthroplasty

Background: The American Shoulder and Elbow Surgeons (ASES) score is a patient-reported outcome measure for shoulder functionality that can be collected at baseline and postoperative time points. In total shoulder arthroplasty (TSA), its temporal relationship with other recovery metrics is unknown. This study evaluates the potential of early ASES changes after TSA to predict other outcomes, particularly active forward flexion (AFF), active external rotation (AER), and VAS pain scores at final follow-up. Methods: A retrospective chart review identified patients who underwent primary TSA between 2018 and 2023. Demographics, postoperative ASES scores, visual analog scale (VAS) pain scores, AFF, AER, and complication rates (revision, readmission, and mortality rates) were recorded. Percentage changes from baseline were calculated for each outcome. Linear regression analyses controlling for age, sex, race, body mass index, and Charlson Comorbidity Index scores were used to assess associations between ASES changes at 6 weeks, 3 months, 6 months, and 1 year and subsequent outcomes. Results: In total, 394 TSA patients were investigated, with a mean follow-up of 2.9 years. Percent changes in ASES scores at 3 months (P=0.023), 6 months (P=0.001) and 1 year (P=0.006) were significantly associated with AFF improvement at 1 year. ASES changes were also associated with VAS pain scores, with 6-week ASES changes correlating with 3-month VAS improvement (P=0.039). A 1% ASES increase at each interval predicted continued 1% gains postoperatively. No significant associations were observed for AER within 2 years postoperatively or any complication rate within 1 year postoperatively. Conclusions: Early improvements in the ASES score can predict later postoperative outcomes after TSA, supporting its use as an indicator of recovery trajectory. Level of evidence: IV.