Effect of patient-reported allergies on reverse total shoulder arthroplasty outcomes at over two years follow-up.

Background/aims: Understanding the factors that lead to poor outcomes after reverse total shoulder arthroplasty (rTSA) is important to appropriate patient counseling. While patient-reported allergies (PRAs) have been shown to be associated with poorer outcomes after both TKA and THA, their effect on rTSA outcomes remains unclear. This study investigated the effect of zero, one, and two or more preoperative PRAs on clinical outcomes after rTSA at over two years follow-up in a cohort of fifty-two patients from our institution. Methods: Patients who underwent rTSA and had a minimum follow-up time of two years were identified from an institutional database. Patients were split into cohorts of zero, one, and two or more PRAs. Range of motion (ROM) was assessed by degrees of forward elevation, external rotation, and internal rotation. Patient-reported outcomes (PROs) were assessed by the Visual Analog Scale (VAS), American Shoulder and Elbow Surgeon (ASES) score, and Simple Shoulder Test (SST) score. Results: Fifty-two patients, 10 of whom reported one allergy and 11 of whom reported two or more allergies, were included in our analysis. Mean ROM and PROs improved after rTSA in each cohort. Differences in ROM and PROs between cohorts did not reach statistical significance; however, patients with PRAs tended to have worse preoperative forward elevation, VAS score, and ASES score. Two patients in the zero-allergy cohort required revision (6 %). Conclusion: This study found no statistically significant difference in clinical outcomes among cohorts of patients with zero, one, or two or more preoperative PRAs after rTSA at over two years follow-up. However, patients with PRAs tended to have lower preoperative functional scores. We postulate that this may be the result of psychosomatic factors at play in these patients. PRAs should not dissuade patients or clinicians from pursuing rTSA.