Comparing Comorbidity Burden Between Patients Undergoing Ambulatory Rotator Cuff Repair Versus Inpatient Anatomic Total Shoulder Arthroplasty

BACKGROUND Rotator cuff repair (RCR) patients routinely undergo same-day discharge in an ambulatory setting, while anatomic total shoulder arthroplasty (TSA) cases have historically been performed in an inpatient hospital setting. For healthier patients, however, TSA has increasingly transitioned to same-day discharge. Understanding whether a true difference in comorbidity burden exists between these patient groups would inform the appropriateness of outpatient TSA in an ambulatory setting. METHODS A retrospective review was performed of patients undergoing primary TSA and same-day, ambulatory RCR performed between September 2017 and May 2021 at a single institution by 3 fellowship-trained orthopedic surgeons. Selected sociodemographic factors and the Elixhauser Comorbidity Index (30 variables) were used to summarize and compare comorbidity burden. Only patients >50 years old were included. Chi-square and Kruskal-Wallis testing was used to compare the prevalence or severity for categorical and continuous variables, respectively. RESULTS 1433 cases met inclusion criteria, including 146 (34%) primary inpatient TSAs and 287 (66%) ambulatory RCRs. There were few differences in comorbidity burden between TSA and RCR, with TSA having a significantly higher prevalence for only 4 Elixhauser comorbidities and RCR having a higher prevalence of 1 comorbidity, although none survive a Bonferroni correction. TSA patients had a significantly higher prevalence of uncomplicated (p = 0.04192) and complicated hypertension (p = 0.0336), chronic pulmonary disease (p = 0.0045), and cardiac arrhythmia (p = 0.0031). The prevalence of diabetes (p = 0.029758) was significantly higher among RCR patients. Additionally, age (p = 0.011) was significantly higher among TSA patients. Of the TSA cohort, there were 10 incidences (1%) of 90-day readmission whereas there were 14 incidences (5%) of 90-day readmissions after RCR. CONCLUSIONS Overall, few differences in the prevalence of individual comorbidities (and sociodemographic parameters) existed between patients undergoing outpatient rotator cuff repair and inpatient primary anatomic total shoulder arthroplasty. Comorbidities with larger differences can be either optimized preoperatively or managed chronically, and given these similarities, TSA may be similarly appropriate for ambulatory settings, particularly as efficiencies in operative time and improvements in regional anesthesia continue to evolve.