Outcomes following ambulatory total shoulder arthroplasty

Background: Total shoulder arthroplasty (TSA) is one of the most common joint replacements aside from knee and hip arthroplasty. In 2003, the Food and Drug Administration approved the use of Reverse TSA for complicated shoulder osteoarthritis and other similar conditions, which resulted in a noticeable increase in overall TSA cases. Approximately 50,000 patients undergo TSA annually in the United States. Prior to 2005, the inpatient setting was the primary location for performing TSA. However, the use of new developments involving local regional pain control and less invasive surgical techniques has allowed for the average length of stay to decrease thus leading to an increase in ambulatory TSA. Objective: To identify the difference in outcomes, if any, between ambulatory and non-ambulatory patients following total shoulder arthroplasty. Methods: The primary source of data was the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP). The cohort was limited to patients with a primary CPT code of 23472, indicating shoulder arthroplasty between 2005 and 2015. The cohort was separated into patients who had a length of stay of zero days (Ambulatory) and those who had a length of stay of at least one day (Non-Ambulatory). A propensity score was used to match 101 ambulatory with 404 non-ambulatory patients. Matching was based on preoperative demographic and medical factors. The primary outcome of interest was unplanned readmission within 30 days following discharge. Other outcomes of interest included reoperation and infection. Logistic regression was used to calculate odds ratios for the outcome of interest. Results: There were 10,467 surgeries identified between 2005 and 2015. When propensity score matched on age, BMI, gender, smoking status, ASA category, history of diabetes, history of COPD, history of hypertension, history of steroid use and select preoperative laboratory values, the result was a cohort of 101 ambulatory surgeries and 404 non-ambulatory surgeries. The average patient was 43 years old with a BMI of 30. The majority (61%) of patients had an ASA classification of 1 or 2 and nearly (93%) all patients were given general anesthesia. The logistic regression showed that there was no difference in unplanned readmissions between groups (1.7% non-ambulatory vs 2.0% ambulatory [OR 1.15, p=0.8665]). There were no infections or reoperations for those who had ambulatory TSA compared to 0.7% and 0.0% in the non-ambulatory patients. However, the differences were not significant. Conclusion: From this study we found that by reducing potential confounding using propensity score matching the effect of whether a surgery was ambulatory or non-ambulatory does not have a significant effect on unplanned readmission in the 30 days following discharge. Therefore, this study demonstrates that ambulatory TSA may be a reasonable alternative to inpatient TSA.