Economic Analysis and Surgical Outcomes of Outpatient Versus Inpatient Total Ankle Replacement Surgery

Abstract

Category: Ankle Arthritis; Ankle; Other Introduction/Purpose: The utilization of total ankle replacement (TAR) for end-stage ankle osteoarthritis continues to increase in the United States. From 2011-2012, 47.5% of all TAR were covered by Medicare insurance, which represents a large insurance market share for inpatient ankle surgeries. However, there is a growing trend in orthopedics toward performing outpatient surgery. There have been studies that demonstrate the cost benefits and safety of outpatient TAR surgery. However, previous cost studies involve a single implant, small sample size, and lack clinical outcomes. Thus, we aim to compare the costs and clinical outcomes associated with TAR in the outpatient versus inpatient settings. Methods: We performed a retrospective study on 178 consecutive patients undergoing primary inpatient versus short-stay designation TAR during the 2016 and 2017 fiscal years. Patient demographics, concomitant procedures, perioperative complications, patient reported outcomes, and perioperative costs were collected. Results: The mean age of our cohort was 62.5 yo. The implant types were: Infinity (39.3%), Salto (38.2%), INBONE (15.2%), Vantage (7.3%), and STAR (3.4%). 47.8% of patients were covered under managed care and 42.1% under Medicare. There were no significant differences in medical comorbidities (p > 0.05) or concomitant surgeries (p=0.4574) between inpatient and outpatient groups. There was no difference in complications between inpatient and outpatient groups (p= 0.9652). Inpatients had a greater improvement in their SMFA function score compared to outpatients (p=0.0442). Both inpatient and outpatient cohorts significantly improved in all other reported patient reported outcomes at final follow-up (0.05). The total direct cost was higher for the inpatient group ($15,340.1) versus outpatient group ($13,002.6) (p<0.0001). Conclusion: While inpatient designation TAR were more comorbid, short-stay designation TAR were associated with a 15.5% reduction in perioperative costs, comparable complication rates, and similar final postoperative patient reported outcome scores compared to inpatient TAR.