DIFFERENTIAL UTILIZATION PATTERNS OF TOTAL ANKLE ARTHROPLASTY VERSUS ARTHRODESIS: A NATIONAL AMBULATORY DATABASE ANALYSIS

End-stage ankle osteoarthritis is a debilitating condition that can be treated surgically with ankle arthrodesis (AA), or more recently, total ankle arthroplasty TAA. Several clinical factors have been implicated in the choice of one treatment approach over the other; however, the effect of demographic, hospital, and socioeconomic factors on this decision remains poorly characterized. The current study aimed to estimate the relative nationwide utilization of these two procedures and delineate patient and hospital factors that are associated with the selection of TAA versus AA for ankle osteoarthritis. TAA and AA procedures performed for ankle osteoarthritis were identified based on CPT and ICD-10 codes in the Nationwide Ambulatory Surgery Sample (NASS) Database. Instances with avascular necrosis of the talus, Charcot neuroarthropathy, lower extremity vascular insufficiency, limb neuropathy, varus or valgus deformity of the ankle, or osteoporosis with concurrent ankle fracture were excluded from the analysis. Cases were weighted using nationally representative discharge weights. Univariate analyses and a combine multiple logistic regression model were used to compare demographic, hospital, and socioeconomic related factors associated with TAA versus AA. In total, 6,577 cases were identified, which represents 9,072 cases after weighting. Of these, TAA was performed for 2,233 (24.6%). Based on the logistic regression model, several factors were associated with increased utilization of TAA versus AA. With regards to patient factors, older patients were more likely to undergo TAA (per decade, Odds Ratio [OR] of TAA = 1.24; p < 0.001), as well as females (OR = 1.28; p < 0.001). Conversely, patients with a higher comorbidity burden were less likely to receive TAA over AA (OR = 0.92; p < 0.001) With regards to socioeconomic factors, urban teaching (OR = 1.62; p < 0.001) and urban non-teaching (OR = 1.42; p = 0.004), hospitals were significantly more likely to utilize TAA compared to rural hospitals. Similarly, privately insured patients (OR = 3.45; p < 0.001) and those with a median household income of $71,000 or more (OR = 1.74; p < 0.001) were also more likely to receive TAA over AA. Lastly, private, not-for-profit (OR = 1.64; p < 0.001) and private, investor-owned hospitals (OR = 1.73; p < 0.001) were significantly more likely to offer TAA over AA. Using a large nationally representative cohort, the current data revealed that only 24.6% of operatively treated cases of end-stage ankle osteoarthritis are treated with TAA. While associations between patient age, comorbidity status and TAA utilization align with functional expectations, socioeconomic and hospital-level associations suggest that other factors may systematically influence surgical treatment type of ankle osteoarthritis. Surgeons should be conscious of these influences when determining the optimal treatment for their patients.