Radiographic Soft Tissue Thickness is not a Risk Factor for Infection after Primary Total Ankle Arthroplasty.

Abstract

As the incidence of total ankle arthroplasty (TAA) for the management of end-stage arthritis is on the rise, identification of risk factors for periprosthetic joint infection (PJI) is essential. There has been limited research exploring the use of radiographic soft tissue thickness in TAA despite its predictive value in other forms of arthroplasty. This study evaluated the predictive capabilities of radiographic soft-tissue thickness for PJI following TAA. A retrospective analysis of 323 patients at a single institution who underwent primary TAA from 2003 to 2019 was conducted. Patient demographics, comorbidities, indication for surgery, prosthesis type and tourniquet time were recorded. Tibial-Tissue and Talus-Tissue distances were measured on preoperative lateral radiographic imaging. Logistic regression was utilized to determine the Odds Ratio (OR) of risk factors for the occurrence of PJI. Of the 323 patients, 6 patients (1.86%) developed a PJI. Average duration of follow-up was 8.42 ± 2.52 years. Neither Tibial-Tissue (OR= 0.975; 95% CI [0.947 - 1.004]; p = 0.09) nor Talus-Tissue thickness (OR= 0.976; 95% CI [0.940 - 1.012]; p = 0.18) were significant predictors of PJI. Although not statistically significant, the infected cohort had smaller average Tibial-Tissue (2.20 vs. 2.53 cm; p=0.05) and Talus-Tissue thickness (2.19 vs. 2.44 cm; p=0.36) compared to the non-infected cohort. Measurements such as Tibial-Tissue length and Talus-Tissue length were not significant predictors of PJI following primary TAA. These findings underscore the necessity for additional research to identify modifiable risk factors aimed at reducing PJI rates and enhancing patient outcomes.