A Propensity Score Matched Exploration of Infection in Primary Total Ankle Arthroplasty

Abstract

Background: Infection is a serious complication of primary total ankle arthroplasty (TAA) and can lead to implant failure and revision surgery. Various demographic, comorbidity, and surgical factors have been associated with an increased risk of infection. However, the evidence base remains limited, and further research is needed regarding infection in TAA. This study aims to analyze risk factors of infection and explore outcomes following infected TAA. Methods: A retrospective cohort study was conducted using data from a single institution from 2002 to 2022. Patients who underwent primary TAA and had subsequent infection were identified through annual registry surveillance and matched using propensity score matching (PSM) based on various demographic, comorbidity, and surgical factors. Demographics were compared between the matched groups using Mann-Whitney U test and Fisher exact test. The outcomes following infection were identified and summarized using descriptive statistics. Results: A total of 1863 patients who underwent primary TAA were identified, and 19 were diagnosed with an infection. The identifiable overall infection rate was 1.0%. After PSM, there were no significant differences in the difference in age, gender, BMI, and smoking status between the infected and control cohort. There was a statistically significant increase in the rate of diabetes in the infected cohort. The subsequent surgical intervention resulted in limb salvage in 18 (94.7%) cases. Out of the total number of cases, 2-stage revision to total ankle replacement was performed in 7 cases, whereas revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. One patient had to undergo amputation; however, at the time of the most recent follow-up, all patients were found to be free of infection. Conclusion This study demonstrated high rates of a history of smoking and diabetes in the infected TAA cohort. The diabetes rate in the infected group was significantly higher than the noninfected controls. Two-stage revision to total ankle replacement was performed in 7 cases, and revision to arthrodesis and isolated polyethylene exchange were each carried out in 4 cases. Overall, a high rate of limb salvage was reported. Level of Evidence: Level III, case-control study.

Association of Timing of Hindfoot Arthrodesis and Early Reoperation Rates for Total Ankle Arthroplasty

“…These cohorts were propensity score matched for covariates of age, gender, and Charlson comorbidity index (CCI), which include variables that have been identified as risk factors for complications after TAA. 1 Propensity score matching was performed in a 4:1 ratio (controls/study) using the nearestneighbor method and a caliper width of 0.1, as described in prior literature. 1 Hindfoot arthrodesis for this study was defined as either subtalar or triple arthrodesis.…”

“…1 Propensity score matching was performed in a 4:1 ratio (controls/study) using the nearestneighbor method and a caliper width of 0.1, as described in prior literature. 1 Hindfoot arthrodesis for this study was defined as either subtalar or triple arthrodesis. The PearlDiver database does not allow for discernment of talonavicular or calcaneocuboid arthrodesis as there is no specific CPT code for those fusions.…”

2023 Evidence-Based Medicine (EBM) Update

“…Looking at infection in primary TAAs, Anastasio et al 3 performed a Level III case-control study of 1863 TAAs, 19 of which were diagnosed with an infection. The identifiable overall infection rate was 1.0%.…”

Association of Radiographic Soft Tissue Thickness With Revision Total Ankle Arthroplasty Following Primary Total Ankle Arthroplasty: A Minimum of 5-year Follow-up

“…Research investigating the use of BMI as a surrogate for risk stratification in primary TAA has not been unifom. 2 , 6 , 17 , 19 , 29 , 39 A database study found that the incidence of TAA failure was higher in individuals classified as obese (BMI ≥ 30) compared to those with a normal BMI. 39 However, recent retrospective studies have demonstrated that obesity was not associated with increased rates of complications after primary TAA 17 and BMI was not a risk factor of implant failure.…”