Validation of the Mayo Periprosthetic Joint Infection Risk Score for Total Ankle Arthroplasty

CATEGORY: Ankle; Other INTRODUCTION/PURPOSE: Periprosthetic joint infection (PJI) is a devastating complication of arthroplasty. The well known PJI risk factors are useful for identifying high-risk patients but would be even more helpful for clinical decision-making if they are converted to a risk assessment scores. The Mayo Prosthetic Joint Infection Risk Score was based on the data of total hip and knee arthroplasty and has not been validated for application for total ankle arthroplasty. METHODS: A series of 398 consecutive cases of total ankle arthroplasty, with minimal follow-up of 6 months, was reviewed for Mayo Periprosthetic Joint Infection Risk Score (Mayo score) and PJI. The patients' Mayo scores and PJI was examined by logistic regression. T-test was performed to compare the Mayo score between the non-infected TAA cases and infected cases. Receiver Operating Characteristic (ROC) was used to identify the critical value of Mayo score for total ankle arthroplasty. RESULTS: There were 12 cases of PJI or 3.0% in the series. Of the 398 patients, the Mayo scores were in the range from -4 to 13 (median 2; interquartile range (IQR) 0-4). Preliminary analysis showed that, by logistic regression, the probability of PJI was increased as increases of the Mayo scores (Fig A). The mean Mayo score of the PJI patients (8.6+-1.8) was significantly greater than the rest of the patients (mean Mayo score 1.9+-3.4; p < .0001). ROC analysis showed that, when a Mayo score was greater than 5, the patient has a high probability of PJI (sensitivity = 100%; specificity = 86.9%; Fig B). CONCLUSION: This study showed a high correlation between the Mayo score and PJI in total ankle arthroplasty, which is the same trend as in total knee and hip arthroplasty. The preliminary results suggest that strategically focusing on the patients, who have a Mayo score > 5, could be a more efficient approach to prevent PJI after total ankle arthroplasty.