Prosthetic Joint Infection in Total Ankle Replacement - The PRINTAR Study

Julia McGovern, Dave Townshend, Rebecca Martin, John Williams, Sarah Johnson-Lynn

Introduction: Prosthetic joint infection (PJI) following total ankle replacement (TAR) is a rare but complex complication. Unlike hip and knee arthroplasty, limited data exist to guide ankle PJI management, particularly regarding microbiology and surgical outcomes. To evaluate the incidence, microbiology, surgical management, and outcomes of TAR PJI in the UK over a 10-year period.

Method: A retrospective service evaluation was conducted across 18 UK centres, capturing 58 PJIs diagnosed between January 2014 and January 2024. Data included infection timing, pathogen profiles, surgical approach, and infection resolution. Diagnostic classification followed IDSA, MSIS, and EBJIS criteria.

Results: Most infections were late (>4 weeks, n=54); only 4 were early (<4 weeks). Staphylococcus (n=13) and Enterobacter (n=8) were most common. Gram-negative organisms accounted for 15/58 cases—higher than typically seen in hip/knee PJI. Twenty-two patients underwent DAIR. Infection free survival at one year was 75% in DAIR for early infection. Outcomes appeared unaffected by organism type. Two-stage revision (n=32) achieved a 91% infection-free rate, comprising 17 revisions to fusion and 15 to arthroplasty. Only four single-stage procedures were performed but all were successful. MDT involvement increased over time and was associated with better outcomes. Overall, 54/58 patients were infection-free at final follow-up; 12 required further surgery, and one patient died.

Conclusion: This UK series highlights the distinct microbiological profile of TAR PJI, with a notable gram-negative burden. Infection clearance was encouraging across various surgical strategies. Increased MDT input over time aligns with improved outcomes and should be routine. Larger studies are needed to define optimal treatment pathways.