Diagnostic yield of preoperative tibiotalar aspiration and bone biopsy before surgery for post-traumatic tibiotalar osteoarthritis: a retrospective single-center study.

Abstract

Persistent infection should be excluded before tibiotalar arthrodesis or total ankle replacement in patients with post-traumatic ankle osteoarthritis and a history of open fracture or previous infection. However, the diagnostic value of routine preoperative microbiological sampling in clinically quiescent ankles remains uncertain. To evaluate the diagnostic yield of routine preoperative tibiotalar aspiration and bone biopsy performed before definitive surgery for post-traumatic tibiotalar osteoarthritis in patients considered at potential risk for persistent infection. Retrospective single-center case series. Twenty-seven patients with isolated post-traumatic tibiotalar osteoarthritis underwent routine preoperative microbiological sampling before tibiotalar arthrodesis or total ankle replacement. Sampling was performed more than one year after the initial septic-risk event. Cultures were considered indicative of infection only when a virulent pathogen was isolated or when the same low-virulence organism was recovered from the majority of specimens. Sampling was performed a mean of 6.6 ± 5.7 years after trauma. Seventeen patients had negative or non-diagnostic cultures, and nine had cultures interpreted as contaminants. Only one patient (4%), who presented with clinical signs of inflammation before sampling, had a clinically actionable positive biopsy that was confirmed intraoperatively. No postoperative infectious complications occurred during follow-up. Routine preoperative tibiotalar aspiration and bone biopsy demonstrated limited diagnostic value in clinically quiescent post-traumatic ankles sampled more than one year after the initial septic-risk event. Positive cultures more often represented contamination than clinically relevant infection, supporting a selective rather than routine use of preoperative microbiological sampling.