Is Definitive Plate Fixation Overlap with External Fixator Pin Sites a Risk Factor for Infection in Pilon Fractures

OBJECTIVES To determine if overlap of definitive plate fixation with external fixator pin sites is a risk factor for infection in pilon fractures. DESIGN Retrospective Cohort SETTING:: Level 1 trauma center PATIENTS:: One-hundred and forty-six patients with pilon fractures treated between 2012 and 2018. INTERVENTION Staged treatment with ankle-spanning external fixation followed by delayed open reduction and internal fixation. MAIN OUTCOME MEASURES Demographic, radiographic, and operative data were reviewed and the distance between the temporary external fixator pin sites and the definitive plate was measured. The primary outcome measure was the development of a deep post-operative infection. RESULTS Overall, 22 (15%) of patients developed deep wound infections. Overlap of definitive plate and external fixation pin-site occurred in 58 (40%) of ankles. Of these, 7 (12%) developed deep wound infection compared to 15 (17%) of patients without overlap (p=0.484). There was no significant difference in amount of overlap (p=0.636) or distance from plate to pin site (p=0.607) in patients with and without deep infection. Of the patients with deep infection, 11 (50%) occurred in patients with open fractures. CONCLUSION Overlap of definitive plate fixation with primary spanning external fixator pin sites is not a risk factor for development of deep infection in a staged treatment of high energy pilon fractures. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.