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 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 postoperative infection.

Results: Overall, 22 (15%) 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 with 15 (17%) 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.

Conclusions: 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.