Definitive plates overlapping provisional external fixator pin sites: is the infection risk increased?

Objectives: The purpose of this study was to compare the infection risk when internal fixation plates either overlap or did not overlap previous external fixator pin sites in patients with bicondylar tibial plateau fractures and pilon fractures treated with a 2-staged protocol of acute spanning external fixation and later definitive internal fixation.

Design: Retrospective comparison study.

Setting: Two level I trauma centers.

Patients/participants: A total of 85 OTA 41C bicondylar tibial plateau fractures and 97 OTA 43C pilon fractures treated between 2005 and 2010. Radiographs were evaluated to determine the positions of definitive plates in relation to external fixator pin sites and patients were grouped into an "overlapping" group and a "nonoverlapping" group.

Intervention: Fifty patients had overlapping pin sites and 132 did not.

Main Outcome Measure: Presence of a deep wound infection.

Results: Overall, 25 patients developed a deep wound infection. Of the 50 patients in the "overlapping" group, 12 (24%) developed a deep infection compared with 13 (10%) of the 132 patients in the "nonoverlapping" group (P = 0.033).

Conclusions: Placement of definitive plate fixation overlapping previous external fixator pin sites significantly increases the risk of deep infection in the 2-staged treatment of bicondylar tibial plateau and pilon fractures. Surgeons must make a conscious effort to place external fixator pins outside of future definitive fixation sites to reduce the overall incidence of deep wound infections. Additionally, consideration must be given to the relative benefit of a spanning external fixator in light of the potential for infection associated with their use.

Level Of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.