Infection after spanning external fixation for high-energy tibial plateau fractures: is pin site-plate overlap a problem?

OBJECTIVES: The purpose of this study was to determine whether overlap between temporary external fixator pins and definitive plate fixation correlates with infection in high-energy tibial plateau fractures.

DESIGN: Retrospective chart and radiographic review.

SETTING: Academic medical center.

PATIENTS: Seventy-nine patients with unilateral high-energy tibial plateau fractures formed the basis of this report.

INTERVENTION: Placement of knee-spanning external fixation followed by delayed internal fixation for high-energy tibial plateau fractures treated at our institution between 2000 and 2008.

METHODS: Demographic patient information was reviewed. Radiographs were reviewed to assess for the presence of overlap between the temporary external fixator pins and the definitive plate fixation. Fisher exact and t test analyses were performed to compare those patients who had overlap and those who did not and were used to determine whether this was a factor in the development of a postoperative infection.

MAIN OUTCOME MEASUREMENTS: Development of infection in those whose external fixation pin sites overlapped with the definitive internal fixation device compared with those whose pin sites did not overlap with definitive plate and screws.

RESULTS: Six knees in six patients developed deep infections requiring serial irrigation and débridement and intravenous antibiotics. Of these six infections, three were in patients with closed fractures and three in patients with open fractures. Two of these six infections followed definitive plate fixation that overlapped the external fixator pin sites with an average of 4.2 cm of overlap. In the four patients who developed an infection and had no overlap, the average distance between the tip of the plate to the first external fixator pin was 6.3 cm. There was no correlation seen between infection and distance from pin to plate, pin-plate overlap distance, time in the external fixator, open fracture, classification of fracture, sex of the patient, age of the patient, or healing status of the fracture.

CONCLUSION: Fears of definitive fracture fixation site contamination from external fixator pins do not appear to be clinically grounded. When needed, we recommend the use of a temporary external fixation construct with pin placement that provides for the best reduction and stability of the fracture, regardless of plans for future surgery.