Objective: To determine the incidence of pin tract infection.
Design: Retrospective chart review.
Setting: Level 1 trauma center in an urban community.
Patients: A total of 285 patients with 285 fractures over a 4-year period (1997–2001).
Intervention: External fixation.
Main Outcome Measurement: Incidence of pin tract infection.
Results: Of 285 fractures, 32 (11.2%) were complicated by infection. The incidence of infection according to montage was 3.9% (3/77) for ring fixators, which was significantly different (P < 0.04) from the 12.9% incidence (23/178) for unilateral fixators and the 20.0% incidence (6/30) for hybrid fixators (P = 0.004). The incidences of pin tract infection for the unilateral fixator group and the hybrid fixator group were not significantly different.
Conclusions: Patients with hybrid external fixators had a similar risk of pin tract infection as patients who had unilateral fixators. The infection rate in the ring fixator group was significantly lower than the hybrid external and unilateral fixator groups.
Pin tract infection is the major complication of external fixation of fractures. The rates of infection range from 0.5% to 30%. 1–3 Pin tract infections can decrease the stability of the pin-bone interface. Conversely, instability of the fixator-pin-bone construct can lead to half-pin loosening and infection.
External fixation wires and pins are colonized with bacteria, usually Staphylococcus aureus and Staphylococcus epidermidis.4 Mahan et al 2 reported 74.8% of screw tips cultured positive at removal, with a higher rate of gram-positive bacteria (90.6%S. epidermidis and 37.5%S. aureus) compared with gram-negative bacteria (9.4%Escherichia coli). The incidence of chronic osteomyelitis, after external fixation, has been reported to be 0% to 4%. 5 The same gram-positive bacterial species associated with pin tract infection often have been found in cultures of chronic osteomyelitis. Infected external fixation pins also increase the complication rate when intramedullary nailing procedures follow external fixation. 6
Contemporary techniques of external fixation using either manually inserted self-drilling half-pins, tapered pins used after drilling a pilot hole, prophylactic oral antibiotics, and tensioned fine wires have been developed to reduce the incidence of pin tract infections and osteomyelitis. The purpose of our study was to assess the incidence of pin tract infection with external fixation using these contemporary techniques.