Risk factors for infection in severe open tibial shaft fractures.

Abstract

To evaluate risk factors for infection in severe open tibial shaft fractures. A secondary analysis of a multicenter prospective study investigated internal versus external fixation of severe open tibia fractures at 20 US Level I trauma centers. Adult patients, aged <65 years, with a Gustilo-Anderson Type IIIB or severe IIIA metaphyseal or diaphyseal tibia fracture were included. All fractures underwent definitive fixation with either a modern ring external fixator, intramedullary device, and/or plate. Fourteen variables previously identified as risk factors for infection were included in the analysis. Deep surgical site infection was defined as an infection treated with surgical debridement within 1 year of index surgery. The study cohort included 430 patients. Deep surgical site infection requiring reoperation occurred in 108 (25 %) patients. The final model identified four risk factors for infection: age >40 years (OR, 2.00; 95 % CI, 1.3-3.1), Gustilo-Anderson Type IIIB (OR, 1.80; 95 % CI, 1.1-3.0), embedded wound contamination (OR, 1.69; 95 % CI, 1.1-2.7), and wound length (OR, 1.02/cm; 95 % CI, 1.0-1.05). The model performed poorly at distinguishing infected from uninfected patients (Area Under the Curve=0.57; 95 % CI, 0.51-0.63). Surgeons can now counsel patients with these risk factors that they are at a markedly higher risk of infection. The identification of these risk factors may direct future research aimed at mitigating the risk of deep surgical site infection in this patient population.