Is the Orthopaedic Trauma Association-Open Fracture Classification Better Than the Gustilo-Anderson Classification at Predicting Fracture-Related Infections in the Tibia?

Objectives: To investigate and compare the predictive ability of the Orthopaedic Trauma Association-Open Fracture Classification (OTA-OFC) and the Gustilo-Anderson classification systems for fracture-related infections (FRI) in patients with open tibia fractures.

Design: Retrospective cohort study.

Setting: Academic trauma center.

Patient Selection Criteria: Patients aged 16 years or older with an operatively treated open tibia fracture (OTA-AO 41, 42, and 43) between 2010 and 2021.

Outcome Measures And Comparisons: The primary outcome was FRI. The OTA-OFC and the Gustilo-Anderson classifications were compared in their ability to predict FRI.

Results: Eight hundred ninety patients (mean age, 43 years [range, 17 to 96]; 75% men) with 912 open tibia fractures were included. In total, 142 (16%) had an infection. The OTA-OFC was not significantly better at predicting FRI than the Gustilo-Anderson classification (area under the curve, 0.66 vs. 0.66; P = 0.89). The Gustilo-Anderson classification was a stronger predictor of FRI than any single OTA-OFC domain, explaining 72% of FRI variance. Only the addition of the OTA-OFC wound contamination domain to Gustilo-Anderson significantly increased the variance explained (72% vs. 84%, P = 0.04). Embedded contamination increased the risk of FRI by approximately 10% as the risk of FRI with embedded contamination was 16% for type I or type IIs, 26% for type IIIAs, 45% for type IIIBs, and 46% for type IIICs.

Conclusions: The more complex OTA-OFC system was not better than the Gustilo-Anderson classification system in predicting FRIs in patients with open tibia fractures. Adding embedded wound contamination to the Gustilo-Anderson classification system significantly improved its prognostic ability.

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