Evaluation of the orthopaedic trauma association open fracture classification (OTA-OFC) as an outcome prediction tool in open tibial shaft fractures

Introduction: It was the goal of this study to determine if the Orthopaedic Trauma Association Open Fracture Classification (OTA-OFC) correlates with complication rates and to determine if it can be used as a predictive tool in the treatment of open tibial shaft fractures. Materials and methods: Retrospective review from two high-volume level 1 trauma centers of open tibial shaft fractures over a 5 year period. Variables of interest included OTA-OFC, type of wound closure, 90-day wound complication, unplanned re-operation, non-union, and amputation. Results: 501 consecutive open tibial shaft fractures. 57.3% (n = 287) were closed primarily; local soft tissue advancement/rotational flap was used in 9.6% (n = 48); free soft tissue transfer used in 22.8% (n = 114); 8.6% (n = 43) required amputation. Of those followed for 90 days (n = 419), 45 (9.0%) had a wound complication, of which 40 (8%) required an unplanned reoperation. 40 (8.0%) patients went on to a documented non-union. All OTA-OFC classification groups significantly correlated with type of definitive closure (r = 0.18–0.81, p < 0.05) with OTA-OFC skin showing the strongest correlation (r = 0.81). OTA-OFC bone loss weakly correlated with wound complication (r = 0.12, p = 0.02) and no OTA-OFC classification correlated with the need for an unplanned secondary procedure. OTA-OFC skin, muscle and arterial all weakly correlated with non-union (r = 0.18–0.25, p < 0.05). OTA-OFC muscle was predictive of non-union (OR = OR = 2.2, 95% CI = 1.2–4.1) and amputation (OR 9.3, 95% CI = 3.7–23.7). OTA-OFC arterial was also predictive of amputation (OR 4.8, 95% CI = 2.5–9.3). Conclusions: The OTA-OFC correlates variably with the type of definitive closure, the development of a 90-day wound complication, and the occurrence of a non-union. Importantly, OTA-OFC muscle classification is predictive of non-union while both OTA-OFC muscle and arterial were predictive of amputation.