The role of three dimension computed tomography in Lisfranc injury diagnosis.

Purpose: To evaluate the intra/inter observer and diagnostic reliability of 3-dimensional (3D) model reconstruction computed tomography (CT) compared to the traditional two-dimensional (2D) CT when evaluating Lisfranc (LF) injuries.

Methods: A retrospective study was performed on CT studies of patients with clinically suspected LF injuries examined in the emergency department at medium size medical center. Each CT study was evaluated for metatarsal fractures and subluxations employing both standard 2D and 3D CT model reconstruction. Four orthopaedists, 2 senior and 2 residents, were assigned to review and evaluate each CT. Each CT study was reviewed twice by each reader in a randomized order. Descriptive statistics were calculated for all measured variables. The intra-observer and inter-observer agreement Kappa coefficients were calculated to evaluate reliability and reproducibility between and within readers for each modality.

Results: The study included 44 patients. Median age was 41.4 years (interquartile range, 23-58). The intra-observer and inter-observer reliability was good (intra-observer; 3D Kappa; 0.76 and 2D Kappa 0.73 p<0.001, inter-observer; 3D Kappa 0.68, 2D Kappa 0.63 and combined 2D and 3D kappa 0.68, p<0.001). Three dimensional CT was found to be more sensitive than 2D CT, specifically when evaluating for second metatarsal dislocation (sensitivity: 70% vs 47%). Combined evaluation of 2D and 3D CT, greatly improved sensitivity rate to 85.7%. In terms of fracture diagnosis, combined evaluation of 2D and 3D CT showed higher sensitivity and specificity rates as compared to 2D or 3D alone.

Conclusion: The employment of 3D CT in LF injury diagnosis, in isolation and in combination with 2D CT, seems to improve the diagnostic accuracy and reliability between and within observers compared to 2D CT alone.