The Reliability and Accuracy of the Medial Malleolar Fracture Classification Based on 3D CT Reconstruction

Objective There is a new medial malleolar fracture classification based on 3D CT reconstruction. However, there is no study assessing the reliability and accuracy of the new classification system and comparison between the new and the classic classification. This study aimed to compare the reliability and accuracy of the medial malleolar fracture classification based on 3D CT reconstruction and the Herscovici classification system. Methods We retrospectively analyzed the consecutive ankle fractures in our hospital from January 2013 to September 2020. Five inexperienced and five experienced orthopedic surgeons were included as observers to assess 68 cases with medial malleolar fractures. Ten evaluators classified the cases according to the two classification systems. The reference results of each case were made by the consensus of three senior trauma surgeons. The interobserver reliability, intraobserver reliability, and accuracy were evaluated at an interval of 6 weeks using Fleiss's kappa (κ) statistics. Results We found substantial interobserver and intraobserver reliability and 81.4% accuracy for the new classification, which was statistically superior to the Herscovici classification ( P < 0.05). The reliability and accuracy of both classifications were similar in inexperienced and experienced groups, except for type III in the new classification. The interobserver reliability of type II was the best ( P < 0.05), and the intraobserver reliability of IVc ranked the worst ( P < 0.05) in the new classification. Conclusion The reliability and accuracy of the new classification are superior to the Herscovici classification. Clinical experiences will not affect the assessment of both classification systems in most instances.