Computed Tomography Changes Diagnosis, Management and Surgical Planning of Ankle Fractures

Abstract

Category: Trauma; Ankle; Other Introduction/Purpose: Ankle fractures correspond to a substantial portion of traumatic injuries assisted in a primary health care unit. These fractures are usually promptly recognized by physical exams and conventional radiographs. Nevertheless, the number and pattern of the lesions and the identification of possible associated injuries still fail when using only these methods. CT scans have developed into an excellent instrument to analyze joint fractures in recent years. This study aims to compare ankle fracture assessment using CR in isolation with CT and CR in combination. This comparison will be performed considering diagnosis, lesions features, and treatment. We hypothesize that CT, in conjunction with CR, can significantly modify the diagnosis, therapeutics, and operative planning of ankle fractures when confronted with isolated CR. Methods: A total of 53 patients (mean age: 42 years, 15 - 75) diagnosed with an ankle fracture between 2011 and 2016, were assessed with CT and CR. Evaluations of the fractures using CR in isolation and CR combined with CT were compared using seven different readers. Fractures were assessed in terms of type, displacement, size, associated injuries, treatment, patient position, the implant of choice, and surgical planning considering the presence or absence of malleolar fractures and potential associated injuries. The concordance was measured for the own examiner's evaluations and between the examiners' assessments (intra-observer and inter-observer) by the Kappa coefficient. The results were determined by relative frequency distribution analysis (in percentage terms) and compared using a two-proportions test. Results: The Kappa index was higher than 0.75 for all interobserver and intra-observer reliabilities. Medial malleolus fractures characteristics (posteromedial fragment and anterior colliculus), the presence of posterior malleolus fracture and its characteristics (displacement, size, posteromedial or posterolateral segment) (ps<0.042), syndesmosis injury (p<0.001), and the absence of deltoid ligament lesion (p<0.001), were more evident with the combination of CT and radiographs. There was an increase in an operative indication (p=0.007), prone positioning (p=0.002), posterior malleolus surgical treatment (p<0.001), posterolateral approach for the lateral malleolus (p=0.003), and syndesmosis fixation (p=0.020) with the association of CT and CR, among all groups of expertise, with high inter-observer reliability (>0.75). Conclusion: Conventional radiographs may fail to demonstrate subtle and more complex lesions of the ankle joint, such as posterior and medial malleolus fractures, undermining its capability to determine the appropriate treatment plan. This study showed evidence that a CT scan, a widespread available exam, and the standard for the study of other articular fractures, increased the diagnostic capability in ankle fractures when used with radiographs. In addition, the combination of methods may improve the quality of the information received by the orthopedic surgeon, providing more details for a proper surgical or non- surgical treatment, positively affecting patient care.