Reference radiologic measurements for the assessment of tibial pilon fractures

Abstract

Objectives: The management of pilon fractures is a challenge and the outcome depends on multiple factors, one of which is the quality of reduction. In the literature, there is no assessment of anatomical reduction in pilon fractures. We also lack standard radiological parameters in large patient groups to measure the reduction. The main aim of this analysis was to define normal standard radiological values and identify potential specific types of ankle joint morphology (morphotypes) that might deserve special attention intraoperatively. Methods: We analyzed data of 103 healthy contralateral ankles collected within an observational and prospective multicenter study about tibial pilon fractures. We divided the patients according to their height into two groups, measured 11 radiological parameters, and compared them with each other and the literature. In addition, using cluster analysis, we could identify three morphotypes. Results: There is a statistically significant difference between the two groups in the lengths of three parameters: Mortise width, medial clear space, and length of the lateral malleolus, but not in the angles. The three morphotypes differ only in body mass index and the length of the lateral malleolus. Conclusion: Reference values from the literature are insufficient to assess a reduction after open reduction and internal fixation of tibial pilon fractures because they depend on the height. This does not apply to angles because they are independent of height. For clinical practice, a radiological control of the contralateral healthy ankle gives the best information about the reduction quality and should always be done, especially in normal weight males.