Reliability of Evaluating Methods using Weightbearing Radiograph of the Foot in Lisfranc Injuries

Abstract

Category: Trauma; Midfoot/Forefoot Introduction/Purpose: Lisfranc ligament is a strong interosseous ligament located between the medial cuneiform (C1) and base of the second metatarsal (M2). Lisfranc injuries occur in approximately 0.2% of all fractures and are often overlooked or misdiagnosed. Weightbearing radiograph of the foot has been used as a diagnostic method for Lisfranc injuries; however, there is no study to evaluate the reliability of the measurement techniques on weightbearing radiographs. While several measurement techniques on weightbearing radiograph have been proposed for evaluating Lisfranc injuries, it remains unclear which measurement is the most reliable. This study aimed to evaluate the intra- and inter-observer reliability of the measurement techniques using weightbearing radiographs. Methods: Seventeen patients who were diagnosed with Lisfranc injuries using weightbearing radiographs and were treated with open reduction and internal fixation in our hospital between January 2013 and April 2019 were included in this study. Patients with multiple fractures were excluded. Four observers were selected, of which two were orthopedic specialists with more than six years of experience, while the remaining two were orthopedic surgeons with less than five years of experience. Observers evaluated the intra- and inter-observer reliability of the five measurement points on weightbearing radiographs on the affected and unaffected sides. The measurement points included the proximal, middle, and distal C1-M2 distance and parallel distance of C1-M2 and C1- the medial cuneiform (C2). Results: The proximal, middle, and distal C1-M2 distance and parallel distance of C1-M2 of The affected sides were wider than those of the unaffected sides with significant difference (p<0.01). The middle C1-M2 distance of the affected sides showed the highest intra-observer reliability (0.92) and the second highest inter-observer reliability (0.8). Other measurements of the affected sides showed comparable intra- (0.76-0.91) and inter-observer reliability (0.62-0.84). In addition, the middle C1-M2 distance of the unaffected sides showed the highest intra- (0.76) and inter-observer reliability (0.64); however, all measurements of the unaffected sides showed lower reliability than all measurements of the affected sides. Conclusion: The most reliable measurement point on the weightbearing radiograph was the middle distance of C1-M2. This result may help avoid overlooking or misdiagnosis of Lisfranc injuries.