Original Research Compatibility of Lauge-Hansen Classification Between Plain Radiographs and Magnetic Resonance Imaging in Ankle Fractures Haluk Çabuk, MD 1 , Filiz Çelebi, MD 2 , Yunus İmren, MD 1 , Süleyman Semih Dedeoğlu, MD 1 , Mustafa Çağlar Kır, MD 1 , Abdullah Faruk Uyanık, MD 3 , Hakan Gürbüz, MD 4 1 Surgeon, Department of Orthopedics and Traumatology, Okmeydanı Training and Research Hospital, Istanbul, Turkey 2 Radiologist, Department of Radiology, Istanbul Bilim University, Istanbul, Turkey 3 Resident, Department of Orthopedics and Traumatology, Okmeydanı Training and Research Hospital, Istanbul, Turkey 4 Professor, Department of Orthopedics and Traumatology, Okmeydanı Training and Research Hospital, Istanbul, Turkey ARTICLE INFO Level of Clinical Evidence: 3 Keywords: deltoid ligament ligamentous injury medial malleolus supination-external rotation A B ST R AC T We evaluated the accuracy of the predictive injury sequences of the Lauge-Hansen (L-H) classification using magnetic resonance imaging (MRI) in patients with ankle fractures and determined the possible causes of mismatch. Sixty-five patients with ankle fractures who had a complete series of anteroposte- rior, lateral, and oblique radiographs and ankle MRI studies available were included. The fracture pattern was assigned by 2 senior orthopedic surgeons according to the L-H classification system. The syndes- motic ligaments, lateral collateral ligaments, and medial deltoid complex ligaments were evaluated on the preoperative MRI scans. Comparisons were performed between the predicted ankle ligamentous injury based on the radiographic L-H classification and preoperative MRI analysis. Of the 65 feet in 65 pa- tients, 50 feet (76.9%) were classified as having a supination-external rotation (SER) fracture, 6 feet (9.2%) as having a pronation-external rotation fracture, 4 feet (6.2%) as having a supination adduction fracture, and 2 feet (3.1%) as having a pronation abduction fracture. The overall compatibility of the radiologic classification with the MRI classification was 66.1%. In the evaluation of 50 feet with the MRI SER des- ignation, maximum compatibility was found for stage 4 (77.3%). The main cause for the discrepancy in the SER designation was missing the presence of deltoid ligament disruption on the plain radiographs, especially in the stage 2 and 3 SER fracture pattern. In the evaluation of deltoid complex injuries, all in- juries were localized to the anterior part of the medial deltoid complex. The validity of the L-H classification system was low. A new classification system is needed to address the medial malleolus fracture or deltoid complex injuries without posterior injury. Also, stress radiographs could be added to standard radio- graphs for the classification to address deltoid complex injuries. © 2017 by the American College of Foot and Ankle Surgeons. All rights reserved. The goal of ankle fracture treatment is to restore tibiotalar joint congruency and stability; therefore, identifying ligamentous injuries in the setting of ankle fractures is critical for treatment decisions (1). Missed injuries carry an inherent risk of poor outcomes. The rate of posttraumatic ligamentous ankle osteoarthritis in a retrospective cohort was 13%, and 36% of these patients had undergone surgical ligamen- tous repair of the involved side (2). Additionally, persistent pain after ankle surgery at 1 year was reported by nearly 60% of patients, with 18.9% of patients reporting severe pain (3). The mechanism of an ankle fracture is complex, and its precise definition is often difficult. In addition to damage to the bone itself, the ligaments can be injured. The Lauge-Hansen (L-H) classification system was designed to predict the mechanism and ligamentous injury patterns of ankle fractures on radiographs. Using biomechani- cal testing on cadaveric ankles, Lauge-Hansen reported reproducible fracture patterns depending on the foot position and direction of the deforming force (4). Although the L-H classification is accepted as a key tool for evaluation of possible ligamentous injuries, the quality, validity, and reproducibility of this system have been chal- lenged (5–7). The low reproducibility rates for L-H classification could have resulted from the lack of stress views for evaluation of medial soft tissue injuries. Previous studies have clearly demon- strated that both gravity and manual stress radiographs have high sensitivity and specificity for medial sided injuries (8). In magnetic resonance imaging (MRI) studies, the compatibility ratio of L-H Financial Disclosure: None reported. Conflict of Interest: None reported. Address correspondence to: Haluk Çabuk, MD, Department of Orthopedics and Traumatology, Okmeydanı Training and Research Hospital, Cumhuriyet Avenue, Çamlıca Street, No: 4-a, 13 Göktürk, Eyüp, Istanbul 38384, Turkey. E-mail address: halukcabuk@hotmail.com (H. Çabuk). 1067-2516/$ - see front matter © 2017 by the American College of Foot and Ankle Surgeons. All rights reserved. https://doi.org/10.1053/j.jfas.2017.12.009 The Journal of Foot & Ankle Surgery ■■ (2017) ■■–■■ ARTICLE IN PRESS Contents lists available at ScienceDirect The Journal of Foot & Ankle Surgery journal homepage: www.jfas.org