Iranian Journal of Orthopedic Surgery

Abstract Background: Diagnosis of associated midfoot fractures in Lisfranc injuries is important for proper treatment. We aimed to describe frequency of different types of Lisfranc injuries in surgically treated cases and to find the accuracy of non-weight bearing radiographs to determine associated midfoot fractures.
Methods: In a retrospective study, preoperative non-weight bearing plain radiographs and CT studies of 118 surgically treated Lisfranc injuries were evaluated by 2 orthopedic surgeons. The sensitivity and specificity of fleck sign, fractures of metatarsal bases, cuneiforms, navicular, and cuboid were calculated.
Results: Among 118 patients with the mean age of 35.0±15.7 years, most were male (77.1%). The most common type was Myerson type B (44.1 %) followed by D2 (40.7%). Fractures of the second metatarsal base (87 patients, 73.7%), the fleck signs (85 patients, 72.0 %), and fractures of the third metatarsal base (65 patients, 55.0 %) were the three most frequent injuries. Oppositely, fractures of the fifth metatarsal base (5 patients, 4.3%), middle cuneiform (14 patients, 12.0%), and navicular (15 patients, 12.7%) were the three least common associated midfoot fractures. Plain radiographs could not show high sensitivity to distinguish associated midfoot fractures in Lisfranc injuries with the highest for the second metatarsal base fractures (78.2%). The maximum specificity was for fractures of the first metatarsal base (100%).
Conclusions: Non-weight bearing radiographs of the foot cannot detect all associated midfoot fractures particularly fleck sign. Therefore, preoperative CT scan is highly recommended.