Subtle Lisfranc Injury: Low Energy Midfoot Sprain

摘要

A year prior to the current presentation, the patient, a 19- year- old Marine, reported injuring his right foot while landing from a jump. Initially the man complained of pain along dorsum of both feet in the region of the first metatarsophalangeal joints. However, over the intervening year, the pain was persistent and increased in the dorsal right foot, noticeably after running. The weight-bearing AP (Figure 1A) revealed a small irregular bony fragment in the region of the Lisfranc ligament between the medial cuneiform and the lateral aspect of base of the second metatarsal, that was best seen magnification of the image (Figure 1B, arrow). In addition, the AP radiograph shows a 2 mm incongruity of the alignment of the medial aspect of the second metatarsal with the medial aspect of the middle cuneiform (Figure 1B, dotted lines). The lateral weight-bearing radiograph (Figure 1C) did not show compromise of the arch height or dorsal subluxation of tarsometatarsal joint. The technetium bone scan (Figure 1D) shows focal increased radionuclide tracer uptake (arrow) over the proximal first and second metatarsals of the medial aspect of the right foot. Computed Tomography (CT) was also performed and confirmed the findings seen on plain radiographs. On CT, both the 2 mm lateral displacement the second metatarsal and the bone fleck (Figure 1E, oblique axial reconstruction, arrow) in the region of the Lisfranc ligament were noted. A second additional avulsion fracture (Figure 1F, arrowhead) was noted adjacent to the plantar aspect of the base of the second metatarsal. While low-energy Lisfranc injuries may seem relatively unimpressive clinically and radiographically, they can have large and lengthy impact on function, particularly for those physically demanding vocations and avocations, such as in the military.