Floating metatarsal: concomitant Lisfranc fracture-dislocation and complex dislocation of the first metatarsophalangeal joint

Abstract

We describe a unique composite injury of the foot, with concomitant Lisfranc fracture-dislocation, and complex dislocation of the first metatarsophalangeal joint. When examining patients with Lisfranc joint injuries, one must keep in mind that the axial compression forces causing the injury may also damage the metatarsophalangeal joints, and direct attention to these structures. The reduction and stabilization of a "floating" first metatarsal should begin at the distal (metatarsophalangeal) end. The reduction of the distal dislocation will release tension on the plantar fascia, enabling the subsequent reduction of the proximal (Lisfranc) dislocation. A medial approach is convenient, affords easy access to the plantar and dorsal aspects of the joint, and repair of the medial joint structures when damaged. The use of screws for fixation of Lisfranc's fracture-dislocation, is well justified by the stability achieved.