Isolated dorsal midtarsal (Chopart) dislocation: a case report.

A case of isolated dorsal midtarsal (Chopart) dislocation resulting from blunt trauma is reported. The mechanism of injury, management, and long-term outcome are discussed. A 45-year-old inebriated man fell from a 4-m height and landed on his feet. He had immediate bilateral foot and back pain. Radiographs showed a burst fracture of the second lumbar vertebra, a left Pott's fracture, and an isolated dorsal dislocation of the right midtarsal (Chopart) joint. No neurovascular deficits or signs of compartment syndrome were noted. The image intensifier showed the unstable midtarsal joint with dorsal translation of the navicular and cuboid from the talus and calcaneum, respectively. Closed reduction of the midtarsal joint was performed with 2 transfixing 3.5-mm AO cortical screws. The right foot was immobilised in a short leg cast for 6 weeks; screws were removed 14 weeks later. At 76-month follow-up, the patient had returned to work as a construction worker, but still had right midfoot pain on prolonged walking or standing, because of persistent plantar opening up and dorsal ossification of the midtarsal joints and degenerative change at the talonavicular joint. With hindsight, open reduction may have led to a better outcome through repair of the plantar ligamentous structures, especially the plantar calcaneonavicular (spring) ligament.