Anatomic Reconstruction of Malunited Chopart Joint Injuries

Abstract

Fractures and dislocations at the mid-tarsal (Chopart) joint are frequently overlooked or misinterpreted at first presentation. Inadequate joint reduction and stabilization almost invariably lead to painful malunions or nonunions, residual instability, and deformity. Because of the central position and the essential function of the mid-tarsal joint, malunions lead to a considerable impairment of global foot function and the rapid development of posttraumatic arthritis. While secondary anatomical reconstruction with joint preservation would be desirable in order to restore normal foot function, it is amenable only if no symptomatic arthritis or avascular necrosis is present. Over a course of 6 years, eight patients have been treated with secondary correction, joint realignment, and internal fixation. In four of these cases, nonunions of the tarsal navicular were debrided and bone-grafted; in the remaining cases, a corrective osteotomy at the navicular or cuboid was carried out. At 2 years followup, all but one patient were satisfied with the result. One patient underwent fusion of the talonavicular joint for avascular necrosis and collapse of the navicular. The mean American Orthopaedic Foot and Ankle Score (AOFAS) improved significantly from 38.8 preoperatively to 80.8 at follow-up. However, the majority of malunited mid-tarsal fracture-dislocations will require corrective fusion of the affected joint(s) with axial realignment because of manifest posttraumatic arthritis at the time of patient presentation.

Keywords: Chopart joint; Correction; Dislocation; Fracture; Malunion; Mid-tarsal joint; Nonunion.