[Simple tibiotalar luxation. Apropos of 16 cases]

Abstract

Tibiotalar dislocations without fracture are extremely rare lesions. This series included 16 patients, 12 of whom have been examined clinically and radiographically. The purpose of this study was to specify the injury mechanism of the various anatomical types and to assess the long term outcome. The group included eight posteromedial dislocations (50%), four posterior dislocations (25%), one anterior dislocation, one high variety, one of the Huguier type, and one complex dislocation. The sex ratio was 14 males/2 females with an average age of 37 years. In half of the cases, dislocations were open. The average follow-up period was 11 years (range, 1 to 26 years). The eight closed dislocations and the open case type I according to the Cauchoix classification received non-operative treatment by reduction in the emergency room and immobilization in a plaster cast for 6 weeks. The seven patients who presented open dislocations Cauchoix type 2 and type 3 were treated by surgical debridement and ligament repair, followed in all cases by a plaster cast boot, and in two cases by temporary transplantar pinning. Twelve patients were reexamined clinically according to the Gay and Evrard modified score, and were radiographically evaluated with lateral and anteroposterior views focused on the tibiotalar joint, on both sides, static and dynamic. Anatomical factors resulting in predisposition such as medial malleolus shortness or lack of coverage of the talus have been evaluated. No patient presented tibiotalar joint instability. A 5 degrees to 10 degrees loss in the range of dorsiflexion was frequently observed. Two patients presented joint stiffness. In four cases, patients complained about paresthesias in the areas of the anterior tibial nerve or intermediary dorsal cutaneous nerve. Four cases of degenerative arthritis were radiographically observed, two of which presented an overall narrowing of the joint over 50%. Degenerative arthritis had occurred within the first four years in these 4 cases. The talus coverage index was similar to the standard population. Shortness of the medial malleolus was present in only two cases. The long-term prognosis after tibiotalar dislocation without fracture proves to be good. One should favor orthopedic treatment. The absence of tibiotalar instability argues against carrying out emergency ligamentous repair. Evolution towards degenerative arthritis is to be anticipated in 25% of cases, especially following open dislocations, or if transplantar pinning was required due to instability of the initial reduction.