[Dislocation of the proximal tibio-fibular joint due to severe leg and knee trauma].
PURPOSE OF THE STUDY: Dislocation of the proximal tibio-fibular joint is a rare lesion generally described in athletes. In our experience, high-energy trauma in traffic accident victims was a frequent cause. Dislocation of the proximal tibio-fibular joint is generally described as anterolateral, posteromedial, superior, or subluxation. We describe an inferior form of dislocation. MATERIALS AND METHOD: The study population included eight men aged 21-55 years (mean 31 years). One patient had bilateral dislocation. There were four superior, one posterior, and four inferior dislocations. All patients also had an associated fracture of the tibia which was an open fracture in eight cases. Five patients suffered a lesion to the common fibular nerve. Three had tibial nerve involvement in a context of inferior disclocation. The lateral collateral ligament was torn in six cases. The central pivot was involved in four. Two patients had an avulsion of the patellar ligament on the tibial tuberosity. Five patients had vessel damage. Three required emergency amputation. Two patients (one superior and one inferior dislocation) underwent emergency bypass surgery but required below-knee amputation later due to persistent ischemia. All dislocations, excepting the one case of complete fibular avulsion and one emergency above knee amputation were treated by transarticular screw fixation of the proximal tibio-fibular joint. RESULTS: Mean follow-up was 5.8 years (1-9 years). At last follow-up, there were no cases of instability or pain in the proximal tibio-fibular joint. The patient with an initial neurapraxia in territory of the common fibular nerve recovered totally. The five amputated patients had prostheses and walked without crutches. DISCUSSION: Dislocation of the proximal tibio-fibuilar joint is a rare entity, but the frequency is probably underestimated. The dislocation can go unrecognized in patients with multiple injuries. Careful search should nevertheless be undertaken due to the risk of secondary involvement of the common fibular nerve. The Harrisson and Hindenach classification, inspired by the Lyle classification, does not mention inferior dislocation of the proximal tibio-fibular joint, a recently described entity. Our series included dislocations resulting from high-energy trauma associated with numerous ligament, nerve, and vessel injuries. In this context, dislocation of the proximal tibio-fibular joint constitutes an epiphenomenon.