Complete posterior dislocation of fractured lateral condyle of tibia with disruption of proximal tibiofibular joint: Technical note

Abstract

Tibial plateau fracture-dislocations are relatively uncommon injuries. They represent instability patterns due to injured collateral ligaments or extensive condylar depression. Medial and lateral subluxations of the fractured fragments represent the majority of these injuries. Posterior dislocations with the tibial plateau fractures are extremely rare injuries. Moreover, isolated posterior dislocations of the tibial condyles with a normally maintained position of the remaining tibia have not been reported in literature. We describe a difficult case scenario in which whole of the articular segment of the lateral condyle of the tibia was separated from its anterolateral rim and completely dislocated posteriorly, with no contact with the lateral condyle of the femur. Besides this, there was a complete disruption of the proximal tibiofibular joint as well. To further add to the problem, the distal pulses in the affected limb had a reduced volume. Stepwise management of all aspects of this injury has been described in this technical note along with a six-month follow-up.

Keywords: Fracture-dislocation; Knee dislocation; Lateral condyle dislocation; Posterior dislocation; Proximal tibiofibular joint; Tibial plateau.

Fig. 1

Preoperative radiological assessment of the present case: a) AP and lateral radiographs suggestive of fractured lateral condyle of the tibia with posterior dislocation of the condylar fragment and disruption of the proximal tibiofemoral joint. b) An axial cross-section through the subchondral region of the tibial plateau suggesting a complete posterior dislocation of the articular segment of lateral condyle compared to an undisplaced lateral condyle fracture. c) Three dimensional (3D) reconstruction images suggesting an intact articular surface of the posteriorly dislocated lateral condyle, with fibular head crumpling inside fracture cavity anterior to the dislocated condylar fragment. A comparative interpretation was performed through a 3D CT scan of an undisplaced tibial plateau fracture. d) The popliteal artery is being pressed upon by the dislocated condylar fragment (double arrows) and the terminal spike of the condylar fragment is close to the level of bifurcation of the popliteal artery (red pointer) at a distance of 4.64 cm from the joint line.

Fig. 2

Steps in reduction and fixation of the posteriorly dislocated condylar: 1. Maneuvering fibular head to create a passage for the dislocated lateral condylar fragment (a,b,c,d). 2. Temporary reduction and stabilization of the lateral condylar fragment using multiple K-wires (e,f). 3. Placement of multiple lag screws to fix the condylar fragment to the intact anterior and medial bone (g,h). 4. Addition of an anterolateral plate to augment the fixation stability (i). Satisfactory healing of both posterolateral and anterior wounds was observed at the time of suture removal(j,k).

Fig. 3

Initial postoperative AP and lateral radiographs following fracture fixation (a,b). Consolidated union of the fracture at three months postoperatively (c,d).