Clinical Details

Clinical and radiological findings:  This case is a hyperextension injury of the left knee with anterior impaction of the medial and lateral tibial plateau articular surfaces. The degree of impaction is more pronounced medially tending into varus, though a significant loss of overall height of both condyles is evident. In addition we note the avulsion fracture of the tip of the proximal fibula implying avulsive disruption of the posterolateral corner ligament complex including the arcuate ligament and the popliteaofibular ligament. As can be seen in the preoperative clinical photos the knee falls into marked hyper extension and varus with posterolateral laxity. The surgical approach began mediately with an initial elevation and reconstruction of the medial joint height. This was unable to be restored in isolation so following provision plate placement and fixation of medial height with k-wires we opened the lateral approach, then moving between medial and lateral sides the entire joint surface could be sequentially elevated en-block. An intra-operative shot of the contralateral uninjured side provided a guide to the inclination of the tibial articular slope and using this as a guide we reconstructed both articular height and tibial slope to comparable pre-injury state. The fixation comprised of medial and lateral 3.5 mm anatomical locking plates. Following bony reconstruction clinical hyperextension was greatly reduced. A further consequence of restoring length of the lateral column was a spontaneous retentioning of the lateral collateral ligament. The disruption to the posterolateral corner however remained clinically evident with residual posterolateral rotatory instability. Addressing the fibula avulsion involved neurolysis and mobilisation of the common peroneal nerve in it's course posterior to the biceps tendon continuing laterally around the fibula neck. Following protection and mobilization of the nerve we then drilled anterograde for placement of a transosseous endobutton suture (Arthrex distal biceps repair system) and anchored the PLC ligament complex with the avulsion fracture.