Arthroscopic identification of the popliteofibular ligament

The popliteofibular ligament has recently received recognition as a distinct structure with a significant contribution to posterolateral stability of the knee. The popliteofibular ligament plays a key role in stabilizing the posterolateral corner of the knee by limiting posterior translation, varus angulation, and external rotation (coupled and primary). During arthroscopic procedures, the senior author (R.D.P.) has observed vertically oriented fibers descending from the inferior surface of the intra-articular portion of the popliteus tendon at the popliteal hiatus. This study was performed to determine if these fibers were actually the popliteofibular ligament.

This is an anatomic study using a cadaveric knee model to identify the popliteofibular ligament both arthroscopically and through gross anatomic dissection.

Eight fresh human cadaveric knees were examined arthroscopically and the vertically oriented fibers from the inferior surface of the popliteus tendon at the popliteal hiatus were identified and marked with a suture using an arthroscopic suture passer. A dissection of the lateral side of the knee was then performed to identify the marked structure.

In all specimens, the dissection revealed that the fibers identified and marked arthroscopically had firm attachments to the popliteus tendon superiorly and inserted distally into the posterior aspect of the fibular head. The labeled structure was, therefore, the popliteofibular ligament. The popliteofibular ligament bifurcated distally with 2 insertion sites onto the fibular head.

From this study, we concluded that the vertically oriented fibers descending from the inferior surface of the intra-articular portion of the popliteus tendon at the popliteal hiatus identified during arthroscopy are indeed those of the popliteofibular ligament. It is hoped that this knowledge will lead to improved outcomes in the treatment of injuries to the posterolateral corner of the knee.