The Posterolateral Corner of the Knee: Evaluation Under Microsurgical Dissection

Purpose: The posterolateral corner (PLC) has been described by several authors, but there are still controversies. We assumed that a microanatomic dissection of this region could answer some of the questions about its complex anatomy. We therefore conducted an anatomic study using microsurgical techniques, aiming at a precise anatomic description of all the structures that form the posterolateral complex. Type of Study: Cadaveric study. Methods: Ten fresh-frozen human adult cadaveric knees were used for the study. Dissection of the knees was performed using microsurgical instruments, magnifying loupes, and an operative microscope. Anatomic variations, ligament shape, separated bundles of the ligaments, and topography of ligament attachments were described and recorded. Results: The rate of the presence of the popliteofibular ligament (PFL), the fabellofibular ligament, and the arcuate ligament were 100%, 40%, and 70%, respectively. The connective attachments of the popliteus muscle to the other posterolateral structures are the PFL and the 2 popliteomeniscal fascicles. Our dissections show that the shape and the fibula attachment of the PFL can vary. Using the surgical microscope, we were able to dissect and identify 2 different fiber groups of the popliteus tendon at its attachment to the lateral femoral condyle. Also, we were able to confirm in 20% of our knees an anatomic variation of the lateral collateral ligament. Conclusions: Our study may answer some of the questions about the complex anatomy of the PLC. The PFL is well established, always recognizable, and significant in size. Clinical Relevance: Being aware of the complex anatomy of the posterolateral corner and its variations may prove useful in repair and reconstruction.