Sectional Anatomy and Three-Dimensional Visualization of the Posterolateral Complex of the Knee Joint Based on Undeformed High-Resolution Sectional Anatomical Images.

The anatomy of the posterolateral complex (PLC) of the knee is usually studied by dissection and magnetic resonance (MR) imaging, which is still controversial. We aim to study it based on the images and an interactive 3D-PDF from the Chinese Visible Human (CVH) datasets. CVH datasets (six transverse and one coronal) of the PLC and its adjacent structures were segmented and three-dimensionally reconstructed. Histological sections images were used to establish criteria for the segmentation. MR images were studied in comparison with CVH images. The PLC was mainly composed of the fibular collateral ligament (FCL), popliteofibular ligament (PFL), arcuate popliteal ligament (APL), popliteus tendon (PT), fabellofibular ligament (FFL) and biceps femoris tendon (BT). These structures had origins or insertions located close to each other and collectively maintained the stability of the PLC. The origins of the PT and the FCL were located on the lateral condyle of the femur. The APL was "Y" shaped and had a 100% occurrence in our study. Its lateral and medial heads originated, respectively, from the posterolateral part and medial-inferior part of fibrous capsule close to the lateral femoral condyle. The FCL, BT, main trunk of the APL, PFL and FFL had adjacent insertions on the posterolateral fibular head. CVH high-resolution sectional anatomical images and a 3D-pdf provided detailed morphological data for the PLC, and improved the identification and diagnostic accuracy for the PLC in MRI. We speculate that APL has a strong biological and mechanistic significance in the PLC. Anat Rec, 301:1764-1773, 2018. © 2018 Wiley Periodicals, Inc.