Anatomical Characteristics and Biomechanical Properties of the Oblique Popliteal Ligament

Xiang-Dong Wu,Shan-Quan Sun,Wei Wang,Wei Huang,Tao Zou,Jin-Hui Yu,Robert F Laprade

doi:10.1038/srep42698

Abstract

This anatomical study sought to investigate the morphological characteristics and biomechanical properties of the oblique popliteal ligament (OPL). Embalmed cadaveric knees were used for the study. The OPL and its surrounding structures were dissected; its morphology was carefully observed, analyzed and measured; its biomechanical properties were investigated. The origins and insertions of the OPL were relatively similar, but its overall shape was variable. The OPL had two origins: one originated from the posterior surface of the posteromedial tibia condyle, merged with fibers from the semimembranosus tendon, the other originated from the posteromedial part of the capsule. The two origins converged and coursed superolaterally, then attached to the fabella or to the tendon of the lateral head of the gastrocnemius and blended with the posterolateral joint capsule. The OPL was classified into Band-shaped, Y-shaped, Z-shaped, Trident-shaped, and Complex-shaped configurations. The mean length, width, and thickness of the OPL were 39.54, 22.59, and 1.44 mm, respectively. When an external rotation torque (18 N·m) was applied both before and after the OPL was sectioned, external rotation increased by 8.4° (P = 0.0043) on average. The OPL was found to have a significant role in preventing excessive external rotation and hyperextension of the knee.

Highlights

The oblique popliteal ligament (OPL) is the largest structure on the posterior aspect of the knee, and given its broad shape, it is probably vulnerable to, or involved in, posterior knee injuries[1]
Given the contradictions and limitations found in the literature, it is necessary to perform further study of the anatomical and biomechanical characteristics of the OPL, which would contribute to the recognition and restoration of OPL injuries and would help surgeons avoid iatrogenic injuries
The OPL was identified in all specimens as a broad and flat ligament that diagonally crossed the posterior knee joint and overlaid the posterior surface of the knee joint capsule

Summary

Introduction

The oblique popliteal ligament (OPL) is the largest structure on the posterior aspect of the knee, and given its broad shape, it is probably vulnerable to, or involved in, posterior knee injuries[1]. Insufficient awareness of the anatomic characteristics, radiographic features, and biomechanical properties of the OPL may result in a failure to recognize and replicate normal anatomical structures and functional rehabilitation in the management of traumatic injuries to the knee joint. A combined anatomical and biomechanical study of the OPL would contribute to “rediscovery” of the posterior structures and corresponding function of the knee, thereby providing a more anatomical and functional basis for the treatment of OPL injuries. There remains a paucity of data describing the external features, anatomical characteristics, and biomechanical properties of the OPL. This study attempted to provide a detailed description of the anatomical structures and to complement the quantitative data on the OPL in the Asian population.

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Conclusion