Summary

menisco-fibular ligament has underestimated role. Failure to diagnose and properly treat this ligament might be an explanation of high long-term failure rate of lateral meniscus suturing in the area of hiatus popliteus as well as in cases of lateral meniscal transplantation. Its evaluation is necessary in all cases of lateral meniscus rupture, or unexplained locking in the posterio-lateral corner.

Abstract

Evolutionary and developmental anatomy is the key to understand the complicated morphology of the posterior-lateral corner structures and its relationship to the lateral meniscus. 360 million years ago in vertebrates as well as during human embryonic development, the fibula articulated with the femur. However, as the vertebrate knee evolved, the fibula and the attached lateral portion of the joint capsule moved distally, resulting in the popliteal hiatus and an intra-articular popliteus tendon. In early evolution - in the moment where the fibula still articulated with the femur – the popliteus tendon had its proximal attachment on the fibular head. In the course of the distal migration of the fibula, the popliteus tendon acquired a new femoral attachment, while retaining its original fibular one (Covey 2001).

The menisco-fibular ligament is a capsular ligament originating from the postero-lateral part of the lateral meniscus, anterior to the popliteal muscle tendon (Bozkurt et al 2004).
This relatively large, often underestimated ligament is believed to position the lateral meniscus and thus having a great impact on its biomechanics. Failure to reconstruct the menisco-fibular ligament might lead to secondary meniscal injures due to impaired biomechanics. Not many surgeons are even aware of existence of this ligament, it is rarely evaluated on the pre-operative MRI neither reconstructed during meniscal suturing nor meniscal allograft transplantation.
In our study we performed 20 anatomical dissections of menisco-fibular ligaments in fresh frozen cadaveric knees. We also performed 20 MRI of intact ligaments. We measured each ligament and compared results from anatomic dissections with the results from MRI. Each ligament was carefully visualized on digital photography as well as on movies.
Subsequently we developed a new visualization protocol to arthroscopicaly evaluate menisco-fibular ligament. We documented images of 20 patients with intact menisco-fibular ligament and the way it is changing its course with knee flexion and extension. We also developed a technique to arthroscopicaly control reconstruction of this ligament in cases of its rupture.

In conclusion we believe that menisco-fibular ligament has underestimated role. Failure to diagnose and properly treat this ligament might be an explanation of high long-term failure rate of lateral meniscus suturing in the area of hiatus popliteus as well as in cases of lateral meniscal transplantation. Its evaluation is necessary in all cases of lateral meniscus rupture, or unexplained locking in the posterio-lateral corner. Defects of this ligament play also important role in complex nature of discoid lateral meniscus.