THE HEALTH | DECEMBER , 2023

BONE TO PICK

One of the key components responsible for maintaining stability in the knee is the Anterior Cruciate Ligament ( ACL ). Comprising two distinct bundles – the anteromedial and posterolateral – the ACL is a critical stabiliser for the knee .

The anterolateral bundle mainly stabilises the knee from the forward motion of the leg . On the other hand , the posteromedial bundle of the ACL , situated on the inner side of the knee joint , plays a crucial role in controlling the internal rotation of the tibia . This movement is frequently associated with various athletic activities .

The posteromedial bundle works in tandem with the other components of the ACL to stabilise the knee joint , especially in situations where rotational forces are applied . This is particularly important in sports that involve quick changes in direction , as well as in everyday activities that require agility .

The posterolateral complex is another important structure of the knee that plays a role in maintaining rotational stability . It is a network of structures on the outer and back aspects of the knee , including the lateral collateral ligament ( LCL ), popliteus tendon , and popliteofibular ligament .

These components work harmoniously to stabilise the knee during rotational movements , such as pivoting , cutting , and changing direction .

CONTROLLING ROTATIONAL STABILITY

The primary function of the posterolateral corner ( PLC ) is to resist excessive external rotation and varus stress applied to the knee . During activities like running , jumping , or participating in sports , the knee is subjected to various forces that can potentially lead to rotational instability .

The PLC acts as a critical checkpoint , preventing the knee from undergoing excessive rotation and maintaining stability during these dynamic movements .

The posterolateral aspect of the knee .

Recent attention has turned to the anterolateral ligament ( ALL ) for its crucial role in controlling rotational stability . This relatively understudied ligament is gaining prominence for its impact on knee function and injury prevention .

The anterolateral ligament is a thin , band-like structure on the outer aspect of the knee joint . It originates near the lateral femoral epicondyle and extends diagonally across the knee to attach to the anterolateral tibia .

Although the existence and function of the ALL have been debated for many years , advanced imaging techniques and anatomical studies have now solidified their place in our understanding of knee biomechanics .

The primary function of the anterolateral ligament is to counteract excessive internal rotation and varus stress applied to the knee during various activities .

This is particularly crucial in dynamic movements such as cutting , pivoting and decelerating . The ALL acts as a key player in preventing the tibia from excessively rotating and contributing to the overall stability of the knee joint .

DISRUPTIONS IN THE INTEGRITY OF THE MENISCUS

Lastly , the menisci between the femur and tibia distribute the load , absorb shock , and stabilise the knee during movement . Ramp lesions and root tears , however , represent disruptions in the integrity of the meniscus .

• Ramp Lesions : Ramp lesions typically occur in the posterior horn of the medial meniscus , where the meniscus attaches to the tibia . These injuries involve a meniscus detachment from the tibial plateau , creating a ramp-like structure . The significance of ramp lesions lies in their potential to cause rotational instability by altering the distribution of forces within the knee .

• Root Tears : The meniscal root is the attachment point of the meniscus to the tibia . Tears at this crucial juncture , known

Dr Jonas Fernandez is an Orthopaedic Surgeon at Putrajaya Hospital . He is also a member of the Malaysian Arthroscopy Society ( MAS ).

Lemaire procedure : lateral extraarticular tenodesis for patients with ALL injury .

as root tears , can compromise the meniscus ’ s ability to resist rotational forces . When the root is damaged , the entire meniscus may become less effective in stabilising the knee , leading to an increased risk of rotational instability .

Relevance in Sports : Athletes involved in sports that require sudden changes in direction , quick pivots , and rotational movements heavily depend on the knee structures to work in harmony for optimal knee stability . Sports like martial arts , rugby , basketball , and football , where players frequently engage in rapid direction changes , highlight the critical role of these structures in preventing injuries and ensuring peak performance . – The Health