Knee injuries in both contact and non-contact sports are relatively common occurrences. Aside from the usual garden variety sprains, strains and bruises, tears in the major ligaments of the knee alter the stability of the joint and in many cases require surgical repair. Ligaments are connective tissue structures that connect from bone to bone. There are four major knee ligament groups and if you follow sports you either know their names or you know their abbreviations.
Knee Ligaments
- Medial Collateral Ligaments (MCL)
- Lateral Collateral Ligaments (LCL)
- Anterior Cruciate Ligament (ACL)
- Posterior Cruciate Ligament (PCL)
Definitions for Anatomic Locations
Knowing the meaning of some of the anatomic terms can help to clarify the location of each structure.
- Medial – Near to, or facing, the midline of the body when looking straight at the front
- Lateral – Away from the midline of the body or towards the outer edges
- Anterior – Towards the front of the body when looking from the side
- Posterior – Towards the back of the body
What Do the Knee Ligaments Do
The ligaments of the knee provide a large part of the mechanical stability of the knee. The collateral ligaments (both the lateral and medial, LCL and MCL) connect from along the outside surfaces of the femur to the tibia (and somewhat to the fibula) and provide stability to prevent the bones from moving too much side to side. The cruciate ligaments, both the ACL and the PCL, are so named because they cross over each other in the internal reaches of the knee joint, in the so-called articular region, the portion of the bones where the ends of the femur and tibia slide across each other. These two ligaments play a critical role in stabilizing the knee from front-to-back during all of its motions.
What Else Stabilizes the Knee
Besides the above ligaments, the muscles and tendons that pass over and around the knee joint are important in stability as well. Inside the joint, the forces that are generated by activity are dissipated through both the lateral and medial meniscus. And the joint surfaces slide very smoothly because of specialized cartilage on the ends of the femur and the tibia. This "articular cartilage" often breaks down over years and this can be a significant cause of later in life knee replacement surgery.
Injuries to the Ligaments
When the ligaments are only partly damaged they can actually heal given enough time. Depending on the ligament and the extent of the damage, immobilization followed by physical therapy can return the person to activity without the need for surgery. In cases where multiple ligaments are injured and some torn completely, surgical reconstruction with grafting of additional tissue into the injury zones can lead to complete recovery of knee function.
Of course, if you injure your knee see your family physician or orthopedist for a complete evaluation.
Kenneth Rosen - I am a medical research doctor with more than 20 years of experience studying how the nervous system and skeletal muscle develop and ...
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