The stability of a joint is increased by the presence of a joint capsule made up of connective tissue, thickened at points of stress to form ligaments.
The ends of the ligaments attach to bone.
The medial collateral ligament (or MCL) is a broad, flat band situated on the inside of the knee.
It is approximately 10cm long and is attached to the femur at its proximal end and to the tibia at its distal insertion.
Mechanism of injury
Injury to the MCL usually occurs as a result of a valgus stress or pressure from the outside of the partially flexed knee forcing it to bend inward.
Therefore, stressing it beyond its capacity. A low rugby tackle for instance is a good example.
MCL tears are classified on the basis of their severity:
- Grade one – mild, first degree
- Grade two – moderate, second degree
- Grade three – complete, third degree
With grade one MCL tear there is local tenderness on the inside of the knee but usually no swelling.
A grade two MCL tear is produced by a more severe stress and when the knee is examined it is acutely painful to touch and a small amount of swelling may be present.
In a grade three tear of the MCL the patient often complains of instability or a “wobbly knee”. The amount of pain is variable and frequently not as severe as one would expect given the nature of the injury.
Initial management of a ligament injury involves first aid treatment to minimise bleeding and swelling around the joint.
If instability is present, then surgery or bracing may be required.
For grade 1 and 2 sprains, the principles of treatment involve promoting tissue healing, mobilisation to prevent joint stiffness, protection to avoid further damage and muscle strengthening to provide stability to the joint.
The treatment of a grade 3 sprain (complete ligament tear) may be either surgical or conservative.
The joint is then fully or partially immobilised to protect the repaired ligament, usually for a period of approximately six weeks.
For more information, see your local Lifecare practitioner. Click here to find your closest Lifecare clinic.