Brief outline of medial collateral ligament (MCL) rupture

A medial collateral ligament (MCL) sprain involves tearing or stretching of this ligament of the knee. The MCL is one of the most common structures of the knee to be injured. This ligament is designed to hold the knee joint together on the medial (inside) surface. Force applied to the outside of the knee (as in football tackle) causes the inside of the knee to open, stretching the MCL. The extent of the stretch determines whether the ligament simple stretches, tear partially, or tears completely.

Cause of medial collateral ligament (MCL) rupture

Force applied to the lateral side (outside) of the knee joint.

Signs and symptoms of medial collateral ligament (MCL) rupture

Pain over the medial portion of the knee. Swelling and tenderness. Instability in the knee and pain with weight bearing.

Complications if left medial collateral ligament (MCL) rupture unattended

The ligament, in rare cases, may repair itself if left unattended, but the injury could lead to a more severe sprain. The pain in the knee an instability of the joint may not go away. Continued activity on the injured knee could lead to injuries of the other ligaments, due to the instability.