A ligament is a band of tissue that connects bone to bone. The collateral ligaments are located on the outside of your knee joint. They help connect the bones of your upper and lower leg, inside your knee joint.
- The lateral collateral ligament (LCL) runs on the outer side of your knee.
- The medial collateral ligament (MCL) runs along the inside of your knee.
A collateral ligament injury occurs when the ligaments are stretched or torn. A partial tear occurs when only part of the ligament is torn. A complete tear occurs when the entire ligament is torn into two pieces.
More About Your Injury
The collateral ligaments help keep your knee stable. They help keep your leg bones in place and keep your knee from moving too far sideways.
A collateral ligament injury can occur if you get hit very hard on the inside or outside of your knee.
Skiers and people who play basketball, football, or soccer are more likely to have this type of injury.