The lateral collateral ligament (LCL) connects your thighbone, or femur, to the fibula, the smaller bone in your lower leg. It helps keep your knee from moving sideways, and can be injured when your knee is forced sideways. Sports injuries are a common cause. When the LCL is injured, other ligaments in the knee are often injured as well.

If just the LCL is injured, you may be able to treat it with non-surgical treatment. If it is torn in the middle or there are other knee ligament injuries that need surgical repair, you may have surgery.

After surgery you may need to wear a brace and use crutches to avoid putting all your weight on your knee while it heals. You will have physical therapy after surgery to help you regain strength in your knee.