Lateral Collateral Ligament (LCL) Tear

The lateral collateral ligament, or LCL, is one of the four major knee ligaments. The LCL connects the end of the thigh bone (the femur) to the top of the smaller shin bone (fibula), on the outside of the knee. The LCL helps to prevent excessive side-to-side movement of the knee joint. When the LCL is torn, the knee joint may bend too far inwards when stressed.

People who injure their knee ligaments may develop sensations of instability of the knee joint. Instability is the symptom of the knee wanting to buckle or give-out. People who have instability of the knee joint may have abnormal sensations of the knee wanting to buckle, or it may suddenly buckle to the point that they fall to the ground.

When the knee is unstable, it is often difficult to perform many activities, especially those that involve side-to-side movements, twisting, cutting, or pivoting. For this reason, often athletic activities like soccer and basketball can be difficult or impossible for people with LCL tears.

Severity

The LCL is most commonly torn during sports activities or traumatic injuries (falls, etc.). The LCL is torn when the knee bends inwards excessively, and the LCL is stretched too far. LCL tears are graded similarly to other ligament tears on a scale of I to III:

• Grade I LCL tear: This is an incomplete tear of the LCL. The tendon is still in continuity, and the symptoms are usually minimal. Patients usually complain of pain with pressure on the LCL and may be able to return to their sport very quickly. Most athletes miss one to two weeks of play.
• Grade II LCL tear: Grade II injuries are also considered incomplete tears of the LCL. These patients may complain of instability when attempting to cut or pivot. The pain and swelling are more significant, and usually, a period of three to four weeks of rest is necessary.
• Grade III LCL tear: A grade III injury is a complete tear of the LCL. Patients have significant pain and swelling, and often have difficulty bending the knee. Instability, or giving out, is a common finding with grade III LCL tears. Grade III LCL tears commonly require surgical reconstruction.

Treatment

Treatment of Grade I and II LCL tears can usually be accomplished with simple steps that allow the ligament to rest and repair itself. The early steps should be aimed at preventing inflammation and allowing the ligament to rest. Helpful treatments include:

• Rest: Patients may do best using crutches to allow the knee to rest. Activities including sports should be avoided until the ligament is healed. A brace can help to support the knee to prevent stress on the healing LCL.
• Anti-inflammatory drugs: Anti-inflammatory medications can help to control swelling and prevent inflammation. These medications should be discussed with your doctor as there are possible side-effects.
• Ice application: Applying an ice pack to the area can help control swelling and pain.
• Knee exercises: Once the acute inflammation has settled down, some basic knee exercise can help to restore mobility to the joint and prevent loss of strength. Return to sports should not be considered until mobility and strength have been restored to normal.

Recent studies have shown that patients who undergo surgical treatment tend to do best with the reconstruction of the ligament with other tissue (a.k.a. a tissue graft) rather than repair of the damaged ligament.

Surgery

When the lateral collateral ligament is completely torn, a surgical procedure is typically recommended to either repair or reconstruct the ligament. When the ligament is torn at the location of the attachment to the bone, a surgical repair may be possible.

If the ligament is torn along the center of the ligament, a reconstruction procedure is typically needed. During this procedure, tissue from elsewhere in the body (or from a donor) is used to create a new lateral collateral ligament.

A Word From Verywell

The lateral collateral ligament is one of the four major ligaments to provide stability to the knee joint. Injuries to the lateral collateral ligament are relatively uncommon compared to injuries to the other major knee ligaments. However, when the LCL is injured, people may have pain, swelling, and instability of the knee joint.

Partial tears of the lateral collateral ligament will typically heal with nonsurgical treatment, whereas complete tears of the ligament often require a surgical repair.