Everything You Need to Know About a Lateral Collateral Ligament (LCL) Tear

What is a LCL Tear?

An LCL tear is an injury to the ligament on the outer side of your knee. The lateral collateral ligament connects your thigh bone (femur) to your shin bone (fibula) and helps keep your knee stable, especially during side-to-side movements. A tear can range from a mild stretch to a full rupture, often causing pain and instability in the outer knee.

An analogy…
Think of the LCL like a rope that keeps a gate from swinging too far open. If that rope gets overstretched or snaps, the gate becomes wobbly and unstable, just like your knee after an LCL injury.

What are other names that LCL tear can be called?

Lateral Collateral Ligament Injury
LCL Sprain
LCL Rupture
Outer Knee Ligament Tear

What causes a LCL tear?
LCL tears usually happen when there is a force pushing the knee inward while the foot is planted, like during a tackle from the inside, a fall, or a sudden twist. Other causes include:

Sudden changes in direction
Direct blows to the inside of the knee
High-impact sports injuries
Hyperextension of the knee
Landing awkwardly during jumping sports

What are the signs and symptoms of a LCL tear?

Pain on the outer side of the knee
Swelling and tenderness along the ligament
Feeling of looseness or instability, especially with side movements
Bruising near the outer knee
Stiffness or difficulty fully bending or straightening the leg
In more severe tears: a popping sound or the knee giving way

What tests are used to diagnose a LCL tear?

Varus stress test: the knee is pushed inward to assess LCL stability
Palpation: pressing along the ligament to locate pain or a gap
Range of motion and strength testing: to evaluate joint function
MRI scan: confirms the location and severity of the tear
X-ray: used to check for fractures or bone avulsion (where the ligament pulls part of the bone off)

How long does a LCL tear take to heal?

Recovery time depends on the severity (grade) of the tear:

Grade 1 (mild stretch): 1–3 weeks
Grade 2 (partial tear): 4–6 weeks
Grade 3 (complete tear): 8–12 weeks or longer, may require surgery, especially if combined with other ligament injuries

How does a LCL tear happen?

An LCL tear happens when there is excessive stress on the outer knee, usually from a sudden force pushing the knee inward. This is common in sports with contact or cutting motions, like football, rugby, skiing, or basketball. It can also happen from falls, awkward landings, or car accidents.

What treatment can help a LCL tear?