Conditions Basics

What is a lateral collateral ligament (LCL) injury?

An LCL injury is a sprain or tear to the lateral collateral ligament (LCL). The LCL is a band of tissue on the outside of your knee. It connects your thighbone to the bone of your lower leg and helps keep the knee from bending outward.

You can hurt your LCL during activities that involve bending, twisting, or a quick change of direction. For example, the LCL can be injured in football or soccer when the inside of the knee is hit. This type of injury can also occur during skiing and in other sports with lots of stop-and-go movements, jumping, or weaving.

What are the symptoms?

An injury to your LCL may cause:

  • Swelling, pain, and tenderness, especially on the outside of your knee. Several hours after the injury, your pain may get worse. And it might be harder to move your knee.
  • Bruising.
  • An unstable feeling in your knee, like it may lock up, buckle, or give out.

How is it diagnosed?

The doctor will examine you and ask questions about your past health. He or she will also ask how you injured your knee and about your symptoms at the time you injured it.

Your doctor will carefully examine your knee and leg. He or she will look and feel to see if there is swelling and may gently push on certain places to find spots that are most tender. Then your doctor will move your knee and leg in certain ways to help check for stability. He or she will also look at the rest of your leg to make sure that blood is flowing, the leg works well, and there are no other injuries above or below the knee.

You may have some tests, such as an X-ray, an MRI, or an ultrasound.

How is an LCL injury treated?

Most LCL injuries can be treated at home with:

  • Rest and protecting your knee.
  • Ice or a cold pack.
  • Wrapping your knee with an elastic bandage (compression).
  • Propping up (elevating) your knee.
  • Anti-inflammatory medicine.

Your doctor may suggest that you use crutches to limit how much weight you put on your leg. He or she may also suggest that you wear a brace that protects and supports the knee but allows for some movement.

You may need to be less active for a while. But doing gentle stretching and range-of-motion exercises as advised by your doctor will help you heal.

A severe tear may need surgery. But this usually isn't done unless you also injure other parts of your knee, such as the anterior cruciate ligament (ACL) or meniscus.

Your treatment will depend on how severe your injury is and whether other parts of your knee are injured.

Mild or grade 1.

These injuries may only need home treatment along with using crutches for a short time. You may also need to wear a hinged knee brace when your doctor says it's okay for you to put weight on your leg. Many people are able to be active again after about 3 to 4 weeks.

Moderate or grade 2.

These injuries may require using crutches and wearing a hinged knee brace. Many people are able to be active again after about 8 to 12 weeks.

Severe or grade 3.

These injuries may require wearing a hinged brace for a few months, and limiting weight on the leg for at least 6 weeks. In some cases, surgery may be needed. Many people are able to be active again after about 8 to 12 weeks.

Your doctor may recommend physical therapy to increase range of motion and strengthen your muscles.

How can you care for yourself?

  • Put ice or a cold pack on your knee for 10 to 20 minutes at a time. Try to do this every 1 to 2 hours (when you're awake) for the first 3 days after your injury or until the swelling goes down. Put a thin cloth between the ice and your skin.
  • Prop up your leg on a pillow when you ice it or anytime you sit or lie down. Do this for about 3 days after your injury. Try to keep your knee above the level of your heart. This will help reduce swelling.
  • Take anti-inflammatory medicines to reduce pain and swelling. These include ibuprofen (Advil, Motrin) and naproxen (Aleve). Be safe with medicines. Read and follow all instructions on the label.
  • Follow instructions about how much weight you can put on your leg and how to walk with crutches, if your doctor recommends them.
  • Wear a brace, if your doctor recommends it, to protect and support your knee while it heals. Wear it as directed.
  • Do stretches or strength exercises as your doctor suggests.