What are knee ligament injuries?

The knee ligaments are short bands of strong, flexible connective tissue that hold the knee together. Knee ligament injuries can be caused by trauma, such as a car accident. They can also be caused by sports injuries. For example, a knee injury due to a twisting motion while playing basketball or skiing.

The knee has 4 main ligaments. Ligaments connect bones to each other. They give the joint stability and strength. The 4 ligaments of the knee connect the femur to the tibia. These ligaments are:

• Anterior cruciate ligament (ACL): This ligament is in the center of the knee. It controls the rotation and forward movement of the tibia bone;
• Posterior cruciate ligament (PCL): This ligament is at the back of the knee. It controls the backward movement of the tibia bone;
• Medial collateral ligament (MCL): This ligament provides stability to the inside of the knee;
• Lateral collateral ligament (LCL): This ligament provides stability to the outside of the knee;

What causes knee ligament injuries?

Cruciate Ligaments

The ACL is one of the most commonly injured ligaments. The ACL is often stretched or torn during a sudden twisting motion. This happens when the feet stay planted in one direction, but the knees turn in the other direction. Slowing down during a run or landing improperly from a jump can cause ACL injuries. Skiing, basketball, and football are sports with a higher risk of ACL injuries.

The PCL is also a frequently injured ligament in the knee. But a PCL injury often happens during a sudden, direct impact, such as in a car accident or during a football tackle.

Collateral Ligaments

The MCL is more often injured than the LCL. Stretching and tearing injuries of the collateral ligaments are often caused by a blow to the outside of the knee. This can happen playing hockey or football.

What are the symptoms of knee ligament injuries?

Cruciate Ligament Injury

A cruciate ligament injury is often painful. You can often hear a popping sound when the injury occurs. Then, your leg gives way when you try to stand. The knee also swells. You are also unable to move your knee as you normally would. You may also feel pain along the joint and pain when walking.

The symptoms of a cruciate ligament injury can resemble other health problems. Always consult your healthcare provider for a diagnosis.

Collateral Ligament Injury

A collateral ligament injury also causes the knee to give way and buckle. It also causes pain and swelling. Often, you will have pain on the sides of your knee and swelling at the injury site. If it's an MCL injury, the pain is on the inside of the knee. An LCL injury may cause pain on the outside of the knee. The knee is also unstable, as if it is going to give way.

How are knee ligament injuries diagnosed?

Your healthcare provider will ask about your medical history and perform a physical exam. You may also need one or both of these tests:

• An X-ray: This imaging test helps rule out a bone injury rather than a ligament injury. It uses energy beams to make images of internal tissues, bones, and organs on film;
• An MRI: This exam uses powerful magnets, radio waves, and a computer to produce detailed images of organs and structures in the body. It often helps detect injuries or diseases in the bones and surrounding ligaments, tendons, or muscles;

Why might I need knee ligament repair?

Medical treatment for knee ligament injuries

Early medical treatment for a knee ligament injury may include the following:

• Rest;
• Applying an ice pack (to reduce swelling that occurs in the hours after the injury);
• Compression (using an elastic bandage or brace);
• Pain relievers;

A torn knee ligament may be treated with the following:

• Muscle-strengthening exercises;
• Knee brace (to be used during exercise);
• Activity limitations;

Knee ligament repair is a treatment for a complete tear of a knee ligament that results in knee instability. People with a torn knee ligament may be unable to perform normal activities that involve twisting or rotating the knee. The knee may buckle or give way. If medical treatments are unsatisfactory, ligament repair surgery may be an effective treatment.

Surgical repair of knee ligament injuries

Surgery to repair a torn knee ligament involves replacing the ligament with a piece of healthy tendon. A tendon from the kneecap or hamstring muscle, for example, is grafted in place to support the knee joint. The grafted tendon may come from the person (autograft) or an organ donor (allograft).

There may be other reasons why your healthcare provider recommends knee ligament repair.

What happens during knee ligament repair?

Knee ligament repair may be performed while you are asleep under general anesthesia, or while you are awake under spinal anesthesia. With spinal anesthesia, you will not feel anything from your waist down. Your healthcare provider will discuss this with you beforehand. The surgeon performs the operation using an arthroscope, a small tube-like instrument that is inserted into a joint. He or she may reattach the torn ligament or reconstruct it using a part (graft) of the patellar tendon (which connects the kneecap to the tibia), hamstring tendon (at the back of the thigh), or other autografts. The tendon graft may come from the person (autograft) or an organ donor (allograft).