Ligament Injuries

A collateral ligament injury occurs when the ligaments are stretched or torn. A partial tear occurs when only part of the ligament is torn. A complete tear occurs when the entire ligament is torn into two pieces.

The collateral ligaments help keep your knee stable. They help keep your leg bones in place and keep your knee from moving too far sideways.

A collateral ligament injury can occur if you get hit very hard on the inside or outside of your knee, or when you have a twisting injury.

Skiers and people who play basketball, football, or soccer are more likely to have this type of injury.


These injuries occur when excessive pressure or stress is placed on the knee, forcing it sideways. MCL damage often is the result of a blow to the outside of the knee during sports activities.

The ligament may also become damaged from a fall on ice, as slipping causes the foot to move outward while the body weight comes down. Pivoting and changing directions quickly can also stretch or tear the MCL.

The LCL is injured when the knee is forced to bend inward, usually during a direct impact to the knee joint. In most cases of stretches or tears to this ligament, the injury occurs during contact sports.


  • A loud pop when the injury occurs
  • Your knee is unstable and can shift side to side as if it “gives way”
  • Locking or catching of the knee with movement
  • Knee swelling
  • Knee pain along the inside or outside of your knee


  • An MRI of the knee. An MRI machine takes special pictures of the tissues inside your knee. The pictures will show whether these tissues have been stretched or torn.
  • X-rays to check for damage to the bones in your knee.


  • Crutches to walk until the swelling and pain get better
  • A brace to support and stabilize your knee
  • Physical therapy to help improve joint motion and leg strength

Most people do not need surgery for an MCL injury. However, you may need surgery if your LCL is injured or if your injuries are severe and involve other ligaments in your knee.


The MCL can tear if an injury stretches it too much. The tear might be partial (through a part of the MCL) or complete (all the way through the MCL).


Most medial collateral ligament tears happen during athletic activity, such as when someone:

  • Changes direction or twists the knee while running
  • Jumps and lands in a way that twists the knee

The MCL also can tear if the knee is hit forcefully from the side.


Most people who tear their MCL feel pain and a “pop” in their knee when the injury happens. Their knee usually swells soon after the injury, most of the time around the inside part of the knee.

After the swelling goes down, they usually can walk, but feel pain when the inside of the knee is stretched, Also, the knee may feel unstable and can “give way” and make the person stumble or fall.


To diagnose a torn MCL, health care providers ask about the injury and do an exam. During the exam, the health care provider presses on the knee and legs and moves them in certain ways. This can help show if the MCL is torn.

Imaging tests done can include:

  • X-rays to check for injuries to the bones
  • Sometimes, an MRI to check if the tear is partial or complete and to see if the knee has other injuries


Right after the injury, treatment may include:

  • Over-the-counter pain medicine such as acetaminophen or ibuprofen
  • RICE: Rest, Ice, Compression (with an elastic bandage), and Elevation (raising the knee)
  • Bracing: The health care provider will advise you about the best type of brace to protect the MCL and the knee joint during the healing process.

Other treatments may include:

  • Using crutches during recovery
  • Physical therapy (PT) to help with strength and flexibility
  • Surgery


The LCL is a band of connective tissue called a ligament. It runs along the outside of the knee and connects the femur (thigh bone) to the smaller bone (calf bone) in the lower leg, called the fibula. The lateral collateral ligament is extremely rarely injured except as part of a high energy injury with complex and multiple ligamentous instabilities.


A person with an LCL injury will typically experience sudden pain on the outside of the knee after a traumatic event to the area, such as a blow to the knee, sudden twist, or a fall.

  • Stiffness and difficulty moving the knee
  • Swelling and tenderness on the outside of the knee
  • Bruising
  • Feeling that the knee is unstable, may lock up, or will give out when putting weight on it


Anything that puts force on the LCL may put the person at risk for an LCL injury. Injuries may be more likely to occur when a force or impact pushes the knee sideways or in a direction it should not move. With enough force, this can result in an injury to the stabilizing structures in the knee such as the collateral ligaments.

Sports that are more likely to result in LCL injuries include:

  • Football
  • Soccer
  • Gymnastics
  • Volleyball
  • Basketball
  • Baseball/Softball
  • Lacrosse
  • Swimming and Diving
  • Tennis


Doctors can diagnose an LCL injury by first doing a physical exam and asking the person about the event that led to the symptoms.

They may ask specifics about the event, such as where the blow came from, how the person fell or twisted the leg, or other specifics. They may ask the person to move the knee or move the knee themselves and look for other signs of damage and swelling.

Doctors may order imaging tests such as X-rays or MRI scans to look at the tissues and structures inside the knee to decide what type of treatment the person requires.


Treatment will vary based on the structures involved in the injury and the severity. For most LCL injuries, doctors may recommend home care, and advise tips such as:

  • Resting and elevating the knee as much as possible
  • Using splints, braces, or crutches to protect the knee when moving
  • Compressing the area with an athletic wrap
  • Using prescription or over-the-counter pain relievers and anti-inflammatory medications
  • Applying ice or cold pack to the area regularly to reduce swelling and pain
  • Being less active and performing gentle stretches

A physical therapist may work with the person to help regain strength and range of motion in the knee’s surrounding muscles.

More severe injuries or those that include other structures in the knee may require surgical treatments. This may involve repairing, joining, or reconstructing severed ligaments.