Knee + Leg

Ligament Tears in the Knee


The knee is comprised of four ligaments:

Anterior Collateral Ligament (ACL)
The ACL is one of the main stabilizing ligaments in the knee and is commonly injured. Injuries are typically caused by a sudden stop or change in direction. Other ligaments and the meniscus are occasionally affected when an ACL tear occurs.

Medical Collateral Ligament (MCL)
The MCL is located on the inside of the knee. This ligament is commonly injured by a direct blow to the outside of the knee. It can also be injured in conjunction with an ACL injury.

Posterior Collateral Ligament (PCL)
The PCL, located in the back of the knee, keeps the tibia from moving backwards too far. An injury to the PCL requires a powerful force such as a bent knee hitting a dashboard in a car accident or landing on a bent knee.

Lateral Collateral Ligament (LCL)
The LCL is located on the outside of the knee. A blow to the inside of the knee would typically cause an injury to this ligament.

Ligaments can be partially or completely torn. Tears of the ligaments often leads to a feeling of instability in the knee.

  • Occurs with a sudden change of direction or direct blow (a tackle, landing awkwardly)
  • Often there is a popping sound when the ligament ruptures
  • Pain and significant swelling
  • Loss of full range of motion
  • Discomfort while walking
  • Instability or giving away of the knee

When you are first injured, the RICE method - rest, ice, gentle compression and elevation - can help speed your recovery and reduce pain.


The diagnosis can be made by a physical examination. X-rays are also commonly performed to rule out a bone injury. An MRI can be helpful to confirm the injury as well as to look for damage to other structures within the knee.

Treatment Options

Depending on which ligament is involved, the severity of the tear, your lifestyle, and your symptoms, you and your doctor will determine the best treatment for you. Physical therapy, bracing, and medications are nonsurgical options. Surgery is typically recommended for the following individuals:

  • Young and wish to maintain an active lifestyle
  • Play sports involving twisting activities (soccer, football)
  • Physically demanding occupation (policeman, fireman, roofer)
  • Your knee gives way with activities of daily living

ACL reconstruction is performed using a camera and tools inserted through small incisions. The ruptured ligament is removed and then tunnels (holes) in the bone are drilled to accept the new graft. This graft (which replaces your old ligament) is taken either from a donor or more commonly from your own tissue -- hamstring, quadriceps, or the patella tendon. There are advantages and disadvantages of each option. Your surgeon will determine what is best for you.

The graft is prepared and passed through the drilled holes in the bone. The new tendon is then fixed into the bone to hold it into place while the ligament heals into the bone (usually 6 months). The rest of the knee is also visualized and other damage treated appropriately.

Physical Therapy

Physical therapy is often advised prior to surgery to regain motion, reduce swelling, and strengthen the muscles as much as possible. After surgery, it is very important to follow instructions from your physical therapist and surgeon regarding brace usage, weight bearing, and activities.