Accessibility Tools
Collateral Ligament (MCL / LCL) Tear/Reconstruction

Knee Anatomy

The knee is made of the femur (Thighbone) and the tibia (Shinbone) that are connected with ligaments to hold the bones together and stabilize the knee. Collateral knee ligaments are located on the sides of the knee. The medial collateral ligament (MCL) is on the inside, and the lateral collateral ligament (LCL) is on the outside of the knee. These ligaments control the ability of the knee to move sideways and brace the knee to prevent abnormal movement.

What causes MCL or LCL Injuries?

Most often they result from sudden knee impact caused by an auto accident or traumatic sports injuries. Sports like soccer, football, and skiing carry a high risk of MCL injuries.

MCL and LCL Injuries

Injury to the LCL and MCL don’t usually occur alone. In the majority of cases, the Anterior Cruciate ligament (ACL) is also involved.


  • Grade I: Microscopic injury and hemorrhage, mild pain and tenderness
  • Grade II: Partial tears of the medial collateral ligament, more severe pain, tenderness and instability or obvious looseness of the knee.
  • Grade III: Complete tear of the MCL, loss of function and severe pain.

What are the symptoms?


  • Pain
  • Stiffness
  • Swelling
  • Tenderness
  • Feeling that the knee may give way
  • Instability with knee extension
  • Difficulty going up and down stairs
  • Difficulty cutting or pivoting
  • Lateral joint pain and swelling


  • Feeling the knee may give way
  • Locking and catching in the joint
  • Numbness and weakness in the foot
  • Pain
  • Stiffness
  • Swelling and tenderness

How is it diagnosed?

Evaluation will include physical examination, discussion of how the injury occurred, and your symptoms. Special range of motion tests may produce pain but are needed to help Dr. Stark make a diagnosis. Imaging studies including x-rays, stress x-rays, and MRI may be ordered.

How are these injuries treated?

The type and severity of the injury will determine the treatment approach. Most ligament injuries do not heal on their own, except MCL ligaments which have a rich blood supply, which means they have good self-healing ability. Most isolated MCL injuries can be treated conservatively with bracing or casting, and early knee movement. But, LCL injuries do not heal well and may require surgery.

However, injury to the collateral knee ligaments often also involves another ligament injury. Multiple injuries will require surgery. Injury to either of these ligaments that causes a complete tear and side-to-side instability requires surgery. Surgery is very effective to restore side to side stability.

Depending on the severity of your injury, Dr. Stark may suggest a trial of nonsurgical treatment. This would include PRICE: Protection, Rest, Ice, Compression and Elevation, plus cold therapy, and early knee movement with a brace.

Studies continue to show that the best approach is ligament reconstruction (replacement) over repair because repair leads to a higher reoperation rate. Dr. Stark has offices in Carlsbad.