Lateral Collateral Ligament Sprain

The collateral ligaments are located on the sides of the knees. The lateral collateral ligament (LCL) is located within the knee joint, connecting the outer side of the thigh bone (femur) to the fibula, the smaller bone in the lower leg. The LCL provides strength and stability to the joint and helps the knee to resist force and stay stable during unusual movement. The collateral ligaments also control the sideways motion of the knee. This ligament may become torn or damaged as a result of direct impact or force that may push the knee sideways. An injury may cause the LCL to loosen, stretch, and possibly tear, resulting in pain and inflammation on the outer part of the knee. An LCL sprain commonly occurs in athletes who participate in collision sports such as rugby and football.

Symptoms of an LCL Sprain

Patients with an LCL sprain may experience the following symptoms on the outside of the knee:

  • Pain
  • Tenderness
  • Swelling

After an LCL sprain, individuals may also experience, instability, or the feeling that the knee is going to give way.

Diagnosis of an LCL Sprain

An LCL sprain is diagnosed through a physical examination of the knee. Additional imaging tests may include an X-ray or MRI scan. Imaging tests allow the doctor to see whether the injury is associated with a broken bone as well as get a more accurate view of the injury to determine treatment.

Types of LCL Sprains

The doctor determines the grade of the sprain based on the extent of damage, which may range from a mild tear to a complete rupture. LCL sprains may be classified as:

  • Grade 1 sprains occur when the ligament is mildly damaged
  • Grade 2 sprains occur when the ligament has been stretched and loosened
  • Grade 3 sprains occur when the ligament is completely torn

When the lateral collateral ligament is injured, other structures within the joint are commonly injured as well.

Treatment of an LCL Sprain

Treatment for an LCL sprain varies based on the severity of the injury, but it can normally be treated with conservative methods that may include:

  • Rest
  • Ice
  • Compression
  • Elevation
  • Knee brace

Individuals are advised to avoid any exercise or physical activity for several weeks after the injury to ensure complete healing. As the ligament heals, a physical therapy program may help to strengthen and restore function to the knee. In severe cases, when the ligament has torn completely and not healed properly, surgery may be necessary for repair.

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