Anatomy

Cruciate Ligaments: These are found inside your knee joint. They cross each other to form an “X” with the anterior cruciate ligament in front and the posterior cruciate ligament in back. The cruciate ligaments control the back and forth motion of your knee.
Collateral Ligaments: These are found on the sides of your knee. The medial or “inside” collateral ligament (MCL) connects the femur to the tibia. The lateral or “outside” collateral ligament (LCL) connects the femur to the smaller bone in the lower leg (fibula). The collateral ligaments control the sideways motion of your knee and brace it against unusual movement.

The MCL is injured more often than the LCL. Due to the more complex anatomy of the outside of the knee, if you injure your LCL, you usually injure other structures in the joint, as well.

Causes
  • Injuries to the collateral ligaments are usually caused by a force that pushes the knee sideways.
  • Medial collateral ligament tears often occur as a result of a direct blow to the outside of the knee. This pushes the knee inwards (toward the other knee).
  • Blows to the inside of the knee that push the knee outwards may injure the lateral collateral ligament.
Symptoms
  • Pain at the sides of your knee
    • MCL – pain on inside portion of your knee
    • LCL – Pain on outside portion of knee
  • Swelling over the site of injury
  • Instability – feeling like your knee is giving way

There are several grades of sprains for all ligaments. They are:

  • Grade 1. The ligament is mildly damaged. It has been slightly stretched, but is still able to help keep the knee joint stable.
  • Grade 2. Stretches the ligament to the point where it becomes loose. This is often referred to as a partial tear of the ligament.
  • Grade 3. This type of sprain is most commonly referred to as a complete tear of the ligament. The ligament has been split into two pieces, and the knee joint has lost stability.
Treatment
  • Rest. Avoiding movements that exacerbate your pain.
  • Ice: Ice can be applied to reduce pain and swelling. Apply for 20 minutes at a time, several times a day, to keep swelling down. Do not apply directly to the skin.
  • Bracing
    • ACL knee stabilizing brace
  • Physiotherapy
    • As swelling goes down, a careful rehabilitation program is started. This will add stability to the knee and strengthen the remaining muscles and ligaments
    • Strengthening exercises of quadricep and hamstring
  • Medications
    • Nonsteroidal anti-inflammatory medicines. Drugs like ibuprofen and naproxen reduce pain and swelling. Like any over the counter medication, please read and follow the label. If you have a history of stomach ulcers, bleeding ulcers or heart conditions, these medications might not be right for you. Consult your physician if you have any questions.
    • Topical anti-inflammatories
      • Compound Topical Creams
      • Voltaren
  • Injections
    • Blood (PRP – Platelet Rich Plasma)

Most isolated collateral ligament injuries can be successfully treated without surgery. If the collateral ligament is torn in such a way that it cannot heal or is associated with other ligament injuries, your doctor may suggest surgery to repair it.