The lateral collateral ligament is one of the four main ligaments that stabilize the knee. The collateral ligaments allow us to move our knee sideways within normal range. The lateral collateral ligament is located on the outside of the knee and connects the thighbone with the lower leg bone called the fibula. It restrains the knee from excessive bending outward. An isolated tear of the lateral collateral ligament is a relatively rare injury, accounting for only 2-8% of all knee ligament injuries. However, a lateral collateral ligament tear is rarely injured in isolation. It usually occurs along with a tear of the ACL or another knee ligament. Note that the lateral collateral ligament is also called the fibular collateral ligament (FCL).
Most lateral collateral ligament (LCL) tears occur as a result of a direct blow to the inside of the knee from such as sports as football, soccer and skiing. The force of the impact can cause the ligament to stretch or tear on the outside of the knee. In some cases, the ligament may be completely torn in two. The lateral collateral ligament can also tear as a part of a larger injury in which other ligaments from the knee are also torn – this is known as a multi-ligamentous knee injury which can be a very severe injury. Adjacent to the LCL are other smaller structures that work in conjunction to provide stability; together this complex is often known as the posterolateral corner (PLC).
Lateral collateral ligament tears can occur in high contact sports and sports that require high velocity pivoting and jumping like soccer and football.
- Pain and swelling on the outside of the knee
- Bruising and tenderness
- Difficulty walking or bearing weight on the affected leg
- Knee instability, particularly when trying to pivot or turn
- Feeling like the knee is “giving out”
Lateral collateral ligament tears are graded just like MCL tears.
- Grade 1: A mild ligament strain with small tears but no instability
- Grade 2: Partial tear with looseness, pain, tenderness and swelling on the inner side of the knee
- Grade 3: Complete tear is usually associated with other related injuries
Lateral collateral ligament tears are a challenge to diagnose. Left untreated they can lead to instability especially when they are part of multi-ligament knee injuries. Dr. Patel will review your medical history including when and how you injured your knee, and your symptoms. He will perform an orthopaedic exam testing your range of motion and other special stress tests and will order stress x-rays to view the bones dynamically and an MRI to evaluate soft tissues.
Treatment options depend on the grade of the injury and whether there are associated injuries. Grades 1 & 2 lateral collateral ligament tears often heal with 4-12 weeks of conservative management including crutches for the first few weeks, a hinged knee brace, anti-inflammatory medications, icing and physical therapy.
Treatment for Grade 3 injuries where the ligament is torn off the bone will require ligament reconstruction vs repair, particularly when the lateral collateral ligament is injured along with other knee ligaments. Studies show that repairs are indicated in only very specific indications; otherwise, reconstruction is the surgery of choice. Ligament reconstruction of the lateral collateral ligament is an open surgical procedure under general anesthesia. The torn ligament is removed and replaced with a tissue graft.
It can take up to eight weeks to recovery completely after conservative management. Recovery from ligament reconstruction can take four to six months or more depending on the number of ligaments reconstructed. Return to play depends on the severity of the injury and associated injuries.
Dr. Ronak M. Patel is a double board-certified orthopaedic surgeon and sports medicine physician trained at Northwestern University and received a fellowship at the Cleveland Clinic. He specializes in the treatment of complex knee, shoulder and elbow injuries and degenerative conditions. Contact him to schedule a consultation to learn more about how he can help you return to the life you love and the activities that make life worth living. He serves teens and adults in Chicagoland and NW Indiana.
At a Glance
Ronak M. Patel M.D.
- Double Board-Certified, Fellowship-Trained Orthopaedic Surgeon
- Past Team Physician to the Cavaliers (NBA), Browns (NFL) and Guardians (MLB)
- Published over 49 publications and 10 book chapters
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