The lateral collateral ligament (LCL) and medial collateral ligament (MCL) are important for avoiding rotational instability of the knee joint, as well as preventing cartilage damage. A collateral ligament injury often requires reconstruction using the patient’s own tissue or donor tissue.
What is the purpose of the collateral ligaments?
The LCL is on the outer portion of the knee, and it connects the thigh bone (femur) to the leg bone (fibula). This
ligament’s purpose is to avoid stress across the knee where it buckles outward. Along with other ligaments, the LCL forms a complex that provides external rotation stability. The MCL connects the thigh bone (femur) to the shin bone (tibia). It keeps the knee from buckling inward.
What are the symptoms of lateral collateral ligament injuries?
Injury to the LCL can lead to buckling of the knee. A direct blow on the inside of the knee can cause hyperextension stress on the LCL. This ligament often is torn along with the anterior cruciate ligament, which occurs from high-force sporting injuries. Symptoms include instability of the knee joint, mild knee pain, tenderness and swelling on the outer region of the knee, as well as weakness and/or numbness of the foot.
What are the symptoms of medial collateral ligament injuries?
With MCL injuries, you can have pain, tenderness, and swelling. Several hours after the initial injury, the pain may increase. You may also notice some bruising on the inner aspect of the knee.
How are collateral ligament injuries diagnosed?
The doctor diagnoses collateral ligament injuries based on symptoms, history of injury, physical examination, and magnetic resonance imaging (MRI) scans. X-rays can be normal, but MRI has a 90% accuracy rate for showing ligament tears. Ligament injuries are graded using a scale as follows:
- Grade 1 injuries – Mild and usually gets better within 1-3 weeks. Only requires non-surgical treatment and use of crutches for a short while.
- Grade 2 injuries – Moderate and usually gets better in 4-6 weeks. May require wearing a hinged knee brace and limited weight-bearing.
- Grade 3 injuries – Severe and require wearing a hinged brace for several months. Weight-bearing is limited for 4-6 weeks. Often requires surgery.
What is the treatment for collateral ligament injuries?
The LCL does not heal as well as the MCL. For minor tears, the doctor will recommend rest for a few weeks, use of ice to decrease swelling, elevation of the leg, and a compression bandage (ACE wrap). Physical therapy is used to restore strength and range of knee motion.
For high-grade tears, surgery is necessary. The doctor will reattach the ligament using large stitches or a suture anchor. If the ligament is torn into two pieces, the pieces can be sewed together. When a graft is used, the new structure is attached to replace the torn ligament.
How common are collateral ligament injuries?
According to statistics, the incidence of acute knee injury in the U.S. is 300 cases per 100,000 persons per year. Collateral ligament injuries make up 25% of all acute knee emergency room visits. These injuries are more common in adults aged 20 to 34 years. The NCAA reports 2 collateral injuries per 1,000 player exposures in a year.
OSPI has been the top sports medicine orthopedic doctors in the East Valley for years, with sports medicine physicians providing comprehensive operative and nonoperative care for all types of knee injuries. Call us today!
National Collegiate Athletic Association. NCAA Injury Surveillance System. 1999-2000.
Yawn BP, Amadio P, Harmsen WS, et al. Isolated acute knee injuries in the general population. J Trauma. 2000 Apr. 48(4):716-23.