The knee is the largest joint in the body and – unfortunately – it’s also one of the easiest joints to injure. In particular, the ligaments in the knee are prone to sprains and tears in athletes and other active individuals. While strength training and conditioning can help support the knee and protect the ligaments from injury, some ligament injuries are unavoidable.
What is the lateral collateral ligament (LCL)?
Many people are familiar with anterior cruciate ligament (ACL) injuries and tears, as the ACL is the most commonly injured ligament in the knee. LCL sprains and tears, however, are much less common knee injuries.
The knee is a complex joint made up of bones, cartilage, tendons and ligaments. Three bones come together to form the knee joint – the femur (thighbone), tibia (shinbone) and patella (kneecap) – and ligaments act as anchors, holding these bones together to keep the knee stable.
There are four main ligaments in the knee that work together to control the back and forth and side-to-side motion of the knee. These ligaments are called cruciate ligaments and collateral ligaments.
The knee’s cruciate ligaments – the ACL and the posterior cruciate ligament (PCL) – cross each other inside the knee, creating an “X” shape of interior support. These ligaments control the back and forth motion of the knee and commonly are injured together.
The knee’s collateral ligaments – the LCL and the medial collateral ligament (MCL) – are located on either side of the knee and control the sideways motion of the joint, protecting it from unusual movement side-to-side. The MCL runs along the inside of the knee and the LCL runs along the outside of the knee.
Types of LCL Injuries: LCL Sprains and LCL Tears
All ligament injuries fall into three categories: Grade 1 Sprains, Grade 2 Sprains and Grade 3 Sprains. While many people are used to hearing distinctions between ligament sprains and tears, technically all ligament injuries are varying severity of sprains.
Grade 1 LCL Sprain
In a Grade 1 Sprain, the ligament has been stretched and mildly injured but is still able to help keep the knee stable and functional.
Grade 2 LCL Sprain
Often called a partial LCL tear, Grade 2 Sprain occurs when the ligament is stretched or stressed enough to become loose.
Grade 3 LCL Sprain
A Grade 3 Sprain is a complete LCL tear. This means the ligament is torn into two separate pieces and the joint is no longer stable.
Common LCL Injury Causes
The knee’s ligaments and surrounding muscles are what keep the joint stable. Because the knee joint is vulnerable to direct impacts and hard muscle contraction – caused by quick cuts or changing direction suddenly while running – knee ligament injuries are common in athletes. And while the MCL is more commonly injured than the LCL, LCL sprains and tears typically result in other knee injures thanks to the complex nature of the outside of the knee joint.
The root cause of LCL injuries is inward stress on the knee, which can cause the LCL ligament on the outside of the knee to stretch, sprain or tear. This inward stress can be caused by traumatic contact or force, jumping, twisting, and quick changes of direction, or from lateral movements that subject the knee to unnatural motion. Football players, soccer players, basketball players and skiers are all prone to LCL injuries.
LCL Injury Symptoms
LCL sprains and LCL tears have similar symptoms that can vary in severity depending on the grade of injury. Symptoms include:
- LCL pain that is mild or acute
- Swelling, tenderness or bruising on the outside of the knee
- A locking or catching in the joint when moved
- Joint stiffness
- A feeling that the knee is unstable or may give out under weight
Diagnosis, Treatment and Recovery
Most LCL injuries can be diagnosed with a physical exam by an orthopedic specialist, though MRIs and X-rays can help determine if there is definite ligament damage or broken bones affecting the LCL, respectively.
Surgery on collateral ligaments – LCL and MCL – is not as common as surgeries for ACL and PCL injuries. However, LCL injuries tend to involve other structures in the knee that may require additional treatment. If treated correctly, most LCL sprains will heal
The three main nonsurgical treatments for LCL injuries are ice, bracing and physical therapy. Immediately after injury, ice applied to the injured area for 15 to 20 minutes at a time every hour can help reduce swelling and inflammation of the joint. Bracing the knee to protect the ligament from further sideways movements can also help speed the healing process.
Finally, your orthopedic knee specialist may prescribe physical therapy to strengthen the muscles around the knee. A good physical therapist will teach you specific exercises to help restore function while improving strength and stability.
If you are suffering from LCL pain or believe you have a ligament injury, please feel free to contact us with any questions or concerns and one of our orthopedic surgeons will do what they can to help.