Overview of MCL Injuries

The medial collateral ligament (MCL) is a crucial ligament located on the knee joint’s inner side. MCL injuries are common and can range from mild sprains to complete tears. They often occur due to sudden impacts or twisting motions that put excessive stress on the ligament. MCL injuries also often occur at the same time as an anterior cruciate ligament (ACL) injury.

Anatomy of the Knee

The knee is made up of three bones: the femur (thighbone), the tibia (shinbone), and the patella (kneecap). The kneecap sits in front of the joint to provide some protection.

Bones are connected to other bones by ligaments. Ligaments are tough bands of connective tissue that act like strong ropes to hold the bones together and stabilise your knee joint.

There are four major ligaments in the knee. Two cruciate ligaments: the anterior and posterior cruciate ligaments and the lateral and medial collateral ligaments.

The cruciate ligaments 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 front and back motion of your knee.

The two Collateral ligaments are found on the sides of your knee. They control the side-to-side motion of your knee and brace it against unusual movement.

• The medial collateral ligament (MCL) connects the femur (thigh bone) to the tibia (shin bone) on the inner side of the knee. It provides stability to the joint and helps prevent excessive sideways movement.
• The lateral collateral ligament (LCL) is on the outside. It connects the femur to the fibula (the smaller bone in the lower leg).

Causes of MCL Injuries

The knee joint relies on the ligaments and surrounding muscles for stability. Any direct contact to the knee or excessive force from a sudden trip or fast change of direction while running can injure a knee ligament.

The MCL is injured more often than the LCL. MCL injuries can result from various causes:

• Direct Impact: A blow to the outer side of the knee can cause the inner side of the joint to open, straining or tearing the MCL.
• Twisting Movements: Rapid pivoting or twisting motions can stress the MCL beyond its normal range of motion. This could be from a quick change of direction or a trip or fall.

Athletes in contact sports, like football or rugby, are particularly prone to MCL injuries. MCL injuries are also very common in skiers.

Symptoms of MCL Injuries

Symptoms of an MCL injury can include:

• Pain: Pain on the inner side of the knee, which may range from mild discomfort to severe pain.
• Swelling: Swelling around the affected area, typically within the first few hours after the injury.
• Instability: A feeling of the knee “giving way” or buckling, especially during weight-bearing activities.

Diagnosis of MCL Injuries

Your consultant will first take a full subjective history of your injury and ask you a series of questions about your pain and symptoms. They will want to know about any medication you are taking and your medical history and injuries.

This information will allow them to hypothesise about your injury, and they will then carry out a thorough physical assessment to confirm their diagnosis.

Physical Examination

Your Physical Assessment will involve your consultant assessing your pain, tenderness, and knee joint stability. They will look at any swelling or bruising and test your muscles, balance and mobility. Depending on the severity of your symptoms, you may also be asked to perform a few simple exercises such as squats, step-ups, or jumps.

Imaging Tests

X-rays do not show soft tissue but sometimes x-rays are required to rule out fractures. MRI scans are the gold standard of imaging tests as they provide an in depth 3D picture of ligament damage.

Ligament injuries are graded on a severity scale 1-3.

• Grade 1: The ligament is mildly damaged in a Grade 1 sprain. It has been slightly stretched but is still able to help keep the knee joint stable.
• Grade 2: A Grade 2 sprain 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 torn in half or pulled directly off the bone, and the knee joint is unstable.

Treatment Options for an MCL Injury

Treatment of a partial tear or stretch injury is almost always conservative. Treatment for MCL injuries depends on the severity of the injury; most injuries that are partial and isolated can be treated without surgery.

Conservative Management

• RICE Protocol: Rest, ice, compression, and elevation in the initial stages to reduce pain and swelling.
• Bracing: Using knee braces or supports to stabilise the joint and prevent excessive movement during the healing process.
• Physiotherapy: Rehabilitation exercises to improve knee strength, stability, and range of motion.
• Anti-Inflammatory Medications: Nonsteroidal anti-inflammatory drugs (NSAIDs) to manage pain and reduce inflammation.

Surgical Options

Surgery is rarely necessary for MCL injuries, and it’s typically reserved for severe cases:

• MCL Reconstruction: Surgical repair or reconstruction of the MCL using sutures or grafts.

Questions & Answers

Can MCL injuries heal on their own without surgery?
Yes, many MCL injuries, especially mild to moderate sprains, can heal with appropriate rest, rehabilitation, and support.

Can I continue playing sports with an MCL injury?
Depending on the severity of the injury, your healthcare provider will guide you on whether it’s safe to continue sports activities or if you should rest and undergo rehabilitation.

How long does it take to recover from an MCL injury?
Recovery time varies based on the severity of the injury. Mild sprains may take a few weeks, while more severe tears may require several months.

Can MCL injuries lead to chronic knee instability?
Proper treatment and rehabilitation usually lead to good outcomes. However, inadequate healing or untreated injuries can potentially contribute to chronic instability.

Can MCL injuries be prevented?
While accidents are not always preventable, proper warm-up, using protective gear, and practising safe movement techniques can reduce the risk of MCL injuries, especially in sports.