LCL Tear

The lateral collateral ligament (LCL) is one of four primary ligaments that stabilize the knee joint. It is located on the outer (lateral) side of the knee and connects the femur (thigh bone) to the fibula (smaller bone of the lower leg). The primary function of the LCL is to prevent excessive side-to-side movement of the knee, particularly forces that push the knee inward while forcing the lower leg outward.

Unlike the medial collateral ligament (MCL), which is on the inner side of the knee and frequently injured, LCL injuries are less common but often more complex due to their association with other ligamentous and structural damage in the knee.

An LCL tear occurs when the ligament is overstretched or completely ruptured due to excessive force. LCL injuries range from mild sprains to complete ligament tears, often depending on the intensity of the force applied to the lateral knee.

LCL injuries are classified into three grades based on severity:

• Grade I (Mild): The ligament is stretched but not torn, leading to minimal instability.
• Grade II (Moderate): There is a partial tear, causing noticeable instability and pain.
• Grade III (Severe): The ligament is completely torn, often resulting in significant knee instability and requiring surgical intervention.

LCL tears typically occur due to trauma, direct impact, or excessive stress on the outer knee. Common causes include:

• Direct blow to the inner knee: Contact sports such as football, soccer, and basketball frequently involve collisions or tackles that push the knee outward, placing excessive strain on the LCL.
• Sudden changes in direction: Sports that involve cutting, pivoting, or rapid lateral movements, such as tennis or skiing, can put excessive strain on the LCL.
• Hyperextension of the knee: Overextending the knee beyond its normal range can stretch or rupture the LCL, particularly in activities like gymnastics or martial arts.
• Falls or missteps: Landing awkwardly from a jump or stepping into an uneven surface can create lateral instability, resulting in an LCL injury.
• Knee dislocations or multi-Ligament injuries: The LCL is frequently injured alongside other ligaments, such as the posterolateral corner structures, ACL, or PCL, making these cases more complex.

Symptoms of an LCL tear vary depending on the severity of the injury but often include:

• Pain on the outer knee: Localized pain along the outer side of the knee, which may worsen with movement or weight-bearing.
• Swelling and bruising: Inflammation can develop within hours of injury, leading to visible swelling and bruising around the lateral knee.
• Instability or giving way: Patients with moderate to severe LCL tears often experience knee instability, particularly when pivoting or walking on uneven surfaces.
• Stiffness and limited range of motion: The knee may feel stiff, making it difficult to fully extend or bend.
• Tenderness along the LCL: Palpation along the outer knee can elicit pain and tenderness.
• Locking or popping sensation: Some individuals report a popping sound at the time of injury, followed by difficulty moving the knee normally.

Dr. Gazzaniga and his team at the Newport Orthopedic Institute utilize a comprehensive clinical evaluation and imaging studies to accurately diagnose LCL tears. Dr. Gazzaniga will perform a thorough a physical clinical assessment including:

Physical exams

• Varus Stress Test: The knee is gently pushed outward while stabilizing the thigh to evaluate lateral stability. Increased laxity suggests an LCL injury.
• Palpation of the lateral knee: Tenderness or swelling along the ligament can indicate damage.
• Assessment of knee stability: Evaluating the knee’s response to movement and weight-bearing can help identify ligamentous insufficiency.

Image studies

To confirm the diagnosis and assess associated injuries, imaging tests may be ordered:

• X-rays: While X-rays cannot visualize ligaments, they help rule out fractures or bone avulsions that may accompany LCL injuries.
• MRI: The most definitive imaging tool for assessing soft tissue injuries, an MRI provides a detailed view of the LCL, allowing for accurate grading of the tear and identification of concurrent ligament or meniscus injuries.
• Ultrasound: Occasionally used to assess ligament integrity in real time, particularly in dynamic conditions.