ACL Tears

The anterior cruciate ligament (ACL) is a strong, fibrous band of tissue that connects the femur (thigh bone) to the tibia (shin bone) in the knee joint. It is one of the four major ligaments in the knee joint and plays a critical role in maintaining stability and preventing excessive knee joint movement.

The ACL helps to control forward movement and rotation of the tibia in relation to the femur, which is important for maintaining normal function of the knee joint during physical activities such as walking, running, and jumping. When the ACL is torn, it can lead to pain, instability, and decreased knee joint mobility. The ACL also protects the meniscus against developing tears. The meniscus helps protect the knee cartilage from breaking down.  If cartilage breaks down, that can lead to the development of early arthritis and pain.

Anterior Cruciate Ligament (ACL) tears are a common injury. You can think of the ACL as a rope connecting the femur (thigh bone) and tibia (shin bone). When this rope snaps, you lose one of the important connections holding the bones together. This injury can be painful and debilitating and can significantly impact an individual’s ability to engage in physical activities such as sports or exercise due to knee instability.

• Sports-related injuries: ACL tears involving contact and non-contact injuries are common in sports. Sudden stops and changes in direction common in sports like basketball, soccer, gymnastics, skiing, and football can lead to a non-contact ACL injury. Non-contact ACL tears represent over half of all ACL injuries sustained in team ball sports.
• Trauma: ACL tears can also occur due to trauma, such as a fall or a motor vehicle accident.
• Sport-specific technique: Certain sport-specific techniques can increase the risk of an ACL tear, such as landing incorrectly from a jump or pivoting on a locked knee.
• Genetics: Some people may be more predisposed due to many factors, including tissue laxity. Native knee anatomy (leg alignment, tibial slope) can also factor in.
• Gender: Females are at higher risk of an ACL tear than males due to differences in anatomy, hormones, and biomechanics. Women are particularly at risk in their teens and again in their 40s.

The symptoms of an ACL tear can vary depending on the severity of the injury, but may include:

• Pain in the knee joint, especially when bearing weight or during physical activity
• Swelling and stiffness in the knee, which may develop within hours of the injury
• A popping or snapping sound at the time of injury
• Instability or a feeling of the knee “giving out.”
• Limited range of motion in the knee joint
• Difficulty walking or standing
• Tenderness along the joint line

To diagnose an ACL tear, knee surgeon Dr. Daniel Kaplan will start by asking you questions about your symptoms and how you were injured.  He will then physically examine your knee, which may involve testing your range of motion, stability, and strength. Dr. Kaplan may also perform specific tests to assess the integrity of the ACL, such as the Lachman or Pivot shift tests.

Imaging tests, such as X-rays or an MRI (magnetic resonance imaging) scan, may also be ordered to confirm the diagnosis and evaluate the severity of the injury. An MRI can provide detailed images of the soft tissues in the knee joint, including the ligaments, meniscus, and cartilage, and can help determine whether the ACL is partially or completely torn, along with any other associated injuries.

When you or a loved one experiences pain and swelling in the knee, it is important to consider an ACL injury and contact Dr. Kaplan for his opinion to ensure you receive the correct diagnosis, are treated appropriately, and prevent further damage.