Anatomy of the ACL

The anterior cruciate ligament (ACL) is a critical stabilizing structure in the knee joint. It prevents excessive forward movement of the tibia (shinbone) relative to the femur (thighbone) and provides rotational stability. The ACL is one of the four primary ligaments in the knee.

Structure and Function of the ACL

• Location: The ACL runs diagonally from the front of the tibia to the back of the femur inside the knee joint.
• Role: It prevents the tibia from sliding forward relative to the femur and provides stability during movement.
• Protection: The ACL helps protect the knee’s menisci (cartilage pads) from excessive stress and damage.

Common Causes of ACL Injuries

ACL injuries are common in athletes, especially those involved in sports that require quick direction changes, jumping, or pivoting.

• Direct Impact: A strong force or blow to the knee (e.g., during a tackle or fall).
• Twisting or Pivoting: Sudden changes in direction or awkward landings can put excessive strain on the ACL.
• Overstretching: The ACL can tear if it is stretched beyond its normal range of motion.

Studies indicate that around 200,000 ACL injuries occur in the United States every year, ranging from mild sprains to complete tears that require surgery.

Symptoms of an ACL Injury

• Pain: Ranging from mild discomfort to severe pain.
• Swelling: Rapid swelling, often occurring within a few hours of injury.
• Limited Range of Motion: Difficulty fully bending or straightening the knee.
• Instability: A feeling that the knee "gives out" during movement.

A partial ACL tear may cause mild instability, while a complete tear often leads to severe pain, swelling, and loss of function.

Diagnosing an ACL Tear

If an ACL injury is suspected, Dr. Khaleel, Senior Consultant Arthroscopic Knee and Sports Surgeon at Kims Alshifa, Perintalmanna, Kerala, India, will perform a thorough evaluation, including:

• Physical Examination: Tests such as the Lachman Test, Pivot Shift Test, and Anterior Drawer Test assess knee stability.
• Imaging Tests: X-rays and MRI scans confirm ACL damage and check for additional injuries (e.g., meniscus tears).

Early diagnosis is essential to determine the best treatment approach and ensure a smooth recovery.