Basic ACL Injury Info

The ACL, or anterior cruciate ligament, is a key ligament in the center of the knee that connects the thighbone (femur) to the shinbone (tibia) and helps stabilize the joint by preventing the tibia from sliding forward.

Function

• Provides stability: The ACL keeps the thighbone and shinbone aligned and prevents the knee from giving out during pivoting, twisting, and jumping motions.
• Controls movement: It limits the forward movement of the tibia relative to the femur, acting as a crucial restraint for knee joint stability.
• Works with other ligaments: It forms an "x" with the posterior cruciate ligament (PCL), which prevents the shinbone from moving backward. 

An ACL injury is a sprain or tear of this ligament, most often occurring during sports that involve sudden stops, changes in direction, and jumping. Tears can be partial or complete. A partial tear involves stretching the ligament, while a complete tear is a full rupture and is the most common and severe type. Since the ACL receives little blood supply, a complete tear cannot heal on its own. 

• Sudden changes in direction (cutting): Planting your foot and quickly pivoting.
• Awkward landings: Landing incorrectly from a jump.
• Sudden stops: Decelerating rapidly while running.
• Direct impact: Receiving a direct blow to the knee, such as in a football tackle.
• Hyperextension: Over-straightening the knee joint.
• Gender: Female athletes have a higher risk of ACL injuries due to differences in anatomy, muscle strength, and neuromuscular control

A person who injures their ACL may experience the following symptoms: 

• A loud "pop" or "popping" sensation in the knee at the time of injury.
• Severe pain that prevents you from continuing the activity.
• Rapid swelling, which typically occurs within the first few hours.
• A feeling that the knee is unstable or "giving way".
• Loss of the full range of motion in the knee.
• Inability to bear weight on the leg.

The appropriate treatment for an ACL injury depends on its severity and the patient's activity level. Nonsurgical treatmentMinor sprains and partial tears may be treated without surgery, especially for individuals with low activity levels. Treatment includes: 

• RICE therapy: Rest, ice, compression, and elevation.
• Pain medication: Over-the-counter anti-inflammatory drugs.
• Physical therapy: Exercises to reduce swelling, restore range of motion, and strengthen the muscles around the knee.
• Bracing: Using a brace to stabilize the knee. 

Surgical treatmentSurgery is often recommended for athletes or active people with a complete ACL tear to restore knee stability and allow them to return to demanding physical activities. 

• Procedure: During ACL reconstruction, the damaged ligament is replaced with a graft, which is a piece of tendon taken from another part of your knee or a donor.
• Recovery: Following surgery, a lengthy and rigorous rehabilitation program, which can take six months to over a year, is necessary to regain full strength and function.