ACL

What is the anterior cruciate ligament (ACL)?

Your thighbone, shinbone, and kneecap meet to form your knee joint. The kneecap (patella) is the small bone that rests at the front of your knee and provides some shielding for the joint.

Bones in your knee joint are connected to the other bones by four primary ligaments which hold the bones in place. The collateral ligaments are found on the sides of your knee.

Your knee also contains an anterior cruciate ligament (ACL) and a posterior cruciate ligament (PCL), which are located within the joint. They form an X across your knee with the anterior cruciate in front and the posterior in the back.

The ACL keeps your shinbone from sliding out in front of your thighbone whenever you stand, walk, run, or bend your knee.

What causes an ACL injury?

Professional or recreational athletes participating in sports, such as basketball, soccer, and football, are at a higher risk of damaging their ACL. However, any activity that stresses or strains your ACL can cause an injury. This includes:

• Changing direction rapidly
• Stopping suddenly
• Slowing down while running
• Landing from a jump incorrectly
• Trauma sustained during a fall or other accident

What are the symptoms of an ACL injury?

Many patients report a popping noise in their knee at the time of the injury. You may also feel your knee give way. Other symptoms typically include:

• Pain with swelling that may resolve on its own after rest
• Instability in your knee when you attempt to a return to sports without treatment, which can damage other structures in your knee, including your cartilage
• Loss of full range of motion of the affected knee
• Knee discomfort while walking

What is the treatment for an ACL injury?

If the damage to your ACL is mild, typically described as a grade 1 sprain, treatment may involve rest and guided physical therapy. Dr. Cunningham also specializes in regenerative sports medicine and may recommend therapy with orthobiologics, such as Platelet Rich Plasma (PRP) injections, or Cell-Based (formerly "Stem Cell") therapy to help speed healing.

Moderate to severe ACL injuries typically produce a tear that severs the ligament. This type of injury requires surgery using a tissue graft to reconstruct the ACL. Dr. Cunningham may also recommend the use of orthobiologics at the time of surgery to help with the healing process.