Anterior Cruciate Ligament (ACL) Surgery

What is anterior cruciate ligament (ACL) surgery?

ACL surgery is the surgical reconstruction or replacement of the anterior cruciate ligament (ACL) in your knee. Your thigh bone (femur), shin bone (tibia), and patella (kneecap) meet to form your knee joint. Ligaments connect these bones to each other. Your ACL is one type of knee ligament. It is a band of tough, fibrous connective tissue that stabilizes your knee. Injuries requiring reconstruction or replacement of the ACL are common, especially among athletes. ACL surgery can help restore pain-free range of motion, stability, and function to a knee joint after ACL injury.

ACL surgery is a common but major surgery with significant risks and potential complications. You may have less invasive treatment options depending on your specific circumstances. You should consider a second opinion about all of your treatment choices before having ACL surgery.

Types of ACL surgery

Injured or torn ACLs do not heal well by sewing the ligament back together. Instead, ACL surgery uses a connective tissue graft to reconstruct or replace your injured ACL. Both ligaments and tendons are connective tissues. Your body heals around the graft over several months.

The types of ACL surgery procedures include:

• Allograft reconstruction. An allograft is a piece of cadaver connective tissue, usually a tendon. Allografts come from a tissue bank. Allograft reconstructions require only one incision and cause less pain than an autograft fusion. However, there is a small risk of acquiring serious infections through allograft reconstructions. These infections include HIV and hepatitis.
• Autograft reconstruction. An autograft is a piece of your own connective tissue. Your doctor will usually take an autograft from a piece of your patellar (kneecap) tendon. This is the gold standard for ACL autograft reconstruction. Your patellar tendon will heal itself and re-grow the missing portion over time. Other autograft sites are your hamstring tendon and your quadriceps tendon. However, these sites do not heal as reliably as your patellar tendon. An autograft requires an additional large incision, lengthens surgery time, and causes more post-operative pain.
• Synthetic or artificial graft reconstruction. Artificial ligament graft materials have been studied in experimental trials. However, they have not performed as well as human tissue grafts. At this point, synthetic grafts are still experimental.
• Xenograft reconstruction. A xenograft is a piece of connective tissue taken from non-human animal sources. Currently, medical scientists are conducting human trials of xenograft reconstructions.

Other procedures that may be performed

In addition to ACL surgery, your doctor may also recommend one or more other procedures. These procedures include:

• Meniscectomy is the surgical repair or trimming of a torn meniscus. Your knee contains two menisci. They are made of cartilage, and function as shock absorbers for your knee joint.
• Other ligament reconstructions. Your knee contains four ligaments including your ACL. Depending on your injury, the other three knee ligaments may also need reconstruction.
• Patellar realignment is the surgical repositioning of your kneecap.
• Synovectomy is the surgical removal of part of an inflamed synovial membrane. Synovial membranes are tissues that line joints, including your knee.

Why is anterior cruciate ligament (ACL) surgery performed?

ACL surgery is a major surgical procedure that your doctor may recommend to treat a torn anterior cruciate ligament (ACL) in your knee. Your doctor may only consider ACL surgery for you if it suits your needs and lifestyle. Choosing to not reconstruct a torn ACL may cause more tissue damage and early arthritis. However, this may be a good option for elderly people with a low activity level. Talk with your doctor about all of your treatment options and consider getting a second opinion.