ACL injury

The anterior cruciate ligament in the knee is one of the ligaments responsible for the knee's stability, meaning it prevents the knee from moving where it shouldn't.

In fact, it is the most important primary stabilizer. The anterior cruciate ligament prevents the tibia, or the lower bone, from moving excessively forward and from subluxating, which protects the cartilage and menisci from damage. When this anterior cruciate ligament ruptures, stability is lost, and the knee can begin to deteriorate.

Types of Injuries

There are different types of injuries: there are partial tears, minor sprains, and complete tears.

If it is a partial injury, just a tear but still functional, it can be given a chance with some physical therapy. The idea is for it to continue functioning. However, in the case of a complete partial injury where the cruciate ligament is non-functional, replacing it is recommended.

ACL Surgery

The surgery consists of an arthroscopy to clean out the remnants of the old anterior cruciate ligament. A new graft is passed through, which in this case is made from tendons that, over time and with certain stimuli, will transform into a ligament. This is done through two tunnels: one tunnel in the femur where we pass the graft, and another tunnel in the tibia where it will be anchored. We then perform certain tests to ensure it is stable.

Graft Types

It also depends on the patient, as there are many types.

There is one called a bone-tendon-bone graft, which is taken from the patient's patella or kneecap. There is another called a hamstring graft, which is taken from the inner part of the knee. There is one from the quadriceps, from the upper part of the knee, among others.

It can be taken from the patient themselves (autograft), or a graft from a donor, called a cadaveric graft (allograft), can be used.

Choosing one over the other has its pros and cons. The one that integrates best is the patient's own because it carries the person's cells and integrates faster. The problem is that it can be somewhat painful at the harvest site. The other (cadaveric) doesn't cause harvest site pain, but it is more expensive and takes a bit longer to integrate.

Depending on the person, some may be more interested in or benefit more from their own graft, while others will do better or feel more comfortable with a cadaveric graft. But that depends on each individual.

Sometimes, depending on the size of the patient's own graft, they may not have the ideal volume we normally look for, which is above eight millimeters in thickness for the ligament to function well. If it is sometimes too thin or weak, we make a hybrid or a combination of the two (autograft and allograft) to achieve this size, because in the end, what will matter here is the size.

Pre-Surgery Considerations

There are other things in the knee that can influence the progression of your recovery. If there is a meniscus injury, the type of meniscus injury, if there is another injury in any of the other ligaments, or if your knee, for example, is misaligned or very angled, can be a determining factor for your anterior cruciate ligament to fail.

If there was a previous ACL injury and you had surgery, and this is a revision surgery, we must consider whether it will be done in one stage or two stages, if a bone graft needs to be added, among many other things. It's not just about replacing the ligament in the best-case scenario; well, that will be your case, but if not, the patient has to be highly individualized so that the new cruciate ligament can function and last without the need for a revision.

If you have more questions about this topic, which is quite extensive, you can send a message to schedule an appointment, or you can leave a little message or comment below. It reaches us by email, and we will respond as soon as possible.