Description of ACL Injuries
The anterior cruciate ligament, or ACL, is one of four major ligaments that make up the knee. Ligaments are in place to stabilize the femur (thigh bone), which sits just above the tibia (shin bone).
The ACL is critical to maintaining knee stability. ACL injuries are very common among athletes of all ages and competitive levels. Approximately 10,00,000 ACL injuries are reported each year in the World. Football, Kabbadi are one of the common sports which put athlete at high risk of ACL injury. Also it is not uncommon in our part of the world to have a ACL tear following a Vehicular accident.
Symptoms of an ACL Injury:
- Patients with an ACL tear often report instability in the knee.
- Feeling as if the knee will “give out”, or pop out of place
In addition to role in providing stability, the ACL also provides protection for the menisci of the knee. When the knee continues to have instability episodes, it is not uncommon for the medial or lateral meniscus to tear. However, with the presence of a meniscal tear there is much higher risk of developing osteoarthritis. Because of this, Dr Vadi usually recommends ACL reconstruction for an ACL tear in young or otherwise active patients, in patients who have meniscal tears, and in almost all patients who report instability with twisting or turning activities.
Treatment:
Patients having Grade 1& 2 injury of the ACL will get better with the help of rest, ice application and physiotherapy.
Patient having Grade 3 injury(Complete tear) are candidates for surgery, as they have high chance of further injuries to cartilage and meniscus if left untreated. In last 5-10 years, the method of doing ACL Reconstruction has changed dramatically. Currently, Anatomical ACL reconstruction, where graft is placed in the center of the native ACL footprint is the method of choice.
Post operative Care:
It is absolutely essential that the patient follows a well-supervised physical therapy protocol following ACL reconstruction surgery. Reactivation of the quadriceps mechanism, edema control, patella mobilization, maintenance of full knee extension and regaining knee motion are absolutely essential to obtaining optimal post-operative outcomes.
Return to Sports/Running/Cutting/Pivoting usually takes 9-10 months after the surgery, as early return to sports is associated with high chances of Re-tear of the ACL graft.
Frequently Asked Questions
When to have ACL surgery after injury?
Athletes who have any difficulty with twisting, turning, or pivoting after an ACL tear should consider having their ACL reconstructed. This is because repeated twisting and turning mechanisms can damage both the cartilage in the joint and also the menisci. The medial meniscus is the most at risk to injury with an ACL tear because the medial meniscus takes over a lot of the function of the ACL when it is torn to prevent the knee from slipping forward. In addition, patients who may have a repairable meniscus tear at the time of their ACL tear should consider surgery to prevent the tear from becoming non-reparable. In general, most people who tear their menisci will be developing arthritis and having symptoms within 8-10 years after their ACL tear. Thus, one of the main reasons for the general public to consider having an ACL reconstruction is both to repair any meniscal tears which are repairable, and also to prevent meniscal tears from developing if their knee is unstable.
What is ACL reconstruction surgery?
ACL reconstruction surgery consists of replacing a torn ACL with another ligament or tendon. This can be from one’s own body (an autograft) or from a donor (an allograft). In an ACL surgery, tunnels are reamed at the normal attachment site of the ACL on both the femur and tibia and the graft is secured either inside or outside these tunnels. The type of graft from one’s own body and whether one should use a cadaver graft tissue or not can depend on multiple factors. This can include the patient’s age, if they have hyperlaxity, where they participate in contact sports, and other factors.
How is an ACL reconstruction done?
An ACL reconstruction is done by replacing the torn ACL with tissue that is placed at the normal attachment sites of the native ACL. This involves reaming a tunnel in the femur (posterior to the lateral intercondylar ridge) and also in the tibia (adjacent to the anterior horn of the lateral meniscus) and then securing the graft within those tunnels. There are multiple ways to secure the graft, and this can include fixation within the tunnels with metal or bioabsorbable/plastic screws or through a loop and button placed on the outside of the tunnels. In general, the fixation of the grafts is performed according to the way the surgeon was originally taught, with the gold standard being screws placed within the tunnels for patellar tendon grafts and looped sutures with cortical buttons or screws within tunnels for hamstring ACL reconstruction grafts.
When should an ACL be repaired?
The main time that ACLs can be repaired is when an ACL is torn with a piece of bone, usually off the tibia, which is much more common than when torn off the femur. In this circumstance, if there is not a lot of intrasubstance stretch within the torn ACL, the bony can be refixed at its normal attachment site and secured such that early motion can be started. In those instances where the tissue is not strong enough to allow early motion, there is a much higher risk of stiffness if immobilization is required after surgery.
In terms of a repair of the ACL, there are perhaps 10% of patients who may have injury only to the attachment site on the femur or tibia and sutures can possibly be placed in to do a repair. In those circumstances, research is still ongoing to try to improve outcomes because attempts at repairs in the literature previously have not shown good outcomes over time. Thus, more research is necessary to define better techniques to perform ACL repairs in those circumstances. It is important that these techniques be based upon good science and not on marketing by device companies because previous attempts at ACL repairs did not show failures until after two years after surgery.
How long is an ACL surgery recovery?
One of the most important things for preventing a retear of an ACL reconstruction is to ensure that the patient has gone through the proper recovery phase after surgery. In the past, many surgeons tried to get their patients back to full activities by 5 or 6 months. However, more recent data has suggested that waiting up to 9 months may be more advantageous in that the rate of retear goes down significantly after the 9- month timeframe for a return to activities after ACL surgery. In general, it is important to make sure that an athlete has a full return of proprioception, strength, agility, and endurance to minimize their risk of reinjury.
When I can run after ACL surgery?
The ability to return to running after an ACL surgery is dependent upon many factors. If the surgery is only the ACL, and there are no other ligaments or meniscus tears treated, and the cartilage surfaces are intact, then one has to go through a proper rehabilitation program first. In general, we feel that an athlete has to wait a minimum of 4 months after their ACL reconstruction return to running. In addition, they should have appropriate quadriceps strength. Our main goal is to be able to have them perform a single-leg squat with no bending of the knee inwards (valgus collapse) during the single leg squat. In these circumstances, if the patient has a good return of function, good motion, and does not have a valgus collapse when performing a single-leg squat, they are generally able to initiate a return to their running program at about the 4-month timeframe. This allows the quadriceps mechanism to be strong enough to prevent extra stress on the knee which can lead to knee swelling (effusions) and possibly damage the cartilage which would not be noticed until several years later.
What causes ACL reconstruction failure?
The number one cause of ACL reconstruction failure in all of the literature is improperly placed ACL grafts at the initial surgery. This can cause extra stress on an ACL reconstruction graft which can lead to its failure. In addition, a missed other ligament problem at th time of the ACL surgery, such as an MCL or a posterolateral corner injury, can also put significant stress on an ACL reconstruction graft, which can lead to its failure. Other factors that can cause an ALC graft to fail can include the lack of the posterior horn of the medial meniscus. This is because the posterior horn of the medial meniscus is the next structure that prevents the knee from sliding forward. In patients who may not have their medial meniscus, the ACL graft generally tends to be looser than in patients who do have their medial meniscus. Thus, in some patients, this can lead to the graft being overloaded and it can cause the ACL graft stretch out over time.
Other factors that can lead to ACL reconstruction failure are patients that have soft tissue grafts, such as hamstrings grafts, that have hyperlaxity. These patients who have a significant increase of heel height (more than 4-5 cm) have a much higher risk of having these grafts stretch out versus a patellar tendon graft. Other factors include patients with a large increase in their posterior tibial slope (sagittal plane tibial slope) which can cause an ACL graft to be overloaded and stretch out over time.