Anterior cruciate ligament (ACL) reconstruction
KNEE ANATOMY
The knee has four main ligaments. The anterior cruciate ligament (ACL) is one of these four main ligaments within the knee joint, and it connects the femur to the tibia. This ligament is crucial for providing stability to the knee and for preventing the tibia from sliding out in front of the femur, besides restraining tibial rotation.
By avoiding these movements, the level of stress on the knee joint is reduced, especially in physical activities such as jumping, landing, pivoting movements and rapid decelerations.
ACL INJURY
ACL tears are common knee injuries, mostly as a result of turning on the knee, stopping suddenly, quickly changing directions or landing on one foot after a jump. ACL injuries are frequently seen in sports that involve pivoting and jumping, such as basketball, football, and contact sports like rugby. Sometimes you will hear a popping sound at the time of injury, and subsequent instability of the knee.
Sometimes an injury to the anterior cruciate ligament occurs along with damage to other structures, such as meniscus or other ligaments.
Some individuals may feel few symptoms with a ACL injury, and it will hardly interfere with their daily activities. These patients would be benefited from a physical therapy program to help them regain knee strength and stability.
For other patients, pain and instability on the knee will definitely interfere with their everyday life and in sporting. This kind of patients would benefit from ACL reconstruction to relieve the symptoms. Surgery must be decided based on the patient’s age, physical activity, instability level and other injuries related to the knee.
HOW TO DIAGNOSE ACL TEAR
There are many ways to diagnose ACL tear. First, patient will seek to see a doctor due to knee instability -inability to trust the knee for support, and/or pain. With these symptoms, your doctor will be able to check knee instability and displacement through physical examination.
Imaging tests such as a Magnetic resonance imaging (MRI) scan may help to confirm your diagnosis.
Additionally, X-rays can show whether the injury is associated with a broken or injured bone in your knee.
ACL RECONSTRUCTION
ACL cannot heal on its own, that is why surgical treatment is the best option.
The torn ACL is generally replaced by a substitute graft made of tendons from the same knee, becoming a new ligament. Grafts taken from a cadaver may also be used. The graft will be placed in bone tunnels which are drilled into the tibia and the femur. The graft is then fixed in the tibia and femur using screws or other fixation devices.
Although there are variations on this surgical ACL reconstruction technique, the current consensus is that two tunnels should be drilled into the femur and the tibia to accurately reproduce ACL anatomy. Anyway, this two-tunnel technique has its own indications.
Graft integration within the bone tunnel will increase over time, as with the original ligament.
Other injuries associated with ACL injury may be repaired during that same surgical intervention.
This surgery is performed as an arthroscopically assisted procedure, and will take around two hours. This means that the surgical instruments will be inserted through smalls incisions, as well as a small camera to visualize the inside of the knee.
Arthroscopic surgery has many advantages over open surgery, such as faster recovery as it is is less invasive, there is less scarring and less risk of bleeding or infection.
RISKS OF ACL RECONSTRUCTION
As with all types of surgery, there are some risks associated with ACL reconstruction. They include: pain, stiffness, poor healing, infection and nerve injury. In the majority of cases, these complications are not permanent and should resolve over time, or are reversible with appropriate treatment. Your surgeons will make every effort to minimize these risks.
RECOVERY AND OUTCOME
Recovery after ACL reconstruction takes months of hard work to rehabilitate the leg in order to achieve a full range of motion and adequate strength for a high level of physical activity. It takes 6 to 12 months of rehab before returning to high intensity physical activity, depending of the type of graft, the surgical technique and the patient’s own biology.
Following surgery, your knee will never feel exactly the same as it did prior to the injury, but the goal is to end up with a knee that feels strong, stable, pain free, and which gives you the confidence to pursue all of your physical activity goals and to return to your pre-injury level of sports. Although this goal is achieved in most patients, some will find that although their knee is improved, they are unable to return to their pre-injury level of activity following surgery, especially in elite athletes.
Following ACL reconstruction, you have a re-rupture rate of approximately 7%, which is less than the risk of rupturing your ACL on the opposite knee.
RECOVERY TIME
Recovery is a process that will be different for everyone. It depends on a number of factors including the work and motivation the individual puts into rehab. Nevertheless, you will need to give your body time to heal -"Patience is more powerful than strength”.
FIRST MONTH AFTER SURGERY
During this time, it is not uncommon to experience some pain, discomfort and swelling in your knee, calf and thigh.
Pain medication, ice, and elevation can be used to minimize this discomfort. Ankle pumps are also useful in reducing swelling.
You will probably notice some areas of numbness around your knee. This is normal. Some of the numbness around the incision may be permanent as well.
You should use crutches during this period, but can start weight-bearing as tolerated with the crutches. A knee brace or orthoses is ideally not needed. You should begin to work on regaining full straightening (extension) of the knee up to 90 degrees.
It is recommended to begin some home exercises including:
- Gently bending and straightening the knee ten times, three times a day.
- Straight leg raises, fifteen to twenty times, three times a day -called isometric quadriceps exercises.
SECOND MONTH AFTER SURGERY:
During this time, the pain in your knee should decrease greatly, although some pain and swelling are still normal.
By the end of this period you should have achieved full range of motion on your knee, and you should be walking without any walking support such as sticks or crutches.
You should have begun attending physiotherapy to work on exercises which help restore muscle tone and range of motion. Closed-chain strengthening exercises (those where the proximal part of the segment moves to the distal one, such as squats and leg press, are the best form of exercise. The stationary bike is also useful. Open-chain exercises must not be performed, like leg extension or leg extension seated - pulley.
THIRD MONTH AFTER SURGERY:
By this point, you should have achieved good quadriceps strength, minimal swelling and a normal walking gait on level surfaces.
Although your leg may feel very strong at this point, your graft is still healing and it is extremely important to continue to protect it. “No overconfidence”
You may begin using the Stairmaster and elliptical trainer in the gym. Running is still not allowed at this time, but you may begin pool running if desired.
Your goal for this period is to regain full extension and to increase leg strength and balance.
You will come in for a follow-up appointment at about 3 months after surgery.
FROM THIRD TO SIXTH MONTH AFTER SURGERY:
By this point, you should have close to complete range of motion. You will probably notice that your knee becomes tired quickly with physical activity, this will improve over time.
3 months after surgery, if you demonstrate sufficient muscle strength, you may begin running on a treadmill. You should start with short runs (around 5 minutes) and avoid any twisting or pivoting movements.
By the end of this period you should continue to improve strength, aiming for muscle strength of at least 70% compared to the uninvolved leg, until you achieve 100% by the end of the sixth month after surgery.
You will come in for a last follow-up appointment at the end of this period to evaluate knee stability, muscle strength, proprioception and range of motion, and also to determine whether or not you are ready to resume partial or full physical activity or, if you are an elite athlete, to resume competitive sports.
For most patients who are physically active or amateur athletes, the recommendation is to extend this period of time until your doctor checks that the graft is fully integrated. This usually takes 9 months for autografts, while it takes 12 months for allografts or grafts taken from cadavers.