The first year of recovery after the status of the knee largely dictates an ACL reconstruction before surgery and your desired level of activity. Overall, recovery will follow a natural progression based on the timeline of healing for different tissue types in your body and what kind of graft is used for the reconstruction.
As recovery progresses, more sport and activity-specific rehabilitation will begin to help you reach your goals. Many patients can indeed return to doing what they love, but the more challenging and intense the activity is, the harder this may be. While this is not meant to scare you, it is meant to inform you to stay motivated to follow rehabilitation protocols to help you be as successful as possible.
Activities and sports that require high speed and cutting activities are the hardest to return to sports fully, but remember, it is not impossible to do, especially when you know the potential risks and how to avoid them. As we go through the first year of recovery, remember that different grafts will have slightly different protocols. You can read more about patella tendon versus hamstring tendon grafts here.
Some patients may be candidates for an ACL repair. These procedures require a different recovery protocol. The hope with ACL repair is that you may be able to maintain your original ACL without loss of tendon or muscle strength.
But recovery is also based on the status of the knee before surgery. If you can achieve full knee extension and adequate quadriceps activation, the muscle above your knee, then you will be off to a great start before you even have surgery.
Once you have surgery, here is what you can expect throughout your first year of recovery.
The First Month of Recovery after ACL Reconstruction
The first month after surgery is about managing swelling and pain and protecting the healing graft while gaining full knee extension and increasing quadriceps strength.
You will be using crutches and wearing a knee brace locked at 0 degrees to help provide stability and protection while also helping you to straighten your knee fully. If you have a meniscus tear, Dr. Morton may advise that you follow additional restrictions. Once you have the ability to demonstrate good quadriceps activation, you can discontinue using the crutches.
However, you will continue to use the brace for quite some time, progressing from constantly wearing it fully locked out to then allowing it to have the ability to bend and then to wearing it only during challenging activities.
Throughout the first month, your ability to bend your knee will also progress. You may not be able to bend it as far as your non-surgical leg, but you are on your way.
You should progress from gentle seated or supine exercises to ride a stationary bike, perform mini squats, and start balancing activities during this time.
Your first step to avoiding the risk of re-rupture or other injury begins in the first month. The ability to fully extend the knee and engage the quadriceps cannot be stressed enough. These are the first steps in avoiding re-rupturing the ACL. Early discharge of the crutches and brace also contributes to the risk of rupturing the new graft.
Three Months After ACL Reconstruction
The brace should still be worn for more intense exercises such as stairs, loaded exercises, squatting activities, and challenging balance exercises in the next three months. There is a fine line of strengthening these movements using a brace for support and decreased risk of injury and adequately challenge the leg enough to promote strength and function.
Sport-specific or activity-specific training needs to begin during this time-frame. A focus on neuromuscular re-education, balance, and controlling the surgical leg with different movement patterns is essential in avoiding the risk of re-rupturing the ACL.
Near the end of the first eight weeks, range of motion should be smooth and easy, a single leg squat should be performed from 0-90 degrees, and walking for 1 mile with a functional brace should be no problem.
As you near the end of the first four months of recovery, you should be able to bend your knees equally on both sides, run one 1 mile without pain, and begin sport or activity training with modifications as needed.
To avoid the risk of re-rupture during this time-frame, make sure that this is a gradual return to activity. The strength of the surgical leg is within 25% of the power of the opposite leg. Your Physical Therapist can help to assess the strength of your legs.
But strength is not the only thing to watch out for. Another way to ensure you do not re-injure your knee is to move with good body mechanics. Ensure you have reasonable control of your knee positioning, which can be obtained through education on improving movement mechanics and having adequate core and hip strength to control the knee. Remember to work on the entire leg, not just your knee, but throughout your recovery.
One more thing to watch out for is discontinuing the use of your brace too early. During earlier stages, you progressed from wearing the brace to only wearing it during walking and challenging activities. And now is still not the time to altogether discontinue the use of your brace. Continue to use this until your whole kinetic chain is strong and stable.
The 6 Month Mark
At the six month mark of your recovery, you may start to feel like yourself again. More strength and power activities can begin, running, plyometric training, and other functional activities.
However, just as with every other phase, you need to gradually progress, ensuring you are moving with good body mechanics, maintaining adequate stability, and using pain as your guide.
Having at least 85% of contralateral strength in your quadriceps and hamstrings, meaning the leg that had surgery is at least 85% as strong as your other leg can give you the green light in returning to running and accessible cutting sports like soccer, tennis, and football.
However, more challenging jumping sports and activities should be put on hold until closer to the nine-month mark to avoid the risk of injury or re-rupture. The impact and eccentric loading of jumping activities place a different stress on the new ACL than other sporting activities.
To avoid injury during this time, make sure to use a functional brace still, don’t progress too quickly, and don’t start to show some slack in following your protocol.
The 9 – 12 Month Time-frame
Even during this time, a functional brace is still recommended. Some patients continue with a functional brace during activities up to 2 years postoperatively.
If your goal is to return to a high-level sport, then full speed running, cutting, high jumps, rebounds, long jumps, etc. should be trained and progressed towards during this time-frame.
No matter your goal, even if you have reached it, you need to continue to maintain the outcomes you have achieved to help avoid any risk of injury or re-rupture. Unfortunately, one of the risk factors for re-injury is time. As time goes on, your risk can increase, so it is essential to maintain what you have gained.
During this recovery stage, a full battery of tests can be performed to see if you are ready for a maximum return to your sport or activity. These tests may look different depending on where you go for rehabilitation, your goals, or what activities you may want to get back to.
But most tests have some requirements in common, including:
Both knees demonstrate an equal range of motion without pain;
Quadriceps strength comparison bilaterally is 80% or greater;
Hamstring to quadriceps ratio of the involved leg is 66-75% or greater;
Acceleration rate of at least .2 seconds; and
Functional hopping test comparison bilaterally is 85% or greater.
Ensuring you can hit the mark on all of these things, with adequate strength of surrounding muscles, good balance, and control of your body mechanics, should result in less risk of re-injury.
Unfortunately, the risk of re-rupturing the same ACL or even the opposite ACL does exist. Ensure you do everything you can to follow your Physical Therapist’s guidelines, recovery protocols, and maintain what you have gained.
Re-rupture is not the only risk that needs to be taken into consideration. Other risks include:
Arthrofibrosis: The knee joining capsule becomes chronically inflamed and thick. This happens if there is a lack of knee joint movement. Full immobilization is the worst thing you can do after ACL surgery.o avoid this, make sure to begin rehabilitation right away and begin weight-bearing with your crutches and your brace to promote healing.
Anterior Knee Pain: The front of your knee hurts, generally around your kneecap. This can occur if your ACL was reconstructed with a portion of your patella tendon. Or it can happen if you don’t adequately strengthen your quadriceps tendon. This is less serious than a re-rupture or arthrofibrosis. However, you still want to address this not to be affected by it throughout your full recovery.
Arthritis: Patients who have an ACL rupture, regardless of whether they have the ACL reconstruction surgery or not are at higher risk of development of knee arthritis. This is due to the damage of the cartilage of the knee at the time of injury.
The recovery throughout the first year after an ACL reconstruction is significant. It needs to be taken seriously, not just to avoid rupturing your new ACL but also to help you return to what you love. Don’t take the recovery lightly, and watch out for warning signs for any of these risks.
All-inside ACL Reconstruction
There are multiple techniques used in ACL reconstruction. The anatomic all-inside technique is a newer technique. By placing the ACL in an anatomic position, it is less likely to fail. The all-inside technique involves using specialized instruments that only drill on the “inside of the knee” and does not drill into the hard outer shell of the bone. The all-inside technique involves less bone removal and can be done with smaller skin incisions. Studies have shown that patients who undergo the all-inside technique have less knee pain compared to those who undergo the traditional technique. This is true as far out as 2 years postoperatively. Studies also show that the knee function scores and the joint anatomy outcomes are the same as the traditional method.
After surgery, patients have to undergo a significant period of physical rehabilitation. The rehab emphasizes joint mobility and strength. In patients who are hoping to return to sports, rehab may last as long as 9 months.
ACL repairs failed in the past as the normal synovial fluid in the joint would prevent the healing of this ACL. This process is called resorption, where your body slowly breaks down and absorbs the repair over time.
So surgeons began searching for a way to encourage your body to accept the repair and enable it to heal on its own. The first major breakthrough in this area was the development of the autograft, which uses a tendon from another part of your body to replace your ACL.
While this method was an improvement, it still had its limitations as the new tendon was not always as strong as the original. Additionally, there was still the risk of resorption, albeit to a lesser extent.
The use of an allograft uses a tendon from a deceased donor. This method eliminates the need to harvest a tendon from another part of your body, but there is still the risk of resorption as your body may reject the allograft. In addition, allografts are not as strong as autografts and have a higher failure rate, especially in younger patients.
Frequently Asked Questions
When you tear your ACL, patients often feel a sudden pop and their knee will give out from underneath them. Usually you will feel very unstable after the injury, as though your knee is “floppy”. Many patients will experience significant swelling and pain. The swelling and pain will gradually resolve. Without treatment, many patients continue to have discomfort and difficulty walking. It is important to see an orthopedic surgeon to make sure you have your knee addressed appropriately.
Minor, partial tears may not cause your knee to feel unstable, and you may be able to function fine. Complete tears of your ACL will not heal without surgery. Unfortunately, the ACL is located in an area of the knee joint that it will not heal on its own. However, some patients who are lower demand can consider a rehabilitation program to strengthen their knee and successfully manage their ACL tear without surgery.
Patients who are less active may consider delaying their surgery if they have other obligations. However, patients who continue to perform high levels of activity are placing the cartilage and meniscus at risk for further injury. Further injury to the knee can lead to arthritis later in life.
Yes, you can walk. Often times the knee is very swollen after the injury. Once you recover from the initial injury, However, without an ACL patients sometimes feel unstable. Patients who are athletes or require the use of their knee for high demand activities that involve pivoting or jumping are more likely to desire an ACL reconstruction.