The ACL injury guide
If you’ve experienced an ACL injury, then this guide goes through some of the common questions that I get asked during my consultations. An ACL injury is a devastating event in a person’s life because it can prevent sporting activities for several months. As a patient, it is important to have the right expectations about the injury and surgery so you can prepare yourself for the journey ahead.
“What defines us is how well we rise after we fall”
THE ACL INJURY GUIDE OUTLINE
About ACL injuries
What does ACL stand for?
Where do you feel pain with an ACL injury?
Is an ACL rupture the same as a tear?
Can the ACL grow back?
Can I live without an ACL?
Can I put weight on a torn ACL?
What do I do if I have an ACL injury?
What is worse ACL or MCL injury?
What happens if an ACL injury is untreated?
How long does an ACL tear take to heal without surgery?
What are the long-term effects of a torn ACL?
Can I strengthen my knees without an ACL?
How do I prevent an ACL injury?
Can I play sports without an ACL?
ACL surgery
Is it bad to wait for ACL surgery?
How do you prepare for ACL surgery?
How long does ACL surgery take?
What graft choice should I have for my ACL surgery?
Is ACL surgery major or minor surgery?
Can you repair my ACL tear?
How long is the public waiting list for ACL surgery?
How much does ACL surgery cost privately without insurance?
Will my private insurance cover ACL surgery?
How successful is ACL surgery?
Rehabilitation after ACL surgery
What should I do after ACL surgery?
How long is rehabilitation for ACL injury?
What is the fastest way to recover from ACL surgery?
How long does it take to recover from ACL surgery?
Why is ACL recovery so long?
How long will I be on crutches after ACL surgery?
When can I walk after ACL surgery?
When can I squat after ACL surgery?
Can I climb stairs after ACL surgery?
Will my knee ever be the same again after ACL surgery?
Is it easy to retear the ACL after surgery?
How do I know if my ACL graft has failed?
How often does an ACL graft fail?
Is it common to tear your ACL twice?
Is the ACL graft stronger than the original?
Why do ACL allografts fail?
Is it true that using LARS for my ACL surgery will speed up my recovery?
What happens if I return to sport early?
About ACL injuries
What does ACL stand for?
ACL stands for anterior cruciate ligament. The ACL is located within the knee joint and controls the rotation and front-back motion within the knee.
Where do you feel pain with an ACL injury?
The pain associated with an ACL injury is felt within the knee itself. Patients describe a tearing feeling or a pop during the injury. Shortly thereafter, the knee will start to swell due to bleeding from the torn ACL. It can take weeks for the swelling within the knee to settle.
Is an ACL rupture the same as a tear?
A tear of the ACL can be partial (uncommon) or complete. A complete ACL tear is the same as an ACL rupture.
Can the ACL grow back?
No, once there is a complete tear, a new ACL does not grow back. Sometime the torn ACL will heal back to the bone in an abnormal position, but this will render the ACL ineffective i.e. it doesn’t control the stability of the knee like a normal ACL. The most common type of ACL surgery is reconstructive surgery where a graft is used to replace the torn ACL.
Can I live without an ACL?
Yes, despite the importance of the ACL in controlling rotation and front-to-back motion of the knee, you can live a productive and active life without ACL surgery.
Can I put weight on my knee with a torn ACL?
When you sustain an ACL injury, it is important to confirm the diagnosis with a combination of clinical examination and an MRI. Once the diagnosis of ACL injury is confirmed, you can bear weight on the affected leg. Using crutches in the first 1-2 weeks after injury is advised.
What do I do if I have an ACL injury?
If you have injured your knee you should get some crutches, ice the knee and take some anti-inflammatories (if tolerated) prior to seeing a doctor. Keeping the weight off the knee will help in the early stages. If you have access to a compression bandage (e.g. Tubigrip) this can help with the swelling. Sometimes wearing a straight knee brace for the first week after the injury, helps with pain.
The doctor will assess your knee and may perform an X-ray if they are concerned about a fracture. If there is a suspicion you have an ACL injury, you will be referred for an MRI scan and should seek an opinion from an orthopaedic surgeon. Early range of motion exercises are encouraged to prevent stiffness from scarring around the knee joint.
All patients are encouraged to seek assistance from a physiotherapist early. Irrespective of whether surgery is being performed, it is essential in the early stages to control knee swelling, improve the range of motion, and strengthen the muscles around the knee.
MRI of the knee demonstrating a normal ACL (left) and a complete ACL tear (right). Note, the normal ACL appears as a jet black stripe whereas the ACL tear has an indistinct appearance.
What is worse ACL or MCL injury?
ACL and MCL injuries have completely different treatment protocols but can occur together. MCL injuries are the most common knee ligament injury. It is usually caused by the knee buckling outwards. Most MCL injuries heal naturally and cause no long-term consequences. Occasionally, the ligament is completely torn and can cause instability of the knee joint. Surgery to repair the ligament is sometimes performed in this situation.
ACL injuries occur due to a rotational force (pivoting) or a quick change in direction (cutting). They are usually non-contact injuries. Due to the mechanism required to sustain an ACL tear, it can cause the MCL to tear as well. Combined ACL and MCL injuries occur frequently and pose an interesting management dilemma.
If ACL surgery is being considered, performing this when there is a concurrent MCL injury poses two problems. The first is graft choice. For most patients, a hamstrings graft is chosen for their primary ACL surgery. If there is an MCL injury, harvesting the hamstrings will take away the role of the hamstrings as the secondary medial stabiliser of the knee. This can create more laxity on the inside (medial) aspect of the knee. The options in this scenario are using a hamstrings graft from the opposite side of the knee, a quadriceps graft or patellar tendon graft. The second issue is that if the MCL is only partially torn and doesn’t require surgery, it’s important to let it heal prior to proceeding with ACL surgery. If the MCL ligament heals with significant laxity, it may put unnecessary strain through the ACL graft and cause early failure. As such, in the setting of a concurrent ACL and MCL injury, the knee is braced for 6 weeks to allow healing of the MCL and then followed by an ACL reconstruction if indicated.
What happens if an ACL injury is untreated?
Not everyone with an ACL injury requires ACL surgery. The ACL is important for younger active people (under the age of 25) as it protects the meniscus, which in turn protects the cartilage in the knee. It’s also important for people of any age group that are involved in pivoting or cutting sports (e.g. soccer, AFL or netball). The rapid change of direction puts a lot of force through the knee that is normally controlled by the ACL. If the patient is only involved in straight line activities or low demand work, non-operative management and rehabilitation can be considered. Physiotherapy is a form of treatment.
The patients that would benefit from early ACL surgery include:
If the ACL injury is treated non-operatively, seek the help of an experienced sports physiotherapist. They will encourage you to regain your range of motion, thigh muscle bulk and balance to allow you to compensate for the lack of an ACL. A 4-6 month trial of physiotherapy should be completed, and the patient should be reassessed to see whether there is ongoing clinical and functional instability. If there is, then ACL surgery should be reconsidered.
How long does an ACL tear take to heal without surgery?
Complete ACL tears usually occur in the middle of the ligament which has a poor blood supply. The chance of it healing and still working effectively is extremely small. In the unusual occurrence of a true partial ACL tear, the healing process will take around 4 months. In these situations, it is important to reassess the stability of the knee at the end of this period and obtain further imaging to ensure the healing process is complete. In certain patients, non-surgical management of an ACL tear can be very successful.
What are the long-term effects of a torn ACL?
A complete ACL tear can cause secondary damage to the meniscus (or shock absorber of the knee). In this situation, the progression to arthritis will be quicker as the meniscus will not be as effective at taking the load of your body and there will be more pressure on the cartilage within the knee. Patients with an ACL rupture are 4 times more likely to develop knee osteoarthritis.
Can I strengthen my knees without an ACL?
Yes, you can. In fact, all patients should seek the assistance of a physiotherapist soon after discovering they have an ACL injury. Whether you have ACL surgery or not, it is important to rehabilitate and strengthen your muscles so you can compensate for ACL injury.
How do I prevent an ACL injury?
ACL injury prevention programs include dynamic warmups, strength training (core, hip & thigh), technique training and pylometrics. If the principles in these programs are followed, the risk of ACL injury will be decreased.
Steps:
For more information, read about the Fifa 11+ injury prevention program or the KNEE program by Netball Australia.
Can I play sports without an ACL?
The ACL is important in controlling rapid changes in direction (cutting) and rotational (pivoting) movements. Most sport, like rugby, AFL, netball, and basketball, require cutting and pivoting movements. When an athlete sustains an ACL injury, these types of movements can be difficult. To some degree, you can compensate for this instability with strengthening the muscles around your thigh, but it may be difficult to play at the level you were at before the injury. Certain activities, such jogging, running and skiing, do not have as much cutting and pivoting movements and may be able to be resumed safely without ACL surgery.
ACL surgery
Is it bad to wait for ACL surgery?
The optimal time to have ACL surgery is between 4-10 weeks post injury. In general, if it is performed earlier that this, the knee has a risk of becoming stiff after the operation. If it is performed beyond this time, the knee instability may cause secondary damage to the meniscus (which acts as a shock absorber).
How do you prepare for ACL surgery?
It is important to see a physiotherapist prior to your surgery for ‘prehabilitation’. This involves improving the range of motion, reducing the swelling and trying to strengthen the thigh muscles around the knee in preparation for your surgery. The more physically prepared you are for your ACL surgery, the easier your rehabilitation will be.
How long does ACL surgery take?
An ACL reconstruction takes approximately 1 hour to complete. The total operating time depends on various factors. For example, if there’s a complex meniscal tear or an anterolateral corner reconstruction that is being performed, it can take up to 2 hours.
What graft choice should I have for my ACL surgery?
The three main graft choices are the hamstrings, patellar tendon and quadriceps tendon which each choice having advantages and disadvantages. You should have a detailed discussion with your surgeon during the consultation, but a summary will be provided here.
Hamstrings ACL graft
This is the main graft used in Australia. Two hamstring tendons (semitendinosus and gracilis) are harvested through a small oblique incision over the inside of your leg. The advantage is that the initial recovery from surgery is easier, and the incision for the graft harvest is smaller that one for a patellar tendon. The graft rerupture rate is low, but not as low as a patellar tendon. The disadvantages are the slightly higher rate of infection & graft re-rupture, hamstrings weakness and inconsistent graft size. Some patients naturally have smaller sized hamstrings. The size of a hamstrings graft has some correlation to the graft re-rupture rate. In an average sized person, it is ideal to have a graft greater than 8mm in diameter.
Patellar tendon ACL graft
Patellar tendon graft is an excellent choice for athletes. The size of the graft can be determined by the surgeon. The bone plugs at each end of the graft allow fast incorporation into the tunnels made in ACL surgery. The incision to harvest the graft is bigger than a hamstrings graft and the incidence of anterior knee pain is higher. However, the patellar tendon graft has the lowest rate of re-rupture of all three main graft choices.
Quadriceps tendon ACL graft
This is a relatively new ACL graft choice that is being used more frequently. The quadriceps tendon graft has excellent biomechanical strength and requires a small incision for the harvest. The graft size is determined by the surgeon. Anecdotally, some physiotherapists have noticed patients with a quadriceps tendon ACL reconstruction reach their rehabilitation goals slightly earlier than other graft choices. However, one recent registry-based study showed it has a slightly higher re-rupture rate than other graft choices. The finding of this study has not been consistently shown in other studies looking at graft choice.
Is ACL surgery major or minor surgery?
ACL surgery is very safe. Although it can be technically challenging, it is not a ‘major’ surgery. However, for the patients that have ACL surgery, it is a major event in their life. This is due to the long period of rehabilitation that ensues. It is important not to underestimate the investment in rehabilitation that is needed after ACL surgery. A commitment to quality rehabilitation after surgery is the key to a successful ACL surgery.
Can you repair my ACL tear?
ACL surgery either involves reconstructing the torn ACL (most common) or repairing it. An ACL repair is most likely to be successful in a young (< 25 years old) patient where the ACL has torn from its origin off the femur bone. The location of the tear can be seen on the MRI. ACL repair should be performed within 4 weeks of the ACL injury, otherwise the torn ACL shrinks. The advantage of repairing the ACL is that there is no need to harvest a graft. The disadvantage is that the ACL may not be as strong or as stable. Some patients that have an ACL repair end up having a delayed ACL reconstruction because of ongoing knee instability.
How long is the public waiting list for ACL surgery?
It depends on various factors such as the hospital the surgery is booked at, the surgeon who performs your operation, and the other knee injuries you have alongside your ACL injury. Sometimes patients with an ACL injury have also torn their meniscus and present with a ‘locked’ knee that they can’t straighten. As this can damage the meniscus and cartilage further if untreated, they are prioritised more urgently. Most patients with an ACL injury alone are put into Category 3 and should get their ACL surgery within 365 days of being booked on the waiting list.
How much does ACL surgery cost privately without insurance?
Most surgeons work in both the public and private sector. The quality of the surgery does not differ between these two sectors. However, the wait time for surgery is longer in the public sector which is why some patients may consider having their surgery in private.
There are several costs to surgery in the private setting listed below. Typically, the highest costs are associated with the hospital stay and the equipment for surgery. If you are interested in having private care for your ACL injury and do not have private insurance, a quote can be provided after your consultation. This cannot not be determined prior to your consultation as there are many factors that determine the cost of surgery.
The different factors that add to the cost of surgery include the fees from the following providers.
If you would like to get more information about the cost of private surgery, book an appointment with Mr Pai to discuss this.
Will my private insurance cover ACL surgery?
As all insurance policies are different, it is best to check with your health insurance provider whether ACL surgery is covered. You should check with your insurance company whether your policy covers the following commonly used item codes: 49542, 49539.
How successful is ACL surgery?
A ‘successful’ surgery depends your measure of outcome. In a sporting population, success can be defined as a return to playing sport. Return to sport after ACL reconstruction is an area with a lot of ongoing research. Some people have a successful ACL surgery with a stable knee that don’t return to playing sport. We don’t have a firm understanding of all the reasons why certain people never return to sport, but research shows that psychological factors (such as the fear of reinjury) and motivation, all have a part to play. Current literature shows that there is a 50-70% rate of patients returning to sport in younger patients. Although the proportion of patients that return to play appears low, patients are happy with the outcome of their surgery as their function improves because they can trust their knee.
Rehabilitation after ACL surgery
What should I do after ACL surgery?
It’s important to be linked in with a sports physiotherapist to commence rehabilitation. In the first few weeks, the goals are to decrease the swelling, improve the range of motion, and start activating the thigh muscles.
Icing the knee will help with pain. You should apply the ice for 15-30 minutes for 4-5 times a day for the first 2-3 weeks after surgery. Renting a cold compression system (GameReady, Cryocruff) will make you more comfortable post-operatively.
It’s important to not to do too much activity in the early stages. A common sign of overloading is that the knee will become more swollen. Overloading the knee too early will set you back with your rehabilitation. An experienced physiotherapist will guide you on how much exercise you should be doing. A post-operative protocol will be provided to you that your physiotherapist will use for your rehabilitation.
How long is rehabilitation for ACL injury?
A minimum of 12 months following surgery.
What is the fastest way to recover from ACL surgery?
A good recovery is dependent on well performed surgery, supervised rehabilitation, and patient participation with post-operative restrictions. The ACL graft used ends up being broken down by your body and rebuilt to serve the function of the ACL. A large part of this process occurs within 12 months of the ACL surgery. This is why sports should be avoided in this phase of healing. Unfortunately, there is no way to speed up this healing process. Twelve months after your surgery, your physiotherapist will perform tests to ensure you are ready to return to playing sport. This involves checking for symmetrical muscle bulk, strength and balance, prior to returning to competitive sport. Studies have shown that patients that pass their return to play tests, have a lower of reinjury.
How long does it take to recover from ACL surgery?
To decrease the chance of graft re-rupture, competitive sports should not be played for at least 12 months after your surgery. After this point, your return to sport, depends on your muscle bulk, strength and balance. Your physiotherapist will perform certain tests to ensure you are safe to return to sport.
Why is ACL recovery so long?
ACL surgery involves taking a graft from your body (hamstrings, patellar tendon and quadriceps) and inserting in your knee so it can act like your ACL. The graft needs to heal to bone is inserted into bony tunnels that are made in the femur and tibia bones. It takes 6-12 weeks (depending on the type of graft) for healing to bone to occur. The body also needs to break down the graft and rebuild it so it can work properly as an ACL – this process is called ligamentisation. A majority of ligamentisation takes about 12 months. This is why the recovery appears prolonged.
How long will I be on crutches after ACL surgery?
Crutches are required for approximately 2-3 weeks after ACL surgery. They are designed to reduce the force going through the operated knee and make it more comfortable for you to get around.
When can I walk after ACL surgery?
With an ACL reconstruction, you will be able to bear weight through the operated side straight after surgery. The exception to this, is if you have had the meniscus repaired during the same operation. In this situation, you may need to use crutches and not bear weight through the operated leg for 6 weeks after surgery.
When can I squat after ACL surgery?
The rehabilitation after ACL surgery is criteria-based. The main goals of the first 1-2 weeks after surgery is to reduce the swelling in the knee, improving the range of motion, and start activating the thigh muscles. Once these criteria have been met, squats (along with other types of exercise) with resistance can be started.
Can I climb stairs after ACL surgery?
Yes, you can. A physiotherapist will see you after your surgery and assess your safety using stairs before you go home. It is important to be careful when you are moving around after your surgery to avoid re-injuring your knee.
Will my knee ever be the same again after ACL surgery?
ACL surgery decreases the feeling of knee instability and helps get you back to playing sport or other physical activities. As ACL surgery involves replacing your original ACL ligament with a graft, your knee may feel different after surgery. Over time, your body will adjust to this difference. The final result after ACL surgery can take 12-18 months, but most patients will be very happy at the end of this period.
Is it easy to retear the ACL after surgery?
Technical issues with the surgery are the most common cause of injury to an ACL graft. The risk of reinjury is small when ACL surgery is performed with a good graft, good tunnel positions and appropriate attention to repairing the associated injuries. However, well performed ACL surgery needs to be performed in conjunction with supervised rehabilitation from an experienced sports physiotherapist. An early return to sport before you are physically ready is also associated with reinjury.
How do I know if my ACL graft has failed?
A reinjury to your ACL graft will be related to a specific traumatic event and feels like a pop or tear. The knee will swell after the trauma and you may notice the symptoms of knee instability again. It is important to get an assessment by a knee specialist and potentially get an MRI scan to confirm whether there has been a reinjury to the ACL graft. This is clearly a devastating event, but the results of revision surgery can be excellent.
How often does an ACL graft fail?
On average, the failure rate is < 5%. The risk is dependent on the age of the patient, level of activity and type of graft used, amongst other factors.
Is it common to tear your ACL twice?
It is not common to have two ACL injuries on the same side. The average risk of reinjury following ACL surgery is < 5%. However, patients that have an ACL tear on one side have a much higher risk (approximately 8-16%) of having an ACL injury on their other side.
Is the ACL graft stronger than the original?
An ACL graft has a higher load to failure than the native ACL. A biomechanical study showed the following average loads to failure:
However, when the graft is placed in your knee, it doesn’t replicate the exact biomechanics of your original ACL (it gets very close, but it is not the same). As such, even though the graft may be stronger, it can still fail with a significant traumatic event. The average rate of failure is reported to be < 5%.
Why do ACL allografts fail?
Allografts tissue is taken from a cadaver and therefore contains no living cells. It acts as a scaffold. When surgery with an ACL allograft is performed, the living cells from your body need to migrate into the allograft scaffold. This process of incorporation takes much longer than an autograft (your own tissue with living cells). Allograft tissue also undergoes sterilisation to prevent the spread of infection. The sterilisation process can weaken the biomechanical properties of the allograft. It is well known that allograft ACL reconstructions fail at a higher rate. In most situations, ACL allografts are not recommended.
Is it true that using LARS for my ACL surgery will speed up my recovery?
LARS is a synthetic ligament that was designed to avoid the morbidity of a graft harvest and allow patients to return to sport faster (quoted to be 3-4 months after surgery). It was later discovered that the LARS ligament ACL reconstruction had a higher failure rate and caused inflammation of the lining of the knee joint (synovitis). For these reasons, is is not recommended in the setting of ACL reconstruction.
What happens if I return to sport early?
If you play competitive sport earlier than the recommended timeframe (12 months after surgery), there’s a risk you may rupture your ACL graft. A recent study has shown that a return to sport earlier than 9 months following surgery was associated with a higher reinjury rate. For every 1-month delay in return to sport, the reinjury rate drops by 51% (up to 9 months after surgery)!
