ACL Reconstruction

What is a ACL Reconstruction?

The Anterior Cruciate Ligament (ACL) is located in the middle of your knee joint. When it is ruptured, it can lead to the knee feeling ‘unstable’ and may feel like it gives way.

Reconstruction of the ACL involves replacing it with a substitute ligament. This substitute can come from a variety of sources, but the two most common are from your own hamstring tendons or patella tendon.

Also known as:

  • Anterior cruciate ligament repair
  • Knee Reconstruction

Diagram of a tear of the Anterior Cruciate Ligament

Who is this operation for?

Not everyone who has torn their ACL will go on to have reconstruction surgery. There are a number of factors that need to be weighed up when deciding whether to have the operation. You will need to have a discussion with your surgeon to decide if an ACL reconstruction is the right choice for you.

Who may need surgery?

  • If you want to continue to participate in sports which involve pivoting, squatting or work that involves heavy manual labour then most people will require reconstructive surgery.
  • If you have symptoms of instability, which means you feel your knee gives way, then you may need to have the surgery.

Having your ACL reconstructed will not protect you from developing osteoarthritis or ‘wear and tear’ many years after the operation.

Who may not need surgery?

  • If you do not participate in sporting activities and do not have symptoms of instability (the knee giving way), then you may not need an ACL reconstruction.
  • Alternatives non-surgical treatment options include:
    • Activity modification – avoiding sporting or work related activities that require pivoting
    • Physiotherapy for strength, balance, range of motion training and further injury prevention

Diagram of a tear of the Anterior Cruciate Ligament

What are the benefits of ACL reconstruction surgery?

ACL reconstruction is usually a successful operation and will help to:

  • Improve stability of your knee and stop the knee from giving way. This will help you return to activities such as sports which involve pivoting, squatting or work that involves heavy manual labour

What are the possible risks and complications of an ACL Reconstruction?

The complication rate following ACL reconstruction surgery is very low. However like all surgery, there are risks that need to be considered when deciding to have the operation.

Side effects:

Side effects are symptoms that occur after every operation and are a normal part of the recovery from the operation. The main side effects of this operation are:

  • Knee pain
  • Swelling of the knee and bruising around the knee
  • Stiffness of the knee

These side effects are part of the normal recover from the surgery and will improve with time.

Complications

Complications are problems that occur during the operation or after the operation. Most people DO NOT have complications. There are some complications that may occur for any operation. These include:

  • A reaction to the anaesthetic
  • Infection of the wound or joint
  • Excessive blood loss
  • A blood clot, usually in a vein of the leg (known as a deep vein thrombosis or DVT)

Complications that are specific for ACL reconstructive surgery include:

  • Tearing or ‘failure’of the repaired cruciate ligament: Sometimes the repaired ligament may be torn and the original problem returns. Depending on the type of activities you perform after your operation and the extent of the original injury you may be at a greater or lesser risk of this occurring.
  • Pain in the front of the knee: After an ACL reconstruction you may have ongoing pain in the front of the knee. The pain may be particularly felt when kneeling. Pain in the front of the knee is more common in people who have had the patella tendon used as the graft for their surgery
  • Knee stiffness: After an ACL reconstruction, the knee may be stiffer than before the operation. It is important to complete the rehabilitation recommended by your physiotherapist in order to get the best outcome.
  • Instability: Although the aim of the ACL reconstruction is to make the knee strong and stable, sometimes the replaced tendon may stretch which can lead to instability of the knee. This may lead to pain or giving way of the knee.
  • Nerve damage: You may be left with an area of numbness on the inner side of your leg after the ACL reconstruction. This may be permanent or may improve slowly after the surgery.
  • Fracture of surrounding bones (broken bones): A very rare complication of ACL reconstruction is a fracture in the tibia (leg bone) or femur (thigh bone). This is a very rare complication relating to the site of the graft insertion or where the graft was taken from.

Revision ACL reconstruction

If the ACL reconstruction tears, you may need to have another ACL reconstruction. A second ACL reconstruction does not last as well as the first one and can be torn more easily than the first one.

Before the operation

Preadmission Clinic | Preparing for Surgery

Before your operation, you will be seen at the Preadmission clinic to make sure you are fit for the operation and all the necessary tests are performed in preparation for the operation.

During the visit, you will be seen by a

  • doctor
  • nurse
  • anaesthetist (if necessary)

Tests

Tests that may be ordered for you include:

  • Blood tests
  • An MRI of your knee
  • A chest X-ray
  • An ECG

About the Operation

Admission

Most people are admitted to hospital on the day of their surgery.

Anaesthesia

The anaesthetic team will see you and decide the type of anaesthetic that’s best for you.

The different types of anaesthesia include:

  • General Anaesthetic. This type of anaesthetic puts you asleep during the whole procedure and a machine controls your breathing.
  • Spinal Anaesthetic. An injection is placed into your back to numb your hip and legs. You will be awake during the procedure, however a sedative can be given to you to help you doze off.
  • Nerve Blocks. This special injection is used to help with your pain after the operation and often used  in conjunction with a general anaesthetic.

The Operation

The first step of this operation is to remove a piece of tendon that will be used to reconstruct the torn ACL. There are different sites that the tendon can be taken from (see below). Once the tendon is removed, it is prepared in order to be used to replace the ACL.

Next the surgeon will make two small cuts around the knee. These are used to insert a special camera into the knee so the surgeon can see inside the joint. The other hole is used to insert instruments into the knee joint.A MRI showing normal knee anatomy and an intact ACL

A MRI showing normal knee anatomy and an intact ACL

The torn ACL will be removed and and any other damage to the cartilage or joint surfaces will be repaired. Once the ACL is removed, a tunnel is drilled from the shin bone through to the thigh bone. The tendon that has been collected will then be inserted into the tunnel. The final step is to secure the new ligament in the tunnel, usually using special screws or other devices.

The wounds are then closed with sutures or steri strips which completes the operation. The whole operation usually takes 1 – 2 hours to complete. 

What types of grafts can be used?

There are three main types of grafts that can be used. Your surgeon will select the best for your ACL reconstruction. The types of grafts available are listed below:

  • Hamstring tendon: The hamstring muscle is made up of three parts and has three separate tendons. The tenon used for an ACL reconstruction runs on the inner side of the knee. The remaining two hamstring tendons are left in tact.
  • Patella tendon: This is the tendon that joins the knee cap (patella) to the shin bone (tibia). A small piece of bone where the tendon attaches at either side is also removed. Only a small part of the tendon is used and the rest remains in tact.
  • A synthetic graft: Synthetic grafts are not commonly used but a minority of surgeons may use the LARS (Ligament Augmentation and Reconstruction System) method. This method is not suitable for all patients and many surgeons do not use this method of ACL reconstruction. You will need to discuss with your surgeon if you are a candidate for a LARS reconstruction.  

Recovery Room

After the operation, you will be resting in the recovery room, where specially trained nurses will closely monitor you. This usually takes 1 to 2 hours. After which, you will be taken to your hospital room.

After the Operation

Recovery Room

After the operation, you will be resting in the recovery room, where specially trained nurses will closely monitor you. This usually takes 1 to 2 hours. After which, you will be taken to your hospital room.

You may need some pain relief when the anaesthetic wears off and you are able to move and feel the knee again. The anaesthetic will usually wear off 1 – 2 hours after the operation.

Day one 1

You will usually stay in hospital over night after an ACL reconstruction but some people will be able to go home on the day of their operation.

It is important to begin to use your knee as soon as possible in order to avoid stiffness. The physiotherapists will show you some simple exercises to begin to safely use the knee.

You may be given a brace for the first few days after surgery to support the knee. You will usually go home with crutches for support.

Recovery and Rehabilitation

Wound care

Although the wound caused by an ACL reconstruction is small, it still needs to be carefully looked after. The dressing over the wound should remain in place for the first two weeks. You will have a wound check 2 weeks after the operation at which time the dressing will be removed and the stitches taken out if present.

Rehabilitation

Early

In the first two weeks, the knee will need to be regularly iced to reduce swelling. This usually should occur up to three times a day for 10 – 15 mins.

Early exercises are aimed at getting the quadriceps muscle (the muscle on the front of the thigh) strong again.

Later

Rehabilitation is a very important part of ensuring the outcome of the ACL reconstruction is optimal. It is essential that you follow the program given to you by your physiotherapist.

The goal of rehabilitation is to regain the strength of the surrounding muscles and to ensure that the knee moves well avoiding it becoming stiff.

Initially you will be given simple exercises for building up the muscles in a controlled way and improving the flexibility of the knee.

After about 5 weeks you can start exercising on a bike and stair-stepper machine.

It will take up to 6 months before you are able to start to perform some controlled sports related exercises such as running and usually will take up to 12 months to make a full return to sport.

F.A.Q.s | Frequently Asked Questions

How do you know when ACL Reconstruction surgery is necessary?

If your ACL is torn and you play basketball, soccer, rugby, lacrosse, football, hockey, or enjoy rock climbing and do not want to give up these activities, ACL Reconstruction may be the best choice for you. It should also be considered if you have a job that requires manual labour. If you are not athletic but your knee continues to give way or feel that it is “coming apart,” the surgery may be a consideration.

What do I need to do after the operation?

Rehabilitation after surgery is just as important as the surgery itself. It takes time and effort to restore range of motion (how far your knee will bend and straighten) and strength. If you are not willing to do daily exercise for several weeks then surgery may not be for you.

What can I do to prevent an ACL tear?

Properly supervised training, including “Jump Training” which teaches athletes how to jump and land properly can reduce serious knee ligament injuries by around 50%. Jump training includes plyometrics and should also include strength training of supporting muscles such as the hip and core muscles to round out the program.

Are there risks in deciding not to have surgery?

Long term instability may lead to arthritis. If you opt not to have surgery it’s important to minimize the giving way episodes by restricting your activities, strengthening your leg muscles and wearing a brace if necessary.

References

  • Gerdeman AC, Hogan MV, Miller MD. What’s new in sports medicine. J Bone Joint Surg Am. 2009 Jan;91(1):241-56.
  • Lee GH, McCulloch P, Cole BJ, Bush-Joseph CA, Bach BR Jr. The incidence of acute patellar tendon harvest complications for anterior cruciate ligament reconstruction. Arthroscopy. 2008 Feb;24(2):162-6.
  • Robertson GA, Coleman SG, Keating JF. Knee stiffness following anterior cruciate ligament reconstruction: the incidence and associated factors of knee stiffness following anterior cruciate ligament reconstruction. Knee. 2009 Aug;16(4):245-7.
  • S. Nicholas Crawford, M.D., MAJ Brian R. Waterman, M.D. Long-Term Failure of Anterior Cruciate Ligament Reconstruction. Arthroscopy. 2013 Jun 29.
  • Allum R. Complications of arthroscopic reconstruction of the anterior cruciate ligament. J Bone Joint Surg Br. 2003 Jan;85(1):12-6.
  • Segawa H, Omori G, Koga Y. Long-term results of non-operative treatment of anterior cruciate ligament injury. Knee. 2001 Mar;8(1):5-11.
  • S.R. Bollen. BASK Instructional Lecture 3: Rehabilitation after ACL reconstruction. The Knee. Volume 8, Issue 1, March 2001, Pages 75–77