If you tear the anterior cruciate ligament in your knee, you may need to have reconstructive surgery.
The anterior cruciate ligament (ACL) is a tough band of tissue that joins the thigh bone to the shin bone at the knee joint.
It runs diagonally through the inside of the knee and gives the knee joint stability. It also helps to control the back-and-forth movement of the lower leg.
The ACL is the most commonly injured knee ligament.
The ACL can be torn if your lower leg extends forwards too much. It can also be torn if your knee and lower leg are twisted.
Knee injuries can occur during sports such as skiing, tennis, squash, football and rugby. ACL injuries account for around 40% of all sports injuries.
Some common causes of an ACL injury include:
- landing incorrectly from a jump
- stopping suddenly
- changing direction suddenly
- having a collision, such as during a football tackle
If the ACL is torn, the knee becomes
ACL Reconstruction Surgery
A torn ACL cannot be repaired by stitching it back together. However, it can be reconstructed by grafting (attaching) new tissue onto it.
The ACL can be reconstructed by removing what remains of the torn ligament and replacing it with a tendon from elsewhere, for example hamstrings or patellar tendon.
How ACL Reconstruction is Performed?
A number of methods can be used to reconstruct an anterior cruciate ligament (ACL). The most common method is to use a tendon from elsewhere in your body to replace the ACL.
You will either have a general anaesthetic, which means you will be totally unconscious during the procedure, or a spinal anaesthetic where anaesthetic is injected into your spine so that you are conscious but unable to feel pain.
Your surgeon will discuss the procedure with you and can recommend which type of anaesthetic to use. The operation will take 1–1.5 hours and can be done as a day surgery. For some cases, it may require an overnight stay in hospital.
A number of different tissues can be used to replace your ACL.
Tissue taken from your own body is known as an autograft. Tissue taken from a donor is known as an allograft. A donor is someone who has given permission for parts of their body to be used after they die by someone who needs them.
Before your operation, your surgeon will discuss the best option with you. Tissues that could be used to replace your ACL are listed below:
- A strip of your patellar tendon – this is the tendon that runs from the bottom of the kneecap (patella) to the top of the shin bone (tibia) at the front of your knee.
- Part of your hamstring tendons – these run from the back of your knee on the inner side all the way up to your thigh.
- Part of your quadriceps tendon – this is the tendon that attaches the patella to the quadriceps muscle, which is the large muscle on the front of your thigh.
- An allograft (donor tissue) – this could be the patellar tendon from a donor.
The most commonly used autograft tissues are the patellar tendon and the hamstring tendons. Both have been found to be equally successful.
The graft tissue will be removed and cut to the correct size. It will then be positioned in the knee and fixed to the femur (thigh bone) and tibia (shin bone). This is usually carried out using a technique known as a knee arthroscopy.
Recovering from ACL Reconstruction
After knee ACL reconstruction, the wound will be closed with dissolvable stitches. The stitches should disappear after about three weeks.
Your knee will be bandaged and you may also be given a cryocuff to wear. This is a waterproof bandage that contains iced water to help reduce swelling. You may also be given painkilling medication to control any pain.
Your surgeon or physiotherapist will be able to advise you about a structured rehabilitation programme. It is very important that you follow the programme so that your recovery is as successful as possible.
You will be given exercises that you can start in hospital after your surgery and continue when you get home. The exercises will include movements to bend, straighten and raise your leg.
You will also be given crutches to help you move around. You may need to use them for about two weeks, but you should only put as much weight on your injured leg as you feel comfortable with.
Weeks one to two of your recovery
For a few weeks, your knee is likely to be swollen and stiff.
You will be advised to raise your leg as much as possible, for example by putting pillows under your heel when you are lying in bed.
You may be given a cryocuff to take home with you to help ease the pain and swelling. Ask your surgeon or physiotherapist how often you should use the cryocuff. If you do not have a cryocuff, you could place a pack of frozen peas wrapped in a towel on your injured knee.
Weeks two to six of your recovery
Once the pain and swelling have settled, you may be advised to increase or change your exercises. Your physiotherapist will advise you about what exercises to do. These will help you to:
- fully extend and bend your knee
- strengthen your leg muscles
- improve your balance
- begin to walk properly
After two or three weeks, you should be able to walk without crutches.
As well as specific exercises, other activities that do not put much weight on your knee may also be recommended, such as swimming and cycling.
Weeks 6 to 24 of your recovery
Six weeks to six months after your knee operation, you should gradually be able to return to your normal level of activity.
You will be encouraged to continue with activities such as cycling and swimming, but you should avoid sports that involve a lot of twisting, jumping or turning. This is because you need to allow enough time for the grafted tissue to anchor itself in place inside your knee.
After six months
After six months, you should be able to return to playing any type of sport.
Some people may need to take more time to feel confident enough to play sports again, and elite athletes may need longer to return to their previous level of performance.
Returning to work
How quickly you can return to work after knee surgery will depend on what your job involves.
If you work in an office, you may be able to return to work after two or three weeks. If you do any form of manual labour, it could be up to three months before you can return to work, depending on your work activities.
Your surgeon can advise you about when you can drive again. This will usually be after three to four weeks or whenever you can comfortably put weight on your foot.