What is the ACL?
The Anterior Cruciate Ligament (ACL) is a tough band of connective tissue that connects the thigh bone (femur) to the shin bone (tibia). The ACL runs through the centre of the knee in a diagonal direction from the back part of the femur to the front of the tibia.
What does the ACL do?
The ACL is 1 of 4 major ligaments in the knee that help provide stability. The ACL is especially important when performing pivoting and rotational movements.
How is the ACL torn?
ACL injury is one of the most common knee problems. Injury often occurs whilst playing sports such as netball, tennis, squash, skiing, football and rugby.
Common causes
- Sudden change in direction
- Suddenly stopping
- Landing awkwardly
- Direct collision with knee
Common signs & symptoms
- Popping sound
- Knee pain
- Knee swelling
- Buckling of the knee or feeling like your knee is giving way
- Loss of motion in the knee
Associated injuries
ACL injuries often occur alongside other injuries to the knee. These include:
- Meniscal tear
- Articular cartilage damage
- Additional ligament injury
How is an ACL injury diagnosed?
The majority of ACL injuries can be diagnosed from asking specific questions along with a physical examination of your knee. An MRI scan and/or an X-ray can help with diagnose and/or to help treatment planning.
Types of ACL injury
ACL injuries are graded from 1 to 3:
- Grade 1 – mild damage from over stretching
- Grade 2 – partial tear where the ACL is damaged but not completely torn
- Grade 3 – complete tear (rupture) where the ACL is torn into 2 separate parts
What are the treatment options?
Treatment options depend on a number of factors listed in the next section.
Non-surgical treatment
Non-surgical treatment aims to increase knee stability without having an operation. This will involve a rehabilitation programme that aims to use the muscles around the knee to provide the stability required in the absence of an ACL. Some people find using a brace helpful and some people will make adjustments to their activities.
Rehabilitation plans are tailored to each individual and require you to be motivated and actively participate in your recovery.
Surgical Treatment
The aim of surgery is to restore function and relieve instability symptoms. This can be done by repairing the
torn ligament or replacing it which is referred to as an ACL reconstruction.
ACL Repair
Recent developments in surgical technique and devices has meant that ACL repair is a viable option for patients in certain circumstances. Depending on the length of time following injury and the location of the tear, this may be a treatment option.
ACL Reconstruction
If the ACL injury is not repairable, then an ACL reconstruction can be performed. This can be done using a graft of your own tissue, donated tissue from someone else (live donor or cadaveric) or an artificial graft.
Mr Webb’s preferred technique is to use a strip of your own quadriceps tendon as this has been show to be
very strong and to cause less weakness, pain in the front of the knee and areas of numbness.
Lateral Tenodesis
This is an additional procedure to the outer aspect of the knee (lateral) where a strip of the iliotibial band (ITB) is used to provide additional rotational stability. In certain circumstances, it is advised to have this performed at the same time as an ACL repair or reconstruction.
ACL Repair Video
ACL Reconstruction Video
How to decide on treatment?
Deciding what treatment is best for you can be difficult and will require a discussion with Mr Webb and/or your therapist. Factors to take into account are:
- The type of tear
- The location of the tear
- The duration of symptoms
- If there are associated ligament injuries
- Other medical conditions
- Current lifestyle/activities
- Expectations
What does surgery involve?
ACL surgery is usually performed under general anaesthetic. A small camera is used to look around the entire knee and address any other problems that may be present. Generally, two small cuts are made in the front of the knee for this.
Once the inside of the knee is prepared, a 2 to 3 cm cut over the front of the knee, just above the kneecap is made. This is so a strip of the quadriceps tendon can be taken.
This strip of tissue is then passed into the sockets made inside the knee to reconstruct the ACL.
The procedure takes less than an hour and a half in most cases.
What are the risks of surgery?
It is important to discuss the risks to ensure that you can assess whether surgery is right for you.
The specific risks for ACL surgery surgery include:
- INFECTION — this risk of infection is less than 1 in 250 cases. Antibiotics are routinely given at
the time of surgery and the graft is soaked in an antibiotic solution. - BLOOD CLOTS — the risk of developing a blood clot is approximately 1 in 500. Clots in the leg
(Deep Vein Thrombosis/DVT) can travel to the lung (Pulmonary Embolus/PE). - PAIN — people can experience pain following surgery. This is mainly dictated by the degree of
damage within the knee. - NUMBNESS — in less than 1 in 200 cases, patients may experience numbness around the
scars. Weakness is less common. - STIFFNESS — it is important to follow a rehabilitation programme.
- RE-TEAR — a repaired or reconstructed ACL tear can re-tear. People who do not engage in a
rehabilitation programme or try to return to activities too quickly are at a higher risk. - FAILURE TO RETURN TO PRE-INJURY ACTIVITY LEVEL — approximately 80% of people that
suffer an ACL tear get back to the same activities they were participating in prior to the injury.
Of that 80%, 8 out of 10 return to the same level.
What happens before surgery?
Consent
It is important that you understand the potential risks of surgery as well as the benefits. You will have the opportunity to go through these with Mr Webb. Prior to the procedure, an electronic consent form will be sent to you that goes through the risks in detail. Please do not hesitate to arrange an appointment to discuss any questions you have.
Prehabilitation
Mr Webb advises that you start a physiotherapy programme soon after your injury.
The aims of prehabilitation are:
- Reduce swelling
- Improve range of movement
- Muscle strength
- Practice using crutches
What happens on the day of surgery?
You will be asked to come to hospital where one of the nursing staff will prepare you for the procedure. The anaesthetist will meet you to discuss the type of anaesthetic and pain relief plan for after. Mr Webb will confirm the details of the procedure with you, answer any last-minute questions and draw an arrow on your leg.
The procedure normally takes between 1 to 2 hours. Once you have recovered from the anaesthetic, you will get up with your crutches and practice walking. The vast majority of patients go home a few hours after their operation.
What happens after surgery?
It is normal to have pain and swelling following ACL surgery. There are cold therapy machines available to help reduce the swelling. It is a good idea to see your physiotherapist within the first week following your operation.
At approximately two weeks, you will be seen by Mr Webb to review the incisions and go through the details of what was found and performed.
Dressings and wound care
You can remove the bandage after 24 hours. The sticky dressings should remain on until the two week review even if blood stained. If they do come off they can replaced by any simple waterproof dressing.
If the waterproof dressings are intact you can shower, but do not soak the dressings and be careful not to slip or put too much weight through the operated leg.
After your two week review, you can normally have a bath or swim.
Mobility
ACL reconstruction
If there are no other procedures performed, then you will be given crutches to help you to mobilise. You can put as much weight through the leg as you feel comfortable and can stop using the crutches when you feel able to do so. This is usually after a couple of weeks.
ACL repair or ACL reconstruction plus meniscal repair
You will require crutches for 4 to 6 weeks and sometimes will be placed in a knee brace to protect the knee. The brace will allow bending from straight to 90 degrees. If you are not in a brace, you should avoid bending your knee beyond 90 degrees.
- Week 0 – 4 — You will use crutches and you will be allowed to put 50% of your body weight through the operated leg.
- Week 4 – 6 — You will now start to put your full weight through the leg and wean off the crutches as guided by your therapist.
ACL reconstruction and removal of damaged meniscus (meniscectomy)
You will be given crutches to help mobilise, but you can put all your weight through your leg and wean yourself off the crutches as comfort and common sense allows.
When can I get back to my normal activities?
Rehabilitation following an ACL injury cannot be rushed. Following ACL reconstruction it normally takes 12 months before you are ready to participate in activities that require you to pivot. Your return will be based on your strength and control of your knee and it is crucial that this is assessed throughout your rehabilitation.
