ACL Reconstruction

The anterior cruciate ligament is one of the major stabilising ligaments in the knee. It is a strong rope like structure located in the centre of the knee running from the femur to the tibia. When this ligament tears unfortunately it doesn't heal and often leads to the feeling of instability in the knee.

Often other structures such as the meniscus, the articular cartilage (lining the joint) or other ligaments can also be damaged at the same time as a cruciate injury & these may need to be addressed at the time of surgery.

• Most injuries are sports related involving a twisting injury to the knee
  
• It can occurs with a sudden change of direction, a direct blow e.g., a tackle, landing awkwardly
  
• Often there is a popping sound when the ligament ruptures
  
• Swelling usually occurs within hours
  
• There is often the feeling of the knee popping out of joint
  
• It is rare to be able to continue playing sport with the initial injury

Once the initial injury settles down the main symptom is instability or giving away of the knee. This usually occurs with running activities but can occur on simple walking or other activities of daily living.

The diagnosis can often be made on the history alone. Examination reveals instability of the knee, if adequately relaxed or not too painful.

An MRI (Magnetic Resonance Imaging) can be helpful if there is doubt as well as to look for damage to other structures within the knee. At times the final diagnosis can only be made under anaesthetic or with a knee arthroscopy.

The surgery is performed arthroscopically. The ruptured ligament is removed and then tunnels (holes) in the bone are drilled to accept the new graft. This graft which replaces your old ACL is taken either from the hamstring tendon or the patella tendon. There are advantages and disadvantages of each with the final decision based on what Dr Coolican determines is best in your situation.

The graft is prepared to take the form of a new tendon and passed through the drill holes in the bone. The new tendon is then fixed into the bone with various devices to hold it into place while the ligament heals into the bone (usually 6 months).

The rest of the knee can be clearly visualised at the same time and any other damage is dealt with e.g. meniscal tears. The wounds are then closed, often with a drain and a dressing applied.

You will have pain medication by tablet or in a drip (intravenous). Any drains will be removed from the knee. Leave any waterproof dressings on your knee until your post-op review.

You can put all your weight on your leg. A splint is sometimes used for comfort. You will be seen by a physiotherapist who will teach you to use crutches and show you some simple exercises to do at home.


Avoid anti-inflammatories or aspirin for 10 days. Put ice on the knee for 20 minutes at a time, as frequently as possible.

Post-op review will usually be at 7-10 days.

If you have any redness around the wound or increasing pain in the knee or you have temperature or feel unwell, you should contact Dr Coolican as soon as possible.

Physiotherapy is an integral part of an ACL reconstruction and is recommended to start as early as possible. Pre-operative physiotherapy is helpful to better prepare the knee for surgery. The early aim is to regain range of motion, reduce swelling and achieve full weight bearing.

The remaining rehabilitation will be supervised by a physiotherapist and will involve activities such as exercise bike riding, swimming, proprioceptive exercises and muscle strengthening. Cycling can begin at 2 months, jogging can generally begin at around 3 months. The graft is strong enough to allow sport at around 6 months however other factors come into play such as confidence, fitness and adequate fitness and training.

Professional sportsmen often return at 6 months but recreational athletes may take 10 -12 months depending on motivation and time put into rehabilitation.

The rehabilitation and overall success of the procedure can be affected by associated injuries to the knee such as damage to meniscus, articular cartilage or other ligaments.

Learn more about ACL rehabilitation  

As with any major surgery, there are potential risks involved. The decision to proceed is made because the advantages of surgery outweigh the potential disadvantages. It is important that you are informed of these risks before the surgery takes place.

Infection
Approximately 1 in 200. Treatment involves either oral or antibiotics through the drip, or rarely further surgery to wash the infection out.

Deep vein thrombosis

These are clots in the veins of the leg. If they occur you may need blood thinning medication in the form of injections or tablets. Very rarely they can travel to the lung (Pulmonary Embolus) which can cause breathing difficulties or even death.

Excessive swelling & bruising
This is due to bleeding in the soft tissues and will settle with time.

Joint stiffness
Can result from scar tissue within the joint, and is minimised by advances in surgical technique and rapid rehabilitation. Full range of movements cannot always be guaranteed.

Graft failure
The graft can fail the same as a normal cruciate ligament does. Failure rate is approximately 5%. If the graft stretches or ruptures it can still be revised if required by using tendons from the other leg.

Damage to nerves or vessels
These are small nerves under the skin which cannot be avoided and cutting then leads to areas of numbness in the leg. This normally reduces in size over time and does not cause any functional problems with the knee. Very rarely there can be damage to more important nerves or vessels causing weakness in the leg.

Hardware problems
All grafts need to be fixed to the bone using various devices (hardware) such as screws or staples. These can cause irritation of the wound and may require removal once the graft has grown into the bone.

Donor site problems
Donor site means where the graft is taken from. In general either the hamstrings or patella tendon are used. These can be pain or swelling in these areas which usually resolves over time.

Residual pain
Can occur especially if there is damage to other structures inside the knee.

Reflex sympathetic dystrophy
An extremely rare condition which can cause unexplained and excessive pain.

You will have the opportunity to discuss your concerns thoroughly with your Dr Coolican prior to surgery.

General issues with any surgery
Medical complications include those of the anaesthetic and your general well being. Almost any medical condition can occur so this list is not complete. Complications include:

• Allergic reactions to medications
  
• Blood loss requiring transfusion with its low risk of disease transmission
  
• Heart attacks, strokes, kidney failure, pneumonia, bladder infections
  
• Complications from nerve blocks such as infection or nerve damage
  
• Serious medical problems can lead to ongoing health concerns, prolonged hospitalisation or rarely death