Knee ACL Surgery


What is the ACL?

The ACL is an important ligament in the knee that stabilizes the femur (thigh bone) on the tibia (shin bone). It is particularly important in sports or activities to avoid the knee giving way when sidestepping or pivoting. It is often injured when the knee twists abnormally through contact such as a rugby tackle or non- contact such as landing badly in netball and is normally associated with swelling and significant pain.

Following a complete rupture of the ACL, the knee may feel unstable as the ligament generally does not heal, and have repeated episodes of giving way. If these symptoms of instability are frequent despite rehabilitation with physiotherapy then surgery may be required to reconstruct the torn ligament. There may also be an associated meniscal (cartilage) tear of the medial (inner) or lateral (outer) meniscus or both.

Surgical reconstruction is performed by replacing the ligament with a tendon graft harvested from the patella (kneecap) tendon or 2 minor hamstring tendons at the back of the thigh. Additionally, any meniscal tears present will be repaired if possible, or the torn pieces removed if not repairable.

Reconstruction is performed using knee arthroscopy (“keyhole” or “knee scope” surgery) The procedure involves making two small incisions (less than 1cm long) on the front of the knee to create portal. A small telescopic camera (‘scope’) is inserted into one of the portals and this provides a view inside the knee joint. The other portal is used for passing in small surgical instruments. The tendon is placed through drill holes made in the footprint of the original ACL in the knee. There is an additional incision used to harvest the graft on the front or inside of the knee (medial side).

The tendon graft is secured by specialized fixation but is not fully secured for 6 weeks until the bone in the drill tunnels grow into the graft and stabilize it. For this reason physiotherapy rehabilitation is delayed until the graft is stable and safe to start without stretching or loosening the graft.

Your rehabilitation will be discussed in detail by Mr Schluter who will follow you at 2 weeks, 6 weeks and 3 months to provide an outline of what the physiotherapist will work on with you. This is individualized depending on the severity of the injury and the nature of activities and employment that you do.

In general, for the first 6 months always walk in a straight line and avoid sidestepping, pivoting and twisting on the knee no matter how good it feels. The consensus from sports surgeons internationally is that you should not return to sport within the first 9 months to ensure that the knee is fully rehabilitated and reconditioned.

What are the risks of ACL reconstruction?

Commonly, patients experience bruising and swelling around the knee which can take several weeks to settle.

The knee can feel stiff in the first 6 weeks, especially when fully straightening the joint . Working on extending (fully straightening) the knee is an important exercise to start from day 1 post surgery.

Hamstring pain may occur in the first six weeks if a hamstring graft is used but usually resolves after 48 hour with ice and pain relief. If a patella graft is used, it is common to have some pain in the front of the knee for about 4-6 weeks and to experience discomfort on kneeling for 4 -6 months.

It is possible to rupture the graft, especially if you return to sport too early. It is important that the knee is fully rehabilitated with restoration of the thigh muscle bulk (quadriceps) and resolution of the post operative swelling before returning to strenuous physical activity.

It is common for there to be some numbness around the incisions. This will resolve with time.

Serious complications such as infection and blood clots are rare.

Expectations from ACL reconstruction knee surgery

Most people recover well although some individuals do not return to their prior level of function. This is often determined by the associated damage to the joint, for example meniscal tears, articular cartilage damage and additional ligament injuries (medial, lateral collateral ligament or posterior cruciate injuries).

How long does an ACL reconstruction take?

An ACL reconstructive procedure generally takes 90 minutes though this depends on whether other procedures such as meniscal repair or debridement is required.

Generally it will require an overnight stay in hospital although it can be done as a same day procedure. You will need someone to drive you home, and a responsible adult to be with you overnight as you may still be sleepy and require oral pain medications.

What Happens on the day of surgery?

DO NOT EAT OR DRINK from midnight, unless otherwise instructed.

Dr Schluter will meet with you, answer any further questions, check the consent form and mark the operative leg. You will also meet the anaesthetist (specialist doctor) who will be providing the anaesthetic. In most cases the procedure is done under a general anaesthetic. An IV line (drip) will be inserted and you may be given some premedication.

What should I expect immediately after the operation?

After the operation you will go to the recovery room where nursing staff will monitor you until you are awake. You will have a bulky bandage around your knee and an ice pack.

As you wake up you may experience discomfort or a tight/full feeling in the knee, which should be easily managed with pain medication. Once you are alert, you will be encouraged to get up and mobilise slowly with crutches.

You can put your full weight through the leg and bend it from fully straight (0) to 90 degrees. Crutches will be required for 2 weeks after the operation.

What follow up should I expect?

Dr Schluter will review you at a follow up appointment approximately 2 weeks after your surgery. He will review your wounds and remove any sutures. You will be able to discuss the findings of the surgery and talk through the photos/video taken during the procedure.

At this appointment, Dr Schluter will also discuss your ongoing rehabilitation programme.

A further check at 6 weeks and then 3 months post surgery is also arranged.

Work certificates and ACC reports will be issued depending on the nature of the work you do and progress of recovery

How do I look after my knee when I get home?

For the first 5 – 7 days it is very important to elevate the leg when you are resting. Rest is important to allow the swelling and inflammation to settle.

Using an ice pack, or pack of frozen peas, during the first 3 days can help in reduce the swelling and discomfort. Ice can be applied for 20 mins every 2-3 hours. To prevent ice burn, please make sure there is a barrier, such as a hand towel, between the ice and the skin.

Walking and gentle movement from 0-90 degrees are encouraged to prevent stiffness during the first 2 weeks. After two weeks, you may stop using your crutches, walking distances can be increased and further bend is allowed.

Physiotherapy is started when the graft is stable – generally 4-6 weeks post surgery. Remember not to work too hard in the early stages however, as this can cause more swelling.

The incisions should be kept dry for 3 weeks. Your dressings are waterproof and it’s fine to shower with them. Please change the dressing if the dressing becomes soaked.

It is normal to have a small amount of bleeding into the dressing in the first 3 days. If there is ongoing bleeding enough to fully soak the dressing, this may need review. Please contact Dr Schluter’s room for advice.

It is also very normal to have some bruising and swelling around the knee, hamstrings and even the ankle, which may take several weeks to settle.

The discomfort in your knee will improve each day, but you may experience soreness for 4 – 6 weeks after the procedure, especially with deep knee bends. It is important to take the prescribed pain medications regularly as instructed. In general, patients need pain medication for around 5 days.

How long do I need crutches for?

Crutches are needed for the first 2 weeks after the operation and are used to help control the amount of weight that is put on the operated knee. This helps the healing process by protecting the repair.

The time until you can fully weight bear (put your full body weight on the operated knee) will depend on the operation performed. If it is an isolated ACL reconstruction, you can weightbear as tolerated with crutches immediately after the surgery. If you have also had a meniscal repair or microfracture, this would require partial weightbearing for 4-6 weeks.

My knee is still swollen, is this normal?

It is quite normal to have swelling, bruising, clicking and discomfort in your knee for 8 - 12 weeks after the operation. These ongoing symptoms are generally related to the underlying condition of the knee, the extent of the surgery and the amount of activity you have been doing.

If you are concerned about any of these symptoms please contact Dr Schluter’s rooms.

What if I have concerns after my surgery?

Please do not hesitate to contact Dr Schluter’s rooms or your GP if you develop any of the following:

  • Heavy bleeding from the incision

  • Sudden severe pain or tenderness at the wound site or in the joint.

  • Swelling in the calf or thigh, especially if associated with pain or heat

  • Redness around the incision that continues to spreads.

  • Temperature higher than 38.5 °C (fever) or chills.

  • Worsening flexibility or an inability to bend the knee.

  • Any concerns you may have regarding your recent surgery