Ankle Arthrodesis

Introduction

Ankle arthrodesis, (commonly known as ankle fusion), is an operation to fuse or stiffen the ankle joint. The goal of this procedure is to relieve pain and improve the function for a patient with severe ankle arthritis.

Indications for surgery

  • Patients may be considered for ankle arthrodesis if the patient has severe ankle arthritis and:
  • Pain is not relieved by analgesia and non-steroidal anti-inflammatory (NSAID) medication.
  • Pain continues despite modification in activity, use of walking aids or splints, and orthotics devices.

Contra-indication to ankle arthrodesis

  • Insufficient or poor-quality bone for fusion.
  • Neurologic or vascular illness that reduce healing or recovery.
  • Severe deformity of foot.
  • Medically unfit for anaesthetic.
Pre-operative X-ray showing severe ankle joint arthritis.

Peri-operative patient education

At the time of consultation, Dr Lane will give a full explanation of what is involved in ankle arthrodesis, expected recovery and surgical risks. Educational leaflets supplied by the Australian Orthopaedic Association are also given for patient's information.

If there are any further concerns prior to the operation, further consultation and explanation is encouraged with Dr Lane.

If you have a pre-existing medical condition you may be reviewed by a further specialist such as a cardiologist or other specialist physician, as well as the anaesthetist prior to surgery.

Pre-operative Instructions

Anti-inflammatory drugs such as Feldene, Naproyn, Nurofen, Brufen, Voltaren, Mobic and Celebrex should be stopped 5 days before surgery. These drugs increase the risks of bleeding. Aspirin or other blood thinning drug use prior surgery should be discussed with Dr Lane as this would depend on the patients underlying medical condition. The leg and foot to be operated on should be free of cuts, scratches and sores as this can increase the risk of infection. If you have damage to your skin, your surgery will be postponed until healed.

Depending on the time of your operation, you may be admitted the day before or early in the morning of procedure. The reception staff will give clear instructions about your admission time. Your expected stay in hospital is 2 to 3 days.

You should not eat or drink for 6 hours before your surgery.

Bring to hospital:

  • Personal effects such as pyjamas, slippers, dressing gown and toiletries.
  • Current medication.
  • Relevant X- rays.
  • Medicare, DVA or Private Healthcare cards.

Once seen in the Admissions area, you will be taken to the Ward where:

  • You will be admitted by the duty nurse and baseline observations taken.
  • Theatre gown will be given to wear.
  • The leg and foot will be inspected and then dressed with an anti-septic solution and sterile drape.
  • The other leg will have a TED stocking applied to reduce the risk of thrombosis following surgery.

You will be taken to the theatre complex by the nursing staff and then into the anaesthetic bay next to the operating room. There you will meet your Dr Lane and your anaesthetist.

The anaesthetist will tailor the anaesthetic to your needs. This may involve a general anaesthetic (when you are completely asleep) or a local regional block (spinal or epidural using a needle into the lower back) which numbs the legs, used with twilight sedation. Post-operatively, you will receive narcotic type analgesia for pain relief which may be delivered by PCA (Patient Controlled Analgesia) combined with other pain killers and anti-inflammatory medication. Prophylactic intravenous antibiotics are infused prior to surgery. Intravenous fluids will commence to keep you hydrated in theatre and in the immediate post-operative time.

Procedure

Depending on the complexity of the surgery, ankle arthrodesis usually takes about 1-2 hours and has an 80 to 90% success rate.

The surgery may be performed though an incision on the outside or front of the ankle. The joint is opened up and the joint surface, cartilage, is removed and occasionally reshaped to correct deformity. Sometimes a bone graft is used to aid fusion. This may be taken from the pelvis, heel bone or just below the knee. The joint is put into the correct position and fixed with 2 or 3 screws. If a patient has a sub-talar fusion at the same time, a nail may be used to hold the joints in position through an incision at bottom of the heel.

X-rays are used during surgery to check the alignment of the joint and the position of the hardware.

Occasionally tendons, (Achilles or peroneal) are lengthened or repaired.

Incisions are closed with sutures and dressings applied and local anaesthetic is injected around the ankle to reduce the pain after the surgery. A non-circumferential Plaster splint is then applied to keep the joint in position in the immediate post-operative period.

X-ray showing post-operative appearance of pantalar ankle arthrodesis.

Post-operative Instructions

During the immediate post-operative period (until reviewed in Dr Lane’s Rooms) it is important to keep the fused ankle elevated to reduce swelling and aid repair.  Once you are safe on crutches (you will be instructed by the physiotherapist) without putting your weight on your operated foot and comfortable, you will be discharged home. The patient may prefer a wheelchair or knee scooter for mobility. The tibia and talus take at least 6 weeks for the bones to fuse sufficiently to allow weight bearing. However, it may take as long as 10 to 12 weeks. During this period, it is important that the patient DOES NOT WEIGHT BEAR on the operated leg and keep rested with leg elevated as much as possible- particularly in the first 2 weeks following surgery.  The plaster splint and dressings should remain dry. If there is heavy bleeding and soiling of dressings, increasing pain or fever please contact Dr Lane.

10 to 14 days after your operation you will be seen by Dr Lane when your plaster and sutures will be removed.  If all is well, you will be put into a “moon boot”. You should continue using your crutches or other mobility aid and continue to avoid weight bearing on the operated leg.

At about 6-8 weeks after your operation you will come back for review by Dr Lane with a new X-Ray. If there is evidence of bony fusion, you may be able to have graduated weight bearing with the moon boot. At 10 to 12 weeks another X-Ray is taken and if all well, the moon boot is then weaned. Full recovery from this surgery typically takes 9 to 12 months.

After your moon boot is removed you can start taking increasing exercise. A physiotherapist may aid in your recovery. Start with walking and cycling, building up to more vigorous exercise as comfort and flexibility allows. Most people find that the foot is more comfortable than before surgery but the joint will be stiffer. This makes walking on rough ground more difficult. The good news is that once the ankle is fused you will be able to return to most of your pre-operative activities such as walking long distances, hiking, cycling, manual labour, climbing ladders and skiing but running is discouraged.

Risks

General risks associated with Anaesthetic

During surgery, your body is stressed and pre-existing conditions such as heart, respiratory or circulatory conditions may worsen.

Rare complications:

  • Death.
  • Myocardial infarction (heart attack) and cardiac arrhythmia.
  • Stroke.
  • Pneumonia (lung infection).
  • Short term confusion.
  • Deep venous thrombosis (blood clots).

Local risks (uncommon)

  • Infection.
  • Damage to nearby nerves.
  • Bleeding.
  • Bones not joining together properly (non-union). Reported rate of 10 to 20%. This will require further surgery such as bone grafting to help bones unite.
  • Misalignment of the bones.
  • New arthritis in nearby joints (common). This usually takes several years to develop and may or may not be symptomatic.
  • Pressure sore or thermal burn from plaster splint (rare).

Patients who are smokers, diabetic, have poor bone density or have multiple pre-existing medical conditions are at a higher risk of complication.