Ankle Replacement vs. Ankle Fusion

What is it?

Ankle replacement and ankle fusion are two different surgical techniques used in the treatment of end-stage ankle arthritis. The main principle of the ankle replacement, also called arthroplasty, is to replace a damaged ankle joint with an artificial one. Meanwhile, the ankle fusion technique, also known as arthrodesis, means that the bones of the ankle are grown solidly together in order to make the joint completely stiff.

Who needs this?

Ankle replacement and ankle fusion are both considered to be the last treatment option for patients who suffer from persistent ankle pain and reduced ability to move. A surgery is required when the ankle joint is severely damaged and the symptoms cannot be relieved by conservative treatment. Factors that could cause damage to the ankle joint include rheumatoid arthritis, osteoarthritis, bone fracture, severe infection, obesity and genetics.

Which method is better?

There is no undisputable evidence that one ankle surgery method is better than the other. Both methods are considered to be beneficial and equally effective in relieving pain. Naturally, each of these procedures has certain advantages as well as disadvantages (Tab. 1). Moreover, there are many patient-associated circumstances influencing the choice of the treatment method, including age and physical activity of the patient and the severity of the ankle joint damage. The ideal candidate for the ankle replacement procedure is a patient without major deformity of the ankle and who is about 55 years and older. Meanwhile, ankle fusion is considered to be more appropriate to younger patients who require heavy use of the ankle. However, the best and most reliable way to find the most beneficial type of ankle surgery is to discuss it with your doctor.

Ankle replacement: advantages and disadvantages

Consideration about the pros and cons of surgical treatment methods of end-stage ankle arthritis is closely related to the age and physical activity of the patient. Recent studies have shown that in elderly patients total ankle replacement is more beneficial than ankle fusion. First of all, older people are not as physically active as people of a younger age. Thus, the risk of the prosthesis wear and tear is significantly lower. Meanwhile, younger patients wear out prostheses much faster and may need a revision surgery in which the old prosthesis is replaced by a new one. Moreover, postoperative rehabilitation is easier and the recovery period is shorter after ankle replacement than after ankle fusion. Another advantage of ankle replacement that is important to both age groups of patients, is that ankle replacement restores the biomechanics of the ankle better. This means that your gait (a manner of walking) will remain the same or will only change slightly after ankle replacement. However, ankle replacement is associated with many more complications and is not available in the cases when the ankle joint is severely damaged.

Ankle fusion: advantages and disadvantages

The main advantage of ankle fusion is that it is completely permanent and will never ‘wear out‘. Furthermore, this method is superior in such disorders accompanying ankle arthritis as ankle instability, deformity and bone loss. However, there is a big concern about the effect on the neighbouring joints. When the ankle joint is locked up, the joints above and below get more stress and they get arthritis. Moreover, the rehabilitation period after ankle fusion could be quite challenging and it takes a while to fully recover. The joint is fused and becomes stiff. This means that up-and-down or side-to-side movements are no longer available. These changes affect the gait of the patient and it takes a while till he or she regains the natural manner of walking.

 Ankle replacementAnkle fusion
Other namesAnkle arthroplastyAnkle arthrodesis, artificial ankylosis, syndesis
The principle of the procedureTo replace the ankle joint with a prosthesis.To fuse and immobilise the ankle joint.
Best candidateOlder patient, less damaged joint.Younger patient.
Complete recoveryEasier, up to 3 months.More difficult, 4-6 months.
Issues with gaitMore natural gait.Slightly altered gait (not necessarily).
Risk of revision surgeryHigh, if surgery is performed at a young age.No risk.
The length of the procedureApproximately 2 hours.Approximately 2 hours.

Tab. 1. The comparison between the ankle replacement and ankle fusion.