Which is better? Ankle Replacement or Ankle Fusion

“Which is better, a total ankle replacement or ankle fusion surgery?” Is a question asked by every patient thinking about surgery for ankle arthritis. In this article we try to answer the question ankle replacement or ankle fusion?

Ankle Replacement Vs Ankle Fusion

Most ankle arthritis can be treated without surgery. Non surgical treatments include activity modification, physical therapy, weight loss, supportive boots or ankle braces, and pain killers. Once non surgical treatments have been exhausted then you may consider surgery. There are two recognised treatments for ankle arthritis. The traditional method for treating arthritis of the ankle is to convert a stiff painful joint into a stiff but painless one. This is called an ankle fusion or ankle arthrodesis. The second option is an ankle replacement where the joint is resurfaced, just like a hip or knee replacement, with an aim to preserve motion. Whilst a lot of general practitioners do not know an ankle replacement is even possible, fortunately, advances in technology plus our advanced understanding of how the ankle complex works, means that it is now very possible to replace the human ankle joint.

Ankle Fusion Surgery

This is still the commonest procedure carried out worldwide and can be a very successful treatment, but has its downsides. Because the ankle and foot have about 30 mobile joints, fusing just the ankle doesn’t mean you would walk with a peg leg, far from it. The other 29 or so joints compensate and so if you have healthy adjacent joints, then it might not be possible for someone watching you to tell if you have had an ankle fusion as your walking may be entirely normal. However, because the ankle joint itself is now stiff then of course the other joints around it have to take on the extra load and they can, with time wear away and become arthritic and hence painful. Long term studies have shown that 100% of patients who have an ankle fusion have X-ray evidence of wear and tear of the adjacent joints within 10 years, but only a third of these patients limp and struggle because of this. The healthier the adjacent joints, the better you do from a fusion. In contrast, if you have wear and tear of the adjacent joints before you have an ankle fusion, then you may not do as well.

Ankle Replacement Surgery

An ankle replacement is where the ankle joint is resurfaced with metal implants and a plastic liner and because an ankle replacement maintains motion, theoretically this should lower the risk of adjacent joint arthritis, but this remains to be proven. The main downside to an ankle replacement is that it is a mechanical joint and so will not last forever. The current research suggests that ankle replacements fail at about a 1.5%-1.9% each year. This means that after 10 years, it’s reasonable to expect that about 15-20% of ankles will have needed to be redone. Because the most modern of implants have only been around for the last 10 years we do not know how they will perform longer term. It is expected that the results will equal or better the literature but only time will tell.

Ankle Replacement Vs Ankle Fusion Further Research

The most important point is that for most patients both an ankle fusion and an ankle replacement can significantly improve one's quality of life and also improve function. A lot of factors will come into play in making a decision. These include your age, whether or not you have deformity (such as a flat foot or titled ankle) or other associated medical problems, such as poorly controlled diabetes or neurological disease. Most importantly, will be how healthy the joints around the ankle are. There are 30 joints in the foot and ankle and if they have disease, then fusing the ankle might not give you the flexibility you desire. Its also important to know whether you have arthritis of the hip or knee, as this can also impact on your outcome as well. Its important that you ask your surgeon to comment on the health of all the joints in your lower limb before having surgery as this is possibly one of the most important signals for outcome of surgery.

There has been one randomised controlled trial that compared ankle replacement versus ankle fusion. This study was a high-quality clinical study, called TARVA. The study was funded by a large public grant (an NHS NIHR HTA study) and was a randomised controlled trial involving 17 NHS centres across the UK and involved over 40 surgeons. The Chief Investigator was Mr Andrew Goldberg OBE, but each centre had a Primary Investigator and the group of surgeons were known as the TARVA Study Group. The TARVA study aimed to answer the question, “In patients over 50 years old with end stage ankle arthritis, is an ankle replacement or an ankle fusion more likely to give a better outcome as judged by a clinical score”. The study not only looked to assess clinical outcomes, but also complications and cost effectiveness of ankle replacement and ankle fusion. The initial early results have been published in the Annals of Internal Medicine and the full report is available in the NIHR Library The long term 2, 5 and 10 year results will follow later on.

You can follow the trial on Twitter @TARVA_Trial.