If you have end-stage ankle arthritis, you have probably heard that there are two main operations: ankle replacement and ankle fusion. Both are well-established. Both relieve pain for most people. Neither is "better" across the board. The right choice depends on your ankle, your health, your age and activity, and what matters most to you.
First: have you exhausted the non-surgical options?
Surgery is not the first step. Painkillers, activity changes, weight management, physiotherapy, supportive footwear, bracing and sometimes steroid injections can all help. Many people manage well for years without an operation. Surgery is worth discussing when arthritis pain limits your daily life despite these measures.
What each operation does
Ankle fusion (arthrodesis) removes the worn cartilage and fixes the bones of the ankle joint together with screws, or sometimes a plate or rod, so they heal into one solid bone. A fused ankle no longer moves up and down at that joint, but it no longer hurts from arthritis either. It is often done by keyhole (arthroscopic) surgery where the joint shape allows.
Ankle replacement (total ankle arthroplasty) removes the worn joint surfaces and resurfaces them with metal components separated by a plastic bearing — the same principle as hip and knee replacement. The aim is to relieve pain while keeping some of the ankle's natural movement.
What the evidence says
The largest UK study to compare the two directly is the TARVA trial, a randomised controlled trial run across NHS hospitals. It found that both operations gave substantial improvements in pain and quality of life at one year, with no overall significant difference between them in the main outcome measure. In other words: both work well for the right patient. The choice rests on the trade-offs below, not on one operation being clearly superior.
The core trade-off: movement vs durability
Fusion is the more durable, predictable operation. Once the bones have joined, there is no implant to wear out or loosen. The main long-term concern is that the neighbouring joints in the foot take on extra work, and some people develop arthritis in those joints over the years, which can itself become painful. In a minority of patients — typically quoted at around 5–10% — the bones do not join fully (non-union) and further surgery may be needed.
Replacement preserves movement, which can make walking feel more natural, especially on slopes and stairs, and may reduce the load on neighbouring joints. The trade-off is that it is a mechanical implant: components can wear, loosen or sink into the bone over time. UK registry and published data suggest most modern ankle replacements are still functioning at ten years, but a proportion need further surgery, and that likelihood rises the longer you live with the implant. If a replacement fails, the revision options — a repeat replacement or a conversion to fusion — are bigger, more complex operations than a first-time fusion would have been.
A useful way to frame it: fusion trades movement for durability; replacement trades some durability for movement.
Who tends to suit which?
There are no absolute rules, but broadly:
Fusion is often favoured for:
- Younger, heavier or more physically demanding patients, because implants wear faster under high load
- Significant ankle deformity or poor bone quality
- Previous deep infection in the joint
- Ankles that are already very stiff — there is less movement to preserve
Replacement is often favoured for:
- Patients in later middle age and beyond with lower-impact lifestyles
- Ankles with reasonably good alignment, bone stock and surrounding ligaments
- Patients who already have arthritis or stiffness in the neighbouring foot joints, where fusing the ankle as well would leave the foot very stiff
- Arthritis in both ankles
Smoking, diabetes, circulation problems and some medications affect healing and infection risk for both operations, and form part of the assessment.
Recovery — realistic expectations
The early recovery is broadly similar for both. Expect a period in a cast or boot, usually with restricted weight-bearing for the first few weeks, then a staged return to walking. Swelling commonly persists for months. Most people need time off work — longer for physical jobs — and cannot drive until they can perform an emergency stop safely, typically some weeks after surgery on the right side.
- Fusion: the bones usually take around 10–14 weeks to join, confirmed on X-ray, before full unprotected walking. Overall improvement continues for up to a year. Most people walk without a limp on level ground; running and uneven ground are harder, and the gait change is permanent.
- Replacement: weight-bearing often begins a little earlier once the wound has healed, with physiotherapy to restore movement. Improvement also continues for up to a year. High-impact sport is discouraged to protect the implant; walking, cycling, swimming and golf are realistic goals for many.
Neither operation returns the ankle to a pre-arthritis state. The goal is a much less painful, more usable ankle — not a normal one.
Risks — the honest list
All ankle surgery carries risks, including infection, wound-healing problems, blood clots (DVT or pulmonary embolism), nerve or blood-vessel injury, ongoing pain or stiffness, complex regional pain syndrome, anaesthetic risks, and the need for further surgery. Specific to each:
- Fusion: non-union or malposition of the fusion; later arthritis in neighbouring joints; prominent metalwork that occasionally needs removing.
- Replacement: implant loosening, wear or subsidence; fracture of the bone around the implant; and more complex revision surgery if it fails.
Serious complications are uncommon, but they are real, and they belong in the decision. Your individual risk depends on your health and your ankle, and we go through it in detail before any decision is made.
How the decision actually gets made
In clinic we look at your X-rays and often a CT scan, examine your ankle and the joints around it, review your general health, and — most importantly — talk about your life: your work, your activities, and what a good result would look like for you. Some patients are clearly better suited to one operation; for many, either is reasonable and the choice comes down to your priorities. There is rarely a rush. It is entirely sensible to go away, think, and come back with questions. Formal, structured consent is completed well before the day of surgery.
Next step
If ankle arthritis is limiting your life and you would like to discuss whether surgery — and which operation — is right for you, you are welcome to book a consultation at my private clinic in Southampton. Bring your questions; the appointment is for exactly that.
This article is general information and does not replace an individual consultation. Independent patient information on both procedures is available from the British Orthopaedic Foot and Ankle Society (BOFAS) at bofas.org.uk.