“Lasting” means “not revised.” Registries count operations, not comfort. A replacement can be counted as a success while giving imperfect movement, and can be counted as a failure for a problem that was fixable.

Most of those figures come from older implants. The registry data spans 1993 to 2019, so it includes early designs that are no longer used. Current implants are expected to do better — but nobody yet has fifteen-year data on them, and any surgeon who tells you otherwise is guessing.

The most common reason for failure is loosening of one of the components from the bone. Alignment, bone quality and how well any deformity was corrected at the time of surgery all influence this.

If it does fail, there are options — a revision replacement or a conversion to fusion — but both are more demanding than the original operation.

Almost every patient considering an ankle replacement asks some version of it, and rightly so. If you are 58, you are not really asking about ten years. You are asking whether you will need another operation in your seventies, and what that would involve.

It is also the question most likely to get a vague answer. “They last a good while” is not useful when you are deciding between an implant and a fusion. So here is what the data actually says, including the parts that are less reassuring.

Joint registries track one thing: whether an implant has been revised. A replacement counts as surviving right up until someone operates on it again.

That definition cuts both ways. Some people have an ankle that has never been revised but is stiff, or aches at the end of the day. Registries record that as a success. Others have a replacement revised early for a problem that had nothing to do with wear. Registries record that as a failure.

So treat these numbers as a measure of how often further surgery is needed — a useful and important thing to know — rather than as a measure of how good the ankle feels.

The largest pooled analysis brought together data from the Australian, New Zealand, Norwegian and Swedish national registries, covering procedures from 1993 to the end of 2019.

Survival was consistently higher in Australia and New Zealand and lower in Sweden and Norway.

A separate UK single-centre series of 118 replacements reported 88% still in place at 7 years, with patient satisfaction of 89% and a large improvement in foot and ankle scores. That sits at the more favourable end of the registry range, which is roughly what you would expect from a specialist unit reporting a consecutive series of one modern implant.

The gap between 66% and 84% at ten years is not statistical noise. Several things drive it:

• Implant design. The data spans nearly three decades. Some early designs performed poorly and were withdrawn. Their results are still sitting in the fifteen-year figures, pulling them down.
• Who gets offered one. Countries differ in how readily they offer replacement rather than fusion, and to whom. A country that reserves replacement for straightforward, well-aligned ankles in lower-demand patients will report better survival than one that offers it more widely.
• Surgeon and unit volume. Ankle replacement is a lower-volume operation than hip or knee replacement, and outcomes are sensitive to how often the surgeon and the team do it.
• When the operation was done. Technique, instrumentation and preoperative planning have all improved. A replacement implanted in 2024 with three-dimensional planning is not the same operation as one implanted in 1999.

The practical implication is that a national average is a starting point for a conversation, not a prediction about your ankle.

Aseptic loosening — one of the components working loose from the bone without infection — is the most common reason for revision. Cysts can form in the bone around the implant and gradually undermine its support.

Malalignment and edge loading. If the ankle is not balanced, load concentrates on one side of the plastic bearing rather than being spread across it. Over years, that accelerates wear and loosening. This is the reason so much attention goes into correcting deformity at the time of surgery rather than accepting it.

Fracture of the malleolus — the bony prominences either side of the ankle — during or shortly after surgery.

Wound-healing problems and infection. The skin over the front of the ankle is thin with a modest blood supply, which is why wound complications are more common here than at the hip or knee.

Ongoing pain without an obvious cause. Occasionally an ankle is revised because it hurts, with no single culprit identified on imaging.

Some factors are fixed, and some are not.

Within your control, to a degree:

• Stopping smoking well before surgery — this has a substantial effect on both wound healing and bone healing. Active smokers can have up to five times the rate of problems. Stopping more than three months beforehand starts to make a difference.
• Body weight, which changes the load the implant carries with every step.
• Sticking to the rehabilitation programme, particularly the protected weight-bearing phase.
• Choosing lower-impact activity long term: cycling, swimming, walking, golf and gym work rather than running and jumping sports.

Decided before or during surgery:

• Whether the ankle can be brought into good alignment, and whether any deformity above or below the ankle is addressed.
• The quality of the bone, particularly the talus.
• Implant choice, matched to your anatomy and demands.
• Accuracy of implantation, which is where preoperative weight-bearing CT and patient-specific planning contribute.

Not in anyone’s control:

• Your age, and therefore how many years the implant has to survive.
• Underlying inflammatory arthritis.
• Previous surgery, scarring and existing metalwork.

This is worth understanding before surgery, not after.

Revision to another replacement. UK registry data on 228 revision ankle replacements found around 88% still in place at 3 years and 78% at 5 years. Purpose-designed revision implants performed better than using standard primary implants for the revision.

Conversion to a fusion. Registry data on 131 patients who had a fusion after a failed replacement found that around a quarter needed a further operation within three years. Salvage fusion works, but it is a bigger undertaking than a primary fusion because bone has been removed, often requiring graft, and it is not a soft landing.

Neither of these is a disaster, and both restore a functioning limb for most people. But they are a real part of the decision-making process when you weigh a replacement against a fusion at the outset, and they are one reason revision work is best concentrated in units that do it regularly.

If you are in your seventies, the arithmetic is relatively straightforward. A ten- to fifteen-year survival figure covers a large part of the remaining time you will be putting heavy demand on the ankle, and the chance of ever needing a revision is modest.

If you are in your fifties, you should plan on the realistic possibility of a second operation at some point. That does not make replacement the wrong choice — fifteen good years of a mobile ankle has real value, and a fusion has its own long-term cost in the joints around it, since ankle fusion can put pressure on the surrounding joints and accelerate wear there. But it should be a decision made with the revision scenario in view rather than assumed away.

If you are in your forties or younger, replacement is used more selectively, and a fusion, a joint-preserving procedure such as a realignment osteotomy, or continuing with non-surgical management often makes more sense.

If you are weighing up an ankle replacement — or you already have one and are concerned about how it is behaving — a specialist assessment can give you figures that relate to your ankle rather than to a national average.

Mr Matthew Welck is a Consultant Orthopaedic Foot & Ankle Surgeon at the Royal National Orthopaedic Hospital, Stanmore, and Honorary Associate Clinical Professor at UCL. His practice covers primary and revision total ankle replacement, complex reconstruction and weight-bearing CT assessment, with clinics across North and Central London.

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