Total ankle replacement surgery is an operation to replace a worn-out ankle joint by resurfacing the ends of your tibia and talus with metal components with a plastic insert in between them to allow gliding motion but how successful are ankle replacements?
How successful are ankle replacements?
The way this question is answered depends on how you measure success. Different people will measure success differently. Success of ankle replacement surgery can be measured by patient reported outcome scores, where the patients themselves rate their condition and symptoms. The most basic outcome score is “Are you pleased with your surgery?” YES, NO, or NOT SURE. This is actually a very good measure as its what a friend may ask you, but its still fraught with difficulties because you may be very pleased with the outcome of your surgery but still riddled with pain, because another problem exists like a bad back, or hip arthritis that makes you still limp.
Doctors and scientists have tried to find other ways to measure outcome. So they introduced Patient Reported Outcome Measure Scores or PROMS. These are based on a validated set of questions before and after the surgery. These outcome scores can be generalised for example looking at quality of life (such as the SF36 or E5D questionnaires) or body part specific so for the ankle, the Manchester-Oxford Foot and Ankle Questionnaire (MOXFQ) or Foot and Ankle Ability Measure (FAAM). The questionnaires are given before the surgery and at various time points after the surgery to look for an improvement. In the same way as “Are you pleased with your surgery?” is riddled with issues – the same can apply to the various PROMS as well. They also have whats known as ceiling effects meaning they may be good at differentiating between people that cant walk and those that can walk 100 yards, but they may not be very good at discerning between a golfer who’s swing is affected and who’s handicap falls from 10 to 20.
The National Institutes of Health also developed a computerised system called the Patient Reported Outcomes Measurement Information System (PROMIS) which is used in the USA by some institutions to capture scores electronically. It might be best to describe this system, which remains in evaluation as showing great promise!
Other ways in which doctors can measure outcome are more objective, for example by complications such as infection rates, readmission to hospital rates and re-operation rates. These are very useful metrics but often not available to help patients make objective decisions. The survivorship of the implant (ie revision rates) are the most standardised way of assessing outcome but of course does not measure patients whom are in agony and unhappy but for whatever reason do not have the surgery revised (eg if their general health is so poor that another surgery may not be safe).
What data can I use to make up my own mind?
Because the process is very complicated, I will try and provide you with some outcome data for ankle replacements to help you make up your own mind.
There are a huge number of papers published in the medical literature on the outcomes of ankle replacements but the main problem with all of the studies is that the quality of the studies is not good. Many studies contain what’s known as reporting bias, meaning that the results need to be read with caution.
Systematic reviews are a technique where lots of papers are reviewed and the findings synthesised to help the reader understand the various messages. The biggest systematic reviews have found an estimated overall 10-year survival rate of 89% with an annual failure rate of up to 1.9% per annum, meaning that after 10 years you can expect up to 19% of implants to have failed. The other way to look at this is that after 10 years 89% of implants are still going.
The same systematic review has also shown an increased range of motion and improved clinical outcomes based on patient reported outcome measures (PROMS) (Zaidi et al., 2013). They have not been able to find differences of the various scoring systems or in range of movement between different designs. Residual pain was common, but the patients were satisfied with the procedure in 79–97%. No superiority of any one design over another could be detected.
National ankle registries, such as the British National Joint Registry for ankle replacements are able to collect a higher number of patients. The UK NJR now has more than 10,000 ankle replacements on its records.
The largest clinical study called the TARVA study, looking at ankle replacement against ankle fusion for ankle arthritis was carried out in the UK by 17 NHS hospitals and this study was funded by the UK NIHR Health Technology Assessment Programme. The initial results were published in 2022 in the Annals of Internal Medicine and you can find out more by visiting the TARVA ankle arthritis website.
Joint deformity or arthritis affecting other joints have a significant influence on the outcome of ankle joint replacements as do medical problems like diabetes, vascular disease or neurological disease. It’s important that you speak to your surgeon about the best options in your specific circumstances.
What Can I Expect After An Ankle Replacement?
Although total ankle replacement provides excellent-pain relief and good function, like all joint replacements are prone to wear and failure with time. This appears more likely to occur in ankle replacement than in hip or knee replacements.
In most cases, the range of motion after a replacement is better than before. In some patients, this is not the case, largely due to stiffness and scarring of the soft tissues. It is important that you discuss the likely range of movement you should expect with your surgeon before having your surgery. This will help you to have realistic expectations.
Walking
In most cases, walking will be normal, so that others may not notice that you have had an ankle replacement. If you walked with a limp prior to surgery because of pain, after the surgery your walking is likely to improve.
Sports
You should be able to return to long walks, hiking, cycling and certain sports such as golf. Here is a full article on when you can get back to sport after an ankle replacement.
Although there are cases where patients have returned to more vigorous activities such as squash, tennis or jogging, we do not recommend them. As they put a lot of stress on the replaced joint which is likely to wear and fail more quickly. There is also a risk of putting stress across the adjacent joints which might wear even in the presence of an ankle replacement.
This article was written by Mr Andrew Goldberg OBE MD FRCS(Tr&Orth), Consultant Orthopaedic Foot and Ankle Surgeon in London and one of the UK’s top ankle replacement surgeons. To make an appointment with Mr Goldberg please contact +44(0)207 042 1828.
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