Clinical comment

Age is probably one of the most important criteria when choosing between AF and TAR, as there is evidence suggesting that age substantially affects the outcomes of TAR.³ Young patients generally have higher demands in terms of functional outcomes, return to work, return to sports, etc. According to the literature, TAR should mostly be considered in patients over 50 years.

Available literature and quality of the evidence

Several level II and III meta‐analyses and reviews, especially national registries are available to answer this question.^4–9 To our knowledge, there is one randomized controlled trial (RCT) currently registered, with results pending.¹⁰

Findings

Currently, the RCT TARVA (total ankle replacement vs arthrodesis) is to our knowledge the first RCT and has completed the data collecting, although results have not yet been published.¹⁰

A level II prospective controlled trial comparing outcomes following TAR versus AF found that the arthroplasty group was, on average, six years older than the arthrodesis group.⁹ A meta‐analysis of comparative studies between TAR and AF found that age at implantation of the compared studies was younger in the AF group; however, no conclusions were drawn regarding age and outcomes.⁴ In a level IV systematic review of the literature (therapeutic studies), patients with TAR were older than patients with AF (mean 58 years vs 50 years, respectively).⁷

Spirt et al., in a retrospective review, reported that age was the only significant predictor of failure and reoperation after TAR.⁶ The five‐year reoperation rate with failure was 80% for all patients and 89% for patients over 54 years. The authors concluded that every one‐year increase in age at implantation of the TAR resulted in a 3.5% decrease in failure hazard.⁶

A Swedish report with 780 TARs showed that patients under 60 years had a 1.8 times higher chance of revision compared to older patients; however, the difference was only found to be significant for women.⁵ The same Swedish study group associated younger age with osteolysis, loosening, and therefore increased risk of revision surgery. However, other national registries, such as the Finnish and the New Zealand Register, have not found a relationship between age and survival rate.^11,12

In an epidemiological study of TAR by Seaworth et al.,¹³ younger age at implantation was found to be a risk factor for failure (patients <60 years). Similarly, the Swedish Ankle Arthroplasty Register observed that lower age at surgery implied an increased risk of undergoing revision surgery.⁸

In a recent case series, the authors compared five‐year outcomes of TAR according to age or diagnosis.¹⁴ They observed that the age group of patients <60 years had significantly worse mean Foot and Ankle Outcome Score (FAOS) scores both preoperatively and at five years.

Lower age at surgery has also been associated with higher risk of revision in a study of outcomes with long‐term follow‐up after TAR.¹⁵ However, TAR is occasionally proposed for younger people in cases of rheumatoid arthritis, bilateral ankle osteoarthritis or low activity level.³

Resolution of clinical scenario

• Both AF and TAR should be considered only when conservative measures have failed and other joint‐preserving options cannot be offered.
  
• AF remains a good surgical option for end‐stage ankle arthritis.
  
• Younger age should remain a contraindication for TAR; however, rather than considering a specific age group as a limit for AF, the desired activity level and the patient’s activity demands should be more important.
  
• TAR could be considered in younger patients with rheumatoid arthritis or other inflammatory diseases.
  
• If considering TAR for a younger patient, an explanation of possible future revisions should be addressed.
  
• TAR in younger patients should also be considered in cases of bilateral ankle arthritis.