Overview of the Results of the TARVA Trial

TARVA stands for Total Ankle Replacement Versus Ankle Arthrodesis and the TARVA study is the world’s first completed randomised controlled trial comparing the two main surgical treatments for ankle arthritis.

Ankle arthritis causes severe pain and disability and has a similar impact on quality of life as end stage hip arthritis, but once non operative treatments have been tried and failed the two surgeries offered are very different, one fusing the bones so there is no ankle joint movement, and the other replacing the joint with the aim of retaining ankle joint movement.

It is difficult for a patient to know which treatment is more suitable for them, most seeking guidance from their surgeon and there is a lack of high-quality evidence to guide and inform patient care.

The TARVA study took place at 17 NHS Trusts across the United Kingdom. 303 patients were randomly assigned to ankle replacement or ankle fusion.

Overall, we did not show superiority of ankle replacement over ankle fusion in terms of our chosen clinical score at 52 weeks following surgery. However, when we considered the type of total ankle replacement implant, we found that the implant most used in the United States and the NHS (a fixed-bearing two-component implant) had better outcomes at 1 year than ankle fusion.

In the study we found that 43% of patients had evidence of wear and tear in the adjacent joints. We carried out subgroup analysis and found that the presence of osteoarthritis in adjacent joints increased the effects noted between groups and predict that this may be a very important prognostic indicator with longer term follow-up.

We did not find a difference between the ankle replacement and ankle fusion in the risks of experiencing any adverse event, however, there were differences in the types of adverse events with more wound healing complications and nerve injuries in the ankle replacement arm but more thromboembolic events in the ankle fusion arm. 12% of the ankle fusion group did not have bony union on plain radiographic review at 52 weeks but just 7% had symptoms and hence we report that the symptomatic non-union rate for ankle fusion is likely to be 7%.

Our data is important to help patients & their surgeons to make decisions on the right surgery for them. We now intend to follow patients for up to 10 years where our findings are likely to become even more important.

You can view the published results of the TARVA Trial here.

Background

The main surgical treatments for end-stage ankle arthritis are ankle arthrodesis or total ankle replacement (TAR). Approximately 3,000 patients with ankle arthritis undergo ankle arthrodesis or TAR in the NHS each year. Both treatments are available on the NHS, and both have been reported to have good results. Some studies suggest that TAR restores a more natural walking pattern than ankle fusion but other studies have suggested that the need for further surgery is higher with TAR than with fusion. Information on all TARs implanted in the NHS has been captured on the National Joint Registry since 2010, but no similar national registry exists for ankle fusion. There has never been a published randomized trial directly comparing the two procedures.

Research Questions

In patients aged 50 or more with end-stage ankle arthritis:

Does total ankle replacement lead to:

• Better patient outcomes in comparison to ankle arthrodesis (fusion)?

• Improved pain free function (as measured by MOXFQ walking/standing domain)?

• Improved quality of life (as measured by EQ5D)?

• Reduced complications?

• Is ankle replacement a cost-effective alternative to ankle arthrodesis?

Objectives

We will determine which treatment offers better pain free function and quality of life, fewer complications and best value for money; to disseminate the trial findings to the public through the patient group involved with our research as well as through peer reviewed journals, conferences, seminars and meetings.

A 6-month feasibility phase was performed to enable us to review and adopt effective patient recruitment and retention strategies; the number of surgeons and centres participating in the trial were increased as a result.

Design & Methods

The TARVA Trial protocol was published in BMJ Open https://bmjopen.bmj.com/content/6/9/e012716

The TARVA Statistical Analysis Plan was published in Trials https://trialsjournal.biomedcentral.com/articles/10.1186/s13063-019-3973-4

Status

The trial started recruiting in 2015 at four pilot sites in Stanmore, London; Wrightinton; Aintree; and Sheffield and by 2017, seventeen sites were recruiting. Recruitment ended in December 2018 and the last surgery took place in early 2019.  The one year results were published in the Annals of Internal Medicine https://www.acpjournals.org/doi/10.7326/M22-2058

The two year data was presented at the American Orthopaedic Foot & Ankle Society (AOFAS) in September 2022 and was the winner of the Roger Mann Award for an Outstanding Clinical Study https://journals.sagepub.com/doi/abs/10.1177/2473011421S00673

Funding

The trial has been funded by the National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme – HTA Project: 12/35/27. In total the trial and study centres received £2,278,246.66.

Approvals

London – Bloomsbury Research Ethics Committees: 14/LO/0807

Trial Identifiers

International Standard Randomised Controlled Trial Number: ISRCTN60672307
ClinicalTrials.gov: NCT02128555
Universal Trial Number (UTN): U1111-1157-4155