Recommendation for NHSScotland

Laboratory-based Synovasure® test, used as part of a bundle of diagnostic tests

It is not possible to establish reliable estimates for the relative accuracy of the laboratory-based Synovasure® bundle of tests compared with standard diagnostic strategies used in NHSScotland. The evidence is insufficient in quality and quantity to draw conclusions on the routine use of Synovsaure® tests as part of a bundle of diagnostic tests for periprosthetic joint infection (PJI).

Currently in Scotland, there is no clearly defined diagnostic strategy for PJI, with variation across hospitals and health boards.

To establish the value in the routine use of the Synovasure® bundle of tests, further research is required to ascertain its relative accuracy compared with current standard diagnostic strategies used in NHSScotland. Research should also capture the impact of the bundle of tests on clinical outcomes and costs.

Point-of-care Synovasure® diagnostic test

The Synovasure® diagnostic test is also available as a point of care test. For people with periprosthetic knee joint infection, the point of care test may represent a valuable additional diagnostic tool for people with equivocal results following standard tests.

NHSScotland is required to consider the Scottish Health Technologies Group (SHTG) advice.

What were we asked to look at?

We were asked to evaluate the clinical and cost effectiveness of a bundle of tests for the diagnosis of hip and knee periprosthetic joint infection (PJI) compared with current practice in NHSScotland. The bundle reflects updated diagnostic criteria, which were proposed at the International Consensus Meeting on orthopaedic infections (ICM 2018), and includes the laboratory-based Synovasure® alpha defensin test. We were also asked to include any clinical and cost-effectiveness evidence relating to the
Synovasure® alpha defensin tests alone for the diagnosis of PJI.

Why is this important?

The Synovasure® test is available in two formats: a point-of-care lateral flow test kit (POCT) and a laboratory-based ELISA (enzyme-linked immunosorbent assay) test. The POCT is available for use in NHSScotland but, at the time of writing (November 2019), laboratory-based testing of alphadefensin is not available in the UK. There have recently been negotiations around siting a laboratory in Scotland that would offer the laboratory-based alpha defensin assay as part of a bundle of tests (mapped to the proposed ICM 2018 criteria). This SHTG technology assessment will help to inform the use of the bundle of tests within NHSScotland.

Referred by

Golden Jubilee National Hospital