Cluster of van der Wurff: SIJ Provocation The Cluster of van der Wurff is an almost equal alternative to the Cluster of Laslett that we presented yesterday. What is the difference then? The cluster of van der Wurff has a slightly lower sensitivity of 85% and a slightly better specificity of 79% for 3 out of 5 positive tests. However, the authors were slightly less strict in the application of the gold standard in which they considered a reduction of 50% of pain after a double nerve block confirm

SPINE ASSESSMENT SERIES PART 26: SIJ PROVOCATION CLUSTER OF LASLETT In comparison with the cluster of van der Wurff, the cluster of Laslett uses only 4 tests to rule in or rule out SIJ pain. The test criteria in the RCT of Laslett were a bit stricter, while the validity is almost identical. With 2 out of 4 positive tests (Sn: 88%, Sp:78%), SIJ pain is diagnosed, with 1/4 it is unprobable and with 0/4 positive tests, it can be completely ruled out. Absence of centralization (according to McKenzie