The wrist hyperflexion and abduction of the thumb (WHAT) test: a more specific and sensitive test to diagnose de Quervain tenosynovitis than the Eichhoff's Test.

De Quervain's disease has different clinical features. Different tests have been described in the past, the most popular test being the Eichhoff's test, often wrongly named as the Finkelstein's test. Over the years, a misinterpretation has occurred between these two tests, the latter being confused with the first. To compare the Eichhoff's test with a new test, the wrist hyperflexion and abduction of the thumb test, we set up a prospective study over a period of three years for a cohort of 100 patients (88 women, 12 men) presenting spontaneous pain over the radial side of the styloid of the radius (de Quervain tendinopathy). The purpose of the study was to compare the accuracy of the Eichhoff's test and wrist hyperflexion and abduction of the thumb test to diagnose correctly de Quervain's disease by comparing clinical findings using those tests with the results on ultrasound. The wrist hyperflexion and abduction of the thumb test revealed greater sensitivity (0.99) and an improved specificity (0.29) together with a slightly better positive predictive value (0.95) and an improved negative predictive value (0.67). Moreover, the study showed us that the wrist hyperflexion and abduction of the thumb test is very valuable in diagnosing dynamic instability after successful decompression of the first extensor compartment. Our results support that the wrist hyperflexion and abduction of the thumb test is a more precise tool for the diagnosis of de Quervain's disease than the Eichhoff's test and thus could be adopted to guide clinical diagnosis in the early stages of de Quervain's tendinopathy.