Description of thumb compression and flexion test for the diagnosis of rhizarthrosis. Cross sectional Cohort Study

Abstract

Background: Thumb pain secondary to osteoarthritis of the trapezium-metacarpal joint is a common condition, especially in women, and causing high levels of disability in some patients. The diagnosis ofrhizarthrosis is based on localised pain, inflammation, and instability on physical examination, in addition to radiographic evaluation. There are currently several semiological tests that can be used in the diagnosis of symptomatic rhizarthrosis, one of which is the Grind or grinding test, which is considered the gold standard. The present study aims to describe and evaluate the thumb compression and flexion test designed for the diagnosis of rhizarthrosis.
Methods: A cross-sectional study was carried out during the period from January 2007 to May 2013. The study included a total of 230 patients that came to the clinic with symptoms suggestive of rhizarthrosis, and on whom the Grind test, the compression test, and flexion were simultaneously performed to confirm the diagnosis.
Results: Of the 230 patients who attended the clinic, 87.8% (202) were women with a mean age of 60 years (32 to 86 years). A bilateral involvement was observed in 14.8% of the patients. Just under half (47.8%) currently had co-morbidities that included, among others, carpal tunnel syndrome (67.3%) and trigger finger (11.8%). The prevalence-adjusted and bias-adjusted kappa
(PABAK) concordance index between the two semiological signs was 0.948, indicating an excellent level of agreement between both. All (100%) of the patients were diagnosed by the flexion and compression test.
Discussion: Due to obtaining a positive test in all the patients evaluated with the compression and flexion test, it should be considered as a complementary test in the clinical evaluation of patients with rhizarthrosis. Further studies are necessary to validate this test in order to establish its sensitivity and specificity.
Evidence Level: II