AB1128 SENSITIVITY AND SPECIFICITY OF THE AUTOMATED SQUEEZE TEST (GAENSLEN’S MANEUVER) FOR IDENTIFYING METACARPOPHALANGEAL SYNOVITIS BY MAGNETIC RESONANCE IMAGING

Abstract

Background It is well known that an early diagnosis and treatment for Rheumatoid Arthritis (RA) prevents its complications, therefore there are many efforts to identify individuals at risk to develop RA. The Squeeze test has been used to detect synovitis in metacarpophalangeal joints, even though it is used in daily practice, there is a great variability in their performance among rheumatologists. [2] Objectives The aim of this study is to determine the diagnostic performance of the automated squeeze test (AST) on the metacarpophalangeal (MCP) joints to detect the presence of synovitis, edema, or erosions by magnetic resonance imaging (MRI) using the rheumatoid arthritis magnetic resonance imaging score (RAMRIS) in first-degree relatives (FDR) of RA patients, of whom clinically suspect arthralgia (CSA) in hands was suspected, as well as in RA patients. Methods It is an observational and cross-sectional study for a diagnostic test. A total of 60 patients, older than 18 years, were included and divided in three groups: CSA group: 22 with less than 1 year with arthralgia and required to be FDR of RA patients; early RA group: 22 patients who met ACR/EULAR 2010 Classification Criteria with less than 1 year with the disease; and late RA group: 16 patients who met ACR/EULAR 2010 Classification Criteria, with more than 1 year with the disease. The AST was performed in the 60 participants’ dominant hand. The device was evaluated by MRI, which examined the same hand in the 60 patients. Results A total of 240 MCP joints were evaluated. The AUC for the total RAMRIS score >10 was [0.480 (95% CI 0.301-0.617) P=0.597], for synovitis RAMRIS score > 7 was [0.459 (95% CI 0.331-0.669) P=0.791], and for the presence of any synovitis by RAMRIS was [0.575 (95% CI 0.428-0.723) P=0.331]. For the RAMRIS synovitis score, the most sensitive and specific cut-off of the force by AST was 4.645 kg with a 66.7% sensitivity and 50% specificity. Conclusion The application of AST with a force of 4.645 kg, to exert pain in the dominant hand, is a sensitive and specific technique to establish MCP joint inflammation, compared with other automated methods that had been recently tested.