AB1258 THE VALUE OF THE SQUEEZE TEST FOR DETECTION OF SUBCLINICAL SYNOVITIS IN PATIENTS WITH ARTHRALGIA SUSPICIOUS FOR PROGRESSION TO RA

Abstract

Background:The squeeze test (or compression test) is often used to quickly screen for arthritis in metacarpophalangeal (MCP)- and metatarsophalangeal (MTP)-joints. A positive test is traditionally assumed to indicate presence of synovitis. Previous studies in early arthritis indeed showed that a positive squeeze test was associated with presence of swollen MCP- and MTP-joints, as well as with local MRI-detected inflammation. The sensitivity of the test, with MRI-detected synovitis as reference, was 31-33%. The field is moving towards identifying patients at risk for rheumatoid arthritis (RA) in the phase of arthralgia. However, it is unclear if the squeeze test in the phase of clinically suspect arthralgia (CSA) is associated with subclinical inflammation, which can be detected with MRI.Objectives:We aimed to assess if a positive squeeze test in patients with CSA is associated with MRI-detected subclinical inflammation, especially with subclinical synovitis and tenosynovitis (the latter is recently identified as a strong predictor for RA-development).Methods:315 patients with recent-onset (<1 year) arthralgia of small joints and a clinical suspicion for progression to RA were consecutively included in our CSA-cohort. At baseline the squeeze test (compression across the knuckles of MCP- and MTP-joints with the force of a firm handshake) and unilateral contrast-enhanced 1.5T MRI of MCP(2-5)- and MTP(1-5)-joints was performed and scored according to RAMRIS. MRI-scores were dichotomized with data from age-matched symptom-free controls as reference. Follow-up ended when patients developed clinically apparent inflammatory arthritis (IA), or else after 2 years. Associations of the squeeze test and MRI-data were studied with generalized estimating equations, associations with IA-development with cox regression.Results:51% of CSA-patients had a positive squeeze test in MCP- or MTP-joints. In univariable analyses a positive test was associated with MRI-detected subclinical synovitis (OR 2.10 (95%CI 1.30-3.40)) and tenosynovitis (OR 1.68 (1.05-2.68)). In multivariable analyses including both inflammatory features only synovitis remained significant (OR 1.90 (1.16-3.13)). Thus, a positive squeeze test is a measure of subclinical synovitis, with a sensitivity of 44% (95%CI 33-55) and specificity of 72% (68-76).A positive squeeze test in CSA was not associated with IA-development in cox regression adjusted for age, gender, CRP and ACPA-status (HR 1.57 (0.77-3.19). This was consistent with the finding that subclinical synovitis was not associated with IA-development in multivariable analysis adjusted for age, gender, CRP, ACPA-status and tenosynovitis (HR 1.40 (0.59-3.31), whilst tenosynovitis was associated (HR 4.94 (2.03-12.06).Conclusion:The squeeze test is a simple test that, when positive in CSA, doubles the probability of presence of subclinical synovitis.Disclosure of Interests:None declared