The very early inflammatory triquetral lesion by MRI - is this the first sign in Rheumatoid Arthritis?

Introduction/aim: Rheumatoid Arthritis (RA) an autoimmune, chronic, and disabling disease if untreated, affects wrist joints, with a diagnostic delay of up to 2 years. Triquetral bone allows rotational movement that pivots over the rest wrist bones, and maintains physiological loads during mobility. Magnetic Resonance Imaging (MRI) is the most sensitive (96%) method for diagnosis, evidencing lesions as early as in the initial RA stages. Our aim was to determine the most frequently affected structures in the hand-wrist joint by MRI using the OMERACT-RAMRIS Score (2003) in three different RA stages, including clinically suspicious arthralgia (CSA) that haven't reported before.

Methods: We performed an exploratory, transverse, observational, descriptive study in 60 patients enrolled and classified by rheumatologists as: CSA, early rheumatoid arthritis (ERA), and established RA, prior to performing a dominant hand-wrist MRI for evaluation and descriptive analysis by an expert radiologist.

Results: Female predominance 83% (50), with a mean age 42+13.5 years; A total of 1,731 hand-wrist bone and joint sites were evaluated using EULAR-OMERACT Atlas (2005), identifying 56% (964 sites) with typical RA lesions: synovitis, erosions, and bone marrow edema (BME or osteitis); synovitis was the most frequent with 46% (445 site-lesion), and triquetral synovitis the most frequent each clinical group: CSA 87% (20/23), ERA 91% (20/22), and RA 93% (14/15).

Conclusion: Synovitis and triquetral synovitis were the most prevalent lesion in three-studied phases. This could suggest the triquetrum as the first morphological site to be affected by RA; so it's assessment should be considered in the RA evaluation when it´s clinically suspected.