What is the additional value of MRI of the foot to the hand in undifferentiated arthritis to predict rheumatoid arthritis development?

Abstract

Background: MRI-detected subclinical joint inflammation in the hand joints of patients with undifferentiated arthritis (UA) predicts progression to rheumatoid arthritis (RA). It is unknown if adding MRI of the foot increases predictive accuracy compared to the hand alone. Methods: 1.5-T contrast-enhanced MRI of the unilateral foot (MTP-1-5) and hand (MCP-2-5 and wrist) was performed in 123 patients presenting with UA (not fulfilling the 2010 RA criteria) and scored for bone marrow edema (BME), synovitis and tenosynovitis. Symptom-free controls (n = 193) served as a reference for defining an abnormal MRI. Patients were followed for RA development ≤ 1 year, defined as fulfilling the classification criteria or initiation of disease-modifying antirheumatic drugs because of the expert opinion of RA. The added predictive value of foot MRI to hand MRI was evaluated. Results: Fifty-two percent developed RA. Foot tenosynovitis was predictive (OR 2.55, 95% CI 1.01-6.43), independent of BME and synovitis (OR 3.29, 95% CI 1.03-10.53), but not independent of CRP and number of swollen joints (OR 2.14, 95% CI 0.77-5.95). Hand tenosynovitis was also predictive independent of BME and synovitis (OR 3.99, 95% CI 1.64-9.69) and independent of CRP and swollen joints (OR 2.36, 95% CI 1.04-5.38). Adding foot tenosynovitis to hand tenosynovitis changed the sensitivity from 72 to 73%, specificity from 59 to 54% and AUC from 0.66 to 0.64; the net reclassification index was − 3.5. Conclusion: MRI-detected tenosynovitis of the foot predicts progression to RA. However, adding MRI of the foot does not improve the predictive accuracy compared to MRI of the hand alone. In view of cost reduction, the performance of foot MRI for prognostic purposes in UA can be omitted.

Reliability of Magnetic Resonance Imaging (MRI) Scoring of the Metatarsophalangeal Joints of the Foot according to the Rheumatoid Arthritis MRI Score

“…In our results, the scores of the MRI features were higher in the hands than in the MTP joints, especially in the wrist. This is in concordance with a recent study performed in patients with undifferentiated arthritis on the development of RA, where adding MRI of the foot did not improve predictive accuracy compared to MRI of the hand alone 33 . This was explained by the finding that inflammation in the foot was indeed an early phenomenon, but it almost never occurred without inflammation in the hands.…”

A core set of risk factors in individuals at risk of rheumatoid arthritis: a systematic literature review informing the EULAR points to consider for conducting clinical trials and observational studies in individuals at risk of rheumatoid arthritis

“…47 In patients with UA, MRI tenosynovitis in the foot was also associated with development of RA, independent of bone marrow oedema (BME) and synovitis (OR 3.3, 95% CI 1.0 to 10.5). 48 However, in this study adding MRI of the foot did not improve the predictive accuracy compared with MRI of the hands alone.…”

Rheumatoid Arthritis and Tenosynovitis at the Metatarsophalangeal Joints: An Anatomic and MRI Study of the Forefoot Tendon Sheaths

“…For the predictive value, we recently observed in a longitudinal study that MTP tenosynovitis in undifferentiated arthritis was associated with the development of RA (35), which underlines the possible diagnostic value of tenosynovitis at MTP joints. It is important to note that although tenosynovitis at the MTP joints is specific for RA, the sensitivity of 41% is low.…”