High-resolution MRI assessment of dactylitis in psoriatic arthritis shows flexor tendon pulley and sheath-related enthesitis

Abstract

ObjectiveDactylitis is a hallmark of psoriatic arthritis (PsA) where flexor tenosynovitis is common. This study explored the microanatomical basis of dactylitis using high-resolution MRI (hrMRI) to visualise the small entheses around the digits.MethodsTwelve patients with psoriatic dactylitis (4 fingers, 8 toes), and 10 healthy volunteers (6 fingers, 4 toes) had hrMRI of the digits using a ‘microscopy’ coil and contrast enhancement. All structures were evaluated including the tendons and ligaments, related enthesis organs, pulleys, volar/plantar plates and tendon sheaths.ResultsIn dactylitis, collateral ligament enthesitis was seen in nine digits (75%), extensor tendon enthesitis in six digits (50%), functional enthesitis (5 digits, 42%), abnormal enhancement at the volar plates (2/5 joints, 40%) and the plantar plate (1/5 joints, 20%). Nine cases (75%) demonstrated flexor tenosynovitis, with flexor tendon pulley/flexor sheath microenthesopathy observed in 50% of all cases. Less abnormalities which were milder was observed in the normal controls, none of whom had any signal changes in the tendon pulleys or fibrous sheaths.ConclusionsThis study provides proof of concept for a link between dactylitis and ‘digital polyenthesitis’ including disease of the miniature enthesis pulleys of the flexor tendons, further affirming the concept of enthesitis in PsA.

High-resolution18F-FDG PET/CT for assessing disease activity in rheumatoid and psoriatic arthritis: findings of a prospective pilot study

“…The pathologic process underlying nail involvement in PsA is not well understood and enthesitis is considered as the driver of this involvement. 41 The detailed visualization of the underlying inflammatory patterns at the enthesis (structures typically ,3 mm) was not possible because of the spatial resolution limitations of our system. For tendons (cross-section ,6 mm), we also believe that the reconstructed radiotracer The control ROIs we employed were drawn on the bone.…”

Approach to hand osteoarthritis

“…[84,85,93] US Doppler ile konvansiyonel grafideki erozyon progresyonu aras›nda da bir iliflki saptanm›flt›r. [94][95][96][97][98] Ayr›ca US, referans metod olarak MR ile valide edilmifltir. [93] …”

Enthesitis of the hands in psoriatic arthritis: an ultrasonographic perspective

“…Thus this feature could potentially be a marker of disease severity, affecting the hand function. Recently, Tan et al demonstrated by magnetic resonance imaging (MRI) inflammatory changes at digital pulleys and tendons in dactylitis in PsA patients, suggesting a form of functional enthesitis that could be related to the dactylitis process [19]. Moreover, Tinazzi et al showed pulley thickening in subjects affected by PsA compared with RA and healthy controls [20].…”

“…In imaging studies (US and MRI), soft tissue oedema and flexor tenosynovitis are the two most important elementary lesions described in psoriatic dactylitis [10,19,22]. Overall, oedema of the soft tissues can be interpreted as an inflammation of the "fibrous skeleton" of the digit, which is made up of ligaments, fibrous capsular bands, palmar fasciae, and fibrous sheaths that attach to the bone or dermis [10].…”