Entheseal Involvement in Patients with Rheumatoid Arthritis

Abstract

heumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation of synovial tissue that leads to damage of cartilage and bone, resulting in irreversible joint destruction. RA is typically a distal, symmetrical, small joint polyarthritis, most commonly involving the metacarpophalangeal (MCP) and proximal interphalangeal joints of the fingers (PIJ), interphalangeal joints of the thumbs, the wrists, and metatarsophalangeal joints of the toes (MTP). Other joints of the upper and lower limbs, such as the elbows, shoulders, ankles, and knees are also commonly affected. The involvement of tempro-mandibular and sterno-clavicular joint and cervical spine is relatively uncommon. Musculoskeletal manifestations include also tenosynovitis (defined as inflammation of the tendon and its enveloping tendons heath) and carpal tunnel syndrome. Enthesopathy is a common feature of Spondyloarthropathy (SpA) but can also be found in RA. It is characterized by inflammation of insertions of tendons, ligaments or capsules into the bone. However, recognizing enthesopathy could be challenging because of low sensitivity and specific clinical testing. To detect enthesopathy, the European League Against Rheumatism (EULAR) recommends magnetic resonance imaging (MRI) or ultrasonography (US). US appears to be interesting for enthesopathy detection. US grey-scale is a performant tool to detect structural modifications of the enthesis such as erosion, bursitis, calcification, thickening or hypo echogenicity. Power Doppler (PD) allows for visualizing hypervascularization. Some studies suggested that US assessment of enthesopathy might be sensitive and specific for SpA diagnosis. However, the diagnostic performance seems variable, and other studies found similar prevalence of US enthesopathy in rheumatoid arthritis (RA) and SpA or psoriatic arthritis. This study was carried on 100 RA patients aiming to assess the prevalence and distribution of entheseal abnormalities in lower limb enthesis by musculoskeletal ultrasound (MSUS) using the grey scale (GS) and power doppler (PD) modalities. None of the patients gave history of lower limb previous surgery or congenital anomalies, diabetes mellitus, neurological diseases, inflammatory bowel disease, psoriasis, or seronegative spondyloarthropathies.