Enthesopathies and enthesitis. Part 2: Imaging studies

Abstract

The pathologies of tendon and ligament attachments are called enthesopathies. Enthesitis is one of enthesopathies and it is considered a characteristic sign of rheumatic diseases from the spondyloarthritis group, including peripheral spondyloarthritis. Therefore, enthesitis has been included in a number of clinical classifications for diagnosing these diseases. Clinical diagnosis of enthesitis is based on rather non-specific clinical signs and results of laboratory tests. It is believed that imaging examinations might improve diagnosis, particularly because numerous papers prove that differentiating enthesitis from other enthesopathic processes is possible. On the other hand, a number of authors report the lack of specific signs in imaging as well as typical histological and immunological features that would enable confirmation of clinical diagnosis of enthesitis. The first part of the publication presented theories on the etiopathogenesis of enthesitis (inflammatory, mechanical, autoimmune and associated with the synovio-entheseal complex) as well as on the formation of enthesophytes (inflammatory, molecular and mechanical). This paper – the second part of the article, is a review of the state-of-the-art on the ability of imaging examinations to diagnose enthesitis. It turns out that none of the enthesitis criteria used in imaging examinations is specific for inflammation. As enthesitis may be the only symptom of early spondyloarthritis (particularly in patients with absent HLA-B27 antigen), the lack of its unambiguous picture in ultrasound and magnetic resonance imaging prompts the search for other signs characteristic of spondyloarthritis and more specific features in imaging in order to make a diagnosis as early as possible.

The sonoanatomy of lumbar erector spinae and its iliac attachment – the potential substrate of the iliac crest pain syndrome, an ultrasound study in healthy subjects

“…Initially, the muscles become bigger and stronger, but as the stress continues, their tendons could develop enthesopathy ( 15 ) . Concerning US assessment of these structures, numerous publications indicate that pathologically transformed entheses display a variety of sonographic markers that allow the differentiation of a normal from abnormal tissue ( 16 ) .…”

Selected issues in diagnostic imaging of spondyloarthritides: psoriatic arthritis and juvenile spondyloarthritis

“…This issue is still under research and several hypotheses published so far propose different mechanisms which might explain that feature [16–18]. The spectrum of changes observed in patients with a clinical diagnosis of enthesitis in MRI and power Doppler ultrasound is identical to that observed in the course of degenerative changes or microinjuries in healthy controls [19–21] (Fig.…”

Anterolateral hip pain: Sonographic evaluation of the proximal iliotibial band and tensor fascia lata

“…In the setting of tendinopathy, the tendon shows increased thickness, a reduction in the typically fibrillar structure and decreased echogenicity of the tendon . Additionally, neovascularization in response to injury may occur in the normally sparsely‐vascularized tendon.…”