Enthesopathies and enthesitis. Part 1. Etiopathogenesis

Abstract

The pathologies of tendon and ligament attachments are called enthesopathies. One of its types is enthesitis which is a characteristic sign of peripheral spondyloarthropathy. Clinical diagnosis of enthesitis is based on rather non-specific clinical signs and results of laboratory tests. Imaging examinations are highly promising. Numerous publications prove that enthesitis can be differentiated from other enthesopathic processes in an ultrasound examination or magnetic resonance imaging. However, some reports indicate the lack of histological criteria, specific immunological changes and features in imaging examinations that would allow the clinical diagnosis of enthesitis to be confirmed. The first part of the publication presents theories on the etiopathogenesis of enthesopathies: inflammatory, mechanical, autoimmune, genetic and associated with the synovio-entheseal complex, as well as theories on the formation of enthesophytes: inflammatory, molecular and mechanical. The second part of the paper is a review of the state-of-the-art on the ability of imaging examinations to diagnose enthesitis. It indicates that none of the criteria of inflammation used in imaging medicine is specific for this pathology. As enthesitis may be the only symptom of early spondyloarthropathy (particularly in patients with absent HLA-B27 receptor), the lack of its unambiguous picture in ultrasound and magnetic resonance scans prompts the search for other signs characteristic of this disease and more specific markers in imaging in order to establish diagnosis as early as possible.

Enthesopathies and enthesitis. Part 2: Imaging studies

“…According to the theories on the etiopathogenesis of SpA ( 1 ) , US and MRI examinations confirmed that the inflammatory process may begin beyond entheses, i.e. in the synovium of the neighboring bursa (bursitis) where it is triggered (according to the mechanical theory) by enthesis microdamage ( fig.…”

“…8 ), in the synovium of the tendon sheath (tenosynovitis, tendovaginitis) or in the peritendineum (according to the functional enthesis theory) as a response to a strain, e.g. pressing the tibialis posterior muscle on the medial malleolus ( 1 , 25 ) ( Fig. 9 ).…”

“…Clinical diagnosis of enthesitis is based on rather non-specific clinical signs and symptoms, i.e. medical history and physical examination ( 1 , 2 ) . More and more often, in order to confirm the initial diagnosis, rheumatologists refer patients to an ultrasound examination (or perform it themselves) in which the diagnosis of enthesitis is established on the basis of features that are frequently observed in other enthesopathies as well.…”

Correlation of enthesitis indices with disease activity and function in axial and peripheral spondyloarthritis: a cross-sectional study comparing MASES, SPARCC and LEI

“…Although enthesitis has traditionally been viewed as a focal abnormality, the inflammatory reaction intrinsic to enthesitis may be quite extensive [1]. In the clinical practice, the diagnosis of enthesitis is based on clinical examination, including interview (pain at the site of an enthesis that subsides following physical exercise) and observing pain in an enthesis upon compression [2]. Ultrasound and magnetic resonance image (RMI) are more direct ways to assess enthesitis although less feasible.…”

Imaging Features of the Juvenile Inflammatory Arthropathies

“…• Specific Indications for MRI in Children with JIA (►Figs. [22][23][24][25][26][27][28] • Evaluation of inflammatory changes in peripheral joints, tendon sheaths, and bursae. In the early phase of inflammation, exudate fluid, thickening, and postcontrast enhancement of the synovial membrane (representing synovitis, tenosynovitis, bursitis) are seen.…”