Ultrasound and Clinical Evaluation of Quadricipital Tendon Enthesitis in Patients with Psoriatic Arthritis and Rheumatoid Arthritis

Abstract

Enthesitis is an inflammatory lesion of the tendon, ligament and capsular insertions into the bone, and it is a fundamental element in the diagnosis of spondyloarthropathies. Sonography is the method of choice for studying periarticular soft tissues because it is capable of detecting both the early (oedema, thickening) and late alterations (erosions and enthesophytes); it is also an inexpensive, biologically harmless and easily repeatable technique. The aim of this study was to compare the prevalence of quadricipital enthesitis in psoriatic arthritis (PsA) and rheumatoid arthritis (RA) patients, and to document any clinical and echostructural differences in this lesion between the two diseases. The results show that enthesitis is more frequent in PsA patients, more than half of whom are asymptomatic. Knee inflammation was found in the PsA patients with enthesitis regardless of the concomitant presence of joint effusion; none of the RA patients suffered from enthesitis alone. Quadricipital enthesitis is more frequent in male patients. There was no significant correlation between the presence of peripatellar psoriatic lesions and enthesitis. Sonographic examinations of patients with enthesitis revealed that those with RA had predominantly inflammatory lesions, whereas PsA patients also showed major new bone deposition.

Patellar Tendon Properties and Lower Limb Function in Rheumatoid Arthritis and Ankylosing Spondylitis versus Healthy Controls: A Cross‐Sectional Study

“…Histological findings from cadavers indicate the underlying structural changes at and around the enthesis including periosteal bone reaction, alterations of the bone structure, and increased bone formation, endochondral ossification, and vascular invasion of the fibrocartilage that facilitates access for inflammatory cells [37]. Our results are in agreement with Balint et al who demonstrated thickening on US of the infrapatellar and tibial entheseal insertions in patients with SpA [38], and with other authors describing tendon thickening on US in SpA [11, 39]. …”

“…The main drivers of the local inflammatory process are TNF- α , interleukin-1 (IL-1) and IL-6 which produce proteolytic enzymes such as matrix metalloproteinases that lead to collagen destruction [32], and the proangiogenic vascular endothelial growth factor, which evokes synovial hyperplasia and infiltration of macrophages and T cells into synovium [14]. According to the different pathologies of RA and AS inflammatory molecules target primarily the enthesis in AS, whereas in RA tendon involvement is thought to be secondary through the proximity to inflamed synovium [10, 11]. Systemically circulating cytokines [33] could have an additional detrimental effect on the tendon in both RA and AS.…”

“…These in turn lead to thickening of the tissue and fibrocartilage formation at the tendon insertions (enthesophytes) and ligaments (such as syndesmophytes in the axial skeleton) and account for the gradual ankylosing of joints and vertebrae with loss of movement. Corresponding structural alterations found on magnetic resonance and ultrasound (US) imaging include thickening and hypervascularity of the tendon and enthesis [10, 11]. While enthesitis is the primary feature of AS, a secondary inflammatory reaction in the synovium and tenosynovium can occur [9].…”

Assessment of patients with psoriatic arthritis: A review of currently available measures

“…MRI and US, especially with the aid of contrast, offer a unique advantage over conventional radiography in the evaluation of enthesopathy, a prominent clinical feature of PsA, as well as in the assessment of sacroiliitis. These techniques can better distinguish the presence and extent of inflammatory activity in these lesions, and potentially may be sensitive tools for assessing the response to therapy (82)(83)(84)(85)(86). The assessment of entheses is particularly important in PsA, since its role in the pathogenesis of the disease has been emphasized (87).…”

Clinical Examination, Ultrasound and MRI Imaging of The Painful Elbow in Psoriatic Arthritis and Rheumatoid Arthritis: Which is Better, Ultrasound or MR, for Imaging Enthesitis?

“…According to this hypothesis, synovitis in PsA is considered to be secondary to the extra-capsular disease. On the other hand, a number of authors have recognised the occurrence of enthesitis as part of the RA disease spectrum [6–8]. It is therefore clear that, by the time the patient presents, both synovitis and enthesitis may occur in both conditions, occasionally making it difficult to distinguish between them on radiological grounds [9].…”