Enthesis erosion in spondyloarthritis is not a persistent structural lesion

Ultrasound Assessment of Entheseal Sites and Anterior Chest Wall in Ankylosing Spondylitis: A Cross-Sectional Study

OBJECTIVES

The study was designed to evaluate entheseal sites and anterior chest wall (ACW) of patients with ankylosing spondylitis (AS) using ultrasound (US) and investigate the correlation between disease activity and US score.

METHODS

This prospective cross-sectional study included 104 patients with AS and 50 control subjects. Each patient underwent US scanning of 23 entheses and 11 sites of the ACW. The US features, including hypoechogenicity, thickness, erosion, calcification, bursitis, and Doppler signal, were evaluated. Disease activity was assessed based on C reactive protein (CRP), erythrocyte sedimentation rate (ESR), disease activity score-C reactive protein (ASDAS-CRP), and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI).

RESULTS

The most commonly involved entheses on US were the Achilles tendon (AT) and quadriceps tendon (QT). The most involved site of ACW was the sternoclavicular joint (SCJ). Compared with the control group, significant differences were observed in the AS group in the rates of US enthesitis and ACW in AT (P = .01), SCJ (P = .00), and costochondral joint (CCJ) (P = .01). Patients with high or very high disease activity had a higher erosion score (P = .02). The erosion score was weakly positively associated with CRP, ESR, BASDAI, ASDAS-CRP, and ASDAS-ESR (correlation coefficient: 0.22-0.45).

CONCLUSIONS

The most commonly involved entheseal sites on US were AT and QT, while the site of ACW was SCJ. The US assessment of AS should take the ACW into account. High disease activity might indicate erosion in AS.

The transition from enthesis physiological responses in health to aberrant responses that underpin spondyloarthritis mechanisms

PURPOSE OF REVIEW

Despite immunology and translational therapeutics advances in inflammatory arthritis over the past two decades, the enthesis, which is the epicentric of the spondyloarthritis family pathological process, retains many mysteries because of tissue inaccessibility that hampers direct immune study. As entheses are subject to almost continuous mechanical stress and spondyloarthritis is linked to microdamage or injury and joint stress, it is cardinal to understand the physiological changes occurring within the entheses not only to be able to differentiate disease from health but also to understand the transition normal physiology break down and its merges into spondyloarthritis-related disease.

RECENT FINDINGS

Imaging has played a major role in understanding the enthesis in human. Remarkable insights from enthesis functioning and microdamage in normal and with ageing including those linked to body mass index is emerging. The impact of mechanical stress and degenerative conditions on the development of the secondary entheseal vascular changes is not understood. Of note, ultrasound studies in psoriasis have shown higher power Doppler changes compared to controls pointing towards a role for vascular changes in the development of enthesitis in psoriatic arthritis.

SUMMARY

The literature pertaining to normal entheses changes with age, microdamage and vascular changes in health is providing a roadmap for understanding of the enthesis and its potential role in evolution of spondyloarthritis including psoriatic arthritis.

Enthesitis: A hallmark of psoriatic arthritis

OBJECTIVE

To describe the growing importance of enthesitis in patients with psoriatic arthritis (PsA) and discuss the advantages and disadvantages of clinical and imaging methods currently used to assess enthesitis.

METHODS

PubMed literature searches were conducted using the terms psoriatic arthritis, entheses, enthesitis, pathology, imaging, ultrasound, magnetic resonance imaging, clinical, and indices. Articles were deemed relevant if they provided insight into the pathology, monitoring, and/or diagnosis of enthesitis in PsA, or if they discussed clinical or imaging indices used to assess enthesitis.

RESULTS

Enthesitis is an early manifestation of PsA that is associated with increased disease activity and reduced quality of life. A variety of clinical indices exist to assess enthesitis in PsA; however, the Leeds Enthesitis Index and Maastricht Ankylosing Spondylitis Enthesitis Score index have been the most frequently used indices in recent clinical trials. Limitations of these indices include an inability to discern structural involvement, risk of missing subclinical enthesitis, and lack of sensitivity in detecting enthesitis, especially in patients with central sensitization and/or pain amplification. Such limitations have led to the emergent importance of imaging techniques in the assessment of enthesitis. Although there have been recent advances in magnetic resonance imaging, ultrasound (US) appears to be the preferred method for detecting enthesitis because it allows for accurate assessment of the soft-tissue components of entheses and also for new bone formation. Hypoechogenicity, increased thickness of tendon insertion, calcifications, enthesophytes, erosions, and Doppler activity have been identified as important US characteristics of enthesitis.

CONCLUSION

Enthesitis is thought to be integrally involved in the pathogenesis of PsA and is associated with worse prognostic outcomes in patients with PsA. A validated US index with entheses that are less confounded by mechanical factors and obesity would be the most effective measure of enthesitis in PsA. As imaging techniques continue to advance, our understanding of enthesitis and its involvement in PsA will also improve.

Construct validity and sensitivity to change of Belgrade Ultrasound Enthesitis Score in patients with spondyloarthritis: a pilot study

The objective of this study was to determine the construct validity and sensitivity to change of Belgrade Ultrasound Enthesitis Score (BUSES) in spondyloarthritis patients. Seventy-six spondyloarthritis patients with enthesitis were included in this pilot, prospective, double-blinded ultrasound study. Thirty-four patients received biological and forty-two patients received non-biological therapy. BUSES was determined at the beginning, after 1, 3, and 6 months. Spearman's correlation coefficient was calculated between BUSES and baseline characteristics. Brunner-Langer mixed non-parametric ANOVA was used to examine sensitivity to change of BUSES and effect of biological therapy on BUSES. Effect of time on the presence of each of the ultrasound enthesitis signs (increased thickness, hypoehogenicity, Power Doppler, enthesophytes, and erosions) was assessed using Cochran Q test. There was a weak, positive correlation between BUSES and disease duration, clinical enthesitis score, BASFI, BASDAI, and ASDAS-ESR/CRP. BUSES was higher at the beginning than after 1 month (p = 0.004), after 3 months (p < 0.001) and after 6 months (p < 0.001), as well as BUSES was higher after 1 month than after 3 months (p < 0.001) and after 6 months (p = 0.002). There is no difference in efficiency between non-biological and biological therapies on BUSES. Increased thickness, hypoechogenicity, and Power Doppler have decreased on Achilles tendon's and plantar fascia's enthesis over time. BUSES has a certain degree of construct validity because of the weak, positive correlation with parameters referring to severity of spondyloarthritis. BUSES demonstrated sensitivity to change over time due to decreasing of ultrasound acute enthesitis signs in treated spondyloarthritis patients. BUSES could be useful for monitoring the progression of enthesitis and effectiveness of the treatment.

Recommendations for the Use of Ultrasound and Magnetic Resonance in Patients With Spondyloarthritis, Including Psoriatic Arthritis, and Patients With Juvenile Idiopathic Arthritis

OBJECTIVE

To develop evidence-based recommendations on the use of ultrasound (US) and magnetic resonance imaging in patients with spondyloarthritis, including psoriatic arthritis, and juvenile idiopathic arthritis.

METHODS

Recommendations were generated following a nominal group technique. A panel of experts (15 rheumatologists and 3 radiologists) was established in the first panel meeting to define the scope and purpose of the consensus document, as well as chapters, potential recommendations and systematic literature reviews (we used and updated those from previous EULAR documents). A first draft of recommendations and text was generated. Then, an electronic Delphi process (2 rounds) was carried out. Recommendations were voted from 1 (total disagreement) to 10 (total agreement). We defined agreement if at least 70% of participants voted≥7. The level of evidence and grade or recommendation was assessed using the Oxford Centre for Evidence Based Medicine levels of evidence. The full text was circulated and reviewed by the panel. The consensus was coordinated by an expert methodologist.

RESULTS

A total of 12 recommendations were proposed for each disease. They include, along with explanations of the validity of US and magnetic resonance imaging regarding inflammation and damage detection, diagnosis, prediction (structural damage progression, flare, treatment response, etc.), monitoring and the use of US guided injections/biopsies.

CONCLUSIONS

These recommendations will help clinicians use US and magnetic resonance imaging in patients with spondyloarthritis and juvenile idiopathic arthritis.

Novel imaging modalities in spondyloarthritis

Novel imaging techniques have emerged in the field of spondyloarthritis. This article will cover the role of, and the sensitivity and specificity of magnetic resonance imaging (MRI) and ultrasound in the diagnosis and monitoring of axial and peripheral SpA. It will discuss how the definition of a 'positive MRI' of the sacroiliac joints and spine is evolving. Differential diagnoses of inflammatory lesions of both the sacroiliac joints and the spine are addressed due to their importance in image interpretation. The article will also discuss the role of sonography in assessing peripheral entheses, joints, tendon sheaths, nails and soft tissues. The utility for clinical as well as an outcome measure will be discussed. We finally aim to give guidance on when and how to use these new modalities and on how to analyse and interpret the imaging findings in daily practice.

Usefulness of ultrasonography in the assessment of peripheral enthesis in spondyloarthritis

Enthesitis is one of the characteristic etiopathogenic manifestations of spondyloarthritis. However, in clinical practice, its presence often goes unnoticed because of the lack of precision and sensitivity of physical examination to detect it. Viable, valid and reliable imaging tests are needed for early diagnosis, as well as a good sensitivity to change to monitor therapeutic response. In this paper we review the most relevant aspects of current knowledge of the enthesis and discusses the validity of ultrasound for assessing enthesitis in spondyloarthritis and its sensitivity to change to monitor therapeutic response.

Three-dimensional versus two-dimensional ultrasonographic assessment of peripheral enthesitis in spondylarthritis

To compare the intra- and interobserver reliability of three-dimensional (3D) volumetric versus conventional two-dimensional (2D) power Doppler ultrasonography (US) in the assessment of peripheral enthesitis in spondylarthritis (SpA). Sixteen patients with SpA according to ASAS criteria were included. Two rheumatologists (one experimented in musculoskeletal US (sonographer 1) and one beginner (sonographer 2)) performed independently a 2D US scoring of the enthesis using the Madrid Sonographic Enthesis Index score followed by a 3D acquisition of the same entheseal sites. The reading of the 3D acquisition was performed a minimum of 1 week apart. Intraobserver reliability was evaluated by a second reading of the same images. The duration of 2D US scanning, 3D US acquisition and reading was recorded. Intraclass correlation coefficients (ICCs) were used for the reliability analysis. Intraobserver reproducibility was good to excellent for 2D US and good for 3D US (ICC (95 %CI) 2D US 0.776 (0.471-0.916) and 0.96 (0.892-0.986) and ICC (95 %CI) 3D US 0.796 (0.498-0.921) and 0.703 (0.325-0.886) for sonographer 1 and 2, respectively). Interobserver reliability was slightly better for 3D US than for 2D US (ICC (95 %CI) 0.776 (0.471-0.916) for 3D US versus 0.641 (0.221-0.859) for 2D US). The mean time (±SD) for 2D US scanning was 23 min (±4) whereas the mean time for 3D US volume acquisition and reading was 16.5 min (±2.6) (p < 0.001). 3D US showed good intra- and interobserver reliability in the assessment of enthesitis in SpA and shortened the needed time for scanning. It can be performed by a nonexperienced examiner without loss of reliability.

[Present and future of echography in spondyloarthritis]

Today ultrasound in spondyloarthritis is being developed in three main areas. Joint ultrasound is similar to that described in rheumatoid arthritis and other synovitis, with extensive literature on the matter. Enthesis ultrasound has a growing number of publications that describe the main elementary lesions. Several ultrasound enthesis scores have been developed that provide an overall view of the patient status and this information is useful both in the field of diagnosis and in assessing disease activity. The sacroiliac joints have also received attention and the published sensitivity and specificity could be useful in clinical practice. The future is unknown, but ultrasound has many possibilities that include improving the reliability, the incorporation of enthesis ultrasound assessment to the diagnostic classification criteria as well as the likelyhood developing simplified scores.