Ultrasound definition of enthesitis in spondyloarthritis and psoriatic arthritis: arrival or starting point?

Ultrasound assessment of Achilles enthesitis: a dedicated training program

OBJECTIVE

To describe an intensive and multimodal ultrasound (US) training program focused on Achilles enthesitis and to illustrate the learning curve of trainees without experience.

METHODS

Three medical students (trainees) and two rheumatologists experienced in musculoskeletal US (trainers) were involved in the training program, which encompassed one preliminary theoretical-practical meeting and five scanning sessions (two patients per session). The students and one expert performed the US examination of the Achilles enthesis bilaterally. The trainees acquired representative images and assessed the presence of Outcome Measures in Rheumatology (OMERACT) US abnormalities of enthesitis. The experts provided feedback addressing trainees' misinterpretations, and the quality of the acquired images was evaluated. A dedicated questionnaire was used to evaluate the students' confidence. After each session, five sets of static images (total=100 images of most commonly scanned entheses) were provided and scored by the students according to OMERACT US definitions. Total agreement and prevalence and bias adjusted kappa (PABAK) were used to evaluate the concordance between the trainees and the expert sonographer.

RESULTS

The total agreement and PABAK significantly improved between the first and fifth scanning sessions (76.2% versus 92.9%, p<0.01, and 0.5 versus 0.79, p<0.01) and between the first and fifth static image sets (64.5% versus 81.9%, p<0.01, and 0.29 versus 0.74, p<0.01). Image quality did not significantly improve (p=0.34). A significant increase in trainees' confidence was registered (p<0.01).

CONCLUSIONS

The described training program rapidly improved the students' performance in the US assessment of Achilles enthesitis, appearing to be an effective starting model for the future development of pathology-oriented teaching programs for the US in rheumatology.

Relationship Between Ultrasound and Physical Examination in the Assessment of Enthesitis in Patients With Spondyloarthritis: Results From the DEUS Multicenter Study

OBJECTIVE

The study objectives were (i) to explore the agreement between the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and physical examination in assessing enthesitis in patients with spondyloarthritis (SpA) and (ii) to investigate the prevalence and clinical relevance of subclinical enthesitis in this population.

METHODS

Twenty rheumatology centers participated in this cross-sectional study. Patients with SpA, including axial spondyloarthritis (axSpA) and psoriatic arthritis (PsA), underwent both ultrasound scan and physical examination of large lower limb entheses. The OMERACT ultrasound lesions of enthesitis were considered, along with a recently proposed definition for "active enthesitis" by our group. Subclinical enthesitis was defined as the presence of "active enthesitis" in ≥1 enthesis in patients with SpA without clinical enthesitis (ie, number of positive entheses on physical examination and Leeds Enthesitis Index score = 0).

RESULTS

A total of 4,130 entheses in 413 patients with SpA (224 with axSpA and 189 with PsA) were evaluated through ultrasound and physical examination. Agreement between ultrasound and physical examination ranged from moderate (ie, enthesophytes) to almost perfect (ie, power Doppler and "active enthesitis"). Patellar tendon entheses demonstrated the highest agreement, whereas Achilles tendon insertion showed the lowest. Among 158 (38.3%) of 413 patients with SpA with clinical enthesitis, 108 (68.4%) exhibited no "active enthesitis" on ultrasound. Conversely, of those 255 without clinical enthesitis, 39 (15.3%) showed subclinical enthesitis. Subclinical enthesitis was strongly associated with local structural damage. However, no differences were observed regarding the demographic and clinical profiles of patients with SpA with and without subclinical enthesitis.

CONCLUSION

Our study underscores the need for a comprehensive tool integrating ultrasound and physical examination for assessing enthesitis in patients with SpA.

Power Doppler signal at the enthesis and bone erosions are the most discriminative OMERACT ultrasound lesions for SpA: results from the DEUS (Defining Enthesitis on Ultrasound in Spondyloarthritis) multicentre study

OBJECTIVES

To assess, in spondyloarthritis (SpA), the discriminative value of the Outcome Measures in Rheumatology (OMERACT) ultrasound lesions of enthesitis and their associations with clinical features in this population.

METHODS

In this multicentre study involving 20 rheumatology centres, clinical and ultrasound examinations of the lower limb large entheses were performed in 413 patients with SpA (axial SpA and psoriatic arthritis) and 282 disease controls (osteoarthritis and fibromyalgia). 'Active enthesitis' was defined as (1) power Doppler (PD) at the enthesis grade ≥1 plus entheseal thickening and/or hypoechoic areas, or (2) PD grade >1 (independent of the presence of entheseal thickening and/or hypoechoic areas).

RESULTS

In the univariate analysis, all OMERACT lesions except enthesophytes/calcifications showed a significant association with SpA. PD (OR=8.77, 95% CI 4.40 to 19.20, p<0.001) and bone erosions (OR=4.75, 95% CI 2.43 to 10.10, p<0.001) retained this association in the multivariate analysis. Among the lower limb entheses, only the Achilles tendon was significantly associated with SpA (OR=1.93, 95% CI 1.30 to 2.88, p<0.001) in the multivariate analyses. Active enthesitis showed a significant association with SpA (OR=9.20, 95% CI 4.21 to 23.20, p<0.001), and unlike the individual OMERACT ultrasound lesions it was consistently associated with most clinical measures of SpA disease activity and severity in the regression analyses.

CONCLUSIONS

This large multicentre study assessed the value of different ultrasound findings of enthesitis in SpA, identifying the most discriminative ultrasound lesions and entheseal sites for SpA. Ultrasound could differentiate between SpA-related enthesitis and other forms of entheseal pathology (ie, mechanical enthesitis), thus improving the assessment of entheseal involvement in SpA.

Enthesitis in Spondyloarthritis Including Psoriatic Arthritis-To Inject or Not To Inject?: A Narrative Review

PURPOSE

Enthesitis is a key manifestation of psoriatic arthritis (PsA) and spondyloarthritis (SpA) and is considered to be the tissue where the disease initiates. Enthesitis leads to pain and substantial limitations in patients with PsA. Treatment is key in achieving remission or minimal disease activity. Whether it is safe to apply injections to entheseal tissue is unknown. This narrative review aimed to summarize the literature on the efficacy and tolerability of entheseal corticosteroid (CS) injections.

METHODS

The published literature was searched through PubMed as well as identifying relevant articles from their citations,  for articles on the anatomic location of the injection, tissue characteristics (eg, whether there is a tendon sheath), blind versus imaging-guided and entheseal versus perientheseal injections, and related studies in animals. Given that articles on SpA are limited, those on mechanical enthesopathies were also included.

FINDINGS

The literature on the efficacy and tolerability of entheseal CS injection in SpA and PsA are limited. In most articles on entheseal injection, the entheseal tissue has not actually been targeted. The decision of entheseal injection should be made on an individual basis, with consideration of the use of CS injection as the last treatment option following more conservative measures such as NSAIDs, physiotherapy, rest, and lifestyle modifications. Entheseal injection should be avoided in high-risk patients, such as those who have rupture at the enthesis. Diagnostic ultrasound is advised to ensure the presence of inflammation that can potentially benefit from corticosteroid injection, as well as the absence of rupture. In the authors' perspective, perientheseal injections should be tried before intraentheseal injections. Finally, ultrasound guidance for needle placement is strongly encouraged.

IMPLICATIONS

The literature on the efficacy and tolerability of entheseal CS injection in SpA and PsA is limited. With the lack of quality data, recommendations on entheseal corticosteroid injection remain expert opinion.

The Usefulness of Cellular Immune Inflammation Markers and Ultrasound Evaluation in the Assessment of Disease Activity in Patients with Spondyloarthritis

BACKGROUND

The systemic inflammation response index (SIRI) and systemic immune-inflammation index (SII) have been introduced as inflammatory markers and predictors of poor prognosis in cancer and cardiovascular diseases. An appropriate evaluation of disease activity in spondyloarthritis (SpA) might be challenging. The purpose of this study was to evaluate the usefulness of cellular immune inflammation markers and ultrasound (US) evaluation of entheses and joints in the assessment of disease activity in SpA patients.

METHODS

This cross-sectional study involved patients with SpA (62 axial SpA, 38 peripheral SpA, pSpA). The clinical data of both tender, swollen joint counts, erythrocyte sedimentation rate, C-reactive protein, white blood cell counts, and disease activity using Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Disease Activity Index for Psoriatic Arthritis (DAPSA), were recorded. The SIRI, SII, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were calculated. US examination was performed (22 small joints, Achilles tendon, and plantar aponeurosis for enthesitis).

RESULTS

The SII, SIRI, NLR, and PLR were higher, and LMR was lower in patients with high disease activity (BASDAI > 4). Higher SII was observed in pSpA patients with moderate/high disease activity (DAPSA > 14). The SIRI was correlated with clinical and laboratory parameters of disease activity. The SII was correlated with US parameters in pSpA. Higher SII and NLR values were found in patients with signs of activity compared with no activity in the US of peripheral joints. There were no associations with US changes in entheses.

CONCLUSIONS

The results of this study point to the value of SIRI and SII as biomarkers of disease activity in patients with SpA. The SII was associated with synovitis in the US of the peripheral joints.

Doppler Signal and Bone Erosions at the Enthesis Are Independently Associated With Ultrasound Joint Erosive Damage in Psoriatic Arthritis

OBJECTIVE

To explore the association of the Outcome Measures in Rheumatology ultrasound (US) entheseal abnormalities with the presence of US joint bone erosions in psoriatic arthritis (PsA).

METHODS

Consecutive patients with PsA were included in this cross-sectional study. Demographic and clinical variables were collected. A bilateral US assessment was carried out at the following entheses: plantar fascia, and the quadriceps, patellar (proximal and distal), and Achilles tendons. The following US entheseal abnormalities were registered: hypoechogenicity, thickening, Doppler signal < 2 mm from the bony cortex, calcification/enthesophyte, and bone erosion. The presence of US joint bone erosions was investigated at the second and fifth metacarpophalangeal joints, ulnar head, and fifth metatarsophalangeal (MTP) joint, bilaterally, as well as at the level of the most inflamed joint on physical examination. Multiple linear regression analysis was performed to identify clinical and/or US variables associated with US-detected joint bone erosions.

RESULTS

A total of 104 patients with PsA were enrolled. At least 1 joint bone erosion was found in 47 of 104 patients (45.2%). Bone erosions were most frequently detected at the fifth MTP joint level (42/208 joints [20.2 %] in 32/104 patients [30.8%]). In the multivariate model, only a power Doppler (PD) signal at the enthesis (P < 0.001, standardized β = 0.51), bone erosions at the enthesis (P = 0.02, standardized β = 0.20), PsA disease duration (P = 0.04, standardized β = 0.17), and greyscale joint synovitis (P = 0.03, standardized β = 0.42) were associated with US-detected joint bone erosions.

CONCLUSION

PD signal and bone erosions at the enthesis represent sonographic biomarkers of a more severe subset of PsA in terms of US-detected joint erosive damage.

Reliability assessment of the definition of ultrasound enthesitis in SpA: results of a large, multicentre, international, web-based study

OBJECTIVES

To investigate the reliability of the OMERACT US Task Force definition of US enthesitis in SpA.

METHODS

In this web exercise, based on the evaluation of 101 images and 39 clips of the main entheses of the lower limbs, the elementary components included in the OMERACT definition of US enthesitis in SpA (hypoechoic areas, entheseal thickening, power Doppler signal at the enthesis, enthesophytes/calcifications, bone erosions) were assessed by 47 rheumatologists from 37 rheumatology centres in 15 countries. Inter- and intra-observer reliability of the US components of enthesitis was calculated using Light's kappa, Cohen's kappa, Prevalence And Bias Adjusted Kappa (PABAK) and their 95% CIs.

RESULTS

Bone erosions and power Doppler signal at the enthesis showed the highest overall inter-reliability [Light's kappa: 0.77 (0.76-0.78), 0.72 (0.71-0.73), respectively; PABAK: 0.86 (0.86-0.87), 0.73 (0.73-0.74), respectively], followed by enthesophytes/calcifications [Light's kappa: 0.65 (0.64-0.65), PABAK: 0.67 (0.67-0.68)]. This was moderate for entheseal thickening [Light's kappa: 0.41 (0.41-0.42), PABAK: 0.41 (0.40-0.42)], and fair for hypoechoic areas [Light's kappa: 0.37 (0.36-0.38); PABAK: 0.37 (0.37-0.38)]. A similar trend was observed in the intra-reliability exercise, although this was characterized by an overall higher degree of reliability for all US elementary components compared with the inter-observer evaluation.

CONCLUSIONS

The results of this multicentre, international, web-based study show a good reliability of the OMERACT US definition of bone erosions, power Doppler signal at the enthesis and enthesophytes/calcifications. The low reliability of entheseal thickening and hypoechoic areas raises questions about the opportunity to revise the definition of these two major components for the US diagnosis of enthesitis.