Ultrasound in the evaluation of enthesitis: status and perspectives

Identifying enthesitis in the sacroiliac joints in patients with axial spondyloarthritis by readers of varying experience: impact of the learning progress

BACKGROUND

This study aimed to investigate the accuracy of identifying enthesitis along with other inflammatory lesions and structural lesions on the MRI of the sacroiliac joints (SIJ) by readers of varying experience and how training sessions and workshops could help improve the accuracy.

METHODS

A total of 224 patients with clinical diagnosis of axial spondyloarthritis who underwent SIJ MRI examinations were retrospectively included in this study. Three readers with 5 years, 3 years and 1 year of experience in musculoskeletal imaging were invited to review the SIJ MRI images independently, while the imaging reports of a senior radiologist (> 10 years' experience) were used as reference. After the first round of image review, a training session and a workshop on the imaging of SIJ in spondyloarthritis were held and the three readers were asked to review the images in the second round. We calculated the accuracy of identifying inflammatory and structural lesions of the three readers as well as the intra-reader agreement.

RESULTS

Enthesitis could be observed in 52.23% of the axial spondyloarthritis patients, while 81.58% of the patients with enthesitis were accompanied with bone marrow edema. All the three readers showed better accuracy at identifying structural lesions than inflammatory lesions. In the first round of image review, the three readers only correctly identified 15.07%, 2.94% and 0.74% of the enthesitis sites. After the training session and workshop, the accuracy rose to 61.03%, 39.34% and 20.22%. The intra-reader agreement of enthesitis calculated as Cohen's kappa was 0.23, 0.034 and 0.014, respectively.

CONCLUSION

Readers with less experience in musculoskeletal imaging showed lower accuracy of identifying inflammatory lesions, notably enthesitis. Training sessions and workshops could help improve the diagnostic accuracy of the junior readers.

Subclinical Enthesopathy in Psoriasis-An Ultrasonographic Study

The present study is aimed at assessing the presence and prevalence of subclinical entheseal changes in Psoriasis (PsO) patients using musculoskeletal ultrasonography (US), conjoined with the analysis of possible differences in terms of demographic, clinical, or biological features. We carried out an observational study on 54 patients with PsO and 40 controls. Subclinical enthesopathy, according to OMERACT definitions, was identified in 20 of the psoriasis patients (37.03%), a significantly difference compared to the controls (5 patients; 10.20%). A comparison between US examinations for psoriasis patients and controls indicates that all the examined areas manifested changes in a significantly higher percentage of patients than the controls. The most common structural changes were represented by thickened tendon (85%), calcification (65%), erosions (35%), power Doppler (PD) signal (20%), and bursitis (5%). The difference in mean MASEI (Madrid Sonographic Enthesitis Index) score between the psoriasis and control groups was statistically significant (10.56 + 2.96 vs. 2.9 + 2.20; p < 0.0001). In conclusion, ultrasound is an easily accessible and vital follow-up method for psoriasis patients to enable an early, subclinical detection of entheseal involvement, i.e., the first red-flag sign for a future transition to psoriatic arthritis (PsA).

Ultrasonographic Synovitis Is Associated with the Development of Joint Destruction in Patients with Psoriatic Arthritis

BACKGROUND

Psoriatic arthritis (PsA) is characterized by enthesitis. As persistent inflammation around joints results in bone and cartilage destruction and physical impairment, a detailed assessment of inflammation is essential. We previously reported the difference between clinical assessment (tenderness) and ultrasound (US) assessment (inflammation) of entheses. Herein, we investigated whether clinical or US assessment of joints and entheses can predict the progression of joint destruction in Japanese patients with PsA.

METHODS

Thirty joints and 14 entheses in 47 patients were assessed using US and clinical examination. The US greyscale (GS) and power Doppler (PD) scores at the ultrasonographic synovitis, the US active enthesitis count, and the clinical tender joint/entheses count were assessed. Additionally, the yearly radiographic progression of the Sharp-van der Heijde scoring method for PsA was assessed. Their correlations were investigated.

RESULTS

About half of the patients with PsA experienced joint destruction during a follow-up period of 20.4 months. Progression of joint destruction in patients with PsA only correlated with joint GS and PD scores, reflecting the severity of ultrasonographic synovitis, not with the tender joint/entheses count.

CONCLUSIONS

US examinations are essential for preventing joint destruction and physical impairment in patients with PsA.

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.

Ultrasonographic Insights into Peripheral Psoriatic Arthritis: Updates in Diagnosis and Monitoring

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis associated with psoriasis, characterized by heterogeneous clinical manifestations and variable disease progression. Ultrasonography has emerged as a valuable tool in the diagnosis and monitoring of PsA, providing real-time visualization of joint and soft tissue abnormalities. This review highlights recent advancements in ultrasonographic techniques for the assessment of PsA, including the identification of typical features, the role of power Doppler imaging in detecting active inflammation, and the potential of ultrasound for guiding treatment decisions. Additionally, we discuss the utility of ultrasound in assessing treatment response and monitoring disease progression in patients with PsA, with a focus on novel imaging modalities. By elucidating the evolving role of ultrasonography in PsA management, this article aims to enhance clinicians' understanding of its utility in facilitating early diagnosis, optimizing treatment strategies, and improving patient outcomes.

Increased Circulating CD14+ Monocytes in Patients with Psoriatic Arthritis Presenting Impaired Apoptosis Activity

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis primarily affecting peripheral and axial joints. The osteolytic effect in the damaged joint is mediated by osteoclast activation. We aimed to investigate differential gene expression in peripheral CD14+ monocytes between patients with psoriatic arthritis (n = 15) and healthy controls (HCs; n = 15). Circulating CD14+ monocytes were isolated from peripheral blood mononuclear cells using CD14+ magnetic beads. Cell apoptosis was measured via Annexin V using flow cytometry. The gene expression profiling was analyzed via microarray (available in the NCBI GEO database; accession number GSE261765), and the candidate genes were validated using PCR. The results showed a higher number of peripheral CD14+ monocytes in patients with PsA than in the HCs. By analyzing the microarray data, identifying the differentially expressed genes, and conducting pathway enrichment analysis, we found that the apoptosis signaling pathway in CD14+ cells was significantly impaired in patients with PsA compared to the HCs. Among the candidate genes in the apoptotic signaling pathway, the relative expression level of cathepsin L was confirmed to be significantly lower in the PsAs than in the HCs. We concluded that the numbers of peripheral CD14+ monocytes increased, and their apoptosis activity was impaired in patients with PsA, which could lead to enhanced macrophage maturation and osteoclast activation. The resistance of apoptotic death in peripheral CD14+ monocytes may contribute to active joint inflammation in PsA.

Achilles tendon and enthesis assessment using ultrashort echo time magnetic resonance imaging (UTE-MRI) T1 and magnetization transfer (MT) modeling in psoriatic arthritis

The purpose of this study is to investigate the use of ultrashort echo time (UTE) magnetic resonance imaging (MRI) techniques (T1 and magnetization transfer [MT] modeling) for imaging of the Achilles tendons and entheses in patients with psoriatic arthritis (PsA) compared with asymptomatic volunteers. The heels of twenty-six PsA patients (age 59 ± 15 years, 41% female) and twenty-seven asymptomatic volunteers (age 33 ± 11 years, 47% female) were scanned in the sagittal plane with UTE-T1 and UTE-MT modeling sequences on a 3-T clinical scanner. UTE-T1 and macromolecular proton fraction (MMF; the main outcome of MT modeling) were calculated in the tensile portions of the Achilles tendon and at the enthesis (close to the calcaneus bone). Mann-Whitney-U tests were used to examine statistically significant differences between the two cohorts. UTE-T1 in the entheses was significantly higher for the PsA group compared with the asymptomatic group (967 ± 145 vs. 872 ± 133 ms, p < 0.01). UTE-T1 in the tendons was also significantly higher for the PsA group (950 ± 145 vs. 850 ± 138 ms, p < 0.01). MMF in the entheses was significantly lower in the PsA group compared with the asymptomatic group (15% ± 3% vs. 18% ± 3%, p < 0.01). MMF in the tendons was also significantly lower in the PsA group compared with the asymptomatic group (17% ± 4% vs. 20% ± 5%, p < 0.01). Percentage differences in MMF between the asymptomatic and PsA groups (-16.6% and -15.0% for the enthesis and tendon, respectively) were higher than the T1 differences (10.8% and 11.7% for the enthesis and tendon, respectively). The results suggest higher T1 and lower MMF in the Achilles tendons and entheses in PsA patients compared with the asymptomatic group. This study highlights the potential of UTE-T1 and UTE-MT modeling for quantitative evaluation of entheses and tendons in PsA patients.

Dickkopf-Related Protein 1 (DKK-1) as a Possible Link between Bone Erosions and Increased Carotid Intima-Media Thickness in Psoriatic Arthritis: An Ultrasound Study

Psoriatic arthritis (PsA) is a heterogenous systemic inflammatory disorder that affects peripheral joints and skin, but also causes inflammation at entheseal sites, digits (dactylitis) and the axial skeleton. Despite considerable advances, our understanding of the pathogenesis and management of PsA is hampered by its complex clinical expression. We enrolled patients who met the ClASsification for Psoriatic Arthritis (CASPAR) criteria for PsA (n = 17), and healthy controls (n = 13). The lipid profile, C-reactive protein (CRP) and Dickkopf-related protein 1 (DKK-1) circulating levels were measured for all subjects. For the patients with PsA, (1) the erosive character of the articular disease was assessed by a musculoskeletal ultrasound and (2) the cardiovascular risk was evaluated using the Systematic Coronary Risk Evaluation (SCORE) chart and the ultrasound measurement of the carotid intima-media thickness. A higher titer of serum DKK-1 was associated with the presence of erosions (p < 0.005) and the cIMT correlated with DKK-1 levels in patients with PsA (r = 0.6356, p = 0.0061). Additionally, we observed a positive correlation between increased cIMT and CRP (r = 0.5186, p = 0.0329). Our results suggest that DKK-1 could be used as an early biomarker for the erosive character of the articular disease and for the assessment of the cardiovascular risk in PsA patients.

Value of Hands Ultrasonography in the Differential Diagnosis Between Psoriatic Arthritis and Rheumatoid Arthritis

OBJECTIVES

Psoriatic arthritis (PsA) can mimic rheumatoid arthritis (RA) at an early stage, especially when psoriasis is lacking. In the absence of specific radiological and immunological markers, the differential diagnosis between these two diseases can be challenging. We aimed to determine whether hands ultrasonography (US) may be useful in the differential diagnosis between PsA and RA.

METHODS

We conducted a cross-sectional study including patients with PsA and RA. All wrists and small joints of the hands were examined using gray-scale and Power Doppler US. The evaluated US lesions were: synovitis, tenosynovitis of extensor carpi ulnaris, extensor communis and flexor tendons, enthesitis of extensor tendons at distal interphalangeal joints, peritendon inflammation of extensor tendons, and soft tissue edema.

RESULTS

Six hundred joints in 20 PsA patients and 900 joints in 30 RA patients were assessed. Extensor enthesitis was significantly more observed in PsA compared with RA (39.4 vs 26.3%, P = .006) with a significant higher frequency of enthesophytes and calcifications (P = .022 and P = .002, respectively). Peritendon inflammation of extensor digitorum tendons was observed in 13% of metacarpophalangeal joints in PsA patients versus 3% in RA patients with a significant difference (P < .001). Soft tissue edema was exclusively observed in PsA (1.5 vs 0%, P = .033). Power Doppler synovitis was significantly more frequent in RA (9.2 vs 5%, P = .002). Extensor carpi ulnaris tenosynovitis was significantly more frequent in RA (18.3 vs 2.5%, P = .017).

CONCLUSION

Extrasynovial US findings may be helpful to distinguish PsA from RA especially in patients with immunonegative polyarthritis and no evidence of psoriasis.

Anatomy and Sonographic Examination for Lateral Epicondylitis: EURO-MUSCULUS/USPRM Approach

OBJECTIVE

The aim of the study is to define a standardized comprehensive sonographic approach for evaluating the different histoanatomical compartments of the lateral elbow.

DESIGN

Using high-frequency ultrasound probes, we tried to match the anatomical features of the lateral elbow and its different sonographic patterns in patients with the diagnosis of lateral epicondylitis. Moreover, high-sensitive color/power Doppler assessments have also been performed to evaluate the microcirculation.

RESULTS

Modern ultrasound equipment seems to provide an extremely detailed sonographic assessment of the different anatomical layers located in the lateral compartment of the elbow. Moreover, high-sensitive color/power Doppler imaging allows for clear visualization of the perfusion patterns in pathological conditions.

CONCLUSIONS

In clinical practice, high-frequency B-mode and high-sensitive color/power Doppler imaging can be integrated with the clinical findings to better define the pain generator(s) for optimizing the management of patients with lateral epicondylitis.

Ultrasonography for Injecting (Around) the Lateral Epicondyle: EURO-MUSCULUS/USPRM Perspective

Lateral epicondylitis (LE) is a very common and painful condition seen in the daily practice of musculoskeletal physicians. Ultrasound-guided (USG) injections are commonly performed to manage the pain, promote the healing phase, and plan a tailored rehabilitation treatment. In this aspect, several techniques were described to target specific pain generators i the lateral elbow. Likewise, the aim of this manuscript was to extensively review those USG techniques together with the patients' pertinent clinical/sonographic features. The authors believe that this literature summary could also be refined as a practical, ready-to-use guide for planning the USG interventions of the lateral elbow in clinical practice.

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.

A clinical practice guideline for the screening and assessment of enthesitis in patients with spondyloarthritis

Objective

The aim of this review is to provide guidance on the selection of approaches to the screening and assessment of enthesitis in patients with spondyloarthritis (SpA).

Methods

Twenty-four questions regarding the approaches to the screening and assessment of enthesitis and the implementation details were devised, followed by a systemic literature review. The Grading of Recommendations Assessment, Development, and Evaluation methodology was employed in the development of this guideline, with modifications to evaluate non-interventional approaches under comprehensive consideration of costs, accessibility, and evidence strength. A consensus from the voting panel was required for the inclusion of the final recommendations and the strength of each recommendation.

Results

Seventeen recommendations (including five strong recommendations) were included in this guideline. The voting panel expressed unequivocal support for the necessity of screening and assessment of enthesitis in patients with SpA. It was agreed unanimously that symptom evaluation and physical examination should serve as the initial steps to the recognition of enthesitis, whereas Maastricht Ankylosing Spondylitis Enthesitis Score is a reliable tool in both clinical trials and daily medical practice. Ultrasound examination is another reliable tool, with power Doppler ultrasound as an informative addition. Notwithstanding its high resolution, MRI is limited by the costs and relatively low accessibility, whereas radiographs had low sensitivity and therefore should be rendered obsolete in the assessment of enthesitis. PET/CT was strongly opposed in the detection of enthesitis.

Conclusion

This guideline provides clinicians with information regarding the screening and assessment of enthesitis in patients with SpA. However, this guideline does not intend on dictating choices, and the ultimate decisions should be made in light of the actual circumstances of the facilities.

Entheseal Involvement in Spondyloarthritis (SpA) and Gout: An Ultrasound Comparative Study

Objective

To compare the assessment of entheses in subjects with spondyloarthritis (SpA) with patients with gout by the Madrid Sonographic Enthesis Index (MASEI).

Method

This cross-sectional study includes videos of entheses evaluated by ultrasound (US) of 30 patients with SpA diagnosed according to the ASAS criteria and 30 patients with gout established by the presence of monosodium urate crystals. Entheses were evaluated for MASEI in 2 Institutes located in two different countries. Demographic and clinical data were registered. Total MASEI score, MASEI-inflammatory, and MASEI-chronic damage were analyzed. Comparisons between groups were obtained by chi-square test and Student's t-test. An inter-reading US reliability was realized.

Results

Patients with gout were older and had significantly more comorbidities than those with SpA. The total MASEI score was not significantly different among diseases (p = 0.07). MASEI-inflammatory was significantly more prevalent at the Achilles tendon in SpA, while the proximal patellar tendon was in gout. Power Doppler was higher in SpA compared to gout (p = 0.005). MASEI-chronic damage related to calcification/enthesophytes predominated in gout (p = 0.043), while calcaneal erosions did in SpA (p = 0.008). The inter-reader concordance was excellent (0.93, CI 95% 0.87–0.96, p = 0.001).

Conclusions

SpA and gout similarly involve entheses according to MASE, however, some inflammatory and chronic lesions differ significantly depending on the underlying disease and tendon scanned.

The Association of Achilles Sonoelastography Findings with Disease Activity, Functional Status and Enthesitis Index in Patients with Axial Spondyloarthritis

Background Sonoelastography (SE) is a new ultrasound (US)-based technique able to assess tissue elasticity. Using conventional US, it is sometimes difficult or even impossible to distinguish pathologic tissue because it often presents with the same echogenicity as the surrounding healthy tissue. This study aimed to evaluate SE findings in Achilles tendons of patients with axial spondyloarthritis (axSpA) and to assess how these findings are associated with disease-related parameters.

Material and Methods Sixty-four consecutive patients (37 men, 27 women; mean age 39.7 years; range 20–65 years) with axSpA and 30 sex and age-matched healthy controls were enrolled in the study. Disease activity was evaluated using the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), whereas functional capacity was evaluated using the Bath Ankylosing Spondylitis Functional Index (BASFI). Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and the Spondyloarthritis Research Consortium of Canada (SPARCC) enthesitis index were recorded. All participants underwent an SE examination of the Achilles tendon and measurement of the strain index (SI).

Results The mean right and left SI were significantly higher in axSpA patients than in controls (2.96±0.94 vs. 1.90±0.45; p<0.001; 2.95±0.95 vs. 1.92±0.48, p<0.001, respectively). In axSpA patients, both right and left SI were significantly correlated with the BASDAI, BASFI and SPARCC enthesitis indices, but not with ESR or CRP.

Conclusion AxSpA patients had an increased SI compared with healthy subjects and these values were associated with disease activity, functional capacity and the enthesitis index. SE may be a useful tool for the evaluation of Achilles tendons in patients with axSpA.

Reactive arthritis before and after the onset of the COVID-19 pandemic

Most accepted definitions of reactive arthritis (ReA) consider it a type of spondyloarthritis (SpA) precipitated by a gut or urogenital infection. A wider definition considers any arthritis that occurs after a mucosal surface infection as ReA. There is limited consensus regarding a working definition, status of HLA-B27, or even classification criteria for ReA. This may also contribute to a lack of systemic studies or clinical trials for ReA, thereby reducing further treatment recommendations to expert opinions only. The emergence of post-COVID-19 ReA has brought the focus back on this enigmatic entity. Post-COVID-19 ReA can present at extremes of age, appears to affect both sexes equally and can have different presentations. Some present with small joint arthritis, others with SpA phenotype-either with peripheral or axial involvement, while a few have only tenosynovitis or dactylitis. The emergence of post-vaccination inflammatory arthritis hints at similar pathophysiology involved. There needs to be a global consensus on whether or not to include all such conditions under the umbrella of ReA. Doing so will enable studies on uniform groups on how infections precipitate arthritis and what predicts chronicity. These have implications beyond ReA and might be extrapolated to other inflammatory arthritides.

Key Points

• Classical reactive arthritis (ReA) has a spondyloarthritis phenotype and is preceded by symptomatic gut or urogenital infection

• The demonstration of antigen and nucleic acid sequences of pathogens in synovium has blurred the difference between invasive arthritis and reactive arthritis

• Post-COVID-19 ReA has a transient phenotype and can have different presentations. All reported cases are self-limiting

• The large amount of literature reporting post-COVID-19 ReA calls for introspection if the existing definitions of ReA need to be updated.

Role of Imaging in Childhood Arthritis

ABSTRACT

Imaging plays a pivotal role in the management of various childhood arthritis. Conventional radiography is the most commonly ordered imaging modality for the evaluation of arthritis. Owing to their higher sensitivity for detecting synovitis, magnetic resonance imaging and ultrasonography are increasingly being used to guide clinical management of various forms of arthritis, especially juvenile idiopathic arthritis. Magnetic resonance imaging is a preferred modality for evaluating more complex sites such as the sacroiliac joint. In this review, we have discussed the rational use and the characteristic imaging features of common childhood arthritis.

Classification Criteria in Axial Spondyloarthritis: What Have We Learned; Where Are We Going?

Spondyloarthritis (SpA) is a chronic inflammatory condition that can have a predominately peripheral or axial presentation. Axial SpA (axSpA) affects the axial skeleton with either radiographic (r-axSpA) or nonradiographic (nr-axSpA) changes. Radiographic changes are a late disease feature and earlier disease stages can be identified by incorporating other imaging methods. The diagnosis of axSpA is a clinical diagnosis and classification criteria are not aimed to be diagnostic tools. The split between r-axSpA and nr-axSpA is artificial and we should move toward the unifying concept of axSpA. Our understanding of genetics, biomarkers, and immunopathophenotypes will drive further refinement of classification criteria.

Entheseal involvement in a group of psoriatic arthritis patients: An ultrasonographic study

Psoriatic arthritis (PsA) is an inflammatory potentially destructive disease that requires early diagnosis and therapeutic approach. Its main pathogenic event and the condition's hallmark is considered to be enthesitis. Clinical examination of the enthesis can be a challenge in the clinical practice; thus, ultrasonography (US) has emerged as an indispensable imaging tool for evaluating both structural and inflammatory changes of this structure. In the present study, we aimed to analyze the type and frequency of entheseal involvement in PsA patients by US examination, performing a retrospective study on 41 patients diagnosed with PsA. Ultrasonographically confirmed enthesitis, identified according to Outcome Measures in Rheumatology group (OMERACT, initially Outcome Measures in Rheumatoid Arthritis Clinical Trials) definitions, was present in 26 of the included patients, Achilles enthesis being the most common site involved. The prevalence of tendon structure abnormalities and the presence of entesophytes underlines the importance of chronic inflammation on entheseal sites. US examination has proven to be a reliable imaging method, with significant and continuous improvement, which is clearly a requisite part for current understanding and diagnosis of enthesitis and more than this, for the patient follow-up algorithm.

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

Enthesitis has a key role in the diagnosis, classification and management of patients with spondyloarthritis and psoriatic arthritis. Clinical assessment of enthesitis is known to be inaccurate mainly due to its poor specificity. In this context, ultrasound has the potential to improve the evaluation of enthesitis and, therefore, the management of patients with spondyloarthritis and psoriatic arthritis. In this viewpoint, we review the Outcome Measures in Rheumatology (OMERACT) definitions for ultrasound enthesitis, highlighting their current limits and potential implications on rheumatology research and clinical practice.

Musculoskeletal Imaging for Dermatologists: Techniques in the Diagnosis and Management of Psoriatic Arthritis

Psoriatic arthritis is an inflammatory condition affecting up to 30% of patients with psoriasis. Patients may experience irreversible joint damage if not treated early, and diagnostic delays of even 6 months are associated with radiographic progression and impaired function. Therefore, early detection and intervention are of critical importance in patients with psoriatic arthritis. Given that psoriasis often precedes symptoms of psoriatic arthritis, dermatologists are uniquely positioned to identify patients with psoriatic arthritis early in their disease course, before permanent damage has occurred. Several screening tools have been developed to help dermatologists identify patients who may have psoriatic arthritis, but these tools may not capture patients with subclinical disease or quantify the type and severity of the underlying tissue insult, which is often the presenting sign of psoriatic arthritis. In these cases, a combination of clinical assessment and musculoskeletal imaging (e.g., ultrasound) is required. This review summarizes three common musculoskeletal imaging techniques used in the diagnosis and management of patients with psoriatic arthritis: conventional radiography, ultrasound, and magnetic resonance imaging. Further understanding of musculoskeletal imaging will assist dermatologists in making treatment decisions and allow them to have a more active role in the detection of psoriatic arthritis.

Enthesis lesions are associated with X-ray progression in psoriatic arthritis

OBJECTIVE

To analyze the relationship among enthesis ultrasound (US) lesions and radiological structural damage in psoriatic arthritis (PsA) patients.

METHODS

Consecutive PsA patients with swelling of at least 1 of the 2nd to 5th metacarpophalangeal joints were included. Clinical and demographic data were collected. The Madrid Sonographic Enthesitis Index (MASEI) was selected to evaluate the enthesis, with its total score and MASEI-activity and MASEI-structural damage subscores. The modified Sharp van der Heijde method for PsA and the New York criteria for sacroiliitis were selected to evaluate cumulative bone damage on X-rays.

RESULTS

Twenty-seven patients were included. Male gender, older age, longer PsA duration and acute reactant factors were associated with greater bone cumulative damage. Enthesis tendon thickening, enthesophytes, total MASEI and the MASEI-structural damage subscore showed significant correlations with radiographic peripheral and sacroiliac damage scores. Tendon thickening and enthesophytes were the enthesis lesions more frequently associated with radiographic damage in PsA.

CONCLUSION

The enthesis MASEI score was associated with axial and articular radiographic structural damage in PsA patients. The MASEI-structural damage subscore correlated better with cumulative bone damage in PsA than the MASEI-activity subscore.

A Systematic Review of the Inclusion of Non-Inflammatory Ultrasonographic Enthesopathy Findings in Enthesitis Scoring Indices

Ultrasound has advanced the diagnosis and management of patients with inflammatory rheumatic conditions. It can be used to identify and monitor enthesitis, a cardinal feature of spondyloarthropthies. Several enthesitis scoring systems utilizing ultrasound to determine entheseal involvement have been developed. These scoring systems generally rely on determining the presence or absence of erosions, tendon enlargement, power Doppler signal, or enthesophytes. This systematic review identified ultrasound scoring systems that have been utilized for evaluating enthesitis and what key components derive the score. Review of these scoring systems, however, demonstrated confounding as some of the score components including enthesophytes may be seen in non-inflammatory conditions and some components including erosions can be seen from chronic damage, but not necessarily indicate active inflammatory disease. What is furthermore limiting is that currently there is not an agreed upon term to describe non-inflammatory enthesopathies, further complicating these scoring systems. This review highlights the need for a more comprehensive ultrasound enthesopathy scoring index.

A comparison of clinical examination and ultrasound enthesitis indices in patients with psoriatic arthritis, adjusted for concomitant fibromyalgia

Objectives:

To: (a) determine the extent of ultrasound (US)-detected peripheral enthesitis in a cohort of patients with psoriatic arthritis (PsA); (b) compare this with three clinical examination (CE) enthesitis indices; and (c) determine the effect of concurrent fibromyalgia on the evaluation of enthesitis.

Methods:

A prospective single-centre cross-sectional study of consecutive outpatients with established PsA undergoing clinical examination for enthesitis and US examination for inflammatory and structural lesions of enthesitis. Multivariable analyses tested for association between US scores, CE enthesitis indices and influence of concurrent fibromyalgia.

Results:

A total of 106 patients were assessed. Of these, 91/106 (85.8%) had CE enthesitis and 105/106 (99.1%) had ⩾1 US feature of enthesitis. There was a moderate correlation between US entheseal inflammation and both the Leeds Enthesitis Index (LEI) (Spearman rank, r = 0.36) and Spondyloarthritis Research Consortium of Canada Enthesitis Index (SPARCC) (r = 0.44). US entheseal damage did not correlate with CE enthesitis indices. Twenty-eight (26.4%) patients were classified as having concurrent fibromyalgia, in whom multivariable regression analyses demonstrated no correlation between US scores and CE enthesitis indices. PsA patients without fibromyalgia demonstrated a statistically significant association between both LEI (r = 0.48, p < 0.0001) and SPARCC (r = 0.62, p < 0.0001) and US entheseal inflammation.

Conclusion:

There is a moderate association between US entheseal inflammation, but not damage, and CE enthesitis indices in patients with PsA. The presence of concurrent fibromyalgia is linked with higher CE enthesitis scores, without an increase in US inflammation, suggesting that CE enthesitis indices should be used/interpreted with caution in these patients. Imaging, including US, should be the preferred modality to detect enthesitis in PsA patients with concurrent fibromyalgia.

Assessment of enthesopathy in patients with acne vulgaris: A case-controlled trial

AIM

This case-controlled study aimed at evaluating whether enthesitis is possibly associated with acne vulgaris.

METHODS

This study was carried out on 90 patients with acne vulgaris and 30 normal individuals who were subjected to full history talking, acne scoring system, general, dermatological, musculoskeletal examination, and musculoskeletal ultrasonography with Doppler flow.

RESULTS

A significant relation (P < 0.05) was discovered between left femoral condyle tenderness, which increased left femoral condyle hypoechogenicity on ultrasound. Moreover, a highly significant relation (P < 0.001) was established between tenderness on clinical examination and hypoechogenicity on ultrasound at three sites (right humerus epicondyle, right femoral condyle, and left humerus epicondyle). An association between tenderness and ultrasound increased thickness was significantly reported in the left femoral condyle (P < 0.05). Hypoechogenicity on ultrasound examination was more statistically evident with increased acne severity at the left Achilles tendon (LA), while enthesis calcifications (enthesophytes) were significantly associated with increased acne severity in the left humerus epicondyle (LA) and the right Achilles tendon (RA) (P < 0.05).

CONCLUSION

There is a solid possibility acne is a systemic disease triggering other co-morbidities beyond skin which needs to be fully elucidated by further research evidence.

A Narrative Review of the Classification and Use of Diagnostic Ultrasound for Conditions of the Achilles Tendon

Enthesitis is a cardinal feature of spondyloarthropathies. The Achilles insertion on the calcaneus is a commonly evaluated enthesis located at the hindfoot, generally resulting in hindfoot pain and possible tendon enlargement. For decades, diagnosis of enthesitis was based upon patient history of hindfoot or posterior ankle pain and clinical examination revealing tenderness and/or enlargement at the site of the tendon insertion. However, not all hindfoot or posterior ankle symptoms are related to enthesitis. Advanced imaging, including magnetic resonance imaging (MRI) and ultrasound (US), has allowed for more precise evaluation of hindfoot and posterior ankle conditions. Use of US in diagnosis has helped confirm some of these cases but also identified other conditions that may have otherwise been misclassified without use of advanced imaging diagnostics. Conditions that may result in hindfoot and posterior ankle symptoms related to the Achilles tendon include enthesitis (which can include retrocalcaneal bursitis and insertional tendonopathy), midportion tendonopathy, paratenonopathy, superficial calcaneal bursitis, calcaneal ossification (Haglund deformity), and calcific tendonopathy. With regard to classification of these conditions, much of the existing literature uses confusing nomenclature to describe conditions in this region of the body. Some terminology may imply inflammation when in fact there may be none. A more uniform approach to classifying these conditions based off anatomic location, symptoms, clinical findings, and histopathology is needed. There has been much debate regarding appropriate use of tendonitis when there is no true inflammation, calling instead for use of the terms tendinosis or tendonopathy. To date, there has not been clear examination of a similar overuse of the term enthesitis in conditions where there is no underlying inflammation, thus raising the need for more comprehensive taxonomy.

Evaluation of enthesitis in patients with juvenile idiopathic arthritis by power color and spectral Doppler ultrasonography

OBJECTIVE

Ultrasonography in patients with juvenile idiopathic arthritis (JIA) could potentially be useful for evaluation of enthesitis. The aim of this study was to evaluate enthesitis in patients with JIA quantitatively by power color and spectral Doppler ultrasonography by determining color fraction (CF) and resistive index (RI).

METHODS

A cross-sectional single-center study was performed in 15 (61 entheseal sites) patients with JIA with clinical enthesitis. A total of 9 age and sex matched healthy controls (53 entheseal sites) were also examined and compared. Entheseal sites (quadriceps tendon, patellar tendon, tendo-Achilles, medial and lateral epicondyles of humerus) were examined on USG B mode for tendon thickening, hypo- and hyper-echogenicity, enthesophytes, and cortical erosions/irregularities by power Doppler ultrasound for the presence of Doppler signal and by power color Doppler and spectral Doppler ultrasonography to derive CF and RI respectively.

RESULTS

The mean thickness of entheseal site in patients and controls were 3.55±0.82 mm and 2.8±0.37 mm, respectively (p<0.001). The power Doppler signal was present in 93.4% of patients (p<0.001). The pooled data of all entheseal sites revealed a significantly higher CF in patients (0.08±0.03) than in controls (0.006±0.008) (p<0.001). The mean RI in patients (0.61±0.09) was significantly lower than that in controls (0.92±0.12) (p<0.001). The cut-off of RI (0.7) and CF (0.029) determined by receiver operating curve analysis revealed a diagnostic accuracy of 94.7% and 96.5%, respectively.

CONCLUSION

Evaluation of enthesitis by determining CF and RI via power color Doppler and spectral Doppler is possible in JIA patients.

[CME Sonography 93: Ultrasound of the Enthesis - Not Every "Enthesitis" Signals a Spondyloarthritis]

CME Sonography 93: Ultrasound of the Enthesis - Not Every "Enthesitis" Signals a Spondyloarthritis Abstract. In this CME we will focus on the ultrasound anatomy of the enthesis. In addition, we describe the terms enthesopathy and enthesitis and discuss related differential diagnostic considerations. It is important to know all the diseases that can manifest themselves at the enthesis, so that diagnoses can be made, and patients classified correctly. At this point it is worth mentioning that the findings of enthesitis do not necessarily need to be associated with spondylarthritis.

Ultrasonographic evaluation of subclinical enthesitis in patients with psoriasis

AIM

The primary objective of this study was to assess the ultrasonographic signs of subclinical enthesitis in patients with psoriasis. Secondary objective was to examine the associations between the clinical assessments of enthesitis, severity of psoriasis, and the ultrasonographic signs of enthesitis.

METHOD

This study included 30 patients with psoriasis who did not have clinically detectable arthritis or enthesitis and 30 healthy volunteers as a control group. In the patient group, PASI, NAPSI, MASES, and SPARCC scores were calculated, and in the control group, MASES and SPARCC scores were calculated. Acute, chronic, and total enthesitis scores were calculated by ultrasonographic examination of the enthesis points that are assessed during calculation of SPARCC score, performed by a researcher blinded to the clinical assessments.

RESULT

In the ultrasonographic assessment, total enthesitis score was significantly higher in the patient group compared with the control group (P = .04). There was no significant difference between the groups regarding acute or chronic enthesitis scores. NAPSI, PASI, MASES, or SPARCC scores did not show correlation with the ultrasonographically acute, chronic, or total enthesitis scores. There was a low-level correlation between MASES and SPARCC scores in the patient group, which was statistically significant (P = .03). No significant correlation was found between other clinical scores. There was no significant difference between patient and control groups in terms of MASES and SPARCC scores.

CONCLUSION

Entheseal changes may be frequently observed in patients with psoriasis who are asymptomatic. Musculoskeletal ultrasonography (MUS) may be utilized to detect such abnormalities at the early period.

Entheses ultrasound assessment in primary Sjogren's syndrome

OBJECTIVE

Musculoskeletal pain is a common complaint among patients with primary Sjogren's syndrome (pSS). Joints clinical examination is oftenly normal. A periarticular origin of this pain may be possible. Since clinical examination lacks sensitivity and precision, the use of musculoskeletal ultrasound (US) is more interesting in the evaluation of the entheses involvement, as it is shown to be a more sensitive tool. Our objective was to assess, by an ultrasonographic study, the entheses involvement in the widespread pain of patients with pSS.

METHODS

This is a prospective study including 25 women with pSS and 25 age and sex matched healthy controls. An ultrasound examination, using grey scale and Doppler US, of five enthesitic sites (distal quadricipital, proximal patellar, distal patellar, distal Achillian and distal brachial tricipital) sought bilaterally the following lesions: hypoechogenicity, thickening, loss of fibrillar structure, erosions, enthesophytes, calcifications or Doppler hypervascularisation. A final score was calculated by summing the abnormalities scores of all entheses.

RESULTS

The mean age was 53.2±11.3 years in the pSS group and 50.6±9.7 years in the control group. The mean number of pathological entheses on ultrasound was 3.92±1.93 in the pSS group versus 4.52±2.27 in the control group (P>0.05). The total score for enthesitis abnormalities was 4.96±2.59 versus 5.72±2.92 (P>0.05), respectively. There was a positive correlation between total score of ultrasound enthesitic abnormalities and age in both groups.

CONCLUSION

In patients with pSS, clinically painful sites were more frequently found than in US. Musculoskeletal pain was not due to enthesitis.

Greater magnitude of entheseal microdamage and repair in psoriatic arthritis compared with ankylosing spondylitis on ultrasound

Objectives

AS and PsA share clinical and immunological features centred on enthesitis. However, a strong association between PsA and preceding injury has been recognized. The aim of this study was to test the hypothesis that the entheseal damage seen by US is commoner in PsA patients than in AS patients.

Methods

Seventy-nine AS and 85 PsA patients had US scans of 1640 entheses to calculate entheseal inflammation (hypoechogenicity, thickening and Doppler) and damage scores (calcifications, enthesophytes and erosions). Regression modelling was done to evaluate the effect of diagnoses on outcomes, controlling for age, gender, BMI, clinical enthesitis, HLA-B27, and anti-TNF use.

Results

Both inflammation and damage scores on US were correlated with BMI (r = 0.392; r = 0.320) and age (r = 0.308; r = 0.538) (P < 0.001), and men had higher inflammation scores than women [12.3 (7.5) vs 8.9 (7.3), P = 0.001]. In multivariate analysis, despite similar (anti-TNF-treated patients) or slightly less inflammation (anti-TNF-naïve patients) in the PsA group, they had 4.22 times more US damage than their counterparts with AS. The difference was even higher in the anti-TNF-naïve patients (5.6 times).

Conclusion

On US assessment, PsA patients have greater entheseal insertion damage scores compared with AS, suggesting potential differences in tissue repair, immunobiology or response to injury at insertions.

OMERACT Definitions for Ultrasonographic Pathologies and Elementary Lesions of Rheumatic Disorders 15 Years On

OBJECTIVE

The Outcome Measures in Rheumatology (OMERACT) Ultrasound (US) Working Group (WG) operates research activities for the validation of US as an outcome measurement instrument according to the Filter 2.0 framework.

METHODS

Original publications on definitions and scoring systems for pathophysiological manifestations and elementary lesions of various rheumatic disorders were reviewed from the onset of the WG research in 2005.

RESULTS

Definitions and scoring systems according to new terminology are provided.

CONCLUSION

We have redefined OMERACT US pathology and elementary lesions as well as scoring systems, which are now proposed for OMERACT approval for application in clinical trials.

Differential pattern of Doppler signals at lower-extremity entheses of healthy children

BACKGROUND

Ultrasonography might be an important imaging method for assessing the pediatric enthesis. To diagnose pathology, knowledge of physiological findings is essential but limited.

OBJECTIVE

To provide a detailed ultrasonographic assessment of four lower-extremity entheses in healthy adolescents as a reference for the correct interpretation of findings in children with rheumatic diseases.

MATERIALS AND METHODS

The quadriceps tendon, proximal and distal patella tendon, and Achilles enthesis were examined in B-mode, Power and color Doppler in 41 boys and girls ages 11-14 years in neutral position and 30° flexion. We assessed Doppler signals at various distances from the enthesis and analyzed the data using a marginal logistic regression model with generalized estimating equation. We assessed agreement between observers using weighted kappa and we determined agreement on repeat scans using prevalence- and bias-adjusted kappa.

RESULTS

Doppler signals were predominantly in the quadriceps and distal patella tendon with odds ratios of 50.85 and 21.35 (P<0.001) compared to the Achilles tendon. They were within 2 mm or 5 mm of the enthesis (odds ratios [ORs] of 4.58 and 4.24, P<0.001), without significant difference between flexion and neutral position and between the right and the left legs. Agreement between first and second assessment was good, with aggregate kappas from 0.79 to 0.90. The inter-reader agreement was also good, with aggregate kappas ranging from 0.75 to 0.95.

CONCLUSION

We found a differential Doppler pattern in lower-extremity entheses, with signals present mostly in the quadriceps and distal patella entheses.

The Relationship Between Physical Examination and Ultrasonography of Large Entheses of the Achilles Tendon and Patellar Tendon Origin

Objective.

To investigate the relationship between physical examination (PE) and sonographic features of enthesitis, based on anatomical sites.

Methods.

The analysis was done using merged raw data of 3 studies on 2298 entheses.

Results.

Patients with clinical Achilles enthesitis had more abnormalities on ultrasound (US): hypoechogenicity, p < 0.001; thickening, p = 0.001; Doppler signals, p = 0.002; and erosions, p = 0.02. The patellar tendon origin also correlated with PE but distal patellar tendon insertion and plantar aponeurosis were uncoupled from the US.

Conclusion.

The relationship between clinical and sonographic findings for large entheses is dependent on the anatomical site. For the patellar tendon origin and Achilles entheses, PE is significantly linked to US findings.

Ultrasonographic and Clinical Assessment of Peripheral Enthesitis in Patients with Psoriatic Arthritis, Psoriasis, and Fibromyalgia Syndrome: The ULISSE Study

Objective.

The purpose of the ULISSE study was to evaluate the prevalence of clinical and ultrasonographic (US) entheseal involvement in patients with psoriatic arthritis (PsA), psoriasis, and fibromyalgia syndrome (FMS).

Methods.

In this cross-sectional multicenter study, patients with PsA and psoriasis (not taking systemic therapy) and FMS underwent a clinical evaluation of the entheses, and a B-mode and power Doppler examination of 6 pairs of entheses.

Results.

The study analyzed 140 patients with PsA, 51 with psoriasis, and 51 with FMS. Clinical and US examinations were performed in 1960 and 1680 entheses in the PsA group, and 714 and 612 entheses both in the psoriasis group and in the FMS group. In both per-patient and per-enthesis evaluation, the frequency of entheseal tenderness was higher in patients with FMS (92% of the patients and 46% of the entheses, compared with 66%/23% in the PsA group and 59%/18% in the psoriasis group). With US examination, signs of entheseal involvement were more frequent in both the per-patient and per-enthesis evaluation in PsA and psoriasis (about 90% of patients in both the PsA and psoriasis groups and 75% of patients in the FMS group had at least 1 site affected, and 54%, 41%, and 27% of the pairs of entheses in, respectively, PsA, psoriasis, and FMS patients showed at least 1 enthesis involved).

Conclusion.

The ULISSE study indicated that enthesitis is a common feature in patients with PsA, those with psoriasis, and in those with FMS if only clinical examination is used. US entheseal assessment showed findings more consistent with the 3 disorders.

The OMERACT Stepwise Approach to Select and Develop Imaging Outcome Measurement Instruments: The Musculoskeletal Ultrasound Example

Objective.

To describe the Outcome Measures in Rheumatology (OMERACT) stepwise approach to select and develop an imaging instrument with musculoskeletal ultrasound (US) as an example.

Methods.

The OMERACT US Working Group (WG) developed a 4-step process to select instruments based on imaging. Step 1 applies the OMERACT Framework Instrument Selection Algorithm (OFISA) to existing US outcome measurement instruments for a specific indication. This step requires a literature review focused on the truth, discrimination, and feasibility aspects of the instrument for the target pathology. When the evidence is completely unsatisfactory, Step 2 is a consensus process to define the US characteristics of the target pathology including one or more so-called “elementary lesions”. Step 3 applies the agreed definitions to the image, evaluates their reliability, develops a severity grading of the lesion(s) at a given anatomical site, and evaluates the effect of the acquisition technique on feasibility and lesion(s) detection. Step 4 applies and assesses the definition(s) and scoring system(s) in cross-sectional studies and multicenter trials. The imaging instrument is now ready to pass a final OFISA check.

Results.

With this process in place, the US WG now has 18 subgroups developing US instruments in 10 different diseases. Half of them have passed Step 3, and the groups for enthesitis (spondyloarthritis, psoriatic arthritis), synovitis, and tenosynovitis (rheumatoid arthritis) have finished Step 4.

Conclusion.

The US WG approach to select and develop outcome measurement instruments based on imaging has been repeatedly and successfully applied in US, but is generic for imaging and fits with OMERACT Filter 2.1.

Musculoskeletal Clinical and Imaging Manifestations in Inflammatory Bowel Diseases

Rheumatic musculoskeletal manifestations are increasingly recognized as a major cause of morbidity and impaired quality of life in patients with inflammatory bowel diseases (IBDs). IBDs are associated with a variety of musculoskeletal pathologies, from peripheral arthritis to axial involvement, and from localized or regional pathologies to diffuse metabolic disorders. Recent advances, especially in imaging techniques, allow a better understanding of these pathologies, and assist their recognition even in the preclinical phase. This review aims to describe the musculoskeletal clinical and imaging manifestations in IBD with special emphasis on the current concepts and the updated radiological work-up.

[Usefulness and reliabitlity of musculoskeletal point of care ultrasound in family practice (1): Knee, shoulder and enthesis]

Musculoskeletal ultrasound (MSU) is a technique which has been extended to practically all medical specialties that comprise this pathology. Family Doctor (FD) has not been away from this process due to its great wide of competences, using it in different scenarios inside his common practice in which he can get profits in a reliable, efficient and effective way. Ultrasound equipment incorporation in Primary Care (PC) centers is an increasing reality, contributing to high ranges of accessibility, immediacy and clinic handle capability, and thus, together with the high prevalence in this area in locomotor apparatus, turns MSU into an strategic action for the improvement of the resolving capacity and consequently for the health care. To ensure proficiency among users, it's being necessary to define the benefits and potential risks its use can cause, as well as its different scenarios, avoiding unnecessary explorations and optimizing the investment of this resource at PC level. This paper pretends to summarize the state of the art of the musculoskeletal ultrasound and its benefits for the FD into this efficient and effective scenarios.

Imaging in Psoriatic Arthritis-Insights About Pathogenesis of the Disease

PURPOSE OF REVIEW

Heterogeneity is a hallmark of PsA as musculoskeletal inflammation can affect different tissues including the synovial joint, tendons, entheses, bursa, and bone.

RECENT FINDINGS

Relying on clinical examination for investigating underlying mechanisms in PsA is limited by the inherent inaccuracies of examination of the joints, enthesis, and spine. In addition, unlike synovial-centered diseases, histology is hard to obtain for the entheses and spine, limiting the knowledge for different manifestations of PsA. These limitations prompted the use of imaging modalities to improve our understanding of the underlying mechanisms in PsA. Imaging modalities can identify and quantify the extent of inflammation and damage in the synovial joints, entheses, and tendons which all contribute to the heterogeneity of PsA. This review summarizes the contribution of imaging to the understanding of the underlying mechanisms of different clinical manifestations of PsA.

Is ultrasonographic enthesitis evaluation helpful for diagnosis of non-radiographic axial spondyloarthritis?

The aim of this study is to evaluate the diagnostic utility of ultrasonographic enthesitis assessment in patients with non-radiographic axial spondyloarthritis (nr-axSpA) and to compare different sonographic scoring methods. Patients with nr-axSpA (n = 30) and mechanical back pain (MBP) (n = 30) were enrolled in the study with standardized clinical criteria. For both of the groups, a total of 18 entheses were evaluated in each patient with B mode ultrasound and power Doppler by a sonographer who is blinded to initial clinical and radiological assessments. Glasgow Ultrasound Enthesitis Scoring System (GUESS), Madrid Sonographic Enthesitis Index (MASEI) and D'Agostino grading system were performed. Intra-rater and inter-rater reliability analyses were evaluated with the intraclass correlation coefficient (ICC). There was at least one enthesitis in 96.7% of patients with nr-axSpA. Median values of the number of enthesitis were 5 in nr-axSpA and 0 in MBP. Mean GUESS total scores were 0.9 in MBP and 4.5 in nr-axSpA. Mean MASEI total scores were 2.3 and 10.5, respectively. The sensitivities were 96.7% and 93.3% for GUESS and MASEI while the detected specificities were 80% for both methods. For Intra-rater reliability analysis, ICC was calculated as 0.981 for GUESS and 0.975 for MASEI, while it was calculated as 0.964 and 0.962 for inter-rater reliability analysis. Thus, evaluation of enthesitis with ultrasound is a reliable, helpful tool for the distinction of patients with nr-axSpA from patients with MBP. We favored the use of MASEI because of assessing upper extremity, using power Doppler and having a correlation with disease activity.

Can power Doppler ultrasound of the entheses help in classifying recent axial spondyloarthritis? Data from the DESIR cohort

Early diagnosis of axial spondyloarthritis (axSpA) remains a challenge due to the lack of specificity of clinical symptoms and variable prevalence of axial imaging findings permitting a definite diagnosis. Power Doppler ultrasonography (PDUS) of the entheses has demonstrated to be a potential useful tool for the classification and diagnostic management of early SpA independently of the phenotype.

Reliability of a consensus-based ultrasound definition and scoring for enthesitis in spondyloarthritis and psoriatic arthritis: an OMERACT US initiative

OBJECTIVES

To evaluate the reliability of consensus-based ultrasound (US) definitions of elementary components of enthesitis in spondyloarthritis (SpA) and psoriatic arthritis (PsA) and to evaluate which of them had the highest contribution to defining and scoring enthesitis.

METHODS

Eleven sonographers evaluated 40 entheses from five patients with SpA/PsA at four bilateral sites. Nine US elementary lesions were binary-scored: hypoechogenicity, thickened insertion, enthesophytes, calcifications, erosions, bone irregularities, bursitis and Doppler signal inside and around enthesis. Kappa statistics were used to evaluate reliability. Sonographers were also asked to state which lesions can be considered as inflammatory or structural and should be included in the final definition of enthesitis. Only the lesions, scored as present in at least 75% of the entheses considered as having an enthesitis, were included in the final definition.

RESULTS

The prevalence of detected lesions was quite low except for enthesophytes (55%) and bone irregularities (54%). Reliability ranged from poor to good (the lowest for thickened enthesis (kappa 0.1 (95% CI 0 to 0.7)) and the highest for enthesophytes (kappa 0.6 (95% CI 0.5 to 0.7)). When adjusted for low prevalence, kappa values increased for all lesions, with the best result observed for detecting Doppler signal at insertion (0.9) and for bursitis (0.8). The US components included in the final definition were hypoechogenicity, increased thickness at enthesis, erosions and calcifications/enthesophytes and Doppler signal at insertion.

CONCLUSION

By using a consensus-based stepwise approach, a final reliable US score and definition of enthesitis in SpA/PsA were produced. Further studies are sought for implementing this score in clinical trials and practice.

The role of imaging in juvenile idiopathic arthritis

INTRODUCTION

The prognosis of juvenile idiopathic arthritis (JIA) has changed dramatically due to the availability of novel drugs. Prompt diagnosis and treatment are essential to prevent permanent joint damage. As a result, methods to improve JIA diagnosis and prognosis are of high priority to tailor treatment strategies and maximize their efficacy. Musculoskeletal ultrasound and magnetic resonance imaging are more sensitive than clinical examination and radiography in the detection of joint involvement and might play a substantial role to optimize the management of JIA. Areas covered: This review compiles an inventory of potential uses of imaging studies in the modern practice of pediatric rheumatology, together with a critical analysis of the major challenges that are still to be addressed. Imaging appearance of normal growth-related changes of the musculoskeletal system will be discussed. Expert commentary: Knowledge of the evolving patterns of skeletal maturity is paramount to define pathological findings and avoid misinterpretations. Establishing a novel radiological algorithm for a rational use of imaging in JIA is of high priority to allow a speedier integration of imaging into the clinical workflow and decision-making process.

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

Background

Iliac crest pain syndrome is a regional pain syndrome that has been identified in many patients with low back pain. Based on anatomical studies, it was suggested that the potential substrate of this syndrome might be the enthesis of the erector spinae muscle at the posterior medial iliac crest. As there have been no imaging studies of this important enthesis, our aim was to assess its characteristics by ultrasound.

Methods

Erector spinae enthesis was first studied in a cadaver. Then its characteristics were recorded in 25 healthy volunteers (median age: 28.92, SD: 5.31, mean Body Mass Index 22.61, SD: 3.38), with Esaote My Lab 7 machine using linear transducer (4–13 MHz).

Results

The cadaver study confirmed the attachment of a substantial part of erector spinae to a well-defined region on the medial posterior iliac crest. The US study in the volunteers consistently showed the entheses as typical hyperechoic fibrillar structures, slightly oblique to the skin in the longitudinal plane and attaching to the iliac crest. In the transverse plane, the entheses were seen as oval, densely dotted structures in contact with the superior edge of posterior superior iliac spine. Their mean thickness (4.9 ± 0.6 and 5.2 ± 0.7 mm longitudinally; 4.3 ± 0.6 and 4.4 ± 0.7 mm transversely), maximum width (16.3 ± 2.8 and 15.7 ± 2.3 mm) and depth (10.8 ± 7.3 and 10.6 ± 6.2 mm) on the left and right side, respectively, as well as their echostructure were recorded and described.

Conclusions

The erector spinae entheses could be assessed in detail by ultrasound, thus their pathological transformation associated with iliac crest pain syndrome could be identified.

ENTHESITIS AND PSORIATIC ONYCHOPATHY AS A FACTOR FOR PREDICTION OF PSORIATIC ARTHRITIS IN PSORIASIS

Psoriatic arthritis is a psoriasis-related spondyloarthropathy that occurs in 20–30 % of patients with psoriasis. Psoriatic arthritis affects the patient’s quality of life indicators and are more often associated with disabilities of working age than psoriasis skin form. Nail psoriasis has been proposed as a predictor for the development of psoriatic arthritis. The inflammation involving the entheses, called enthesitis, is an early inflammatory change seen in psoriatic arthritis, and nail changes appear to result from the close relationship between the nail and the enthesis of the distal interphalangeal extensor tendon, one of the main entheseal compartments affected in psoriatic arthritis. Various imaging studies have demonstrated that there is a considerable proportion of undiagnosed psoriatic arthritis among patients with psoriasis. Since early detection and treatment of psoriatic arthritis could, ultimately, allow the prevention of clinical and radiologic progression of the disease, there is the need to establish clinical indicators to detect this risk.