Musculoskeletal ultrasonography for psoriatic arthritis and psoriasis patients: a systematic literature review

Ultrasonography for the assessment of enthesitis in psoriatic arthritis: systematic review with meta-analysis

OBJECTIVES

The specificity of US for enthesitis in PsA is unclear. The objective was to analyse the specificity of US enthesitis in Mode B and using power Doppler for the diagnosis of PsA through a systematic review with meta-analysis.

METHODS

Systematic review in PubMed 2010 to June 2023 of studies of adult patients with confirmed PsA with or without a control group of non-PsA patients, reporting information on US enthesitis. Data were analysed on (i) the prevalence of US enthesitis (presence of at least one enthesitis) in PsA patients and non-PsA patients, (ii) specificity and sensitivity of US enthesitis and then specifically power Doppler for PsA diagnosis and (iii) most specific localizations of enthesitis in PsA patients. Pooled percentages and means were evaluated using univariate random effects meta-analysis.

RESULTS

In 76 articles, 5927 patients with PsA were compared with 3423 controls (59.0% of whom had psoriasis). The prevalence of US enthesitis was 73.7% (95% CI 56.6-90.9%) in PsA patients vs 12.6% (2.6-22.3%) in controls. The pooled specificity and sensitivity of Mode B US were 73.2% (59.3-87.0%) and 62.1% (47.9-76.4%); and of power Doppler, were 97.9% (96.5-99.5%) and 14.7% (8.2-21.2%), respectively. The site most frequently involved in PsA but not in controls was the Achilles tendon, in which erosions and power Doppler activity were most discriminant.

CONCLUSION

In this systematic review, US enthesitis was highly prevalent in PsA patients. Evidencing enthesitis by US was found to be reasonably specific and could contribute to the diagnosis of PsA; power Doppler was highly specific, however it was rarely present.

The ultrasonographic spectrum of toe dactylitis in psoriatic arthritis: a descriptive analysis

INTRODUCTION

Dactylitis is a hallmark of psoriatic arthritis (PsA). While its assessment is clinical, recently musculoskeletal ultrasonography (MSUS) has been applied to its monitoring. However, the evidence on MSUS application for toe dactylitis is limited. The aim of this study is to characterize the ultrasonographic features of toe dactylitis in PsA.

METHOD

Patients with PsA and painful toe dactylitis were retrospectively identified from clinical records. Demographic and clinical variables were analyzed. Ultrasound images of the affected toe, allowing the assessment of grey scale (GS) and power Doppler (PD) were collected, to evaluate tenosynovitis, soft tissue oedema (STO), synovitis of metatarsophalangeal (MTP), proximal and distal interphalangeal (PIP, DIP) joints (all graded 0-3), and peritendonitis (PTI) at the MTP and PIP (graded 0-1). Clinical and ultrasonographic features were analyzed through descriptive statistics.

RESULTS

The study included 26 patients (30 toes) of which 9 (34.5%) females, with mean (sd) age of 46.8 (11.73). All but one patient had an oligoarticular phenotype. Tenosynovitis was the most frequent lesion, with GS abnormalities in 27/30 toes (90%) and PD in 25/30 (83.3%). STO was common (GS in 28/30 (93.33%) toes and PD in 20/30 (66.66%)). Synovitis was less common (63.33%, 46.66% and 33.33% of MTPs, PIPs and DIPs, respectively), while PTI was uncommon, with no patient presenting with PD.

CONCLUSIONS

Ultrasound showed different elementary lesions in toe dactylitis confirming the complexity of this manifestation also at foot. These findings represent a first step toward the development of further imaging studies assessing toe dactylitis in PsA. Key Points • Tenosynovitis and soft tissue oedema were the most common ultrasonographic elementary lesion in acute toe dactylitis in psoriatic arthritis. • Synovitis was less frequent and peritendonitis was very uncommon. • Musculoskeletal ultrasound confirms the presence of multiple lesions in painful toe dactylitis, confirming the complexity of this manifestation.

Delineating inflammatory from non-inflammatory mechanisms for therapy optimization in psoriatic arthritis

Psoriatic arthritis (PsA) is anatomically much more heterogeneous than rheumatoid arthritis, as, beyond synovitis, it often also involves enthesitis, peritendinitis, tenosynovitis, osteitis and periostitis. This heterogeneity currently precludes a gold standard for objectively defining resolution of inflammation following treatment, with enthesitis posing a particular challenge. Despite these difficulties, we apply lessons learned from rheumatoid arthritis to describe how patients with PsA and an inadequate response to therapy can be designated within two patient subgroups, characterized by persistent inflammatory PsA (PIPsA) and non-inflammatory PsA (NIPsA), respectively. The NIPsA phenotype is defined by the lack of ongoing joint inflammation, as confirmed through clinical assessment and imaging, along with normalized inflammatory marker levels. NIPsA might be associated with obesity, biomechanical-related pain, osteoarthritis, fibromyalgia, secondary post-inflammatory damage and central pain mechanisms. In this article, we frame PsA composite outcomes measures in relationship to the PIPsA and NIPsA phenotypes and propose that this approach might help to minimize unnecessary or ineffective cycling of PsA therapy in patients who acquire dominant non-inflammatory mechanisms and might also inform future trial design.

Peripheral Spondyloarthritis: Conceptualization and Diagnosis as a Distinct Rheumatologic Subset of Disease

Peripheral spondyloarthritis (pSpA) encompasses multiple entities affecting the musculoskeletal system with classic findings of synovitis, enthesitis, and tenosynovitis. It remains poorly defined when compared with the axial spondyloarthritides due to nonspecific symptoms, ill-defined imaging findings, and lack of specific testable biomarkers. Previous research has tried to distinguish between the two disease entities using clinical presentations, scoring systems, and radiographic findings; however, overlap remains. We summarize the current classification of pSpA, imaging findings, and the distinction between these entities and axial spondyloarthritis.

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.

Superior effect of adalimumab versus secukinumab on ultrasound-confirmed synovitis in psoriatic arthritis: comprehensive evidence from musculoskeletal ultrasound and clinical assessments

Background and objectives: Psoriatic arthritis (PsA) is a chronic inflammatory musculoskeletal disorder affecting 30% of psoriatic patients. Effective treatment, especially with biologics like IL-17 and TNF inhibitors, is vital for improving patient outcomes. This study aimed to compare the efficacy of secukinumab and adalimumab in PsA patients through clinical and ultrasonographic evaluations.Materials and methods: We enrolled 116 PsA patients, with 58 patients receiving secukinumab and 58 receiving adalimumab. Regular follow-ups were conducted at weeks 4, 12, 24, and 52. The primary outcome was the proportion of patients achieving at least a 20% improvement in the ACR response (ACR20) at week 12, with additional evaluations for axial arthritis, enthesitis, skin involvement, minimal disease activity, health assessment questionnaire, and ultrasound changes.Results: There was no significant difference in ACR20 response between the two groups at week 12 (OR: 0.59, 95% CI: 0.26-1.37, p = 0.22). However, secukinumab demonstrated superior efficacy in achieving Psoriasis Area and Severity Index (PASI)90 (OR: 2.25, 95%CI: 1.07-4.74, p = 0.03), while adalimumab showed better improvement in ultrasound synovitis count (β: 0.94, 95%CI: 0.09-1.79, p = 0.03) and synovitis PD signal (β: 0.20, 95%CI: 0.03-0.36, p = 0.02).Conclusions: In conclusion, both treatments were highly effective for PsA, with secukinumab being more suitable for severe skin involvement and adalimumab for significant ultrasound-confirmed synovitis.

Imaging in psoriatic arthritis: established methods and emerging techniques

Psoriatic arthritis (PsA) is a heterogeneous, chronic, inflammatory musculoskeletal disease that can lead to peripheral and axial damage and loss of function. A clear difference between PsA and other forms of inflammatory arthritis is the different forms of bone remodeling seen in PSA which incorporates not only increased bone resorption with bone erosions, osteolysis, and loss of bone mineral density but also increased bone formation with periostitis, syndesmophytes, enthesiophytes, and ankylosis. PsA, if diagnosed late, will lead to significant structural damage, the most severe form of which is known as arthritis mutilans, and loss of physical function. Imaging plays a crucial role in diagnosing and monitoring both peripheral and axial conditions associated with PsA. Radiography is currently the main modality used to monitor structural damage in PsA though commonly used scoring systems do not include bony proliferation as a criterion. Besides, radiography is limited in determining the presence and cause of periarticular soft tissue thickening, which may arise from tendinosis, tenosynovitis, synovial proliferation, bursitis, or enthesitis. Recently, much more attention has been paid to determining the imaging characteristics of PsA, which enables more precise identification of disease and severity assessment. Newer imaging technologies also enable variations in normal bone microstructure to be distinguished from disease-related abnormality. This review discusses the current state of innovative imaging modalities in PsA, specifically concentrating on their roles in PsA diagnosis and treatment, improving the early detection of PsA, and identifying patients with skin psoriasis at risk of developing psoriatic arthritis.

The Challenge of IBD-Related Arthritis Screening Questionnaires in Early and Predominantly Entheseal Phenotypes

INTRODUCTION

Inflammatory bowel disease (IBD)-related arthritis is recognized as the most prevalent extraintestinal manifestation (EIM) of IBD. The objective of this study was to determine the prevalence and characteristics of undiagnosed IBD-related arthritis and to compare two screening questionnaires, DETection of Arthritis in Inflammatory boweL diseases (DETAIL) and IBd Identification of Spondyloarthritis Questionnaire (IBIS-q), for early disease detection.

METHODS

Between April and October 2023, both the DETAIL and IBIS-q questionnaires were administered to consecutive IBD outpatients visiting the University Hospital of Udine, Italy. During routine gastroenterology evaluations, patients aged > 18 years with Crohn's disease (CD) or ulcerative colitis (UC) were requested to complete both questionnaires. Subsequently, all patients who completed the questionnaires underwent a blinded rheumatological evaluation within 2 weeks. Patients with a previous diagnosis of IBD-related SpA were then excluded.

RESULTS

Overall, 203 patients were enrolled, of whom 26 were excluded because of a prior diagnosis of inflammatory arthritis. Among the remaining 177 patients, 10/177 (5.6%) received a new diagnosis of IBD-related arthritis. The median duration of symptoms before diagnosis was 4 (IQR 1.8-10.5) months. Imaging-confirmed enthesitis was the predominant pattern in 8 out 10 cases (80%, with 8 out 8 lacking concomitant peripheral arthritis), axial involvement in 1 out 10 cases (10%), and peripheral arthritis in 1 out 10 cases (10%). The DETAIL questionnaire exhibited higher specificity, but lower sensitivity compared to the IBIS-q, with a sensitivity of 40.0% (12.2-73.8) and specificity of 84.4% (78.0-89.6) versus a sensitivity of 70.0% (34.8-93.3) and specificity of 74.3% (66.9-80.7). Both questionnaires performed less effectively than in other studies.

CONCLUSION

This study highlights a significant proportion of undiagnosed IBD-related arthritis (5.6%). Enthesitis emerged as the predominant pattern of newly diagnosed arthritis in our cohort, likely due to the recent onset of symptoms. Our study underscores the importance of entheseal involvement in early IBD-related arthritis and the importance of incorporating entheseal involvement into screening questionnaires.

Updates in Ultrasound in Rheumatology

BACKGROUND

The purpose of the authors' narrative review was to outline the current literature regarding the use of ultrasound in main rheumatic disorders and summarize the updates, specifically about rheumatoid arthritis, psoriatic arthritis, and crystal-induced arthropathies.

METHODS

The authors searched on PubMed for articles discussing the major updates regarding the role of ultrasound in the previously mentioned rheumatic conditions.

RESULTS

The authors have provided the updated definitions, new criteria, and diagnostic scores.

CONCLUSIONS

In rheumatology's dynamic landscape, this review provides valuable insights for researchers and clinicians on ultrasound's role in improving patient care and outcomes in rheumatic diseases.

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).

Validation and incorporation of digital entheses into a preliminary GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis

OBJECTIVES

The main objective was to generate a GLobal OMERACT Ultrasound DActylitis Score (GLOUDAS) in psoriatic arthritis and to test its reliability. To this end, we assessed the validity, feasibility and applicability of ultrasound assessment of finger entheses to incorporate them into the scoring system.

METHODS

The study consisted of a stepwise process. First, in cadaveric specimens, we identified enthesis sites of the fingers by ultrasound and gross anatomy, and then verified presence of entheseal tissue in histological samples. We then selected the entheses to be incorporated into a dactylitis scoring system through a Delphi consensus process among international experts. Next, we established and defined the ultrasound components of dactylitis and their scoring systems using Delphi methodology. Finally, we tested the interobserver and intraobserver reliability of the consensus- based scoring systemin patients with psoriatic dactylitis.

RESULTS

32 entheses were identified in cadaveric fingers. The presence of entheseal tissues was confirmed in all cadaveric samples. Of these, following the consensus process, 12 entheses were selected for inclusion in GLOUDAS. Ultrasound components of GLOUDAS agreed on through the Delphi process were synovitis, tenosynovitis, enthesitis, subcutaneous tissue inflammation and periextensor tendon inflammation. The scoring system for each component was also agreed on. Interobserver reliability was fair to good (κ 0.39-0.71) and intraobserver reliability good to excellent (κ 0.80-0.88) for dactylitis components. Interobserver and intraobserver agreement for the total B-mode and Doppler mode scores (sum of the scores of the individual abnormalities) were excellent (interobserver intraclass correlation coefficient (ICC) 0.98 for B-mode and 0.99 for Doppler mode; intraobserver ICC 0.98 for both modes).

CONCLUSIONS

We have produced a consensus-driven ultrasound dactylitis scoring system that has shown acceptable interobserver reliability and excellent intraobserver reliability. Through anatomical knowledge, small entheses of the fingers were identified and histologically validated.

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.

Unmet needs in psoriatic arthritis, a narrative review

Psoriatic arthritis is a chronic rheumatic disease that poses challenges in its diagnosis, evaluation, and management. The heterogeneity in the manifestations and the absence of definitive diagnosis biomarkers often complicates the process of accurate diagnosis. Furthermore, the involvement of multiple disease domains poses difficulties in assessing disease activity and defining the concept of remission. Despite therapeutic advancements, a subset of patients remains refractory to treatment, leading to the emergence of the concept of "difficult-to-treat" patients and the necessity for novel therapeutic approaches (e.g., drugs with novel mechanisms of action; combinations of treatments). This review addresses key unmet needs in psoriatic arthritis, in terms of diagnosis, classification, evaluation, comorbidities and treatment.

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.

2D shear wave elastography for the assessment of quadriceps entheses-a methodological study

OBJECTIVE

To establish the scanning protocol for 2-dimensional shear wave elastography (SWE) on normal entheses by investigating the possible confounding factors that may increase the variability of measured elasticity.

MATERIAL AND METHODS

30 normal quadriceps entheses were scanned using SWE to compare the stiffness and coefficient variation by changing the ultrasonic coupling gel thickness, knee position, region of interest size, and scanning plane.

RESULTS

No significant difference in median shear wave velocity (SWV) was observed in different coupling gel thicknesses. The median SWV was higher in the knee flexion position than in the extended position (p < 0.001). Increased knee flexion led to stiffer quadriceps enthesis and higher SWV (ρ = 0.8, p < 0.001). The median SWV was higher when the diameter region of interest was 4.0 mm than 2.0 mm (p = 0.001). The median SWV was higher in the transverse plane than in the longitudinal plane (p < 0.001). Strong correlation was found between SWV and the degree of the shear wave to muscle fiber direction (ρ = 0.8, p < 0.001). The coefficient variation was lower in a gel thickness of 2.5 cm, with an extended knee, a region of interest of 2.0 mm, and a longitudinal plane (p > 0.05). For interobserver reliability for the proposed protocol, the intraclass correlation coefficients was 0.763.

CONCLUSION

In this study, we determined supine position with the knee extended; using 2.0 mm diameter region of interest and image acquisition at the longitudinal plane with thicker layer coupling gel seems most appropriate to reliably image healthy quadriceps entheses with SWE.

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.

EULAR points to consider for the definition of clinical and imaging features suspicious for progression from psoriasis to psoriatic arthritis

BACKGROUND

The transition from psoriasis (PsO) to psoriatic arthritis (PsA) and the early diagnosis of PsA is of considerable scientific and clinical interest for the prevention and interception of PsA.

OBJECTIVE

To formulate EULAR points to consider (PtC) for the development of data-driven guidance and consensus for clinical trials and clinical practice in the field of prevention or interception of PsA and for clinical management of people with PsO at risk for PsA development.

METHODS

A multidisciplinary EULAR task force of 30 members from 13 European countries was established, and the EULAR standardised operating procedures for development for PtC were followed. Two systematic literature reviews were conducted to support the task force in formulating the PtC. Furthermore, the task force proposed nomenclature for the stages before PsA, through a nominal group process to be used in clinical trials.

RESULTS

Nomenclature for the stages preceding PsA onset, 5 overarching principles and 10 PtC were formulated. Nomenclature was proposed for three stages towards PsA development, namely people with PsO at higher risk of PsA, subclinical PsA and clinical PsA. The latter stage was defined as PsO and associated synovitis and it could be used as an outcome measure for clinical trials evaluating the transition from PsO to PsA. The overarching principles address the nature of PsA at its onset and underline the importance of collaboration of rheumatologists and dermatologists for strategies for prevention/interception of PsA. The 10 PtC highlight arthralgia and imaging abnormalities as key elements of subclinical PsA that can be used as potential short-term predictors of PsA development and useful items to design clinical trials for PsA interception. Traditional risk factors for PsA development (ie, PsO severity, obesity and nail involvement) may represent more long-term disease predictors and be less robust for short-term trials concerning the transition from PsO to PsA.

CONCLUSION

These PtC are helpful to define the clinical and imaging features of people with PsO suspicious to progress to PsA. This information will be helpful for identification of those who could benefit from a therapeutic intervention to attenuate, delay or prevent PsA development.

Musculoskeletal ultrasonography in rheumatic diseases

Ultrasonography is an imaging technique based on sound waves used for the evaluation of soft tissues. Sound waves have been used for a long time in nonmedical fields, including military defense systems, radar systems, and detection of icebergs. Technological advances resulted in new techniques becoming available for medical imaging, including ultrasonography, magnetic resonance imaging, and computed tomography. Nowadays, the use of imaging has become a gold standard protocol in the diagnosis of many diseases, and recently developed diagnosis and therapy options provide more efficient treatment of rheumatic diseases. Thus, it has become possible to prevent structural damage and disability in patients with rheumatic disease. Musculoskeletal ultrasonography is becoming a preferred imaging technique for rheumatic diseases, as it has many advantages. Among its advantages are being inexpensive, being radiation-free, having a dynamic image capacity, helping to detect disease activity, and helping with early detection and diagnosis of structural damage. This review summarizes the use of ultrasonography in rheumatic diseases.

Can Biologics Be Discontinued in Patients with Psoriatic Arthritis in Stable Remission? A Prospective Single‐CenterClinical and Ultrasound Study

Biologic disease‐modifying antirheumatic drugs (bDMARDs) and particularly tumor necrosis factor inhibitors (TNFi) have dramatically changed the natural history of psoriatic arthritis (PsA), making complete clinical remission possible in most patients. However, TNFi drugs are not without potential adverse effects such as increased infectious risk. In addition, their extensive use is associated with a significant economic burden. This prospective longitudinal cohort study involving 45 PsA patients treated with TNFi in stable remission aimed to evaluate by both clinical examination and ultrasound timing and predictive factors of disease relapse after discontinuation of TNFi treatment. Thirty‐nine (86.6%) of 45 enrolled patients experienced disease relapse during the follow‐up period, while six patients (13.4%) maintained remission beyond the scheduled 104 weeks. The median survival time of drug‐free remission after TNFi discontinuation was 24 weeks (95% confidence interval (CI): 22.6–25.4). Disease relapse was characterized by marked clinical and ultrasound worsening of dermatologic and rheumatologic conditions. However, resuming previously discontinued treatment allowed all patients to quickly regain clinical remission. Interestingly, axial involvement was a key feature of the symptomatological pattern of disease relapse, being the main reason for treatment restart in 26% of our cohort. Based on a multivariate Cox model, three variables (VAS pain, tender joint count, and swollen joint count) of the clinical assessment performed at the time point of TNFi treatment onset negatively influenced the time to disease relapse. In conclusion, temporary discontinuation of TNFi drugs is feasible and relatively safe. However, as few predictors of the risk and timing of disease relapse have been identified, patients should be closely monitored when therapy is discontinued.

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.

Improved diagnostic performance of CASPAR criteria with integration of ultrasound

Background

The difficulty in determining synovitis, tenosynovitis, or enthesitis by physical examination (PE) has limited the diagnostic capability of CASPAR for psoriatic arthritis (PsA). Therefore, we aimed to evaluate the diagnostic utility of CASPAR with the integration of ultrasound (US).

Methods

Patients with a hint of PsA were enrolled. Besides routine PE for tender or swollen joints, enthesitis, and dactylitis, US was performed to evaluate peripheral joints, entheses, and tendons. The additional value of the US to the CASPAR criteria was analyzed.

Results

A total of 326 consecutive patients with 164 PsA and 162 non-PsA were enrolled. A total of 162 non-PsA patients consisted of 58 cases of psoriasis (PsO), 27 osteoarthritis with PsO/family history of PsO, five fibromyalgia with PsO, 69 sero-negative rheumatoid arthritis, and three undifferentiated arthritis. Significantly higher frequencies of tenosynovitis and enthesitis on US and new bone formation on X-rays were found in PsA vs. non-PsA patients (59.1% vs. 13.0%; 63.4% vs. 14.2%; 62.2% vs. 8.0%, p <0.01 for all). Logistic regression analysis showed that dactylitis (OR = 12.0, p <0.01), family history of PsO/PsA (OR = 3.1, p <0.05), nail involvement (OR = 3.5, p = 0.01), new bone formation on X-ray (OR = 14.8, p <0.01), tenosynovitis on US (OR = 21.3, p <0.01), and enthesitis on US (OR = 21.7, p <0.01) were independent risk factors for PsA. By combining US tenosynovitis and/or enthesitis, the diagnostic utility of CASPAR criteria was improved, with superior specificity (91.4% vs. 84.0%) and similar sensitivity (95.7% vs. 94.5%). Replacing X-ray by US or adding US, the CASPAR criteria showed comparable sensitivity and specificity for PsA diagnosis. The diagnostic accuracy was 89.3% for CASPAR criteria based on PE, 93.6% for CASPAR added with US, and 93.3% for CASPAR with US replacing X-ray.

Conclusion

The diagnostic utility of the CASPAR was improved by integrating tenosynovitis and/or enthesitis when using US. US provides additional value for PsA recognition.

Imaging of the nail unit in psoriatic patients:A systematic scoping review of techniques and terminology

BACKGROUND

The growing interest in the visualization of psoriatic nail unit changes has led to the discovery of an abundance of image characteristics across various modalities.

OBJECTIVE

To identify techniques for non-invasive imaging of nail unit structures in psoriatic patients and review extracted image features to unify the diverse terminology.

METHODS

For this systematic scoping review, we included studies available on PubMed and Embase, independently extracted image characteristics, and semantically grouped the identified features to suggest a preferred terminology for each technique.

RESULTS

After screening 753 studies, 67 articles on the visualization of clinical and subclinical psoriatic changes in the nail plate, matrix, bed, folds and hyponychium were included. We identified 4 optical and 3 radiological imaging techniques for the assessment of surface (dermoscopy [n = 16], capillaroscopy [n = 12]), sub-surface (ultrasound imaging [n = 36], optical coherence tomography [n = 4], fluorescence optical imaging [n = 3]), and deep-seated psoriatic changes (magnetic resonance imaging [n = 2], positron emission tomography-computed tomography [n = 1]). By condensing 244 image feature descriptions into a glossary of 82 terms, overall redundancy was cut by 66.4% (37.5%-77.1%). More than 75% of these image features provide additional disease-relevant information that is not captured using conventional clinical assessment scales.

CONCLUSIONS

This review has identified, unified, and contextualized image features and related terminology for non-invasive imaging of the nail unit in patients with psoriatic conditions. The suggested glossary could facilitate the integrative use of non-invasive imaging techniques for the detailed examination of psoriatic nail unit structures in research and clinical practice.

Musculoskeletal Ultrasound to Identify Subclinical Joint and Periarticular Involvement in Patients With Inflammatory Bowel Disease: A Systematic Literature Review

BACKGROUND

Musculoskeletal ultrasonography identifies subclinical joint and entheseal inflammation, and it might be of value in patients with inflammatory bowel diseases (IBD), which are at higher risk of inflammatory arthropathy and disability. Our aim was to retrieve the evidence on the applications of ultrasound in patients with non-arthropathic IBD.

METHODS

Studies enrolling patients with IBD without arthritis, undergoing ultrasound of joints, tendons or entheses were eligible. The outcomes of interest encompassed the frequency of ultrasound-detected lesions, their accuracy in diagnosing arthritis, their prognostic role and sensitivity to change. All study types, excluding case reports, case series and narrative reviews, were included. Search strategies were applied in PubMed and Embase. Abstract and full-texts were evaluated by pairs of reviewers. The risk of bias was evaluated through the Newcastle-Ottawa scale or the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) 2. The protocol was registered in PROSPERO (CRD42021264972).

RESULTS

Out of 2,304 records, eight studies were included, all reporting the frequency of lesions, while only three evaluated also the diagnostic accuracy. All studies had a cross-sectional design, with no evidence on prediction or follow-up. All studies evaluated the entheses, while only three the joints. The most common chronic lesions were entheseal thickening (up to 81.5%) and enthesophytes (67.9%), while entheseal erosions were present in 16%-17% of patients. Among inflammatory lesions, power Doppler was reported in 14%-67% of patients. There were no differences among Crohn's disease or ulcerative colitis and depending on disease activity, while there were contrasting results on different disease durations. When evaluating the diagnostic performance, the best specificity for a diagnosis if IBD was 0.88 (95%CI, 0.8-0.94) for joint abnormalities. Also, the best sensitivity was 0.88 (95%CI, 0.76-0.95) for entheseal lesions. No studies assessed of the combination of lesions. Due to the limited number of studies, meta-analyses were not performed.

CONCLUSIONS

Despite the possible value of ultrasound in IBD, there is limited evidence deriving from cross-sectional studies. Longitudinal studies are needed to clarify the role of this technique, while its current placement might be that of complementing clinical assessment, in particular in early intestinal disease.

Integrating imaging and biomarker assessment to better define psoriatic arthritis and predict response to biologic therapy

The treatment options for PsA have substantially expanded over the last decade. Approximately 40% of patients will not respond to first-line anti-TNF-α therapies. There is limited data to help clinicians select the most appropriate biologic therapy for PsA patients, including guidance for decisions on biologic therapy switching. In this review we will examine the current understanding of predictors of response to treatment. Imaging technology has evolved to allow us to better study psoriatic disease and define disease activity, including synovitis and enthesitis. Enthesitis is implicated in the pathogenesis, diagnosis and prognosis of PsA. It appears to be a common thread among all of the various PsA clinical presentations. Enthesitis mainly manifests as tenderness, which is difficult to distinguish from FM, chronic pain and mechanically associated enthesopathy, and it might be relevant for understanding the apparent 40% failure of existing therapy. Excess adipose tissue makes if more difficult to detect joint swelling clinically, as many PsA patients have very high BMIs. Integrating imaging and clinical assessment with biomarker analysis could help to deliver stratified medicine in PsA and allow better treatment decision making. This could include which patients require ongoing biologic therapy, which class of biologic therapy that should be, and who alternatively requires management of non-inflammatory disease.

Development of a Predictive Model for Screening Patients with Psoriasis at Increased Risk of Psoriatic Arthritis

Introduction

This study aimed to develop a predictive model based on ultrasound variables which can be used to screen patients with psoriasis who are prone to progress to psoriatic arthritis (PsA) in clinical practice.

Methods

This is a cross-sectional study conducted in a single center from October 2018 to November 2020. All subjects (non-PsA group, PsA group, and control group) underwent an ultrasound examination and their ultrasound abnormalities were recorded. On the basis of statistical analysis and clinical experts’ advice, several variables were selected for modelling. We used logistic regression to establish the prediction model. To assess the discrimination and accuracy of this model, internal validation and external validation were performed.

Results

A total of 852 patients with psoriasis but without PsA, 261 patients with PsA, and 86 healthy volunteers were included. Ultimately, the predictive model consisted of six variables, namely hand joint power Doppler (PD) signals (grade 0: OR 2.94, 95% CI 1.94–4.47; grade ≥ 1: OR 109.30, 95% CI 14.35–832.27; P < 0.001), wrist joint synovial thickening (grade 1: OR 1.29, 95% CI 0.69–2.43; grade 2: OR 4.30, 95% CI 1.92–9.65; grade 3: OR 11.05, 95% CI 1.01–120.64; P = 0.001), knee joint PD signals (grade 0: OR 1.01, 95% CI 0.56–1.80; grade ≥ 1: OR 14.77, 95% CI 3.99–54.69; P < 0.001), toe joint PD signals (grade 0: OR 1.18, 95% CI 0.78–1.79; grade ≥ 1: OR 5.74, 95% CI 2.84–11.63; P < 0.001), quadriceps tendon and patellar tendon enthesitis (OR 1.95, 95% CI 1.36–2.78, P < 0.001), Achilles tendon and plantar aponeurosis enthesitis (OR 1.63, 95% CI 1.14–2.32, P = 0.007). C-index for the predictive model was 0.80 (95% CI 0.76–0.83). After bootstrapping validation (1000 times), it was confirmed to be 0.79. The external validation showed the accuracy of the predictive model is 0.87 (95% CI 0.69–0.95).

Conclusion

This study succeeded in developing a predictive model with a high degree of accuracy to predict the risk of PsA in patients with psoriasis.

Psoriatic arthritis often occurs in the population of patients with psoriasis. It brings a huge burden and pain to patients. At present, the diagnosis for psoriatic arthritis is very challenging. Numerous research studies have begun to focus on identifying patients with psoriasis at increased risk of psoriatic arthritis. Among a lot of modalities, ultrasound has been considered as a sensitive and convenient tool for screening early psoriatic arthritis. Our study successfully established a predictive model based on ultrasound variables to screen patients with psoriasis at high risk of transiting to psoriatic arthritis. After internal and external validation, it showed great accuracy and generalizability. We recommend that clinicians perform ultrasound screening of patients with psoriasis in clinical routine and get their risk value of transiting to psoriatic arthritis by using this model. For those patients with a high risk of progression to psoriatic arthritis, clinicians should refer them to a rheumatology department as soon as possible so that they could have access to early and effective management which might bring them good clinical and imaging outcomes.

How Variable Is the Volar Subcutaneous Tissue of the Digits on B-Mode and Color Doppler Ultrasound in Non-Psoriatic Individuals and Could It Be Included in a Dactylitis Score?

BACKGROUND

 Digital subcutaneous tissue (SCT) changes are involved in dactylitis, a hallmark feature of psoriatic arthritis (PsA). There are no studies on the ultrasound (US) characteristics of the digital SCT in the general population.

OBJECTIVES

 To investigate the variability in US-measured thickness (TH) and color Doppler (CD)-detected blood flow of the SCT of the volar aspects of the fingers in a non-psoriatic population and to investigate the impact of the scanning method and demographics and clinical features on these measurements.

METHODS

 SCT TH and semiquantitative (SQD) and quantitative (QD) Doppler signals were measured in the bilateral second finger at the proximal and middle phalanges in 81 non-psoriatic volunteers [49 female, 32 men; 18-78 years]. Two scanning methods with and without (thick gel layer interposition) probe-skin contact were used. Demographics and clinical features were collected.

RESULTS

 There was high variability of SCT TH and Doppler measurements between individuals. All US measurements obtained without probe-skin contact were significantly greater than their corresponding measurements obtained with the probe contacting the skin (p < 0.001). SCT TH was positively related to dominant hand, age, masculine gender, weight, height, body mass index, and alcohol consumption while Doppler measurements were positively related to age and non-dominant hand.

CONCLUSIONS

 US-measured SCT thickness and Doppler-detected SCT blood flow of the volar aspect of the fingers seem to be highly variable in the non-psoriatic population as well as highly dependent on the US scanning method. This variability is of utmost importance for assessing dactylitis in PsA.

Value of imaging to guide interventional procedures in rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

OBJECTIVES

To summarise current data on the value of imaging to guide interventional procedures in patients with rheumatic and musculoskeletal disease (RMDs) informing an European Alliance of Associations for Rheumatology taskforce.

METHODS

A systematic literature review was conducted to retrieve prospective and retrospective studies published in English and comparing different (imaging) techniques, different settings and procedural protocols to guide interventions in patients with RMDs. MEDLINE, EMBASE, the Cochrane Library and Epistemonikos databases were searched through October 2021. Risk of bias (RoB) was assessed using the Cochrane RoB tool for randomised trials V.2 (ROB2), the RoB tool for Non-Randomised Studies of Interventions and the appraisal tool for cross-sectional studies.

RESULTS

Sixty-six studies were included (most with moderate/high RoB); 49 were randomised controlled trials, three prospective cohort studies and 14 retrospective studies. Fifty-one studies compared either one imaging technique with another imaging technique, or with palpation-guided interventions. Ultrasound (US) was most frequently studied (49/51), followed by fluoroscopy (10/51). Higher accuracy was found for US or fluoroscopy compared with palpation-guided interventions. Studies comparing different imaging techniques (12/51) did not endorse one specific method. Different settings/equipment for imaging-guided procedures (eg, automatic vs manual syringes) were investigated in three studies, reporting heterogeneous results. Fifteen studies compared different imaging-guided procedures (eg, intra-articular vs periarticular injections).

CONCLUSION

Higher accuracy of needle positioning at joints and periarticular structures was seen in most studies when using imaging (especially US) guidance as compared with palpation-guided interventions with the limitation of heterogeneity of data and considerable RoB.

Enthesitis in Psoriatic Arthritis, the Sonographic Perspective

Purpose of Review

To provide an overview of the ultrasound (US) studies focusing on enthesitis in psoriatic arthritis (PsA).

Recent Findings

Last-generation US equipment has demonstrated the ability to detect subtle morphostructural and vascular abnormalities at entheseal level. US is able to identify pathologic changes in both “classical” (i.e., the site of attachment of tendons, ligaments, and joint capsules into the bone) and “functional” entheses (i.e., anatomical regions where tendons or ligaments wrap around bony pulleys).

Summary

US has the potential to be the first-line method in the assessment of enthesitis. In the present review we critically discussed the current definitions of US enthesitis, the scoring systems, and the main fields of application (i.e., the detection of enthesitis in PsA and psoriasis, the identification of different disease subsets, and the assessment of response to treatment).

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.

In Patients with Early Peripheral Psoriatic Arthritis Baseline C-Reactive Protein, Pain and Ultrasound-Detected Synovitis Predict Subsequent Treatment with ts/bDMARDs. A Retrospective Analysis

With the availability of effective treatment with targeted synthetic and biologic disease-modifying anti-rheumatic drugs (ts/bDMARDs) for psoriatic arthritis (PsA), it is crucial to identify predictors of access to this treatment since disease onset. We retrospectively enrolled patients with peripheral PsA, assessed in an early arthritis clinic from 2005 to 2020. The main baseline demographic, clinical and ultrasonographic (assessment of bilateral wrist and metacarpophalangeal joints) features were evaluated through descriptive statistics and tested as predictors by univariate and multivariate Cox models. The outcome of interest was the indication for ts/bDMARDs within 2 years from diagnosis. We included 238 patients with PsA, with a mean (sd) age of 51.04 (13.98) years; 90 (37.8%) were male, and the median (IQR) symptom duration was 6.12 (3.29–12.25) months. In univariate analyses, C-reactive protein (RR, 95% CI 1.204 (1.065,1.362)), Visual Analogue Scale (VAS) pain (1.027 (1.005,1.048)), the number of tender joints on 28 joints (1.087 (1.025, 1.153)), and a synovial power Doppler (PD) score > 1 (3.63 (1.307, 10.08)) emerged as significant predictors. C-reactive protein, VAS pain and PD confirmed their predictive value also in multivariate models. These results provide preliminary evidence on the features that might characterize patients with early peripheral PsA requiring more intensive monitoring and treatment escalation.

Unmet needs in psoriatic arthritis

Psoriatic arthritis (PsA) is a chronic inflammatory arthritis with a highly variable clinical presentation that does not have a validated molecular or imaging test, making accurate diagnosis a challenge. Consequences of diagnostic delay include irreversible joint damage and significant morbidity. Over the past few decades, there have been major advances in the understanding and treatment of PsA, leading to more targeted therapies. However, there is no current method to predict optimal treatment strategy to achieve minimal disease activity and prevent medication-related adverse events in the management of early disease. PsA is also associated with other comorbidities that include metabolic syndrome and psychosocial burden; two areas that are often unaddressed in the clinical setting and have associated sequelae. This chapter focuses on key domains of unmet needs, which include diagnostic challenges, delay in diagnosis, prognostication systems and stratified medicine approaches and precision medicine strategies for established and emerging therapies.

Imaging in psoriatic arthritis: Status and recent advances

The heterogeneous nature of psoriatic arthritis (PsA), encompassing several domains, with varied presentations brings about considerable challenges in disease evaluation. Prompt diagnosis and targeted therapy have resulted in disease remission being accepted as an attainable goal in PsA. Imaging has played a pivotal role in early diagnosis, better understanding of pathogenesis, monitoring of disease, and as an outcome measurement tool in clinical trials in PsA. Conventional radiography has been the cornerstone of assessing structural damage. With the advent of ultrasound and magnetic resonance imaging, better delineation of the various structures involved in the disease process is possible, thus enabling sensitive assessment of inflammatory and structural pathologies together. In this review, imaging modalities used in routine assessment and clinical trials in PsA will be discussed in detail, focusing on advances over the past 5 years.

Do tender joints in active psoriatic arthritis reflect inflammation assessed by ultrasound and magnetic resonance imaging?

OBJECTIVE

To investigate the association between clinical joint tenderness and intra- and periarticular inflammation as assessed by ultrasound and magnetic resonance imaging (MRI) in patients with active psoriatic arthritis (PsA) and to explore if the associations differ according to patient-reported outcomes (PROs) and structural damage.

METHODS

Forty-one patients with active PsA and hand involvement had 76/78 joints examined for swelling/tenderness and ultrasound and MRI of 24 and 12 finger joints, respectively. Synovitis, tenosynovitis, periarticular inflammation and erosions were assessed using OMERACT definitions and scoring systems. Correlation between imaging inflammation sum-scores (intra-and periarticular) and tender/swollen joint counts were calculated using Spearman's rho, agreement at joint level was examined using prevalence and bias adjusted kappa (PABAK). Subgroup analyses explored the influence of PROs and radiographic erosive disease on these associations.

RESULTS

No significant correlations were found between tender or swollen joint counts and imaging inflammation sum-scores (rho=-0.31-0.38). In patients with higher level of overall pain, disability and lower self-reported mental health, a tendency towards negative correlations were found. At joint level, intra- and periarticular imaging inflammatory lesions had slight agreement with joint tenderness (PABAK=0.02-0.19) and slight to moderate with swelling (PABAK=0.16-0.54). For tender joints, agreement with imaging inflammation was even weaker in patients with either high overall pain scores, high disability scores, and/or non-erosive disease.

CONCLUSION

Joint tenderness had low association with imaging signs of inflammation in PsA patients, particularly in patients with high self-reported pain, disability and low mental health, indicating that tenderness is influenced by other parameters than local inflammation.

Comparative Efficacy of Different Triage Methods for Psoriatic Arthritis - Prospective Study in a Rapid Access Clinic

OBJECTIVES

The study aimed to identify the optimal combination of triage methods to identify PsA among psoriasis patients with musculoskeletal symptoms in a rapid access clinic and to describe their outcome after 1 year.

METHODS

Patients with psoriasis and no prior diagnosis of PsA were referred for assessment of their musculoskeletal complaints. Each patient was assessed by the following three triage modalities: 1) assessment by an advanced practice physiotherapist; 2) targeted musculoskeletal ultrasound (MSK-US) and; 3) PsA screening questionnaires. The patients were then evaluated by a rheumatologist who determined their disease status and classified them as: "Not PsA", "Possibly PsA" or "PsA". Patients returned for a one year follow up visit and were re-assessed for change in their disease status. Sensitivity and specificity were calculated for each individual modality as well as for combinations of modalities.

RESULTS

203 patients with psoriasis and musculoskeletal symptoms were enrolled. 8.8% were classified as PsA and 23.6% as possibly PsA. There was no significant difference in the individual performance of the modalities. The highest sensitivity was seen with MSK-US (89%) and the highest specificity was found with the Psoriatic Arthritis Screening and Evaluation (PASE) questionnaire (79%). The addition of MSK-US data improved the performance of the modalities. A total of 9 patients converted to PsA after 1 year. All patient reported outcome measures have significantly improved at one year (P<0.001).

CONCLUSION

Combining MSK-US with a screening questionnaire for PsA improved the triage of patients with suspected PsA.

Defining Pre-Clinical Psoriatic Arthritis in an Integrated Dermato-Rheumatology Environment

In excess of three quarters of patients with psoriatic arthritis (PsA) have preceding psoriasis (PsO), which offers a clinical biomarker for the recognition of early PsA. Numerous surveys have shown a remarkably high frequency of clinically occult musculoskeletal symptoms in psoriasis patients. Imaging studies, particularly ultrasound, show a high prevalence of subclinical enthesitis and other inflammatory changes in psoriasis subjects. Since a serum biomarker, such as the case of anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis, neither exists nor seems biologically plausible at this point, this article explores how integration of rheumatological and dermatological assessment can be facilitated for the early recognition of potential PsA. Given that scalp disease is a PsA predictor, but may be managed in the community, then a particular need to access this group is needed. An integrated approach between rheumatology and dermatology can involve joint clinics, parallel clinics with discussion of relevant cases or virtual contact between specialties. Early therapy evaluation and integrated strategies have considerable implications for minimizing suffering and joint damage in PsA.

Imaging in the diagnosis and management of peripheral psoriatic arthritis

Psoriatic arthritis is a heterogenous disease affecting peripheral and axial joints, tendons, ligaments, and their insertions, in addition to the skin and the nails. The complexity of the involved structures has puzzled clinicians trying to understand the underlying pathology that leads to symptoms in order to choose the appropriate medications with different modes of actions. Imaging, mainly ultrasound and magnetic resonance imaging, allows of accurate detection of inflammatory changes in the musculoskeletal structures, which helps to avoid false positive and negative assessments. The linking of different anatomical structures' involvement using imaging also provides insights into the pathogenesis of psoriatic arthritis. In this review, ultrasound and magnetic resonance imaging will be discussed in depth with regard to their use in the field of peripheral psoriatic arthritis, with a focus on the literature from the last 4 years and recent advances.

Innovative Imaging Technique for Visualization of Vascularization and Established Methods for Detection of Musculoskeletal Inflammation in Psoriasis Patients

Psoriasis (PsO) is one of the common chronic inflammatory skin diseases. Approximately 3% of the European Caucasian population is affected. Psoriatic arthritis (PsA) is a chronic immune-mediated disease associated with PsO characterized by distinct musculoskeletal inflammation. Due to its heterogeneous clinical manifestations (e.g., oligo- or polyarthritis, enthesitis, dactylitis, and axial inflammation), early diagnosis of PsA is often difficult and delayed. Approximately 30% of PsO patients will develop PsA. The responsible triggers for the transition from PsO only to PsA are currently unclear, and the impacts of different factors (e.g., genetic, environmental) on disease development are currently discussed. There is a high medical need, recently unmet, to specifically detect those patients with an increased risk for the development of clinically evident PsA early to initiate sufficient treatment to inhibit disease progression and avoid structural damage and loss of function or even intercept disease development. Increased neoangiogenesis and enthesial inflammation are hypothesized to be early pathological findings in PsO patients with PsA development. Different disease states describe the transition from PsO to PsA. Two of those phases are of value for early detection of PsA at-risk patients to prevent later development of PsA as changes in biomarker profiles are detectable: the subclinical phase (soluble and imaging biomarkers detectable, no clinical symptoms) and the prodromal phase (imaging biomarkers detectable, unspecific musculoskeletal symptoms such as arthralgia and fatigue). To target the unmet need for early detection of this at-risk population and to identify the subgroup of patients who will transition from PsO to PsA, imaging plays an important role in characterizing patients precisely. Imaging techniques such as ultrasound (US), magnetic resonance imaging (MRI), and computerized tomography (CT) are advanced techniques to detect sensitively inflammatory changes or changes in bone structure. With the use of these techniques, anatomic structures involved in inflammatory processes can be identified. These techniques are complemented by fluorescence optical imaging as a sensitive method for detection of changes in vascularization, especially in longitudinal measures. Moreover, high-resolution peripheral quantitative CT (HR-pQCT) and dynamic contrast-enhanced MRI (DCE-MRI) may give the advantage to identify PsA-related early characteristics in PsO patients reflecting transition phases of the disease.

Accuracy of Physical Examination to Detect Synovial and Extra-Synovial Pathologies in Psoriatic Arthritis in Comparison to Ultrasonography

We aimed to explore the accuracy of physical examination (PE) to detect the synovial and extra-synovial pathologies in psoriatic arthritis (PsA) in comparison to ultrasonography (US). Twenty-nine PsA patients with hand pain were included in the study. A detailed PE of the hands was performed and US scans were performed for the joints, extensor and flexor tendons, and entheses of the second to fifth fingers of both hands. The agreement between PE and US findings was calculated. The strongest agreement for the joints was between "swollen joints" and power Doppler (PD) signals in the metacarpophalangeal (MCP) joints and grey scale synovitis in the proximal interphalangeal (PIP) joints. The agreement of tender entheses on PE and inflammation on US (hypoechogenicity, thickening, and/or PD signals) was poor for both extensor (Kappa = -0.027, Prevalence Adjusted and Bias Adjusted Kappa (PABAK) = 0.344) and flexor compartments (Kappa = 0.039, PABAK = 0.569). Similar to enthesitis, comparison of any PE and US findings showed a poor agreement at the extensor and flexor tendon regions (extensor: Kappa = 0.123, PABAK = 0.448, and flexor: Kappa = 0.171, PABAK = 0.431). Our study showed that there was a poor to fair agreement of PE and US findings of hands. US can add value when determining the source of pain in PsA in the small joints.

Ultrasound Imaging in Psoriatic Arthritis: What Have We Learnt in the Last Five Years?

Psoriatic arthritis (PsA) is a complex heterogeneous disease with multiple inter-related pathologies such as synovitis, enthesitis, tendinopathy, and dactylitis. Clinical assessment is limited in its detail to assess pathology, thus in recent years, ultrasound (US) has become more popular, given its high sensitivity to detect inflammatory arthritis and ability to inform clinical decisions. Although a qualitative technique, US findings can be graded semi-quantitatively for grayscale (GS) and power Doppler (PD). Synovitis is frequently present in inflammatory arthritis pathologies, and in PsA, recent evidence shows a propensity for tendon and entheseal lesions. The presence of flexor tenosynovitis and flexor tendon insertional enthesopathy at accessory pulleys is supportive of the “Deep Koebner” concept. Peri-tendinous inflammation—mutual to PsA or rheumatoid arthritis (RA), is associated with soft tissue oedema with PD signal frequently at the flexor tendon compartments in PsA. Research on enthesitis in PsA/PsO has improved understanding in subclinical and clinical PsA, explored associations with progression to PsA, and investigated links to prognosis assessment. Dactylitis is a pathognomonic PsA lesion where US has enhanced knowledge of the disease course and pathology of lesions such as: flexor tenosynovitis; synovitis; and soft tissue oedema. Increased US sensitivity has also brought innovation including promising automated ultrasound scanning techniques. So, what have we learnt in recent years and what are the unmet needs to focus future research initiatives in this disabling disease? This narrative review article assesses the neoteric evidence, bringing into context the knowledge gained and highlighting potential areas of research.

Novel and reliable DACTylitis glObal Sonographic (DACTOS) score in psoriatic arthritis

OBJECTIVES

Dactylitis is one of the most typical features of psoriatic arthritis (PsA), with a high lifetime prevalence and inclusion in PsA clinical indices. Musculoskeletal ultrasonography (Msk-US) can readily detect inflammatory involvement of finger anatomical structures particular to dactylitis and monitor therapeutic effects. In this study, we aim to identify the characteristic lesions in PsA dactylitis of the hands, assess the reliability of Msk-US in scoring those lesions and develop a DACTylitis glObal Sonographic (DACTOS) score.

METHODS

After a systematic literature review on the use of Msk-US in PsA dactylitis, 12 rheumatologists participated in a three-round Delphi procedure and consensus meeting to agree on the sonographic elementary lesions characterising dactylitis and on the composition of a global sonographic score. Then, a web-based and a patient-based intra-rater and inter-rater reliability exercise was performed to assess those lesions included in the score.

RESULTS

DACTOS score was obtained by summing the scores of each lesion selected in the Delphi survey: subcutaneous soft tissue oedema, flexor tenosynovitis, peritendon extensor inflammation and synovitis. The DACTOS score ranges from 0 to 25. In the reliability exercises, we obtained moderate-to-excellent agreement for the sonographic lesions included in the score.

CONCLUSIONS

The novel DACTOS score is a reliable measure to interpret the multiple characteristic sonographic features of dactylitis. The DACTOS score provides a useful global analysis of dactylitis of the hand and can represent a support to clinical diagnosis as well as a useful tool for the management and research in patients with PsA with dactylitis.

The Pattern of Musculoskeletal Complaints in Patients With Suspected Psoriatic Arthritis and Their Correlation With Physical Examination and Ultrasound

OBJECTIVE

To describe the pattern of musculoskeletal (MSK) symptoms and their correlation with clinical and sonographic findings among psoriasis patients with suspected psoriatic arthritis (PsA).

METHODS

Patients with psoriasis and no prior diagnosis of PsA were referred for assessment of their MSK complaints. The study included the following steps: (1) assessment by an advanced practice physiotherapist, (2) targeted MSK ultrasound, and (3) assessment by a rheumatologist. In addition, patients were asked to complete questionnaires about the nature and duration of their MSK symptoms and to mark the location of their painful joints on a homunculus. Each patient was classified by a rheumatologist as "Not PsA," "Possible PsA," or "PsA". MSK symptoms and patient-reported outcomes (PRO) were compared between patients with PsA and Possible/Not PsA. Agreement between modalities was assessed using κ statistics.

RESULTS

Two hundred three patients with psoriasis and MK symptoms were enrolled (8.8% PsA, 23.6% Possible PsA). Patients classified as PsA had worse scores on the PsA Impact of Disease (P = 0.004) and Functional Assessment of Chronic Illness Therapy-Fatigue scale (P = 0.02). There was no difference between the 2 groups in the presence, distribution, and duration of MSK symptoms. Analysis of agreement in physical examination between modalities revealed the strongest agreement between the rheumatologist and physiotherapist (κ = 0.28). The lowest levels of agreement were found between ultrasound and patient (κ = 0.08) and physiotherapist and ultrasound (κ = 0.08).

CONCLUSION

The results of this study suggest that the intensity, rather than the type, duration, or distribution of MSK symptoms, is associated with PsA among patients with psoriasis.

From Psoriasis to Psoriatic Arthritis: Insights from Imaging on the Transition to Psoriatic Arthritis and Implications for Arthritis Prevention

PURPOSE OF REVIEW

To describe the recent advances in the field towards the prevention and early recognition of Psoriatic Arthritis (PsA).

RECENT FINDINGS

Defining the preclinical phase of PsA remains challenging since up to 50% of subjects with psoriasis have subclinical imaging enthesopathy, but many of these do not progress to PsA. Nevertheless, there is evidence that subjects with subclinical imaging enthesopathy are at increased risk of developing PsA. In recent years, it has been shown that both PsA and anti-citrullinated protein antibodies (ACPA) positive rheumatoid arthritis (RA) are characterized by a subclinical phase of non-specific or brief duration arthralgia with shared imaging features accounting for joint symptomatology. Sonographically determined tenosynovitis and enthesitis are the key imaging features present in non-specific PsO arthralgia that are at risk of future PsA development. Furthermore, the early phases of PsA are complicated by factors including body mass index (BMI), which is a risk factor for PsA, but BMI is also associated with imaging abnormalities on enthesopathy. Fully disentangling these clinical and imaging factors will be important for enrichment for imminent PsA so that disease prevention strategies can be investigated. Psoriasis patients with arthralgia have a higher prevalence of tenosynovitis and imaging enthesopathy is at higher risk of transitioning to overt PsA.

Differential Diagnosis of Inflammatory Arthropathies by Musculoskeletal Ultrasonography: A Systematic Literature Review

Background: Differential diagnosis in early arthritis is challenging, especially early after symptom onset. Several studies applied musculoskeletal ultrasound in this setting, however, its role in helping diagnosis has yet to be clearly defined. The purpose of this work is to systematically assess the diagnostic applications of ultrasonography in early arthritis in order to summarize the available evidence and highlight possible gaps in knowledge. Methods: In December 2017, existing systematic literature reviews (SLR) on rheumatoid arthritis (RA), osteoarthritis (OA), psoriatic arthritis (PsA), polymyalgia rheumatica (PMR), calcium pyrophosphate deposition disease (CPPD), and gout were retrieved. Studies on ultrasound to diagnose the target conditions and detecting elementary lesions (such as synovitis, tenosynovitis, enthesitis, bone erosions, osteophytes) were extracted from the SLRs. The searches of the previous reviews were updated and data from new studies fulfilling the inclusion criteria extracted. Groups of reviewers worked separately for each disease, when possible diagnostic accuracy (sensitivities, specificities) was calculated from primary studies. When available, the reliability of ultrasound to detect elementary lesions was extracted. Results: For all the examined disease, recent SLRs were available. The new searches identified 27 eligible articles, with 87 articles included from the previous SLRs. The diagnostic performance of ultrasound in identifying diseases was addressed by 75 studies; in most of them, a single elementary lesion was used to define diagnosis, except for PMR. Only studies on RA included consecutive patients with new onset of arthritis, while studies on gout and CPPD often focused on subjects with mono-arthritis. Most of the remaining studies enrolled patients with a defined diagnosis. Synovitis was the most frequently detected lesion; clinical diagnosis was the most common reference standard. The diagnostic performance of ultrasound across different conditions was extremely variable. Ultrasound to identify elementary lesions was assessed in 38 studies in OA, gout and CPPD. Its performance in OA was very variable, with better results in CPPD and gout. The reliability of ultrasound was moderate to good for most lesions. Conclusions: Although a consistent amount of literature investigated the diagnostic application of ultrasound, in only a minority of cases its additional value over clinical diagnosis was tested. This SLR underlines the need for studies with a pragmatic design to identify the placement of ultrasound in the diagnostic pathway of new-onset arthritis.

Transition phase towards psoriatic arthritis: clinical and ultrasonographic characterisation of psoriatic arthralgia

Objective

Non-specific musculoskeletal pain is common in subjects destined to develop psoriatic arthritis (PsA). We evaluated psoriatic patients with arthralgia (PsOAr) compared with psoriasis alone (PsO) and healthy controls (HCs) using ultrasonography (US) to investigate the anatomical basis for joint symptoms in PsOAr and the link between these imaging findings and subsequent PsA transition.

Methods

A cross-sectional prevalence analysis of clinical and US abnormalities (including inflammatory and structural lesions) in PsOAr (n=61), PsO (n=57) and HCs (n=57) was performed, with subsequent prospective follow-up for PsA development.

Results

Tenosynovitis was the only significant sonographic feature that differed between PsOAr and PsO (29.5% vs 5.3%, p<0.001), although synovitis and enthesitis were numerically more frequent in PsOAr. Five patients in PsOAr and one in PsO group developed PsA, with an incidence rate of 109.2/1000 person-years in PsOAr vs 13.4/1000 person-years in PsO (p=0.03). Visual Analogue Scale pain, Health Assessment Questionnaire, joint tenderness and US active enthesitis were baseline variables associated with PsA development.

Conclusion

Tenosynovitis was associated with arthralgia in subjects with psoriasis. Baseline US evidence of enthesitis was associated with clinical PsA development in the longitudinal analysis. These findings are relevant for enriching for subjects at risk of imminent PsA development.

Musculoskeletal ultrasound in monitoring response to apremilast in psoriatic arthritis patients: results from a longitudinal study

INTRODUCTION/OBJECTIVE

Apremilast, PDE4 competitive inhibitor, has been recently introduced in the treatment of adult psoriatic arthritis (PsA) patients, but only preliminary data are available on imaging evaluation. Thus, we evaluated the response to apremilast in PsA patients by ultrasonographic (US) assessment.

METHODS

Thirty-four patients (M/F 7/27; median age 61 years, IQR 15; median disease duration 10 years, IQR 13) treated for polyarticular involvement were longitudinally evaluated. All the patients were assessed at baseline (T0), and after 6 (T1), 12 (T2), and 24 weeks (T3) by DAS28, CDAI, SDAI, and DAPSA. At the same time-points, US assessment was performed in 22 sites (wrists, MCPs, PIPs): synovial effusion/hypertrophy and power Doppler were scored with a semi-quantitative scale (0-3). A total score, corresponding to patient's inflammatory status, was obtained by their sum (0-198). We assessed also the presence of tenosynovitis of flexor _tendons of hands' fingers bilaterally, registering the number of involved tendons (US-tenosynovitis score 0-10).

RESULTS

We found a significant reduction in the US inflammatory score values after 6 weeks (T0, median 15 (IQR 11.2); T1, 6 (10.0); P = 0.0002), confirmed at T2 (4.0 (4.0), P = 0.0002) and T3 (4.0 (6.0); P = 0.0003). Finally, US-detected tenosynovitis was observed in 44.1% of patients: a significant improvement in tenosynovitis score was identified at 6 weeks (T0, median 4 (IQR 4); T1, 1 (2); P < 0.0001) and maintained at T2 (0 (IQR 1); P < 0.0001) and T3 ((IQR 1.25); P < 0.0001).

CONCLUSIONS

Apremilast is able to induce an early and sustained improvement of ultrasonographic inflammatory status at articular and peri-articular level. Key points •Apremilast induces a significant, early, and sustained improvement of inflammatory joint status in psoriatic arthritis patients. •Ultrasonographic assessment is able to monitor articular and peri-articular response to apremilast.

OMERACT agreement and reliability study of ultrasonographic elementary lesions in osteoarthritis of the foot

Objective

To evaluate the level of agreement on ultrasonographic (US) lesions among highly experienced sonographers as well as the intraobserver and interobserver reliability of inflammatory and structural US lesions in patients with osteoarthritis (OA) of the foot.

Methods

After a systematic literature review, a Delphi survey was performed to test definitions of US lesions in OA of the foot, including inflammatory lesions (ie, synovial hypertrophy [SH], joint effusion [JE], power Doppler signal [PD]), and structural abnormalities (ie, cartilage damage [CD] and osteophytes). Subsequently, the reliability of US in assessing the aforementioned lesions was tested on static images as well as during a live exercise. Reliability was assessed by kappa analyses and prevalence-adjusted bias-adjusted kappa (PABAK) on a dichotomous and an ordinal scale.

Results

Intraobserver and interobserver reliability for SH and JE evaluated by binary scoring was good for both components, while the intraobserver reliability for semiquantitative scoring of SH ranged from moderate in the web-based exercise (PABAK 0.49) to good (PABAK 0.8) in the live exercise. Reliability for CD and PD assessments were respectively good and excellent in all exercises (ranged from PABAK 0.61 to 0.79 for CD and 0.88 to 0.95 for PD). The interobserver reliability for the semiquantitative scoring of osteophytes was fair in the live exercise (PABAK 0.36) and moderate in the static exercise (PABAK 0.60).

Conclusions

Consensual US definitions were found to be reliable for assessing inflammatory lesions in OA of the foot, while the use of US to assess structural damage requires further studies.

Peritenon Extensor Tendon Inflammation in Psoriatic Arthritis Is an Enthesitis-related Lesion

Objective.

To analyze the association between enthesitis, synovitis, and peritenon extensor tendon inflammation (PTI) in psoriatic arthritis (PsA).

Methods.

PsA patients with swelling of metacarpophalangeal joints were included. Greyscale and power Doppler (PD) were used for synovitis and PTI ultrasound identification. Madrid Sonographic Enthesis Index (MASEI) was used for enthesitis assessment. PD activity was evaluated using PD item of MASEI and PD Outcome Measures in Rheumatology (OMERACT) definition.

Results.

Synovitis had no association with enthesitis. PTI was associated with PD MASEI and PD OMERACT. Only PD OMERACT showed a positive correlation with PTI.

Conclusion.

In PsA, PTI is associated to enthesitis, as opposed to synovitis.