Review of the Use of Ultrasound for the Diagnosis and Monitoring of Enthesitis in Psoriatic Arthritis

Juvenile-Versus Adult-Onset Spondyloarthritis: Similar, but Different

This article provides an overview of juvenile spondyloarthritis and important differences in the classification criteria, clinical presentation, outcomes, and pathology in juvenile versus adult-onset disease. Key differences in classification criteria between children and adults with spondyloarthritis are important to understand, as they can make transition from pediatric to adult care challenging. MRI and ultrasonography are increasingly relied on for the assessment of adult-onset disease activity and change over time in the pediatric population. The unique features of the maturing axial and peripheral skeleton are described for each modality, as they are key to understand for accurate interpretation of pathology in the pediatric population.

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.

Remission in psoriatic arthritis-where are we now?

Advances in treatments and treatment strategies for PsA have led to many patients responding well to management of their disease, and targeting remission as a treatment goal is now a possibility. Treat to target is a strategy aimed at maximizing benefit, irrespective of the type of medication used, by monitoring disease activity and using it to guide therapy. The measurement of response to treatment has been the subject of wide discussions among experts for some time, and many instruments exist. Comparisons of the different measures and their different strengths and weaknesses is ongoing. The impact of modern imaging techniques on monitoring disease progression is also evolving, and advanced techniques using both MRI and US have the potential to improve management of PsA through identification of risk factors for poor prognosis as well as accurate assessment of inflammation and damage, including subclinical disease. Increased understanding of the pathways that drive the pathogenesis of PsA will be key to identifying specific biomarkers for the disease and developing effective treatment strategies. Targets for response, considerations for use of a treat to target strategy in PsA, different imaging techniques and serological aspects of remission are all discussed in this review, and areas for further research are 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.

Enthesitis: A hallmark of psoriatic arthritis

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Imaging in Juvenile Spondyloarthritis

PURPOSE OF REVIEW

This review aims to provide an update on the use of imaging in the assessment of juvenile spondyloarthritis (JSpA) disease manifestations.

RECENT FINDINGS

Recent studies have demonstrated superior reliability and specificity of MRI for assessment of sacroiliac joint inflammation compared with radiography. The use of gadolinium contrast may not add incremental value to the assessment of inflammatory sacroiliitis. Sacroiliitis is common at diagnosis of spondyloarthritis. Inflammatory changes of the lumbar spine are not uncommon, and changes over time in the sacroiliac and apophyseal joints may not be concordant. Ultrasonography (US) in turn has been recognized as an excellent imaging technique to visualize the peripheral manifestations of JSpA. US does not only add important information to the clinical assessment but also helps to understand the complexity of the enthesis. Recognition of specific aspects in children is important though. The standardization of image acquisition as well as the establishment of the evidence base are underway. MRI and ultrasonography are recognized as increasingly important tools in the diagnosis and management of juvenile spondyloarthritis.

The Epidemiology of Psoriatic Arthritis

Psoriatic arthritis (PsA) is a chronic systemic inflammatory disorder characterized by joint and entheseal inflammation with a prevalence of 0.05% to 0.25% of the population and 6% to 41% of patients with psoriasis. PsA is a highly heterogeneous inflammatory arthritis. In this review, current knowledge is discussed regarding the epidemiology of PsA, including disease manifestations, classification criteria for adult and juvenile PsA, methods for recognizing early PsA, including use of screening tools and knowledge of risk factors for PsA, and medical comorbidities associated with PsA.

Pitfalls in wrist and hand ultrasound

OBJECTIVE

The purpose of this article is to review a number of diagnostic pitfalls related to ultrasound evaluation of the hand and wrist. Such pitfalls relate to evaluation of ten-dons (extensor retinaculum, multiple tendon fascicles, tendon subluxation), inflammatory arthritis (incomplete evaluation, misinterpretation of erosions, failure to evaluate for enthesitis), carpal tunnel syndrome (inaccurate measurements, postoperative assessment), ulnar collateral ligament of the thumb (misinterpretation of the adductor aponeurosis and displaced tear), wrist ganglion cysts (incomplete evaluation and misdiagnosis), and muscle variants.

CONCLUSION

Although ultrasound has been shown to be an effective imaging method for assessment of many pathologic conditions of the wrist, knowledge of potential pitfalls is essential to avoid misdiagnosis and achieve high diagnostic accuracy.

Ultrasound Imaging Module: Report from the GRAPPA 2012 Annual Meeting

At previous annual meetings of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), members resolved to develop dactylitis and enthesitis ultrasound research projects. Sonography can depict many anatomic alterations in the digits of patients with dactylitis and can also study vascularity of these tissues noninvasively. At the 2012 GRAPPA meeting, the ultrasound workgroup outlined steps in developing a dactylitis outcome measure: determining sonographic elemental lesions; testing to see which of these are the most discriminant in separating dactylitic digits from normal digits; selecting final elements for a sonographic dactylitis index; and conducting validity and reliability testing. A brief update of the enthesitis project was also presented.

GRAPPA 2011: Proceedings from the Ultrasound Imaging Module

In a plenary session at the 2011 meeting of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) the use of sonography for evaluating enthesitis and dactylitis in psoriasis and psoriatic arthritis (PsA) was reviewed, and initial proposals were presented to develop ultrasound joint indices to assess enthesitis and dactylitis in PsA. Sonography can depict ultrastructural morphopathological features of an enthesis and its adjoining tissue structures, as well as increased vascularity; candidate entheses were proposed for an initial sonographic PsA enthesitis index. Ultrasound also can readily demonstrate soft tissue changes, synovitis, erosions, and osteoproliferation in dactylitis, and these features were proposed for an initial sonographic dactylitis index. A perspective was also presented on a wider proposed index including the skin, nail, joint, and enthesis.

The use of ultrasound for the assessment of enthesitis in patients with spondyloarthritis

Seronegative spondyloarthritis (SpA) represents a group of diseases that share certain genetic, clinical, and radiographic features. Enthesitis, inflammation at the site of tendon insertion into the bone, involving both the axial and the peripheral joints, is an important sign of SpA. Clinical diagnosis of enthesitis, however, is neither sensitive nor specific; thus, the diagnosis of enthesitis often relies on typical abnormalities in imaging studies. Due to its low costs and availability, ultrasound is emerging as the preferred technique for detection of enthesitis for both clinical and research purposes. Ultrasonographic features of enthesitis include tendon hypoechogenicity and thickening, calcifications, bone erosions, and Doppler signal. Several semi-quantitative scoring systems have been developed to quantify ultrasonographic abnormalities of the entheses. These methods have been used for early diagnosis and classification of SpA as well as for monitoring response to treatment.

Autofeedback from Ultrasound Images Provides Rapid Improvement in Palpation Skills for Identifying Joint Swelling in Rheumatoid Arthritis

Objective.

Joint swelling, an important factor in the classification criteria and disease activity assessment in rheumatoid arthritis (RA), renders joint palpation a necessary skill for physicians. Ultrasound (US) examination that visualizes soft tissue abnormalities is now used to assess musculoskeletal disease. We assessed the usefulness of US assessments in enhancing physical joint examination skills.

Methods.

We examined 1944 joints (bilateral shoulder, elbow, wrist, metacarpophalangeal joints 1–5, and knee joints) in 108 patients with RA during April–July 2011. We first physically examined and confirmed joint swelling; subsequently, the same rheumatologist conducted US examinations and multiple assessors graded the joint swelling. When the 2 results differed, we received autofeedback from the US results to improve the physical examination skills.

Results.

The sensitivities and specificities of physical examination for US-detected swollen joint, the correlation coefficient (CC) of the swollen joint counts, and the concordance rate in each patient for joint swelling sites and power Doppler (PD)-positive sites with the κ coefficients between the physical and US examinations were compared over time. We found that the sensitivity of physical examination increased by 42 percentage points (pp), while the specificity decreased by 18 pp. The average CC in June–July was greater than that in April–May. The percentage of κ coefficients > 0.8 increased from 8.8% to 17% for joint swelling and from 8.3% to 14% for PD-positive sites.

Conclusion.

Our results suggest that autofeedback from US assessment provides quick improvement in palpation skills for identifying joint swelling in patients with RA.

[Psoriasis arthritis. An interdisciplinary challenge]

Psoriatic arthritis (PsA) is classified as a spondylarthropathy based on its clinical and serological characteristics. The clinical manifestations and the association with psoriasis or nail psoriasis have led, together with immunological characteristics, to a further differentiation. The pathophysiological and genetic understanding of this disease has advanced as a result of the development of new treatment strategies and targets in rheumatology and dermatology. Collaborative efforts and increasing multidisciplinary cooperation between rheumatologists and dermatologists have led to an increased awareness in early diagnosis and treatment. New treatment modalities have demonstrated significant efficacy in preventing radiologic progression resulting in amelioration of clinical symptoms, improvement of function and quality of life.