Juvenile Idiopathic Arthritis

Pediatric hand ultrasound: common indications, injury, inflammation and masses

Ultrasound is a uniquely valuable tool for evaluating musculoskeletal problems in the pediatric hand. Acute and chronic injuries involving tendons and ligaments of the hand can be quickly assessed and can guide surgical decision-making. Using ultrasound, palpable lesions and masses can be evaluated for cystic and solid components aiding in differential diagnosis. Additionally, ultrasound provides evaluation of acute versus chronic changes of inflammatory arthritis, assessing disease severity and subclinical synovitis and serving as an adjunct to medical management. This review will cover common indications and ultrasound findings of the pediatric hand, focusing on common injuries, inflammatory arthritis and masses. Important anatomical features of the hand will be discussed as well as imaging technique and evaluation in the pediatric patient.

Reliability of the Preliminary OMERACT Juvenile Idiopathic Arthritis MRI Score (OMERACT JAMRIS-SIJ)

This study reports the reliability of the juvenile idiopathic arthritis magnetic resonance imaging scoring system (JAMRIS-SIJ). The study comprised of eight raters—two rheumatologists and six radiologists—and 30 coronal T1 and Short-Tau Inversion Recovery (STIR) MRI scans of patients with enthesitis-related juvenile spondylarthritis. The median age of patients was 15 years with a mean disease duration of 5 years and 22 (73.3%) of the sample were boys. The inter-rater agreement of scores for each of the JAMRIS-SIJ items was calculated using a two-way random effect, absolute agreement, and single rater intraclass correlation coefficient (ICC 2.1). The ICC was interpreted together with kurtosis, since the ICC is also affected by the distribution of scores in the sample. The eight-rater, single measure inter-rater ICC (and kurtosis) values for JAMRIS-SIJ inflammation and damage components were the following: bone marrow edema (BME), 0.76 (1.2); joint space inflammation, 0.60 (1.8); capsulitis, 0.58 (9.2); enthesitis, 0.20 (0.1); ankylosis, 0.89 (35); sclerosis, 0.53 (4.6); erosion, 0.50 (6.5); fat lesion, 0.40 (21); backfill, 0.38 (38). The inter-rater reliability for BME and ankylosis scores was good and met the a priori set ICC threshold, whereas for the other items it was variable and below the selected threshold. Future directives should focus on refinement of the scores, definitions, and methods of interpretation prior to validation of the JAMRIS-SIJ through the assessment of its measurement properties.

Ultrasound in juvenile idiopathic arthritis

BACKGROUND

In the recent years, musculoskeletal ultrasound (MSUS) has been regarded as especially promising in the assessment of juvenile idiopathic arthritis (JIA), as a reliable method to precisely document and monitor the synovial inflammation process.

MAIN CONTENT

MSUS is particularly suited for examination of joints in children due to several advantages over other imaging modalities. Some challenges should be considered for correct interpretation of MSUS findings in children, due to the peculiar features of the growing skeleton. MSUS in JIA is considered particularly useful for its ability to detect subclinical synovitis, to improve the classification of patients in JIA subtypes, for the definition of remission, as guidance to intraarticular corticosteroid injections and for capturing early articular damage. Current evidence and applications of MSUS in JIA are documented by several authors. Recent advances and insights into further investigations on MSUS in healthy children and in JIA patients are presented and discussed in the present review.

CONCLUSIONS

MSUS shows great promise in the assessment and management of children with JIA. Nonetheless, anatomical knowledge of sonographic changes over time, underlying immunopathophysiology, standardization and validation of MSUS in healthy children and in patients with JIA are still under investigation. Further research and educational efforts are required for expanding this imaging modality to more clinicians in their daily practice.

Juvenile arthritis: current concepts in terminology, etiopathogenesis, diagnosis, and management

The latest change in terminology from juvenile rheumatoid arthritis (JRA) to juvenile idiopathic arthritis (JIA), established by the International League of Associations for Rheumatology (ILAR), has resulted in some confusion for OMFS and other treating clinicians. JIA comprises a group of systemic inflammatory diseases that result in the destruction of hard and soft tissues in a single or multiple joints. In a significant number of patients, one or both temporomandibular joints (TMJ) are also involved. TMJ disease may be accompanied by pain, swelling, and limitation of motion, as well as mandibular retrognathism, open bite, and asymmetry. The purpose of this article is to provide a review, for the oral and maxillofacial surgeon, of the terminology, etiopathogenesis, diagnosis, and management of children with JIA.

Cartilage Thickness of the Knee Joint in Juvenile Idiopathic Arthritis: Comparative Assessment by Ultrasonography and Magnetic Resonance Imaging

Objective.

The functional disability experienced in juvenile idiopathic arthritis (JIA) is primarily caused by joint effusion, synovial membrane hypertrophy, and periarticular soft tissue edema, leading to the degeneration of the osteocartilaginous structures because of the inflammatory process in the synovium. The ability to visualize the inflammatory changes and hence the ensuing osteocartilaginous degeneration is, therefore, of great importance in pediatric rheumatology. Ultrasonography (US) has been validated as a tool for measuring cartilage thickness in healthy children and, previously, we have found good agreement with the measures obtained by magnetic resonance imaging (MRI). Our aim is to validate and compare US with MRI measurements of distal femoral cartilage thickness in the knee joint at the medial condyle, lateral condyle, and intercondylar spots in children with JIA, and to locate the best spot for imaging comparisons.

Methods.

One knee from each of 23 children with oligoarticular JIA were investigated by both MRI and US. Outcome measures of imaging procedures were distal femoral cartilage thickness.

Results.

We found a high level of agreement between MRI and US measurements of mean cartilage thickness, and Rho values between modalities were high (between 0.70 and 0.86, p < 0.05 for all). We found a thinner cartilage thickness at the medial condyle in comparison to the other investigated points. Evaluation of anatomical landmarks for optimal measurement of cartilage thickness was found to be the intercondylar spot, which was easier to locate in addition to a smaller variance around the mean for that anatomical measuring point.

Conclusion.

US measurements of distal femoral cartilage thickness are highly correlated to MRI measurements. The intercondylar notch of the distal femoral cartilage may be the best anatomical point for cartilage thickness measurements of the knee. US is a reliant and nonexpensive, non-invasive modality for visualization of childhood femoral cartilage.

Diagnosis and classification of juvenile idiopathic arthritis

In recent years, it has become increasingly clear that the term Juvenile Idiopathic Arthritis (JIA) comprises not one disease but several. Moreover, recent studies strongly suggest that some of these clinico-pathophysiologic entities appear to cross current diagnostic categories. The ultimate goal of the JIA classification is to facilitate development of better, more specific therapy for different forms of disease though improved understanding of pathophysiology. The past two decades have witnessed significant advances in treatment and improved outcomes for many children with chronic arthritis. However, understanding of the basic biologic processes underlying these diseases remains far from complete. As a result, even the best biologic agents of today represent "halfway technologies". Because they do not treat fundamental biologic processes, they are inherently expensive, need to be given for a long time in order to ameliorate the adverse effects of chronic inflammation, and do not cure the disease. Pediatric rheumatology is now entering an era in which diagnostic categories may need to change to keep up with discovery. A more precise, biologically based classification is likely to contribute to development of more specific and improved treatments for the various forms of childhood arthritis. In this review, we discuss how genetic, gene expression, and immunologic findings have begun to influence how these diseases are understood and classified.

Disease of the year: juvenile idiopathic arthritis-associated uveitis--classification and diagnostic approach

Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease and the most common systemic association of uveitis in children. JIA is subdivided into seven clinically more homogeneous subtypes, using the International League of Associations for Rheumatology (ILAR) classification system: systemic arthritis, oligoarthritis, rheumatoid factor (RF)-negative polyarthritis, RF-positive polyarthritis, psoriatic arthritis, enthesitis-related arthritis, and undifferentiated arthritis. Uveitis is very rare in patients with systemic onset JIA and in patients with juvenile-onset rheumatoid arthritis. Patients with early-onset antinuclear antibody (ANA)-positive oligoarticular JIA have the highest risk of developing chronic iridocyclitis. Ocular involvement in enthesitis-related arthritis is characterized by recurrent acute symptomatic iridocyclitis. The diagnosis and differential diagnosis of JIA are based on history, physical examination, and laboratory investigations, including complete blood count, acute-phase reactants, ANA, RF, HLA-B27, and musculoskeletal imaging studies. Recent studies have revealed distinct gene expression profiles that may be useful in the diagnosis, classification, and follow-up of JIA patients.