A novel radiographic scoring system for growth abnormalities and structural change in children with juvenile idiopathic arthritis of the hip

Background: Approximately 20\u201350% of children with juvenile idiopathic arthritis (JIA) have hip involvement within 6 years of diagnosis. Scoring systems for hip-related radiographic changes are lacking. Objective: To examine precision of potential radiographic variables and to suggest a scoring system. Materials and methods: We reviewed a set of 75 pelvic radiographs from 75 children with JIA hip involvement across two European centres. We assessed findings of (1) destructive change and (2) growth abnormality, according to a pre-defined scoring system. All radiographs were scored independently by two sets of radiologists. One set scored the radiographs a second time. We used kappa statistics to rate inter- and intra-observer variability. Results: Assessment of erosions of the femoral head, femoral neck and the acetabulum showed moderate to good agreement for the same reader (kappa of 0.5\u20130.8). The inter-reader agreement was, however, low (kappa of 0.1\u20130.3). There was moderate to high agreement for the assessment of femoral head flattening (kappa of 0.6\u20130.7 for the same reader, 0.3\u20130.7 between readers). Joint space narrowing showed moderate to high agreement both within and between observers (kappa of 0.4\u20130.8). Femoral neck length and width measurements, the centrum\u2013collum\u2013diaphysis angle, and trochanteric\u2013femoral head lengths were relatively precise, with 95% limits of agreement within 10\u201315% of the observer average. Conclusion: Several radiographic variables of destructive and growth abnormalities in children with hip JIA have reasonable reproducibility. We suggest that future studies on clinical validity focus on assessing only reproducible radiographic variables

2.4 Magnetic resonance imaging, ultrasonography and conventional radiography in the assessment of bone erosions in juvenile idiopathic arthritis

OBJECTIVE: To compare magnetic resonance imaging (MRI), conventional radiography, and ultrasonography in identifying bone erosions in patients with juvenile idiopathic arthritis (JIA), and to determine the validity and reliability of an MRI scale in detecting and grading joint damage. METHODS: In 26 JIA patients, the clinically more affected wrist was studied with MRI, radiography, and ultrasonography, coupled with standard clinical assessment and biochemical analysis. MR images were assessed independently by 2 readers according to an apposite devised scoring system. RESULTS: Of 26 patients, 25 (96.1%) had 1 or more erosions as detected by MRI, whereas conventional radiography and ultrasonography revealed erosions in 13 (50%) of 26 and 12 (50%) of 24 patients, respectively. The ability of MRI to detect erosive changes was significantly higher with respect to conventional radiography (P = 0.002 with Bonferroni correction [P(B)]) and ultrasonography (P(B) = 0.0002) in the group of patients with <3 years' disease duration. Ultrasonography and conventional radiography were of equivalent value for the detection of destructive changes. Wrist MRI score correlated highly with radiographic erosion score (r(s) = 0.82) and with wrist limited range of motion score (r(s) = 0.69). The interreader intraclass correlation coefficient (ICC) for MRI score was excellent (0.97); intrareader ICCs were good for both investigators (0.97 and 0.79). CONCLUSION: MRI seems to be a powerful tool to detect early structural damage in JIA. The proposed MRI scale for bone erosions appears promising in terms of reliability and construct validity. The pathophysiologic meaning and the prognostic value of bone erosions revealed only by MRI remain to be established in longitudinal studies

Preliminary definitions for the sonographic features of synovitis in children

Objectives Musculoskeletal ultrasonography (US) has the potential to be an important tool in the assessment of disease activity in childhood arthritides. To assess pathology, clear definitions for synovitis need to be developed first. The aim of this study was to develop and validate these definitions through an international consensus process. Methods The decision on which US techniques to use, the components to be included in the definitions as well as the final wording were developed by 31 ultrasound experts in a consensus process. A Likert scale of 1-5 with 1 indicating complete disagreement and 5 complete agreement was used. A minimum of 80% of the experts scoring 4 or 5 was required for final approval. The definitions were then validated on 120 standardized US images of the wrist, MCP and tibiotalar joints displaying various degrees of synovitis at various ages. Results B-Mode and Doppler should be used for assessing synovitis in children. A US definition of the various components (i.e. synovial hypertrophy, effusion and Doppler signal within the synovium) was developed. The definition was validated on still images with a median of 89% (range 80-100) of participants scoring it as 4 or 5 on a Likert scale. Conclusions US definitions of synovitis and its elementary components covering the entire pediatric age range were successfully developed through a Delphi process and validated in a web-based still images exercise. These results provide the basis for the standardized US assessment of synovitis in clinical practice and research