Purpose or Case Report: Accurate and reproducible sacroiliac joint (SIJ) assessment on MRI in pediatric patients is challenging, often with high inter-observer variation. To facilitate consistent SIJ assessment, numerous scoring systems have been proposed. We sought to systematically review articles that evaluated diagnostic accuracy and reliability of existing MRI-based SIJ scoring systems for the evaluation of spondyloarthropathy in children and adults, and assess their applicability to pediatric patients.
Methods & Materials: Relevant studies were identified through a systematic literature search that included MEDLINE, EMBASE, and Cochrane Library Database. Studies reporting an element of diagnostic accuracy of an MRI-based SIJ scoring system were included: 1) reliability, 2) construct validity comparing MRI with other clinimetric measures, 3) criterion validity comparing MRI with a gold standard, and 4) ability of MRI to depict responsiveness to treatment. Canadian Task Force on Preventive Health guidelines were used to determine overall strength of recommendation (A-E) for scoring system utilization.
Results: From 38 eligible studies, 5 scoring systems were identified: the Spondyloarthritis Research Consortium of Canada (SPARCC) inflammation and structural scores, and the Leeds, Aarhus, and Berlin scoring systems. No scoring systems dedicated to pediatric patients were found, with none taking into account age-related changes of bone marrow. Only 1 study on the SPARCC scoring systems included pediatric patients, and was not dedicated to solely pediatric patients. Together the SPARCC scores had the highest number of studies reporting reliability (N=13), construct validity (N=10), and responsiveness (N=13). Good inter-observer reliability with intra-class correlation coefficients (ICCs) >0.8 was reported in 9/13 (69%) SPARCC inflammation, structural, 5/6 (83%) Berlin, 1/1 (100%) Leeds, and 0 Aarhus studies examining reliability. Seven (70%) studies demonstrated correlation between SPARCC scores and ESR, CRP, and standardized clinical severity indices. Twelve (92%) studies demonstrated decreases in SPARCC scores (lower scores = less severe disease) with treatment.
Conclusions: Currently no MRI scoring systems are available in the literature focusing on pediatric SIJ assessment. There is fair (grade B) evidence to recommend the use of the SPARCC method use, however adjustments are needed in this scale (e.g. grading for bone marrow changes over time) before routine use can be considered in pediatric patients.