Usefulness of MRI findings in differentiating between septic arthritis and transient synovitis of hip joint in children: A systematic review and meta-analysis.

Purpose: Septic arthritis (SA) of the hip joint is a serious infection which can lead to more irreversible complications. Differentiating Septic arthritis from Transient synovitis (which is the most common cause of painful hip in children) is difficult and very important to prevent serious complications which can occur with Septic arthritis. The aim of this study was to find out the MRI findings which can differentiate between these two conditions. Methods: Systematic literature search was conducted according to the PRISMA guidelines on MEDLINE(PubMed), Google Scholar, ScienceDirect, and world Health Organization Virtual Health Library, up to April 2022. Studies that compared MRI findings between Septic Arthritis and Transient Synovitis of hip joint in children were included. The pooled sensitivity and specificity estimates of these findings were calculated using MetaDTA version 2.0. Results: Six studies were included in qualitative analysis and five were included in quantitative analysis. Pooled sensitivity and specificity of synovial enhancement were 94.2 % (95 % CI, 45.2-99.7 %) and 60.6 % (95% CI, 6-97.4 %) respectively. Soft tissue changes had pooled sensitivity and specificity of 75 % (95% CI, 57.5-86.9 %) and 69.9 % (95 % CI, 46.5-86.2 %) respectively. Pooled sensitivity and specificity of femoral head changes were 41.5 % (95 % CI, 15.9-72.7 %) and 87.3 % (95 % CI, 75.5-93.8 %) respectively. Bone marrow changes had pooled sensitivity and specificity of 70 % (95 % CI, 26.8-93.7 %) and 99.9 % (95 % CI, 28.7-100 %) respectively. Conclusion: MRI findings especially bone marrow changes were found to be useful in differentiating septic arthritis from transient synovitis among children presented with painful hip after exclusion of other causes.