A systematic review of machine learning models for predicting curve progression in teenagers with idiopathic scoliosis.

Background Context
Children with adolescent idiopathic scoliosis (AIS) may show asymmetrical paraspinal muscle characteristics.
Purpose
To summarize the evidence regarding: (1) the associations between various paraspinal muscle characteristics and spinal curvature; (2) whether paraspinal muscle properties significantly differed between children with and without AIS; and (3) whether baseline paraspinal muscle characteristics predicted curve progression.
Study Design/Setting
Systematic literature review
Methods
Five databases (CINAHL, Academic Search Premier, MEDLINE, Scopus, and PubMed) were searched from inception to May 2022. This protocol was registered in the PROSPERO database of systematic reviews CRD 42020171263. The Critical appraisal skills programme, the Appraisal Tool for Cross-Sectional Studies and Quality In Prognosis Studies tool were used to evaluate the risk of bias of the included studies. The quality of evidence of each identified association was determined by the Grading of Recommendations Assessment, Development, and Evaluation System (GRADE).
Results
Of 1,530 identified citations, four cohort, 17 cross-sectional, and 23 case-control studies including 31 with low, nine with moderate and four with high risk of bias were included. Low to very low-quality evidence supported that the convex side of the curve had more type I muscle fibers, higher muscle volume and paraspinal muscle activity, while the concavity had more intramuscular fatty infiltration. Very low-quality evidence substantiated greater side-to-side surface electromyography signals during left trunk bending in prone lying, standing and standing with perturbation between people with and without AIS. Also, low to very low-quality evidence supported that a larger side-to-side surface electromyography ratio at the lower end vertebra predicted curve progression.
Conclusions
Our review highlights that paraspinal muscles on the concavity of the curve demonstrate consistent changes (i.e., altered muscle-related gene expression, muscle atrophy, increased fatty infiltration, reduced type I fibers, and reduced muscle activity), which may be the cause or consequence.