Hybrid vs all pedicle screws constructs in adolescent idiopathic scoliosis: a metaanalysis of clinical and radiological outcomes

Background Adolescent idiopathic scoliosis (AIS) affects around 1 to 3% of young individuals, leading to spinal deformities typically exceeding a Cobb angle of 10 degrees without congenital or neuromuscular causes. Advances in treatment now include various surgical techniques such as posterior fusion utilizing all-pedicle screw constructs or hybrid constructs. Methods PubMed, Cochrane, and Google Scholar (pages 1-20) were searched up until February 2024. Comparative studies in which the cohort was separated into two groups (HC and PSC) were included. Data consisting of, surgery-related outcomes, sagittal radiographic outcomes, coronal radiographic outcomes, and patient-reported outcomes, was extracted and compared. Results Twenty-eight studies including 3435 patients were included. Higher rates of complications (Odds-Ratio = 1.99, p < 0.00001) and reoperations (Odds-Ratio = 2.82, p < 0.00001) were seen in the hybrid group. Better radiographic coronal correction was seen in the PSC group in both the major curve (Mean Difference = 5.97, p < 0.00001) and the secondary curve (Mean Difference = - 10.73, p < 0.0001). However, restoration of sagittal alignment was better in the HC group when assessing thoracic kyphosis (Mean Difference = 2.97, p = 0.02) and lumbar lordosis (Mean Difference = 3.17, p = 0.005). Conclusion While all-pedicle screw constructs demonstrated greater stability in AIS compared to hybrid constructs, resulting in reduced rates of reoperations and complications, as well as improved correction of major and secondary curves, they were unable to fully restore optimal sagittal alignment.