L5S1 spondylolisthesis in children and adolescents.

The precise etiology of childhood and adolescent spondylolisthesis (SPL) remains undetermined, but would seem to be multifactorial, deriving from anthropological adaptations of spinal sagittal balance combined with microtraumatic, genetic and dysplastic factors. Description of sagittal parameters not only lends weight to etiopathogenetic hypotheses, but also seeks to improve the classification of severity so as to optimize treatment according to clinical and radiological presentation. Thus, surgery should not only stabilize the lumbosacral junction by solid fusion but also correct pelvic abnormalities so as to restore overall sagittal balance in the long-term, without requiring spinal, pelvic or sub-pelvic compensation and with the lowest possible energy cost. Methods are still under debate; surgical technique, whether instrumental or not and whether aiming at in situ fusion or to correct lumbosacral deformity, all incur neurological risk of which child and family should be informed. Only long-term follow-up of functional results on quality-of-life scales, combined with radiological results for surgery aiming at lumbosacral angle correction, will be able to demonstrate superiority over in situ fusion surgery.