[Spondylolisthesis in the growing spine].

BACKGROUND: Spondylolisthesis (Greek for sliding vertebra) in children is usually the result of a defect (=lysis) or an elongation of the interarticular portion. The cause can be a congenital dysplasia of the dorsal stabilizing structures or pressure of the facet on the interarticular portion. This is a consequence of lumbar lordosis which is necessary for an upright posture. TREATMENT: The treatment depends on the symptoms and the risk of progression. This is related to the sliding distance, the degree of secondary dysplasia of the vertebral bodies and the sagittal profile, which is considered in the Mac-Thiong classification. For low-grade olistheses, conservative therapy is an option; for a symptomatic lysis without disc degeneration, pars repair should be considered. In higher-grade olistheses, repositioning and spondylodesis are usually recommended. Repositioning improves the fusion rate and sagittal profile, but increases the risk of nerve root damage, so complete repositioning should not be forced.