Congenital Dislocated Spine

Abstract

Congenital dislocation of the spine (CDS) is a rare malformation due to a developmental failure of the spine and the spinal cord at a single spinal level. New embryological and physiopathological findings define CDS as an autonomous entity compared with multilevel pathologies. The severity of CDS neurological outcome requires its treatment by experienced pediatric spine surgeons in a pediatric specialty hospital. This report aims to propose a comprehensive orthopaedic management strategy and operative technique of CDS in 6 new patients. The records of patients treated at our institution for congenital anomalies of the spine were reviewed in a retrospective study. Inclusion criteria were extracted from the actual context of new embryologic theories: single level involvement; sudden mainly sagittal vertebral displacement with anterior translation of the entire cranial vertebral column on the caudal vertebrae ("step-off sign"); underlying spinal malformation at a clearly distinct level; spinal cord intact both cranial and caudal to the malformation; possibility of malformed aspect of the 2 involved vertebrae. Demographic data, family, and clinical history were collected. Complete set of plain radiographs and modern imaging computed tomography and magnetic resonance imaging were analyzed. Six children treated between 1993 and 2007 have been classified as CDS. The mean follow-up to date of the 4 patients alive after the last corrective surgery is 9.8 years (range, 1-14.6 years). All patients alive have at follow-up solid stable fusion and no progression of spinal deformity. Two of the patients are independent walkers. The neurological involvement of CDS if present initially is the consequence of an associated spinal cord malformation without mechanical factor. Adaptation of the therapeutic strategy may avoid secondary neurological damage. Parents should be counseled as soon as the diagnosis is made, the obstetrical and postnatal orthopaedic management has to be adapted. Stabilization of the spine including very early cast immobilization and an early instrumented decompression-stabilization with circumferential fusion in 1 stage is required.