Impact of the Choice of the Distal Vertebral When Posterior Instrumentation in the Surgery of the Thoracic Adolescent Idiopathic Scoliosis

Idiopathic scoliosis is a deformity in three planes of space the child's spine and scalable teenager with growth. In adults is causing severe deformities of respiratory failure responsible and disabling back pain. Scoliosis is most often idiopathic without cause found that the genetic origin is being identified. It is detected by the school doctor, the doctor or pediatrician. The management is based primarily on monitoring small angle discoveries scoliosis and the orthopedic treatment of progressive scoliosis by the specialized services of pediatric orthopedics or rehabilitation as recommended by the HAS (February 2008). Surgical treatment is reserved for the orthopedic treatment failures or advanced scoliosis discovered too late.

The goal of surgery is to reduce as much as possible distortion in the three planes of space and avoid the progression of the deformity in adulthood. Its principle is to correct the deformity using instrumentation and maintain over time this correction with a bone graft. This is commonly called spinal fusion with instrumentation. The instrumentation includes all of the vertebral anchors connected to rods.

Indications are asked in each case most often in adolescence and sometimes in younger children and rarely in adulthood. The procedure performed in adolescence allows to benefit from a flexible spine still allowing good reduction of the deformation, a lesser neurological risk and good consolidation of the bony fusion guarantees a stable income in the long term.

Among all types of curves, thoracic scoliosis pose the problem of choosing the bends to be instrumented. This choice is an essential element for the initial correction and become the long-term. It is the result of a compromise between a long instrumentation that orchestrates all of the deformation to the detriment of the mobility of the lumbar spine and a shorter instrumentation that preserves mobility at the expense perhaps of a smaller reduction. These short instrumentations called selective thoracic instrumentation, the choice of the support or lower vertebra vertebra of instrumentation is an unsolved problem and is the subject of this work.

The immediate results of the posterior vertebral arthrodesis are assessed by the correction of the deformity in three planes of space: measuring the angle of the curvature in the coronal plane, analyzing the return of a physiological kyphosis in sagittal plane and correction of the vertebral rotation in the horizontal plane. The results for medium and long term are assessed by analyzing the maintenance of correction of the deformity and the evolution of the above spine and above underlying arthrodesis. This is appreciated by the coronal and sagittal balance, changing the supporting vertebra and the first non-instrumented vertebra and evolution spine underlying uninstrumented.