Anterior and posterior instrumentation and fusion of thoracolumbar scoliosis due to myelomeningocele.

Twenty-three patients with severe paralytic thoracolumbar scoliosis due to a myelomeningocele were treated by a two-stage procedure. Before operation the mean scoliosis was 98 degrees: after the first-stage procedure, an anterior spinal fusion and correction with Dwyer instrumentation, this was reduced to a mean of 45 degrees. Approximately two weeks later a posterior spinal fusion with Harrington instrumentation was performed, further reducing the scoliosis to a mean of 29 degrees. The pelvic obliquity also was reduced from a mean of 32 degrees to 6 degrees. Although such management carries risks (one patient died of cardiorespiratory failure after the first stage and one patient was made worse), 21 of the 23 patients had improved posture and function.