Thoracic spinal stenosis above severe thoracolumbar kyphosis a report of three cases

The neurological deficit can be seen in severe thoracolumbar kyphosis caused by spinal tuberculosis (early or late onset), fracture and congenital deformities. It is commonly believed that spinal cord compression at the severe kyphotic segment is mainly responsible for the neurological deficit. The purpose of this paper was to describe here a new entity of neurological deficit mechanism due to the thoracic spinal stenosis produced above the severe thoracolumbar kyphosis (transition zone from severe kyphosis to compensatory or structural lordosis). Three patients who were presented with this problem are described. The appropriate surgical treatment revealed the disappearance of the symptoms. We believe in that facet orientation change and direction of them towards spinal canal cause spinal canal stenosis and foraminal stenosis in the compensatory lordotic segment, which eventually becomes structural lordosis above the severe kyphotic segment. These changes result in shearing stresses in long period and cause facet hypertrophy and spinal canal narrowing.