Can a short spinal cord produce scoliosis?

Some patients with scoliosis have a relatively short vertebral canal. This poses the question of whether a short spinal cord may sometimes cause scoliosis. The present paper presents two observations that may support this concept. It presents a scoliosis model demonstrating what effect a short, unforgiving spinal cord might have on the spinal column. The model uses two flexible parallel tubes with the facility to tighten one. It demonstrates that a short, unforgiving spinal cord could produce the abnormal rotatory anatomy observed at the apex in scoliosis, with first lordosis, then lateral deviation and finally a rotation of the vertebral column, with the rotation occurring between the canal and the vertebral body, around the axis of the cord. The anatomy of the apical vertebra is described from two museum specimens, a computed tomography (CT) myelogram and seven magnetic resonance imaging (MRI) studies. The study confirms that the vertebral canal and the intervertebral foraminae retain their original orientation. The spinal cord is eccentric in the canal towards the concavity of the curve; the major component of rotation occurs anterior to the vertebral canal and the axis of this rotation seems to be at the site of the spinal cord. These observations do not establish that a short spinal cord will result in scoliosis, but the results are compatible with this hypothesis, and that impairment of spinal cord growth factors may sometimes be responsible for scoliosis.