Achondroplasia and spinal cord lesion. Three case reports.

The most important complications encountered by achondroplastic dwarfs are neurological problems related to a narrowed spinal canal. Stenosis of the spinal canal is secondary to abnormalities of endochondral ossification with premature synostosis of the ossification centres of the vertebral body and the posterior arch, resulting in thickening of the lamina, shortening of the pedicles, and reduced height of the vertebral bodies. Additional factors such as prolapsed intervertebral discs, osteophytes and progressive thoracolumbar kyphosis contribute to the narrowing of the spinal canal. Three achondroplastic dwarfs having spinal stenosis and spinal cord lesion representing typical clinical courses are described.