Achondroplasia was first described in 1878 and is the most common form of human skeletal dysplasia.
Spinal manifestations include thoracolumbar kyphosis, foramen magnum, and spinal stenosis.
Progressive kyphosis can result in spinal cord compression and paraplegia due to the reduced size of spinal canal. The deficits are typically progressive, presenting as an insidious onset of paresthesia, followed by the inability to walk and then by urinary incontinence.
Paraplegia can be the result of direct pressure on the cord by bone or the injury to the anterior spinal vessels by a protruding bone.
Surgical treatment consists of posterior instrumentation, fusion with total wide laminectomy at stenosis levels, and anterior interbody support. Pedicle screws are preferred for spinal instrumentation because wires and hooks may induce spinal cord injury due to the narrow spinal canal. Pedicle lengths are significantly shorter, and 20-25 mm long screws are appropriate for lower thoracic and lumbar pedicles in adult achondroplastic There is no information about the appropriate length of screws for the upper thoracic pedicles. Tracheal injury due to inappropriate pedicle screw length is a rare complication 1).