Abstract
We report three cases of pre-exisiting ankylosing spinal hyperostosis (ASH) and vertebral fractures at the thoraco-lumber level. The cases consisted of two males and one female. Their ages ranged from 77 to 86 years. All vertebral fractures were at the thoraco-lumber level and occurred when the patients fell down. Bone union at the fractured parts was delayed, and they developed pseudarthrosis. All cases showed delayed paralysis. One case was treated with anterior fixation and two cases were treated with posterior fixation. Pre-exisiting ASH causes adjacent intervertebral stability and mechanical power to concentrate on fractured parts, which cause the fractured parts to become pseudarthrosis easily. In order to decide treatment, X-ray examination with body flexion and extension positions and evaluation of instability are very important. In cases of neurological paralysis, instability of the fractured parts or continuing severe pain, surgical treatment should be performed as soon as possible.
