Mobile thoracolumbar gibbus in Morquio type A: the cause of paraparesis and its management.

Four children with Morquio A syndrome had neurologic deterioration related to a progressive thoracolumbar gibbus. Findings on the magnetic resonance imaging scan did not suggest a significant canal compromise, but X-rays taken in the erect position showed a much larger kyphosis, and thus more canal compromise. All patients recovered neurologically after anterior decompression and correction of kyphosis. We believe that the cause of cord dysfunction is mobility at the kyphus and compression by the bulging discs and the internal gibbus.