Clinical findings in 12 patients with MPS IV A (Morquio's disease). Further evidence for heterogeneity. Part III: Odontoid dysplasia.

Odontoid dysplasia in the absence or presence of atlanto-axial instability was found in all cases. In general, this correlated well with the overall clinical severity of the condition and illustrates the importance of careful follow-up of these patients. Symptoms or signs of cervical cord compression merit further investigation. Proven compromise of the upper cervical cord is an indication for posterior fusion of the upper cervical spine.