History: 52-year-old male patient with deep seated neck pain and reduced range of motion.
There is an extensive amount of spinal hyperostosis noted from C2 through C6 on the anterior aspect of the vertebral bodies. This spinal hyperostosis is very characteristic of diffuse idiopathic skeletal hyperostosis (DISH). These patients have a reduced range of motion and can experience dysphagia. An additional finding in this patient is degenerative disc space narrowing at the C2/3 level. All the remainder of the cervical discs and the facets are reasonably well preserved. That is often a characteristic finding of patient’s with DISH.
This patient additionally has congenital agenesis of the posterior arch of the atlas with a posterior arch and tubercle of the atlas fusing to the spinous process of C2 creating a characteristic “mega spinous process sign”. Note the anterior tubercle of the atlas is enlarged by means of hypertrophy. This occurs as a result of altered upper cervical biomechanical movement.
An additional finding associated in some patients with DISH is ossification of the stylohyoid ligament which is noted here. This is seen just above the hyoid bone and extending to the styloid as a very large ossific bar. Patients with DISH on occasion may fuse the posterior longitudinal ligament (OPLL). Ossification of the posterior longitudinal ligament may produce spinal stenosis and symptoms in the upper and lower extremity. These findings should be looked for very closely clinically. This appearance of spinal fusion is quite different than the finer and delicate areas of bone spurring and fusion associated with ankylosing spondylitis.