4- Diffuse Idiopathic Skeletal Hyperostosis (DISH)

Question 1

What is DISH?

Answer 1

It is a spinal and extra spinal articular disorder were there is Ligamentous calcification and ossification

• mainly the anterior longitudinal ligament
• its a distinct entity and doesn’t represent ankylosing spondylitis or DJD.

Question 2

What are the clinical features of DISH?
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Answer 2

− Morning stiffness, bone/joint pain
− 20% have dysphagia due to bone growth (>1 cm thick)
− Increase kyphosis/decrease lordosis
− 90% in C-spine, C5-C7 levels
− 13-32% correlation w/diabetes mellitus

Question 3

What are the radiographic features of DISH?

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Answer 3

A. Classic diagnostic criteria (radiographic)
− Flowing hyperostosis at four continuous vertebral levels − Relative preservation of disc height
− Absence of lower SI/apophyseal involvement

B. Additional radiographic findings:
− T-spine (R) side only, from aortic pulsations
− 20% of patients have involvement of the costal joints
− Can cause ankylosis of the upper portion of the SI joint = “star sign”
− Peripheral skeleton may demonstrate enthesopathy (wiskering) or significant
ligamentous/ tendinous ossification
− Can see associated OPLL