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Diffuse idiopathic skeletal hyperostosis (DISH)—also known as Forestier's disease—is a non-inflammatory systemic condition characterized by ossification of ligaments and entheses, especially involving the anterior longitudinal ligament of the spine.

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https://youtu.be/_WB-z5Kd7Fk

Etiopathophysiology

Factor Description
Cause Idiopathic; exact pathogenesis unclear
Mechanism Enthesopathy leading to ossification at ligament/tendon attachment sites
Risk factors Age >50, male sex, obesity, type 2 diabetes mellitus, metabolic syndrome

Clinical presentation

Feature Notes
Often asymptomatic Incidental finding in elderly
Spinal stiffness Especially in thoracic region
Dysphagia Due to anterior cervical osteophytes
Back pain Less inflammatory than spondyloarthropathy
Myelopathy/radiculopathy Rare, if ossification causes spinal canal narrowing

Sites of Involvement:

Region Common Findings
Spine (thoracic most common) Flowing anterior ossification along 4+ contiguous vertebral bodies
Cervical spine Can lead to dysphagia or airway obstruction due to anterior spurs
Lumbar spine Often involved, with preserved disc height and SI joints
Peripheral skeleton Enthesopathy at pelvis, patella, calcaneus (e.g., Achilles tendon insertion)

Radology

Resnick & Niwayama Radiographic Criteria (1976):

  1. Flowing ossification along the anterolateral aspect of ≥4 contiguous vertebrae
  2. Preservation of IV disc height
  3. Absence of sacroiliitis or apophyseal joint ankylosis

Spinal Imaging:

https://youtu.be/0KTagFqoaeo

Imaging Feature Description
"Flowing wax" or "candle-wax" appearance Undulating ossification of anterior longitudinal ligament
Bridging osteophytes Broad and bulky, not sharp like degenerative osteophytes
Disc space Maintained disc height despite extensive ossification
Facet joints and SI joints Normal (unlike ankylosing spondylitis)
CT Better for evaluating ossification and potential spinal stenosis