Diffuse idiopathic skeletal
Choithram Hospital & Research Centre,
• Diffuse idiopathic skeletal hyperostosis
or Forestier disease is a common condition
characterized by bone proliferation at sites of
tendinous and ligamentous insertion.
• It most commonly affects the elderly
(especially 6th to 7th decades).
• Its estimated frequency in the elderly is at ~ 5-
• Pathologic features of spinal DISH include:
• Focal and diffuse calcification and ossification of the
anterior longitudinal ligament,
• Paraspinal connective tissue and annulus fibrosis,
• Degeneration in the peripheral annulus fibrosis fibers,
• Anterolateral extensions of fibrous tissue,
• Chronic inflammatory cellular infiltration,
• Periosteal new bone formation on the anterior surface
of the vertebral bodies.
• Ossification of the posterior longitudinal
• Approximately one-third of patients test
positive for human leukocyte antigen
• Florid, flowing ossification along the anterior
or right anterolateral aspects of at
least four contiguous vertebrae.
• Disc spaces are usually well preserved.
• Ankylosis is more commonly seen in the
thoracic than in the cervical or lumbar spine.
Frequently incomplete can have interdigitating
areas of protruding disk material in the
Extra spinal features
• Enthesopathy of:
• iliac crest,
• ischial tuberosities,
• greater trochanters,
• spur formation in the appendicular skeleton
Ankylosing Spondylitis – Radiological
• early spondylitis is characterized by small erosions at
the corners of vertebral bodies with reactive sclerosis
• squaring of the vertebral body
• diffuse syndesmophyitic ankylosis can give a "bamboo
• interspinous ligament calcification can give a "dagger
• ossification of spinal ligaments, joints and discs.
• Psuedoarthroses may form at fracture sites.
• enthesophyte formation from enthesopathy.
• Romanus lesions of the spine - shiny corner sign.
Fluorosis - radiological features:
• The earliest radiological findings appear within six
mouths of continuous exposure to high intakes of
fluoride and include periosteal and endosteal
reactions, coarse axial trabcculations and osteopenia in
the metaphyseal regions, sclerosis, and modelling
abnormalities of the epiphyses, carpal and other bones
of the hand, more particularly observed in growing
• The incidence of spinal osteoporosis is significantly low
and of osteomalacia and secondary hyperparathyroid
bone disease significantly higher in women residing in
endemic fluorosis villages.
Paget’s disease – Spine Radiology
• Spine: cortical thickening encasing the vertebral
margins, which gives rise to the picture frame sign on
radiographs in mixed phase disease.
• On lateral radiographs flattening or squaring of the
normal concavity of the anterior margin of the
vertebral body also adds to the rectangular
• The osteoblastic activity is seen along all four margins
of the vertebral body cortices.
• The vertical trabecular thickening pattern in Paget
disease is coarser than the more delicate pattern seen
in hemangiomas with which it can be confused.
Paget’s disease – Radiology Pelvis
• Paget disease of the pelvis usually manifests
with cortical thickening and sclerosis of the
iliopectineal and ischiopubic lines. These
findings are often asymmetric and for some
reason, may be more commonly seen on the
right side. Enlargement of the pubic rami and
ischium are also often seen.
Information contained and transmitted by this presentation is
based on personal experience and collection of cases at
Choithram Hospital & Research centre, Indore, India.
Some of the representative x-rays and relevant text is taken
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