DISH Flashcards
What does DISH stand for?
Diffuse Idiopathic Skeletal Hyperostosis (DISH)
What is DISH?
A systemic condition characterised by ossification patterns that can occur in the spine and peripheral entheses
The exuberant, broad, and irregular bridging ossification encompasses the annulus fibrosis, anterior longitudinal ligament (ALL), and paraspinal connective tissue, with an anterior distribution
The bridging ossifications are thickest at the level of the disc space and attach to the adjacent vertebral bodies
Broad areas of the proximal and distal thirds of the vertebral bodies are covered by the ossifications, leaving the sites above and below their attachment with the least amount of hyperostosis
What are the clinical presentations of DISH?
- Stiffness that’s usually worse in the morning
- Pain (cervical, thoracic or lumbar spine)
- Limited ROM
- mild to moderate reduction (flattening) of C-spine and L-spine lordosis with mild to moderate increase in T-spine kyphosis.
- Hoarseness or trouble swallowing due to nerve compression
- negative lab findings unless diabetes
What are the causes of DISH?
- Unknown
- Male > Female (2:1)
- >50yoa(very uncommon <45yoa)
What is the location of DISH?
- M/C affects the spine
- Thoracic spine (T7 – T11) > cervical (C4 – C7) > lumbar
What are the risk factors of DISH?
- Gout
- Diabetes
- Age
- High BMI
- Metabolic Conditions
- Uric acid
What are the complications of DISH?
- Lumbar Spine:
- Lumbar spinal stenosis (secondary to hypertrophy of the ligamentum flavum or bone proliferation about apophyseal articulations)
- Cervical Spine:
- dysphagia and stridor
- hoarseness
- sleep apnoea
- cervical myelopathy
- Spinal stenosis due to ossification of posterior longitudinal ligament (PLL)
- spine fracture and instability
What are the spinal features of DISH?
Thick flowing ossification of ALL, flowing ossification along the anterior (or rightanterolateral) aspects of at least four contiguous vertebrae
disc spaces are usually well preserved
Ankylosis (fusion-complete bridging that unites vertebral segments) is rare but may involve the thoracic region rather than cervical or lumbar spine
frequently incomplete
can have radiolucent spaces where protruding disc material projects into the flowing ossifications
Nosacroiliitis (inflammatory change)or articular facet joint ankyloses.
What are the radiological findings for DISH?
- Flowing ossification and Ca++ along Anterior longitudinal ligament (ALL) of at least 4 contiguous vertebral bodies.
used to differentiate (DDX) from DJD - Preservation of the disc heights
absence of other major IVD related degenerative changes
used to DDX from DDD/DJD - Absence of ankylosis of the SI’s, and apophyseal joints
used to DDX from ankylosing spondylitis (AS)
What are the extraspinal features of DISC?
Enthesopathy (at areas of tissue attachment to bone)at the iliac crest, ischial tuberosities, and greater trochanters (consider which structures attaches at these regions)
M/C sites are pelvis, calcaneus, foot, THEN elbow, hand, wrist, and patella
spur formation in the appendicular skeleton (olecranon, calcaneum, patellar ligament) frequently present
‘Whiskering’enthesophytes (irregularities that project away from the bone) at points of soft tissue attachment.
What does OPLL stand for?
Ossification of the Posterior Longitudinal Ligament
What is OPLL?
Rare but potentially devastating cause of degenerative cervical myelopathy (DCM)
Cause is unclear but likely multifactorial
What is the clinical presentation of OPLL?
Clinical Presentation:
- Men > Women
- 50 – 70yoa
- NO lab findings
- May be asymptomatic
- when symptomatic - generally insidious.
- may be initiated by a traumatic event (20%)
- paresthesia
- motor disturbances
- stiffness
- headache
What are the locations affected in OPLL?
cervical (Mid Cervical spine C4 – C6):75%
- thoracic:15%
- lumbar:10%
What are associated factors with OPLL?
- race
- gender
- diabetes
- obesity
- high salt-low meat diet
- poor calcium absorption
- mechanical stress on posterior longitudinal ligament
