History and exam

Other diagnostic factors

common

spinal pain

The prevalence of pain in DISH varies, and some studies suggest that the prevalence of back pain may be no higher in patients with DISH than in the general population.[2][25][26]​​​[46]​​ In one study of 200 patients with DISH, 72% experienced back pain.[1]​​[9][25]​​​

Bear in mind that many patients with DISH are asymptomatic and pain-free; DISH is often an incidental finding discovered during routine imaging.[2][25][26] One hypothesis is that DISH may increase the stability of the spine as a result of the naturally occurring fusion, therefore reducing pain.[2][27]

The etiology of pain in people with DISH is not well understood and may result from either inflammation or bone proliferation.[4]

stiffness of the spine

The patient may experience difficulty flexing the spine, leading to functional impairment.[2]​ Look for evidence of a poor range of motion on physical exam.

Stiffness of the spine is a common consequence of DISH. Morning stiffness of the spine was reported in two-thirds of 200 patients with DISH.[1][9][25]

Data regarding back pain and stiffness are conflicting, with some reports suggesting that DISH-related spinal fusion may increase the stability of the spine and prevent back pain.[2][26][27]

kyphosis

Observe the patient's posture and note any evidence of kyphosis on physical exam.

It has been postulated that stooped posture may result from abundant new bone formation causing stiffening of the spine, but there are no definitive data to support this hypothesis.

Can in some cases resemble the characteristic posture associated with ankylosing spondylitis.

decreased range of motion

Look for evidence of a decreased range of motion on physical exam.

Reported in approximately 50% of patients with DISH.[9][25]

uncommon

spinal fracture

May, rarely, be the first presenting sign of DISH. The ankylosed spine in DISH distorts the previously deformable articulating structures. This deviation prevents the distribution of energy resulting from low-impact trauma that would normally take place in the different spinal segments and subsequently increases the risk of fractures.[9]

DISH may also increase the risk of secondary neurologic deficits (often as a consequence of the fracture).[9]

pain, stiffness, and decreased range of motion in other joints

DISH may not be limited to the thoracic spine.

Elicit a history regarding peripheral joint pain. Extraspinal manifestations of DISH lead to involvement of entheses and peripheral joints not typically involved in osteoarthritis including the metacarpophalangeal joints, elbows, shoulders, and ankles.[9] This is a consequence of ossification and calcification of entheses adjacent to joints. Inconsistent findings have been found in the few controlled trials that have evaluated pain in hyperostotic peripheral joints.[31][32]​ Calcification and ossification of the peripheral entheses in the heels, ribs, and pelvis has been reported.[9][33][34]

Patients may have poor grip strength, leading to functional impairment.[2][35]

lumbar radiculopathy

Exuberant bone formation may contribute to lumbar spinal stenosis and lumbar radiculopathy.[28]

cervical myelopathy

Occurs as a consequence of cervical involvement.[2][29]​ Cervical enthesophytes may cause other complications including dysphagia, aspiration pneumonia, esophageal obstruction, stridor, hoarseness, and thoracic outlet syndrome.[29]

dysphagia

Occurs as a consequence of cervical involvement.[2][29] Cervical enthesophytes may cause other complications including myelopathy, aspiration pneumonia, esophageal obstruction, stridor, hoarseness, and thoracic outlet syndrome.[29]

dyspnea

Occurs as a consequence of cervical involvement.[2][29] Cervical enthesophytes may cause other complications including dysphagia, myelopathy, aspiration pneumonia, esophageal obstruction, stridor, hoarseness, and thoracic outlet syndrome.[29]

sleep apnea

Occurs as a consequence of cervical involvement.[2][29] Cervical enthesophytes may cause other complications including dysphagia, myelopathy, aspiration pneumonia, esophageal obstruction, stridor, hoarseness, and thoracic outlet syndrome.[29]

stridor

Occurs as a consequence of cervical involvement.[2][29] Cervical enthesophytes may cause other complications including dysphagia, myelopathy, aspiration pneumonia, esophageal obstruction, hoarseness, and thoracic outlet syndrome.[29]

Risk factors

strong

age >50 years

The prevalence and incidence of DISH increases with age, with men ages over 50 years being most commonly affected.[9]

male sex

Based on observations in clinical practice, men are more frequently affected by DISH than women. Studies support this with data suggesting a male:female ratio ranging from 2:1 to 7:1, although the study sizes were small and confounding factor adjustment was not consistently conducted.[6][7][8]​ In one US study of people over 50 years old, the prevalence of DISH in men was 25% and in women was 15%; in those over 80 years old, it was 28% in men and 26% in women.[10]

obesity

Obesity is an established risk factor for DISH, with several studies demonstrating a significant correlation between DISH and an elevated BMI.[2][18][19][20][21][22][23]​​​​​​​​​​​

weak

genetic risk factors

Single-nucleotide polymorphisms in the COL6A1 and FGF2 genes may be linked to the development of DISH, according to preliminary data.[2][4]​ HLA-B8 has also been noted to be present in some patients with DISH.[14]

metabolic disorders

Diabetes mellitus, metabolic syndrome, gout/hyperuricemia, dyslipidemia, and hypertension are associated conditions and often precede the diagnosis of DISH.[2][16][17]

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