DISH (Diffuse Idiopathic Skeletal Hyperostosis)

Diffuse Idiopathic Skeletal Hyperostosis (DISH) is a condition in which ligaments and tendons along the spine — and sometimes at other sites in the body — calcify and harden into bony growths. It most commonly affects the thoracic spine and is more prevalent in older adults and individuals with metabolic conditions such as type 2 diabetes and obesity.

DISH is one of several conditions that cause progressive spinal stiffness and bony overgrowth. It is important to distinguish it from Ankylosing Spondylitis, which produces similar spinal fusion but through a different inflammatory mechanism. The bony bridging in DISH can also contribute to Spinal Stenosis and Foraminal Stenosis when osteophytes encroach on nerve channels, and shares some overlap with Facet Disease in older patients.

Causes

Metabolic and systemic factors.

The exact cause of DISH is not fully understood, but it is strongly associated with metabolic conditions including type 2 diabetes, obesity, high blood pressure, and elevated cholesterol. Insulin and other growth factors are thought to stimulate abnormal bone formation along spinal ligaments and tendons.

Other contributing factors

DISH is more common in men and in individuals over age 50. Genetic predisposition and long-term use of certain medications, particularly retinoids (vitamin A derivatives), have also been associated with its development.

Symptoms

Many patients with DISH have no symptoms and are diagnosed incidentally on imaging. When symptoms occur, they typically include stiffness and reduced range of motion in the back, particularly in the morning. Patients may also experience mild to moderate back pain, and in some cases, difficulty swallowing (dysphagia) if large bony growths form in the cervical spine and compress the esophagus. Rarely, large osteophytes can compress nerves.

Diagnosis

DISH is primarily diagnosed through imaging. X-rays typically show the characteristic "flowing" calcification along at least four consecutive vertebral levels, predominantly on the right side of the thoracic spine. CT scan provides detailed visualization of bony bridging and helps distinguish DISH from other conditions such as Ankylosing Spondylitis.

A cervical or lumbar spine MRI is used to evaluate soft tissue involvement and any associated nerve or spinal cord compression from osteophyte encroachment.

Diagnostic Criteria

The Resnick criteria are commonly used to diagnose DISH on imaging.

• Flowing calcification along the anterolateral aspect of at least four contiguous vertebral bodies.
• Relative preservation of intervertebral disc height without significant degenerative disc disease.
• Absence of facet joint bony ankylosis and sacroiliac joint erosion, distinguishing it from ankylosing spondylitis.

Treatments

DISH is a chronic, progressive condition with no cure, but symptoms can be managed effectively in most patients. Treatment focuses on reducing pain, maintaining mobility, and addressing associated metabolic conditions.

Lifestyle modifications including weight management, blood sugar control in diabetic patients, and regular low-impact exercise are important components of long-term management.

Conservative treatment: Non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics help manage pain and stiffness. Physical therapy focused on maintaining spinal flexibility and range of motion is beneficial, particularly in patients with significant stiffness.

Interventional and surgical options

Corticosteroid injections may be used for localized pain relief. Surgery is rarely needed for DISH itself but may be required in cases where large osteophytes cause dysphagia, significant nerve compression, or spinal canal stenosis that does not respond to conservative care.

Related Spine Conditions

• Ankylosing Spondylitis
• Spinal Stenosis
• Foraminal Stenosis
• Facet Disease
• Degenerative Disc Disease
• Back to all Spine Conditions