What is diffuse idiopathic skeletal hyperostosis (DISH)?
Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory condition marked by abnormal calcification and ossification of ligaments and tendons, especially at their attachment points to bones. While it mainly affects the spine, DISH can also impact the pelvis, elbows, knees, and heels.
Unlike other forms of degenerative arthritis, DISH primarily affects ligaments and entheses rather than joint spaces, including the posterior longitudinal ligament in the spine. It often leads to the formation of large bony bridges, particularly in the thoracic spine, which involve structures like the anterior longitudinal ligament. However, intervertebral disc spaces are usually preserved, distinguishing DISH from other spinal disorders.
Symptoms of diffuse idiopathic skeletal hyperostosis (DISH)
The symptoms of DISH can vary widely, ranging from mild to severe. The condition is often asymptomatic and is discovered incidentally during imaging for unrelated issues. However, when symptoms do occur, they may include:
- Spinal stiffness and pain: The most common symptoms are stiffness and pain, particularly in the thoracic spine. In cases with more severe symptoms, patients might experience significant difficulty with movement or chronic pain.
- Reduced range of motion: As the condition progresses and bone spurs begin to form, the formation of bony growths can limit the range of motion, especially in the spine. This can lead to difficulty bending or twisting the torso.
- Difficulty swallowing (dysphagia): In severe cases, particularly when the cervical spine or spinal fractures are involved, bony growths can impinge on the esophagus, leading to difficulty swallowing or sleep apnea.
Causes of this disease
The exact cause of DISH is unknown, which is why it is termed "idiopathic." However, several factors have been associated with the development of the condition:
- Aging: DISH is more common in older adults, particularly those over the age of 50. The likelihood of developing DISH increases with age.
- Metabolic factors: Conditions such as obesity, diabetes mellitus, and metabolic syndrome are strongly associated with DISH. These metabolic disturbances are thought to play a role in the abnormal bone growth seen in DISH.
- Genetic predisposition: DISH may have a genetic component, as it sometimes occurs in families, suggesting that genetic factors may influence susceptibility.
- Mechanical stress: Chronic mechanical stress on certain ligaments and tendons, particularly in areas subjected to repetitive movements or strain, may contribute to the development of DISH.










