Diffuse idiopathic skeletal hyperostosis is a disease which accounts for ossification of ligaments.It mostly affects the spinal cord. Ossification of the longitudinal ligaments mainly the anterior ligaments of the spine produces a tortuous paravertebral mass anterior to and distinct at least radiologically from the vertebral bodies.Commonly known as “DISH” worldwide this disease relates back to ancient zoological and paleontologic record. It was found in animals like baboons, monkeys,gorillas etc and also even in dinosaurs. DISH is a completely asymptomatic phenomenon; no alterations are detectable based on history or through physical examination.It is also known as forestier disease.Clinical features vary from monoarticular synovitis to dysphagia and even airway obstruction.
Symptoms may include pain, stiffness and restricted movements of the affected areas. Osteophytes may rarely cause symptoms by mechanical compression or by causing an inflammatory reaction. When an upper segment of the cervical spine is involved, particular at the C3-C4 level, the larynx may be affected. This could be result of hoarseness, stridor, laryngeal stenosis and obstruction. Sometimes vocal fold paralysis may result from injury to the recurrent laryngeal nerve.
Generally the disease id diagnosed by X-rays which include: Characteristic appearance of 'wax dripping from a candle', distinct from the vertebral bodies, Thoracic vertebrae are involved in 100%, lumbar in 68-90%, and cervical in 65-78% of affected individuals. CT and MRI scans are better at detecting associated findings (eg, ossification of the posterior longitudinal ligament of the cervical spine) and complications (eg, spinal cord compressive myelomalacia).
The treatment mainly includes:
•Non-steroidal anti-inflammatory drugs (NSAIDs) are prescribed for symptomatic relief.
•Physiotherapy has been used to good effect.
•Ossification around hip and knee joints may require arthroplastic surgery.
•Upper respiratory problems may require initial stabilisation of the airway with tracheostomy, followed by osteophysectomy, which is usually effective.
Diffuse idiopathic skeletal hyperostosis (DISH) is present in approximately 19% of men and 4% of women older than 50 years. The anterior longitudinal ligament is calcified in 24% of patients with posterior longitudinal ligament ossification. Diffuse idiopathic skeletal hyperostosis (DISH) was reported in 17% of individuals in the Ireland, paradoxically with male predominance. .It commonly affects the elderly and estimated frequency is 5-15%.The prevalence may be as high as 28%.