Diffuse idiopathic skeletal hyperostosis | |
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Other names | Forestier's disease, senile ankylosing spondylosis, ankylosing hyperostosis |
DISH in an 80 year old female, also with T11 fracture. | |
Specialty | Rheumatology |
Diffuse idiopathic skeletal hyperostosis (DISH) is a condition characterized by abnormal calcification/bone formation (hyperostosis) of the soft tissues surrounding the joints of the spine, and also of the peripheral or appendicular skeleton. [1] In the spine, there is bone formation along the anterior longitudinal ligament and sometimes the posterior longitudinal ligament, which may lead to partial or complete fusion of adjacent vertebrae. The facet and sacroiliac joints tend to be uninvolved. The thoracic spine is the most common level involved. [2] In the peripheral skeleton, DISH manifests as a calcific enthesopathy, with pathologic bone formation at sites where ligaments and tendons attach to bone.
Symptoms may include pain, stiffness, and restricted movements of the affected areas. The majority of people with DISH are not symptomatic, [3] and the findings are an incidental imaging abnormality.
In some, the x-ray findings may correspond to symptoms of back stiffness with flexion/extension or with mild back pain. [2] Back pain or stiffness may be worse in the morning. [4] Rarely, large anterior cervical spine osteophytes may affect the esophagus or the larynx and cause pain, difficulty swallowing [5] [6] or even dyspnea. [7] Similar calcification and ossification may be seen at peripheral entheseal sites, including the shoulder, iliac crest, ischial tuberosity, trochanters of the hip, tibial tuberosities, patellae, and bones of the hands and/or feet. [6]
DISH can be a complicating factor when suffering from trauma involving the spine. It increases the risk of unstable fractures involving the intervertebral disc and the calcified/ossified ligaments which influences the need for surgical treatment. [8]
DISH most commonly affects the elderly, especially 6th to 7th decades. The estimated frequency in the elderly is ~10% – 20%, with a slight male predominance.
The exact cause is unknown. Mechanical, dietary factors and use of some medications (e.g. isotretinoin, etretinate, acitretin and other vitamin A derivatives) [9] may be of significance. There is a correlation between these factors but not a cause or effect. The distinctive radiological feature of DISH is the continuous linear calcification along the antero-medial aspect of the thoracic spine. DISH is usually found in people in their 60s and above, and is extremely rare in people in their 30s and 40s. The disease can spread to any joint of the body, affecting the neck, shoulders, ribs, hips, pelvis, knees, ankles, and hands. The disease is not fatal; however, some associated complications can lead to death. Complications may include paralysis, dysphagia (difficulty swallowing), and lung infections.
Although DISH manifests in a similar manner to ankylosing spondylitis, they are separate diseases. Ankylosing spondylitis is a genetic disease with identifiable marks, tends to start showing signs in adolescence or young adulthood, is more likely to affect the lumbar spine, and affects organs. DISH has no indication of a genetic link, is primarily thoracic and does not affect organs other than the lungs, and only indirectly due to the fusion of the rib cage. [10]
Long-term treatment of acne with vitamin derived retinoids, such as etretinate [11] and acitretin, [12] have been associated with extraspinal hyperostosis.
DISH is diagnosed by findings on x-ray studies. Radiographs of the spine will show abnormal bone formation (ossification) along the anterior spinal ligament. The disc spaces, facet and sacroiliac joints remain unaffected. Diagnosis requires confluent ossification of at least four contiguous vertebral bodies. [2] Classically, advanced disease may have "melted candle wax" appearance along the spine on radiographic studies. [13] In some cases, DISH may be manifested as ossification, or enthesis, in other parts of the skeleton.
The calcification and ossification is most common on the right side of the spine. In people with dextrocardia and situs inversus this calcification occurs on the left side. [10]
There is limited scientific evidence for the treatment for symptomatic DISH.
Symptoms of pain and stiffness may be treated with conservative measures, analgesic medications (such as non-steroidal anti-inflammatory drugs), and physical therapy. [14]
In extraordinary cases where calcification or osteophyte formation is causing severe and focal symptoms, such as difficulty swallowing or nerve impingement, surgical intervention may be pursued. [15]
Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In some types of arthritis, other organs are also affected. Onset can be gradual or sudden.
An intervertebral disc lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint, to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine.
Ankylosing spondylitis (AS) is a type of arthritis characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bowel problems—as well as back pain—may occur. Joint mobility in the affected areas sometimes worsens over time. Ankylosing spondylitis is believed to involve a combination of genetic and environmental factors. More than 90% of people affected in the UK have a specific human leukocyte antigen known as the HLA-B27 antigen. The underlying mechanism is believed to be autoimmune or autoinflammatory. Diagnosis is based on symptoms with support from medical imaging and blood tests. AS is a type of seronegative spondyloarthropathy, meaning that tests show no presence of rheumatoid factor (RF) antibodies.
Osteophytes are exostoses that form along joint margins. They should not be confused with enthesophytes, which are bony projections that form at the attachment of a tendon or ligament. Osteophytes are not always distinguished from exostoses in any definite way, although in many cases there are a number of differences. Osteophytes are typically intra-articular.
Ankylosis is a stiffness of a joint due to abnormal adhesion and rigidity of the bones of the joint, which may be the result of injury or disease. The rigidity may be complete or partial and may be due to inflammation of the tendinous or muscular structures outside the joint or of the tissues of the joint itself.
Arachnoiditis is an inflammatory condition of the arachnoid mater or 'arachnoid', one of the membranes known as meninges that surround and protect the central nervous system. The outermost layer of the meninges is the dura mater and adheres to inner surface of the skull and vertebrae. The arachnoid is under or "deep" to the dura and is a thin membrane that adheres directly to the surface of the brain and spinal cord.
Spondylitis is an inflammation of the vertebrae. It is a form of spondylopathy. In many cases, spondylitis involves one or more vertebral joints, as well, which itself is called spondylarthritis.
Myositis ossificans comprises two syndromes characterized by heterotopic ossification (calcification) of muscle. The World Health Organization, 2020, has grouped myositis ossificans together with fibro-osseous pseudotumor of digits as a single specific entity in the category of fibroblastic and myofibroblastic tumors.
An enthesopathy refers to a disorder involving the attachment of a tendon or ligament to a bone. This site of attachment is known as the enthesis . If the condition is known to be inflammatory, it can more precisely be called an enthesitis.
The ligamenta flava are a series of ligaments that connect the ventral parts of the laminae of adjacent vertebrae. They help to preserve upright posture, preventing hyperflexion, and ensuring that the vertebral column straightens after flexion. Hypertrophy can cause spinal stenosis.
Etretinate is a medication developed by Hoffmann–La Roche that was approved by the FDA in 1986 to treat severe psoriasis. It is a second-generation retinoid. It was subsequently removed from the Canadian market in 1996 and the United States market in 1998 due to the high risk of birth defects. It remains on the market in Japan as Tigason.
The BASDAI or Bath Ankylosing Spondylitis Disease Activity Index is a validated diagnostic test which allows a physician, usually a rheumatologist, to determine the effectiveness of a current drug therapy, or the need to institute a new drug therapy for the treatment of Ankylosing spondylitis (AS). The BASDAI is one of a group of classification criteria for spondyloarthropathies.
Jacques Forestier was a French internist who was a pioneer in the field of rheumatology.
The Risser sign is an indirect measure of skeletal maturity, whereby the degree of ossification of the iliac apophysis by x-ray evaluation is used to judge overall skeletal development. Mineralization of the iliac apophyses begins at the anterolateral crest and progresses medially towards the spine. Fusion of the calcified apophyses to the ilium then progresses in opposite direction, from medial-to-lateral.
Ossification of the posterior longitudinal ligament (OPLL) is a process of fibrosis, calcification, and ossification of the posterior longitudinal ligament of the spine, that may involve the spinal dura. Once considered a disorder unique to people of Asian heritage, it is now recognized as an uncommon disorder in a variety of patients with myelopathy.
Axial spondyloarthritis is a chronic, immune-mediated disease predominantly affecting the axial skeleton. The term itself is an umbrella term characterizing a diverse disease family united by shared clinical and genetic features, such as the involvement of the axial skeleton. The 2009 introduced term axial spondyloarthritis is a preferred term nowadays and substitutes the old term ankylosing spondylitis.
Diagnostic delay is the time interval between the onset of symptoms and confirmed diagnosis of a disease. For a variety of reasons, including the mitigation of disease severity and financial expense, it is desirable for this delay to be minimized.
In the skeleton of humans and other animals, a tubercle, tuberosity or apophysis is a protrusion or eminence that serves as an attachment for skeletal muscles. The muscles attach by tendons, where the enthesis is the connective tissue between the tendon and bone. A tuberosity is generally a larger tubercle.