Syndesmophytes are bony growths that often occur in the spine and can cause fusion of the joints. Their formation is a clinical feature of ankylosing spondylitis (AS), a rare type of arthritis.
Syndesmophytes, which form in the ligaments of the spine, create irreversible spinal damage and can lead to vertebrae fusing.
These bony growths can sometimes form due to other causes. However, as they are a clinical feature of AS, doctors can use their presence to help diagnose the condition.
This article explores syndesmophytes and their connection to AS. It also examines the possible causes, the signs that they may be developing, and how doctors diagnose them.
AS is a type of inflammatory arthritis.
- vision changes and eye pain
- shortness of breath, if AS affects the joints connecting the ribs
- skin rashes
- abdominal pain and loose bowel movements
- loss of appetite and unexplained weight loss
Although researchers know that syndesmophytes are a hallmark of AS, they are unsure why these growths develop.
According to the authors of a 2020 study, systemic bone loss, known as osteoporosis, and the formation of new bone both contribute to AS.
Previously, researchers hypothesized that inflammation leads to bone loss, which then triggers an attempt to form new bone, or syndesmophytes, to repair the bone and provide stability to the spine.
However, the 2020 study found that there did not appear to be a relationship between bone mineral density and the formation of syndesmophytes.
Other research from the same year notes that among people with advanced AS, the risk factors for the progression of syndesmophytes include old age and having had the disease for a long time.
A person with AS often experiences symptoms associated with the back, including stiffness and a limited range of motion.
However, as bony growths form and start to fuse the spine, a person may notice that their flexibility and mobility become more limited.
In the long term, AS can also increase the risk of a spinal fracture, which can cause sudden pain and lead to nerve damage.
Anyone who experiences the following after a fall should contact a doctor straight away:
- new or worsened spinal pain
- numbness or tingling in the arms
- numbness or tingling in the legs
A doctor may use imaging tests such as X-rays or MRI scans to detect syndesmophytes, although an X-ray will not likely show any growths in the early stages of the disease.
The doctor may also use blood tests and other diagnostic tools to diagnose AS.
Once a person receives a diagnosis of AS, a healthcare professional will continue to monitor them and check for any development of bony growths.
Although syndesmophytes are a hallmark clinical feature of AS, their slow growth rate means that it can take
However, a doctor may sometimes be able to see early signs of syndesmophytes using imaging tests.
A doctor will likely recommend conservative treatment options that may include exercise and physical therapy. They might suggest:
- a group exercise program
- an individual exercise program
- massage to relieve pain and improve movement
- hydrotherapy, which involves exercising in water
It is important to note that the masseuse should avoid manipulating the bones, as this can lead to injury.
Medications that may help include:
- nonsteroidal anti-inflammatory drugs (NSAIDs) or other pain and inflammation medications
- biological treatments, such as anti-tumor necrosis factor (TNF) medications and monoclonal antibody treatment
- corticosteroids in the form of an injection or tablet
- disease-modifying antirheumatic drugs
Learn more about biologics for AS.
In rare cases, surgery may be an option. A doctor may recommend surgical repair of the spine to help a person look forward and stand straight when walking.
People may also benefit from using assistive devices and braces during waking hours and supportive pillows during sleep or rest.
According to the United Kingdom’s National Health Service (NHS), osteophytes are another type of bony growth that typically occurs due to osteoarthritis.
They appear next to the joints that osteoarthritis affects. Osteoarthritis damages the joints, which can trigger the development of new bone in the form of osteophytes.
Although these growths typically occur due to osteoarthritis, they can sometimes form in the spine as a result of AS, leading to stiffness and pain.
They can also grow in the:
- big toe
Syndesmophytes are bony growths that can occur in AS. They develop slowly but are responsible for the spine fusing in more severe cases of AS.
There does not appear to be any treatment option to slow the development of syndesmophytes. However, treatment can help improve AS symptoms and prevent the spine from fusing. Treatment often involves pain management, exercise, physical therapy, and the use of assistive devices.
If the growths cause fusion in the spine, a doctor may recommend surgery to help improve spinal function and mobility.