What is Spondyloarthritis?
Spondyloarthritis (SpA) is a group of conditions that cause inflammatory arthritis affecting primarily the spine. Other joints in the body can be affected as well as other areas of the body.
Conditions within the group include:
- Axial spondylitis (axSpA)- primarily affecting the spine
- Ankylosing spondylitis (AS)
- Inflammation resulting in pain and stiffness in the spine. X-Ray changes
- Non-radiographic axial spondyloarthritis
- Similar symptoms to AS but without changes on imaging such as X-rays or MRI scans
- Psoriatic Spondyloarthritis (PsA)
- A form of psoriatic arthritis related to psoriasis (a skin condition)
- Enteropathic-related Arthritis
- Arthritis related to inflammatory bowel disease such as Crohn’s colitis or Ulcerative colitis
- Reactive Arthritis
- Arthritis following an infection
- Juvenile onset spondyloarthritis
- Spinal arthritis that presents as a child
- Peripheral spondyloarthritis
- Arthritis occurring mostly in other joints than the spine
The management of spinal disease is similar in all conditions, therefore the focus is on the most common condition, Ankylosing Spondylitis.
What is Ankylosing Spondylitis?
Ankylosing Spondylitis (AS) is a spondyloarthritis that causes inflammation in the spine. This results in stiffness in the neck, back and pelvis. The inflammation results in the body laying down extra calcium around the back bones which can result in the bones fusing together (Ankylosis). If this is left untreated it can result in permanent spine curvature and loss of movement. The most common areas to be involved are the joints between the back bones and between the backbones and pelvis (sacroiliac joints).
Inflammation is usually caused by the body to help deal with infection and trauma, however in certain conditions, the immune system triggers inflammation inappropriately resulting in damage to healthy bones and joints.
Causes of Ankylosing Spondylitis
The exact cause of AS is still unknown, but there are some well known genetic markers that are associated with developing the condition. This is related to the genetic inheritance of a gene called HLA-B27. Therefore if a first-degree relative suffers from AS, the risk of developing it is around 15-20%. There is also involvement of environmental factors and the gut microbiome.
AS is more common in males and those from North European ancestry.
Symptoms of Ankylosing Spondylitis
- Pain and stiffness in the back, usually worse in the mornings and can last over 30 minutes each day
- The stiffness can occur after periods of inactivity and improves with exercise
- Often the pain can keep you awake at night
- Some people feel the pain in their buttocks or thighs.
- Pain in the front of the chest can occur from joints around the ribcage being involved
- Low mood
- Enthesitis is inflammation in the attachment of tendons to bones and often affects the back of the heel, knees and elbows.
- Pain and swelling in other joints such as hips, knees, shoulders, elbows and ankles
- Inflammation in the eyes causing difficulty looking at light and painful red eyes. (Uveitis or Iritis)
- Inflammatory bowel disease- diarrhoea, abdominal pain and blood in your stool
- In a small number of people, the heart can be involved
- Rarely AS in later stages can cause scarring in the lungs called fibrosis
If left untreated over a long period of time, the bones in the back can fuse together (Ankylosis) which leads to permanent restriction in movement. This can result in thinning of the bones (osteoporosis) and increased risk of spinal fractures.
How do we diagnose Ankylosing Spondylitis?
Ankylosing Spondylitis is diagnosed based on history, examination and imaging of the spine. Investigations that are carried out are listed below:
- Full blood count
- Kidney and liver function
- Inflammation markers- ESR and CRP
- Genetic tests
- HLA-B27 testing, although being positive for this gene is not diagnostic
- Pelvis, spinal and joint X-Rays can be helpful to see if there is damage or fusion present. However early on in the condition, these can be normal
- MRI scans
- These can show early inflammation in the joints that is not yet seen on X-rays
Initial treatment of the spinal disease is with exercise and stretching and NSAIDs to reduce the inflammation.
Should NSAIDs not improve symptoms in the spine then biological therapies are used. The most common first line treatment is with adalimumab an Anti-TNF medication.
If other joints outside of the spine are involved, these can be treated with DMARD therapy and steroids.
Rarely if other joints such as the hips or neck become very damaged, surgery might be required to replace or support the joint.
Assessment of disease activity
To ensure that the treatments are working, we usually monitor your joints in our clinics to assess activity.
This is done by assessing the range of movement in the areas of the spine, examination of any other joints that might be tender or swollen and assessment of symptoms using a BASDAI score.
Versus Arthritis: http://www.versusarthritis.org
National Axial Spondyloarthritis Society (NASS): https://nass.co.uk