What is it?
Ankylosing spondylitis, or AS, is a variation of arthritis that affects the spine and pelvis. As an inflammatory disease it can, over time, cause some of the vertebrae in the spine to fuse, making it less flexible and resulting in a hunched-forward posture. If the ribs are affected, it can also be difficult to breathe deeply.
Why does it occur?
The underlying cause is unknown, but 90 per cent of those affected in the UK test positive for the HLA-B27 antigen, suggesting environmental factors underpinned by an autoimmune response.
What are the symptoms?
AS symptoms appear gradually, often resulting in chronic lower back pain and stiffness, which is particularly acute in the early morning. As the condition progresses, there is a loss of spinal flexibility and a limit to your range of movement, particularly when it comes to bending and straightening your lower back. In some cases, certain vertebrae will fuse, resulting in a very hunched-over posture.
How is it diagnosed?
AS can be difficult to diagnose because the symptoms are similar to a number of other conditions. Your consultant will give you a thorough medical examination and talk to you about the history and your symptoms. They will also use blood tests and imaging before coming to a definitive diagnosis.
How is it treated?
Anti-inflammatory drugs and disease-modifying anti-rheumatic medication to relieve pain and stiffness, and slow the progression of the disease, will be prescribed. Physiotherapy is often helpful, in addition to medication, in helping to reduce pain and stiffness.
Very occasionally and only in severe cases, surgery may be required to correct spinal deformity or to replace joints.
Consultant Spinal Surgeon FRCS (Orth)
Pain Management Consultant FRCA FFPMRCA