Ankylosing spondylitis also known as Bechterew’s disease is a medical condition characterized by fusion of several bones (vertebra) in the spine (vertebral column). Although it mainly affects the axial skeleton, the part of the skeleton mainly formed by the skull bones and the vertebral column, sometimes peripheral bones like peripheral bony joints and other systems of the body mainly the cardiovascular system may also be affected.
This is a form of spodyloarthropathies (any type of joint diseases affecting the vertebral column) with tendency to run in families. Other than the bony joints in the spine the sacroiliac joints in the pelvic area may also be affected. Due to fusion of the adjacent vertebral bones the flexibility of the spine as whole is compromised resulting into abnormal hunched posture. If the bones in rib cage are affected then breathing difficulty may arise due to limited movement of the chest during entry of air in the lungs.
This condition usually occurs in young adults (usually during the third decade) and men are at increased risk of suffering from this condition. As it is an inflammatory condition, inflammatory changes may occur in other body parts namely the eyes.
As such there is no cure for ankylosing spondylitis however treatment options are available to manage the symptoms.
Symptoms
Initially ankylosing spondylitis presents as increased pain and stiffness in the lower back area and in the hips leading to limited mobility. These symptoms typically occur in the early morning after waking up or after a long period of inactivity. The symptoms may also exaggerate or get relieved at intervals. One typical character of the pain is that it gets relieved with rest and become worse with rest.
The most commonly involved areas are the joints in between the end of the vertebral column (sacrum) and the pelvic bone (ilium), the sacroiliac joint, vertebral bones in the lower part of the spine, hip and shoulder joints, the cartilage in between the breastbone (sacrum) and the ribs, the areas on the bone where tendons and ligaments are attached etc.
Sometimes compression fractures of the vertebral bones may also occur during early stage of the disease due to thinning of the vertebral bones. Other than inability to maintain normal fracture compression fracture may lead to damage to the adjacent various nerves leaving the vertebral column and different neurological symptoms namely tingling numbness in the lower limbs, loss of control over bowel and bladder functions.
Certain other symptoms involving other systems of the body other than the skeletal system may also arise. These are
1. Uveitis: inflammatory changes in the anterior chamber of the eyes occur in about 405 of the patients of ankylosing spondylitis. Presenting symptoms include redness, pain in the eyes, intolerability to light, appearance of non existent floating objects within the visual field (floaters) etc
2. Lung involvement: fibrosis of the apical parts of the lungs leading to impaired respiration, repeated chest infection etc may also occur
3. Cardiac involvement: common associated heart conditions are aortitis when the largest artery of the body, the aorta becomes damaged due to inflammation, aortic valve insufficiency etc
4. Prostitis: inflammatory damage to the prostate may also occur in males
Causes
As such the exact underlying cause triggering the damaging inflammatory changes in ankylosing spondylitis is not known however genetic factors seem to an important role as people with HLA B27 gene are at increased risk of suffering from ankylosing spondylitis.
The main symptoms of ankylosing spondylitis (pain and stiffness of the joints) arise as the body tries to compensate for the inflammatory damages to the bones by forming new bones between the affected bones and leading to fusion of the bones, thus making that portion of the spine stiff and inflexible.
Risk factors
Common risk factors include being male, early adulthood (most commonly affected people are between 15 and 45 years of age) and having HLA B27 gene, although not everyone having this gene suffers from ankylosing spondylitis.
Treatment
The goal of treatment is to relieve symptoms and prevent complications. Treatment options include
Drugs: NSAIDs to relieve pain, TNF blockers like adalimumab, etanercept etc
Physical therapy: to facilitate joint movement and reduce stiffness
Surgery to improve joint mobility.