Ankylosing spondylitis
Introduction
- Ankylosing spondylitis or rheumatoid spondylitis is a type of arthritis that affects the spine.
- Ankylosing spondylitis (AS) is characterised by a chronic inflammatory arthritis predominantly affecting the sacroiliac joints and spine, which can progress to bony fusion of the spine.
Incidence
- The onset is typically between the ages of 20 and 30, with a male preponderance of about 3 : 1. The condition has a strong HLA-B27 association and may have associated inflammatory diseases such as inflammatory bowel disease, anterior uveitis and Reiter’s syndrome.
- The overall prevalence is less than 0.5% in most populations.
- Over 75% of patients are able to remain in employment and enjoy a good quality of life. Even if severe ankylosis develops, functional limitation may not be marked as long as the spine is fused in an erect posture.
Symptoms
The cardinal feature is low back pain and early morning stiffness with radiation to the buttocks or posterior
thighs. Symptoms are exacerbated by inactivity and relieved by movement. The disease tends to ascend slowly, ultimately involving the whole spine, although some patients present with symptoms of the thoracic or cervical spine. As the disease progresses, the spine becomes increasingly rigid as ankylosis occurs.
Secondary osteoporosis of the vertebral bodies frequently occurs, leading to an increased risk of vertebral
fracture.
The most common early symptoms of ankylosing spondylitis include:
- Pain and stiffness : Constant pain and stiffness in the low back, buttocks, and hips that continue for more than three months. Spondylitis often starts around the sacroiliac joints, where the sacrum (the lowest major part of the spine) joins the ilium bone of the pelvis in the lower back region.
- Bony fusion : Ankylosing spondylitis can cause an overgrowth of the bones, which may lead to abnormal joining of bones, called “bony fusion.” Fusion affecting bones of the neck, back, or hips may impair a person’s ability to perform routine activities. Fusion of the ribs to the spine or breastbone may limit a person’s ability to expand his or her chest when taking a deep breath.
- Pain in ligaments and tendons : Spondylitis also may affect some of the ligaments and tendons that attach to bones. Tendonitis (inflammation of the tendon) may cause pain and stiffness in the area behind or beneath the heel, such as the Achilles tendon at the back of the ankle.
Extra-articular features of ankylosing spondylitis are :
- Anterior uveitis (25%) and conjunctivitis (20%)
- Prostatitis (80% men): usually asymptomatic
- Cardiovascular disease
• Aortic incompetence
• Mitral incompetence
• Cardiac conduction defects
• Pericarditis - Amyloidosis
- Atypical upper lobe pulmonary fibrosis
Diagnosis
The diagnosis of ankylosing spondylitis is based on several factors, including:
- Clinical symptoms
- Findings of a physical exam
- X-rays of the back and pelvis
- Measurements of the chest when breathing
- Results of lab tests
Diagnostic criteria for ankylosing spondylitis are :
1. Imaging
- Bilateral sacroiliitis on X-ray, even if changes are mild
- Unilateral sacroiliitis on X-ray if changes are definite
2. History
- Back pain > 3 mths improved by exercise and not relieved by rest
3. Clinical examination
- Limitation of lumbar spine movement in sagittal and frontal planes
- Chest expansion reduced
4. Ankylosing spondylitis can be diagnosed when X-ray evidence of sacroiliitis occurs with one other feature on history or clinical examination.
Treatment
All management of AS should include an exercise program designed to maintain posture and range of motion.
1. Physical and occupational therapy : Early intervention with physical and occupational therapy is important to maintain function and minimize deformity.
2. Exercise : A program of daily exercise helps reduce stiffness, strengthen the muscles around the joints and prevent or minimize the risk of disability. Deep breathing exercises may help keep the chest cage flexible. Swimming is an excellent form of exercise for people with ankylosing spondylitis.
3. Medications
- Nonsteroidal anti-inflammatory drugs (NSAIDs) – first line of pharmacologic therapy for AS.
- Methotrexate or sulfasalazine – for Peripheral arthritis but these drugs have no effect on axial disease.
- Anti-TNF-α therapy – Patients with AS treated with infliximab (chimeric human/mouse anti-TNF-α monoclonal antibody), etanercept (soluble p75 TNF-α receptor–IgG fusion protein), adalimumab, or golimumab (human anti-TNF-α monoclonal antibodies, or certolizumab pegol [humanized mouse anti-TNF-α monoclonal antibody])
- Ustekinumab (anti-IL-12/23) and secukinumab (anti-IL-17) monoclonal antibodies have shown promising efficacy in clinical trials, but have not yet been approved for use in AS.
- Local corticosteroid injections can be useful for persistent plantar fasciitis, other enthesopathies and peripheral arthritis.
- Oral corticosteroids may be required for acute uveitis but do not help spinal disease.
4. Surgery : The most common indication for surgery in patients with AS is severe hip joint arthritis, the pain and stiffness of which are usually dramatically relieved by total hip arthroplasty.
In addition, people with spondylitis are urged to not smoke or chew tobacco products because smoking aggravates the condition. Certainly, all of the other reasons why doctors discourage smoking also apply here as well. People with spondylitis are encouraged to sleep on a firm mattress with the back straight. Placing large pillows under the head is discouraged, since it may promote neck fusion in the flexed position. Similarly, propping the legs up on pillows should be avoided because it may lead to hip or knee fusion in the bent position. Choose chairs, tables, and other work surfaces that will help avoid slumping or stooping. Armchairs are preferred over chairs without arms.
Since those with ankylosing spondylitis could easily hurt their rigid necks or backs, special care should be taken to avoid sudden impact, such as jumping or falling.
