Ankylosing Spondylosis

Ankylosing spondylitis has no known specific cause, though genetic factors seem to be involved. In particular, people who have a gene called HLA-B27 are ata greatly increased risk of developing ankylosing spondylitis. However, only some people with the gene develop the condition.

Risk Factors:

Onset generally occurs in late adolescence or early adulthood. Most people who have ankylosing spondylitis have the HLA-B27 gene. But many people who have this gene never develop ankylosing spondylitis.

Presenting complaints: This is a disease of young adults, more common in males (M:F = 10:1). The following clinical presentations may be seen:

• Classic presentation: The patient is a young adult 15-30 years old male, presenting with a gradual onset of pain and stiffness of the lower back. Initially, the stiffness may be noticed only after a period of rest, and improves with movement. Pain tends to be worst at night or early morning, awakening the patient from sleep. He gets better only after he walks about or does some exercises. There may be pain in the heel, public symphysis, manubrium sterni and costo-sternal joints. In later stages, kyphotic deformity of spine and deformity of the hips may be prominent features.

• Unusual presentations: Patient may occasionally present with the involvement of peripheral joints such as the shoulders, hips and knees. Smaller joints are rarely involved. Sometimes, a patient with ankylosing spondylitis may present with chronic inflammatory bowel disease; the joint symptoms follow.

• Thoraic spine involvement: Maximum chest expansion, from full expiration to full inspiration is measured at the level of the nipples. A chest expansion less than 5 cm indicates involvement of the costo-vertebral joints.

Extra-articular manifestations: In addition to articular symptoms, a patient with ankylosing spondylitis may have the following extra-articular manifestations:

• Ocular: About 25 percent patients with snkylosing spondylitis develop at least one attack of acute iritis sometimes during the natural history of the disease. Many patients suffer from recurrent episodes, which may result in scarring and depigmentation of the iris.

• Cardiovascular: Patients with ankylosing spondylitis, especially those with a long standing illness, develop cardiovascular manifestations in the form of aortic incompetence, cardiomegaly, conduction defects, preicarditis etc.

• Neurological: Patients may develop spontaneous dislocation and subluxation of the atlanto-axial joint or fractures of the cervical spine with trivial trauma, and may present with signs and symptoms of spinal cord compression.

• Pulmonary: Involvement of the costo-vertebral joints lead to painless restriction of the thoracic cage. This can be detected clinically by diminished chest expansion, or by performing pulmonary function tests (PFT). There may also occur bilateral apical lobe fibrosis with cavitation, which remarkably simulates tuberculosis on X-ray.

• Systemic: Generalised osteoporosis occurs commonly. Occasionally, a patient may develop amyloidosis.

Complications:

In severe ankylosing spondylitis, new bone forms as part of the body's attempt to heal. This new bone gradually bridges the gap between vertebrae and eventually fuses sections of vertebrae. Those parts of the spine become stiff and inflexible. Fusion also

can stiffen the rib cage, restricting lung capacity and function.

Other complications might include:

• Eye inflammation, called uveitis: One of the most common complications of ankylosing spondylitis, uveitis can cause rapid-onset eye pain, sensitivity to light and blurred vision. See your health care provider right away if you develop these symptoms.

• Compression fractures: Some people's bones weaken during the early stages of ankylosing spondylitis. Weakened vertebrae can crumple, increasing the severity of a stooped posture. Vertebral fractures can put pressure on and possibly injure the spinal cord and the nerves that pass through the spine.

• Heart problems: Ankylosing spondylitis can cause problems with the aorta, the largest artery in the body. The inflamed aorta can enlarge to the point that it distorts. the shape of the aortic valve in the heart, which impairs its function. The inflammation associated with ankylosing spondylitis increases the risk of heart disease in general.