WHEN TO SEE A SPINE SPECIALIST

You should seek the advice of a spine specialist if neck or back pain persists for more than two weeks or if it is progressive in intensity and/or distribution. You should seek immediate healthcare attention if neck or back pain occurs as the result of an injury or if it is associated with serious illness and/or a high fever. Additional signs and symptoms which warrant prompt medical attention include:

• Neck or back pain associated with bowel and/or bladder dysfunction
• Neck or back pain associated with extremity weakness or difficulty with coordination
• Extremity numbness or muscle weakness
• Neck or back pain that is associated with impaired walking (gait) or difficulty with balance
• Numbness, tingling and/or muscle weakness associated with a back or neck injury

 SCREENING AND DIAGNOSIS

One of the first diagnostic signs of AS is X-ray evidence of extra bone formation (ankylosis) or erosion of the sacroiliac joints. Clinical exam findings, X-ray signs and positive lab testing for HLA-B27 is usually all that is needed to make the diagnosis. Characteristic X-ray findings include erosive and sclerotic boney changes at multiple levels of the spine. There is often thinning of the cartilage endplate between the disc and adjacent vertebrae.

There may be a bamboo like appearance of the spine due to calcification of spinal ligaments and secondary to boney bridging (ankylosis) between adjacent vertebrae.  The fine imaging detail of the CT scan will often reveal early sacroiliac changes associated with AS. The CT scan may also reveal involvement at the level of rib-spine connection (costotransverse and costovertebral joints). MRI and nuclear imaging will also reveal some of the characteristic findings. The presence of a positive serum HLA-B27 test increase the likelihood that characters imaging findings are the result of AS.

Conditions which can mimic AS that need to be ruled out in the diagnostic workup include:

•        Rheumatoid arthritis
•        Sacroiliac infection
•        Diffuse idiopathic skeletal hyperostosis (DISH)
•        Retinoid therapy
•        Juvenile chronic arthritis

NATURAL HISTORY AND PROGNOSIS

The severity of AS varies greatly from person to person. Everyone who develops AS will not experience the more serious complications or have spinal fusion. Some people will only experience intermittent back pain, discomfort and/or stiffness. Others will experience severe pain and stiffness over multiple areas of the body. AS can progress to become disabling.

COMPLICATIONS

Most cases of AS are limited to involvement of the sacroiliac joints. These are the joints that connect the sacrum to each large pelvic bone. With more severe cases the disease may progress to involve widespread arthritic involvement of the sine and extremities. The disease may be associated with progressive inflammatory bowel disease, inflammation of the aorta, heart and lung disease. The development of bone bridging between adjacent vertebrae can result in severe limitation of spinal mobility and increased risk for spinal fractures. The excessive proliferation of bone and swelling of soft tissues can also result in narrowing of the spinal canal, a condition referred to a spinal stenosis. Severe spinal stenosis can casue comprise of the spinal cord and/or spinal nerves.