What is Ankylosing Spondylitis, Orthopedic Perspective?

Ankylosing spondylitis (AS) is a chronic inflammatory disorder of the spine and the area where the spine connects to the pelvis (known as the sacroiliac joints). Sacroiliac joint involvement is considered the hallmark of this disorder and is a requirement for diagnosis. Ankylosing spondylitis is categorized as a seronegative spondyloarthropathy. The term seronegative means that a blood test result does not show the presence of rheumatoid arthritis, and the term spondyloarthropathy means a disease that affects the joints of the spine. These inflammatory disorders affect multiple systems of the body. Other disorders in this category include: Reiter syndrome (reactive arthritis); arthritis associated with inflammatory bowel disease, such as Crohn disease and ulcerative colitis; psoriatic arthritis; undifferentiated spondyloarthropathies; juvenile chronic arthritis; and juvenile-onset ankylosing spondylitis. Ankylosing spondylitis affects a small portion of the world population and is more prevalent in individuals of Northern European ancestry. People with ankylosing spondylitis often have a family member with the disease or one of the other spondyloarthropathy disorders listed above.

Source: http://www.emedicinehealth.com