Ankylosing spondylitis

Ankylosing spondylitis can be broken down - Ankylosing means stiffening, spondylo- refers to the vertebra, and -itis refers to inflammation.

So ankylosing spondylitis is a chronic inflammatory disease that affects the vertebral joints and makes the spine really stiff, but can also cause inflammation in other parts of the body like the eyes and blood vessels.

Ankylosing spondylitis, also called Bechterew disease, is part of a group of diseases called seronegative spondyloarthropathies.

Spondyloarthropathies are all autoimmune diseases that affect the joints, and they’re seronegative, which refers to the fact that rheumatoid factor, which is an autoantibody, is not found in the blood.

Alright, so in the healthy adult, the vertebral column is made up of 33 bones.

From top to bottom, the first seven bones are the cervical vertebrae, the next twelve are the thoracic vertebra and the next five, are the lumbar vertebrae.

Below that is a bone called the sacrum, which is attached to the pelvic bone on either side, called the ilium, and where they meet is the sacroiliac joint.

Below the sacrum is a tiny bone called the coccyx or tailbone.

There are two types of joints between the vertebra.

Between each of the vertebral bodies is an intervertebral disc which is made of type I and type II collagen and has two parts, the annulus fibrosis, an outer fibrous ring, and the nucleus pulposus, an inner jelly-like substance.

This disc forms a joint between each vertebra, and it allows slight movement and acts as a shock absorber.

In addition to the intervertebral discs, each vertebra has joints called facet joints with the vertebra above and the vertebra below, one on each side.

These joints are synovial, meaning they have a joint capsule and a small amount of synovial fluid in between.