Define interface: a surface forming a common boundary of two bodies, spaces, or phases â interface in a sentence a surface forming a common boundary of two bodies, spaces, or phasesâ¦ See the full definition
Ankylosing Spondylitis (AS) is a type of progressive arthritis that leads to chronic inflammation of the spine and sacroiliac joints. It can also affect other joints and organs in the body, such as the eyes, lungs, kidneys, shoulders, knees, hips, heart, and ankles.
1 Ankylosing spondylitis is a form of arthritis featuring chronic inflammation of the spine and the sacroiliac joints.  Ankylosing spondylitis belongs to a group of arthritis conditions that tend to cause chronic inflammation of the spine (spondyloarthropathies).