Although AS predominantly affects the spine, it also can affect other joints such as the hips, the shoulders, and occasionally, other joints including the knees, ankles, feet, and hands. Ankylosing spondylitis may also affect other parts of the body besides the skeleton, such as the eyes, heart, and lungs. The prognosis is generally good, but long-term medications and physical therapy are needed to control pain and to maintain mobility.
Source: http://www.emedicinehealth.com