About Ankylosing Spondylitis. Ankylosing spondylitis is a form of progressive arthritis due to chronic inflammation of the joints in the spine. Its name comes from the Greek words  ankylos,  meaning stiffening of a joint, and  spondylo,  meaning vertebra.nkylosing Spondylitis. A form of arthritis that affects the spine, the sacroiliac joints, and sometimes the hips and shoulders. In severe cases, the joints of the spine fuse and the spine becomes rigid. PubMed Health Glossary. (Source: NIH-National Institute of Arthritis and Musculoskeletal and Skin Diseases).
The most common cause of numbness in the part of the hand that you describe (the ring finger) would be carpal tunnel syndrome, which is a condition in which the median nerve, which runs down the center of the wrist, becomes pinched or inflamed.
Finger numbness can significantly affect your ability to perform daily tasks. Normal sensation allows you to type without looking at your fingers, and prevents you from burning yourself or touching a sharp object. Although finger numbness is typically caused by nerve compression, it may be associated with an underlying medical condition. Numbness specifically in the pinkie points to involvement of particular nerves in specific locations. See your doctor to determine the cause and appropriate treatment for your pinkie finger numbness. Video of the Day