Hand arthritis is typically diagnosed with x-rays. Osteoarthritis (OA) is the most common form of arthritis. This is caused by wear-and-tear, genetics, injuries, and it is often a normal part of the aging process. An arthritic joint will show decreased space between the bones as the cartilage thins, bone spurs or calcium deposits on the edges of the joint, small cysts within the bone, and sometimes deformity of the joint, causing it to look crooked. See the x-rays below for common findings in osteoarthritis of the hand and compare this to the normal hand x-ray. The joints closest to the fingertip (DIP joints) and the joint at the base of the thumb (thumb CMC joint) are the most common joints in the hand affected by osteoarthritis. Of note, the letters on the xray images are NOT patient initials.