Doctors use X-rays and other imaging studies to look at joints. Arthritis begins with damage to the lining of the joint that eventually leads to thinning of the joint space. The narrower the space, the more advanced the arthritis.

Other changes in the joint signal a worse condition. Bone spurs may form around the joint and prevent normal motion. The doctor may see cysts on either side of the joint, along with a flattening of the upper end of the humerus (upper arm bone).

Loss of motion, chronic partial or complete dislocation, and bone damage are All signs that point to a serious or advanced case of arthritis.