Your shoulders are a common area in which to develop arthritis. In a diseased shoulder, inflammation causes pain and stiffness. Your shoulder is made up of three bones: your upper arm bone (humerus), your shoulder blade (scapula), and your collarbone (clavicle). The head of your upper arm bone fits into a rounded socket in your shoulder blade. This socket is called the glenoid. A combination of muscles and tendons keeps your arm bone centered in your shoulder socket. These tissues are called the rotator cuff.
There are two joints in the shoulder, and both may be affected by arthritis. One joint is located where the clavicle meets the tip of the shoulder blade (acromion). This is called the acromioclavicular (AC) joint. Where the head of the humerus fits into the scapula is called the glenohumeral joint. It is important for your physician to determine which joint and/or structures and what type of arthritis you have. Although there is no cure for arthritis of the shoulder, there are many treatment options available. Using these, most people with arthritis are able to manage pain and stay active.
The most common symptom of arthritis of the shoulder is pain, which is often made worse and even more uncomfortable with increased activity and movement. If the glenohumeral shoulder joint is affected, the pain is typically located in the back of the shoulder and may get worse with weather changes. Many patients complain of an ache deep in the joint. If the acromioclavicular (AC) joint is affected the pain is typically on the top of the shoulder and the pain can sometimes radiate or travel to the side of the neck.
Besides shoulder pain, another common symptom of shoulder arthritis is a limited range of motion. It may become more difficult to lift your arm to comb your hair or reach up to a shelf. You may hear a grinding, clicking, or snapping sound as you move your shoulder. As the disease progresses, any movement of the shoulder causes pain. Night pain is common and sleeping may be difficult.