There are two main joints in the shoulder: the AC joint (acromioclavicular) and the glenohumeral joint. The AC joint is the joint on the top of the shoulder where part of the shoulder blade (the acromion) meets up with the collar bone (the clavicle). You can frequently see or feel a small bump on the shoulder where these two bones come together. Over time, this joint frequently becomes arthritic, with bone spur formation and loss of cartilage between the bones. This can cause pain in the top of the shoulder with over head movement or reaching across the body. It can also cause tenderness or pain with pressure on it from a back pack strap, bra strap, or any other pressure. There is very little motion that occurs at this joint. It is basically a junction between two bones with limited motion. The glenohumeral joint, though, has incredible motion. It is the junction of the glenoid (the cup or saucer) and the humeral head (the ball in the shoulder). This is the joint that allows the shoulder to move over a larger range than any other joint in the body. Over time, this can also become arthritic. Arthritis is the loss of cartilage in the joint that can be caused by trauma, genetics, or overuse. When the main shoulder joint (the glenohumeral joint) becomes arthritic, shoulder motion may decrease. This can cause pain and stiffness. When one or more of these joints is affected by arthritis, even simple activities can become difficult. Although there are many types of arthritis, most fall into one of two major categories: osteoarthritis and rheumatoid arthritis, or RA. Both are diseases of the joint, but symptoms, causes, methods of diagnosis, and treatments may differ for each.
Swelling, pain, limited motion, and weakness are all common symptoms of arthritis. Other symptoms may also occur, depending on the type and severity of the disease, location in the body, and other factors. In osteoarthritis of the glenohumeral joint in the shoulder, the first sign may be pain at night or decreased range of motion. Early symptoms of arthritis in AC joint are similar, but usually more localized to the top of the shoulder and motion is not usually significantly decreased. Increased joint use, such as with overhead lifting may be followed by pain immediately or many hours later. Pain and stiffness in the morning is typical, and in advanced cases, joint pain may even wake you up at night. Adapting use of the shoulder can help to prevent pain.
Additional symptoms may include a sensation of grating or grinding (crepitation) that is felt in the affected joint as damaged surfaces of cartilage rub together. If the arthritis is caused by damaged ligaments, the joint may feel unstable or loose. In advanced cases, changes in the bone, loss of cartilage, and swelling may cause the joint to appear larger than normal (hypertrophic).
To diagnose arthritis of the shoulder, and the category of disease, your physician may use a variety of diagnostic tools, including patient history, physical examination, blood tests, and X-rays. When X-rays appear normal but arthritis is still suspected, an MRI can show more detail. Arthroscopy may also be used to allow direct inspection of the joint. During this procedure, the surgeon inserts a small camera inside the joint, allowing the clearest view possible without requiring a large incision. This diagnostic tool is used only in certain situations however, because although the incision is small, it is an invasive procedure.
There are several options for nonsurgical treatment of arthritis, depending upon: how far the disease has progressed; how many joints are involved; your age, activity level and other medical conditions; whether or not the dominant hand is affected; your personal goals and home support structure; and your ability to understand your treatment and comply with a therapy program. Following a prescribed exercise program can also help improve strength and range of motion in the affected joint.
When nonsurgical treatment does not provide the desired outcome, a variety of surgical options may be considered. For the AC joint, shoulder arthroscopy with a distal clavicle excision (removing the end of the collar bone to open space between the two bones) will usually provide permanent relief of pain. For glenohumeral arthritis (the main shoulder joint), shoulder resurfacing or replacement surgery can greatly improve symptoms. The appropriate option will depend on a variety of factors, including: the severity of disease; other medical conditions; and your age, goals, activity level, and home support structure. Your orthopaedic surgeon will review surgical treatments with you, and discuss which ones offer the highest potential for long-term relief of pain and allowing you to return to normal activity.
Following surgery, a trained therapist will help you maximize your recovery. The length of time needed for recovery varies, depending on the extent of the surgery and individual factors. Most people are able to return to most, if not all, of their daily activities about three months after major joint reconstruction.