Osteoarthritis is the most common type of arthritis. It does not occur as commonly in the shoulder as the weight-bearing joints (the knees, feet, hips, spine). A shoulder that develops osteoarthritis usually has been previously injured. The joint between the collarbone and shoulder blade (the acromioclavicular joint) is affected more often than the “main” shoulder joint (glenohumeral joint) where the head of the upper arm meets the shoulder blade.
Arthritis in the shoulder is not as common as soft tissue injuries such as injury to the rotator cuff.
Osteoarthritis is caused by gradual degeneration of the smooth cartilage that coats the ends of the bones in a joint. The ends of the bones in a joint are coated with smooth articular cartilage, which allows the bones to glide smoothly against each other. When the cartilage breaks down and becomes rough, friction occurs between moving bones. Irritation and damage to the bones result. In severe cases, cartilage is totally worn away and bone rubs against bone. This causes the ends of the bones to thicken, and bones spurs may form.
Age – Incidence of osteoarthritis increases with age.
Past injury to the joint
Genetics – Some people may be genetically predisposed to developing osteoarthritis.
Symptoms of Shoulder Osteoarthritis
In the early stages, there may be no symptoms. Though symptoms generally get worse as the osteoarthritis progresses, symptoms also fluctuate for not apparent reason. A person may have good days and bad days. Some people are affected by changes in the weather.
The main symptoms of shoulder osteoarthritis are pain and stiffness of the shoulder. Pain increases upon movement. There may be a grinding sensation in the joint. There is not usually any swelling of the joint in the early stage of osteoarthritis but it swelling can occur with more advanced osteoarthritis. Sometimes a piece of cartilage breaks away and irritates the soft tissue around the joint, causing inflammation.
Though the cartilage cannot be seen on a regular x-ray, x-rays may be used to assess the progression of osteoarthritis over time. This is because the space (the “invisible” cartilage) between the bones on the x-ray gets narrower as the cartilage degenerates. Damage to the ends of the bones and bone spurs can also be seen.
Blood tests may be taken to rule out rheumatoid arthritis, a disease that attacks the lining of the joints and causes inflammation of the joints. Rheumatoid arthritis affects the entire body, not just the joints, and often causes fatigue and fever. Rheumatoid arthritis is thought to be an autoimmune disease (a disease in which the body’s immune system produces antibodies against its own tissues).
Treatment of Shoulder Osteoarthritis
Heat and Cold
*Do not apply heat to a swollen joint.
*Do not apply heat or cold if you have nerve damage or circulation problems unless recommended by your physician.
Heat and cold are both effective in relieving pain.
Cold reduces both pain and inflammation. Do not apply ice directly to the skin. Wrap ice in a cloth to and apply to the shoulder for 20 minutes. Icing the joint may be repeated every four or five hours. Do not apply ice for more than 20 minutes at a time to avoid frostbite.
Heat increases circulation and increases the elasticity of muscles. Muscles around an arthritic joint may contract in response to pain, which causes more pain. Heat helps relax muscles to relieve pain. Heat is also very soothing and distracts from the pain. Apply heat to the shoulder for 20 minutes. Heat may be provided by a heating pad, hot water bottle, or by a warm bath or shower. Wait at least an hour between heat applications to avoid overheating of the tissues.
Stretching exercises improve range of motion and help maintain normal shoulder functioning. Exercises to strengthen the shoulder are also important. Pain may cause a person with shoulder arthritis to avoid using the shoulder. Limiting shoulder movement causes muscles to weaken. Weak shoulder muscles increase the risk of injury to the shoulder. Certain shoulder exercises may cause undue stress on the joint. Consult a physician or physical therapist before beginning shoulder exercises.
Tip: Apply heat before exercise; apply cold after exercise. Applying heat (using heating pad, hot water bottle, or warm shower or bath) before exercising increases the elasticity of muscles and reduces the risk of injury. Applying cold (ice wrapped in cloth) immediately after exercise can reduce post-exercise pain.
Painkillers such as Tylenol relieve pain, but not inflammation. Tylenol should not be taken with alcohol as the combination can damage the liver.
NSAIDs (non-steroidal anti-inflammatory drugs) relieve both inflammation and pain. Most people have no problems tolerating NSAIDs with short-term use. Short-term use may cause stomach upset, nausea or heartburn in some people. Taking NSAIDs with a meal reduces stomach upset. Long-term use may erode the stomach lining and cause ulcers. Consult your physician if you have a history of ulcers before using NSAIDs.
Slow-release NSAIDs dissolve mostly in the small intestine – after they have passed the stomach – and help decrease the chance of upset stomach. However, NSAIDs reduce the production of substances that protect the stomach lining from stomach acid; side effects may still occur with the slow-release form.
There are prescription creams that contain an NS AID (non-steroidal inflammatory medication). The cream is applied over the joint and the NSAID is absorbed through the skin to the area where it is needed; only a small amount of the medication is absorbed into the bloodstream. This helps minimize side effects associated with oral NSAIDs. As some medication does get into the bloodstream, if you take oral NSAIDs the dosage may have to be reduced.
Deep heating rubs are applied to the skin over the joint create surface heat. The heat provides a distraction from the pain.
Capsaicin is a substance derived from hot chili peppers. Capsaicin works over several weeks to gradually reduce a substance in the nerve endings that transmit pain. Capsaicin Cream also provides temporary surface heat.
Cortisone (steroid) Injections
Cortisone has powerful anti-inflammatory properties. An injection of cortisone into a joint often provides rapid relief of pain and inflammation. When injected into the joint, only a small amount of cortisone is absorbed into the blood stream. Cortisone injections are often limited to three injections because overuse of cortisone injections can actually cause further damage to the cartilage.
Glucosamine and Chondroitin
Glucosamine and chondroitin occur naturally in the body and are found in and around cartilage. Glucosamine and chondroitin are believed to relieve the symptoms of osteoarthritis for many people though it usually takes several weeks to obtain results. Cartilage has a limited ability to repair itself but these supplements may slow down the degeneration of cartilage. These supplements also seem to relieve pain and inflammation
Glucosamine and chondroitin are generally well tolerated but can cause nausea or indigestion in some people. Consult your physician if you are on medication or have a medical condition before taking glucosamine or chondroitin. Supplements sometimes interfere with medications or affect other conditions.
Shoulder Replacement Surgery
If advanced shoulder arthritis causes severe pain and interferes with day-to-day living, shoulder replacement surgery is an option. This is elective surgery.