Shoulder arthritis is becoming a more recognized diagnosis for shoulder pain. While not as common as arthritis of the hip and knee, it can still be a significant source of disability. Arthritis usually affects people over 50 years of age but is becoming more common in younger patients due to a more active lifestyle. Heavy physical activity, such as weight lifting, can cause the shoulder joint to wear out faster.
What is arthritis?
The term "arthritis" simply means a wearing away of the normal smooth gliding surface of the joint called the articular cartilage. As the cartilage starts to wear away, the underlying bone is exposed. The cartilage does not have any nerve endings. As the bone becomes exposed, pain will develop because the bone has a rich nerve supply. The wearing of the cartilage and exposure of the bone will create inflammation in the joint which is also painful. Any overuse activity that causes the cartilage to wear out faster will precipitate the onset of arthritis.
What areas become arthritic?
The most common area of the shoulder to develop arthritis is the acromioclavicular (AC) joint. This is a small joint at the end of the clavicle. AC joint arthritis often develops at an early age especially in heavy laborers or people who have participated in sports when they were younger. This type of arthritis is usually not as debilitating and many can live with the arthritic pain. Treatment options include activity modification, medication, steroid injections and, as a last resort, arthroscopic excision of the arthritic joint. This last option typically works very well for permanent resolution of the arthritis pain.
The main joint of the shoulder is the glenohumeral joint. Arthritis in this location will cause more disability. The pain is typically more severe and motion of the shoulder joint decreases. Arthritis is a gradually progressive disease. Unfortunately, there is no cure. As the articular cartilage continues to wear away, there will eventually be bone against bone contact. This results in more severe shoulder pain and limited use.
What are the types of arthritis?
There are 5 primary types of arthritis that can affect the shoulder.
1. Osteoarthritis is the most common type of arthritis. This is the wear and tear type of arthritis. As noted above, the articular cartilage covering of the end of the bone gradually wears away due to overuse, previous injury or surgery, or genetic factors that predispose to developing arthritis in multiple joints.
2. Rheumatoid arthritis is an inflammatory disease that affects multiple joints. The body literally attacks itself. The lining of the joint (synovium) becomes inflammed and eventually leads to destruction of the cartilage and softening of the bone. Swelling is more common than in osteoarthritis but the range of motion is usually not as affected.
3. Posttraumatic arthritis develops as a result of a previous injury or surgery. A fracture or dislocation can damage the joint and lead to an earlier wear of the articular cartilage. Surgery can also produce damage to the joint and may lead to an earlier arthritic onset.
4. Rotator cuff arthropathy is a type of arthritis unique to the shoulder joint. The rotator cuff helps hold the humeral head (ball) in the glenoid (socket). In the presence of a large tear of the rotator cuff, the humeral head will displace upward against the bone of the shoulder blade (acromion). The articular cartilage of the humeral head will rub against the bone of the acromion and cause arthritis to develop. This type of arthritis requires a different treatment because the rotator cuff is no longer repairable.
5. Avascular necrosis (AVN) is a loss of blood supply to the humeral head. Because the bone dies, the overlying articular cartilage is destroyed. The bone eventually collapses and results in damage to the glenoid socket. AVN is typically caused by high-dose steroids (such as prednisone), heavy alcohol consumption, sickle cell disease or trauma.
Treatment for arthritis
Shoulder arthritis is initially managed without surgery. Rest or avoiding heavy activities is often helpful. Patients who participate in sports may need to limit overhead activity or heavier lifting. Anti-inflammatory medication such as ibuprofen may help reduce inflammatory pain. Some patients prefer heat or ice. Both may be of benefit. Gentle therapy exercises may help improve range of motion and increase strength in the surrounding musculature. However, aggressive stretching and strengthening should be avoided as this may aggravate the arthritic inflammation.
Corticosteroid injections ("cortisone") are often a good temporary treatment to reduce inflammation and pain. Each person's response to the injections is different and depends on the severity of the arthritis. Injections will often last for months and can be repeated several times a year. Lubricating type of injections, such as those used for knee arthritis, have not yet been approved for treatment of shoulder arthritis. However, some preliminary studies have demonstrated their benefit.
Mild glenohumeral arthritis that does not respond to nonsurgical treatment may benefit from arthroscopic management. The frayed and torn cartilage can be smoothed along with removal of any loose fragments, inflamed synovium and treatment of any tendon pathology. Arthroscopy is also beneficial for treatment of acromioclavicular joint arthritis.
Advanced arthritis of the glenohumeral joint may require replacement surgery. The damaged parts of the joint are removed and replaced with artificial components.
Total shoulder replacement
When the arthritis has become severe enough to affect the glenoid socket, both sides of the joint are replaced. A plastic socket can be cemented onto the glenoid so that the metal ball articulates with the plastic socket. The entire damaged shoulder joint surface has been replaced and arthritis removed. Shoulder replacement surgery is becoming more frequent. Over 40,000 Americans will have a shoulder replacement each year. Recent advancements in shoulder technology allows the shoulder replacement to perform the stability and function of the normal joint. Shoulder replacement surgery is a technically demanding operation that requires experience to perform well. In the United States, two thirds of all shoulder replacements are performed by surgeons who do less than five a year. Not surprisingly, the clinical outcomes in this low surgical volume group are not as good as the results of those surgeons who do a higher volume. It is important to choose a surgeon and hospital that are accustomed to doing shoulder replacements at a high volume to insure the best results.
Reverse shoulder replacement
Since 2004 in the Unites States (and since the 1980s in Europe), a revolutionary type of shoulder replacement has been available for those with previously inoperable shoulder conditions. In this design, the ball and socket are reversed. The socket is placed where the ball (humeral head) is normally located and the ball is fixed to the scapula where the socket is normally located. This reverse design allows the ball and socket joint to be more constrained which means the ball can't slide in the socket. The two parts are held tightly together. In a standard replacement, the design is more anatomic. Thus, the socket is shallow to allow a normal sliding of the ball as it rotates in the socket. This design requires an intact rotator cuff to stabilize the ball. Otherwise, the ball can slide too far and potentially displace on the edge of the socket or dislocate completely. The reverse design does not require a rotator cuff for stability so it is useful for patients who have a large, irrepairable rotator cuff tear. Rotator cuff arthropathy was previously a difficult problem to treat. Patients often could not lift their arm to reach their face and had pain to do so. The reverse shoulder replacement uses the intact deltoid muscle to elevate the arm without requiring the rotator cuff. With this replacement, these patients are now reaching overhead with minimal to no pain in most instances. The indications for a reverse replacement have been extended to include other difficult shoulder problems. It is now demonstrating good results for significantly displaced shoulder fractures in the elderly, revision shoulder replacements and as a primary replacement for those with significant bone loss. I have been using the reverse replacement since it was first introduced in the United States and has much experience in this procedure.
Key Points In Treating Shoulder Arthritis
1. When nonoperative measures for treating shoulder arthritis (injections, medication, rest, therapy, etc.) have failed, shoulder surgery is a good option for pain management.
2. Shoulder replacement surgery is becoming more common but still the great majority of the procedures are performed by surgeons who do less than 5 replacements per year.
3. Advancements in the design of replacements have made them more anatomic to reproduce a more normal shoulder function.
4. The reverse shoulder replacement has provided patients with previously difficult problems the ability to regain shoulder movement and reduce pain.
5. Since shoulder replacement is a techniquely demanding procedure, the success of the replacement surgery has been proven to be dependent on the volume of replacements the surgeon has performed. Dr. Payne performs many replacements for all types of arthritis each year and has done so for 25 years.
Arthritic AC Joint
Osteoarthritis of the Glenohumeral Joint
X-Ray of Rotator Cuff Arthropathy
Note the humeral head is displaced
upward out of the socket.
X-Ray of Shoulder AVN
The top of the humeral head
head has lost it's blood supply
The Tornier AscendTM Shoulder Replacement
Provides a more normal replacement of the shoulder
Reverse Shoulder Replacement for Fracture
Note the ball is fixed to the shoulder blade
with screws and the socket is fixed to the upper end of the arm