Simply defined, arthritis is inflammation of one or more of your joints. In 2011, more than 50 million people in the U.S.A. reported that they had been diagnosed with some form of arthritis. In an arthritis shoulder, inflammation causes pain and stiffness.
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 shoulder is a ball-and-socket type joint made up of three bones:
The head of the humerus fits into a socket (called the “Glenoid”) in the shoulder blade. A group of muscles and tendons keeps the shoulder centred in the shoulder socket. These muscles are called the rotator cuff. They cover the head of humerus and attach it to your scapula. There is a lubricating sac called a bursa between the rotator cuff and the bone on top of your shoulder (acromion). This bursa allows the rotator cuff tendons to move freely when you move your arm in all directions.
The biceps muscle (in front of your upper arm) helps you bend your elbow and rotate your forearm. It also stabilizes the shoulder. The biceps muscle has two tendons that attach it to bones in the shoulder.
The Glenoid (socket) is lined with soft cartilage structure called the labrum. This tissue helps to stabilize the head of the humerus into the shoulder socket.
To provide you with effective treatment, your physician will need to determine which joint is affected and what type of arthritis you have.
Osteoarthritis is a condition that destroys the smooth outer covering (joint cartilage) of bone. As the cartilage wears away, it becomes thinned and rough, and the protective space between the bones decreases. The bones of the joint rub against each other (“bone-on-bone”), causing grinding sounds, stiffness and pain.
Osteoarthritis usually affects people over 50 years of age and is more common in the acromion-clavicular joint than in the gleno-humeral shoulder joint.
(Left) An illustration of damaged cartilage in the glenohumeral joint.
(Right) This x-ray of the shoulder shows osteoarthritis and decreased joint space (arrow).
Rheumatoid arthritis (RA) is a chronic disease that attacks multiple joints throughout the body. Rheumatoid arthritis is an autoimmune disease. This means that the immune system attacks its own tissues. In RA, the defences that protect the body from infection instead damage normal tissue (such as cartilage and ligaments) and soften bone.It is symmetrical, meaning that it usually affects the same joint on both sides of the body.
The joints of your body are covered with a lining (synovium) that lubricates the joint and makes it easier to move. Rheumatoid arthritis causes the lining to swell, which causes pain and stiffness in the joint.
Rheumatoid arthritis is equally common in both joints of the shoulder.
A form of osteoarthritis that develops after an injury (such as a fracture or dislocation of the shoulder)
Arthritis can also develop after a large, long-standing rotator cuff tendon tear. The torn rotator cuff can no longer hold the head of the humerus in the glenoid socket, and the humerus can move upward and rub against the acromion. This can damage the surfaces of the bones, causing arthritis to develop.The combination of a large rotator cuff tear and advanced arthritis can lead to severe pain and weakness, and the patient may not be able to lift the arm away from the side.
Avascular necrosis (AVN) of the shoulder is a painful condition that occurs when the blood supply to the head of the humerus is disrupted. Because bone cells die without a blood supply, AVN can ultimately lead to destruction of the shoulder joint and arthritis.
Causes of AVN include high dose steroid use, heavy alcohol consumption, sickle cell disease, and traumatic injury, such as fractures of the shoulder. In some cases, no cause can be identified; this is referred to as idiopathic AVN.
After discussing your symptoms and medical history, your doctor will examine your shoulder.
During the physical examination, your doctor will look for:
X-rays of an arthritic shoulder will show a narrowing of the joint space, changes in the bone, and the formation of bone spurs (osteophytes).
To confirm the diagnosis, your doctor may inject a local anaesthetic into the joint. If it temporarily relieves the pain, the diagnosis of arthritis is supported.
As with other arthritic conditions, initial treatment of arthritis of the shoulder is nonsurgical. Your doctor may recommend the following treatment options:
Your doctor may consider surgery if your pain causes disability and is not relieved with nonsurgical options.
(Left) A conventional total shoulder replacement (arthroplasty) mimics the normal anatomy of the shoulder.
(Right) In a reverse total shoulder replacement, the plastic cup inserts on the humerus, and the metal ball screws into the shoulder socket.
Replacement surgery options include:
Recovery: Surgical treatment of arthritis of the shoulder is generally very effective in reducing pain and restoring motion. Recovery time and rehabilitation plans depend upon the type of surgery performed.
Complications: As with all surgeries, there are some risks and possible complications. Potential problems after shoulder surgery include:
Your surgeon will discuss the possible complications with you before your operation.
Every year, thousands of conventional total shoulder replacements are successfully done in the United States for patients with shoulder arthritis. This type of surgery, however, is not as beneficial for patients with large rotator cuff tears who have developed a complex type of shoulder arthritis called "Rotator cuff tear arthropathy." For these patients, conventional total shoulder replacement may result in pain and limited motion, and reverse total shoulder replacement may be an option.
Description: A conventional shoulder replacement device mimics the normal anatomy of the shoulder: a plastic "cup" is fitted into the shoulder socket (glenoid), and a metal "ball" is attached to the top of the upper arm bone (humerus). In a reverse total shoulder replacement, the socket and metal ball are switched. The metal ball is fixed to the socket and the plastic cup is fixed to the upper end of the humerus.
A reverse total shoulder replacement works better for people with cuff tear arthropathy because it relies on different muscles to move the arm. In a healthy shoulder, the rotator cuff muscles help position and power the arm during range of motion. A conventional replacement device also uses the rotator cuff muscles to function properly. In a patient with a large rotator cuff tear and cuff tear arthropathy, these muscles no longer function. The reverse total shoulder replacement relies on the deltoid muscle, instead of the rotator cuff, to power and position the arm.
(Left) Rotator cuff arthropathy.
(Right) The reverse total shoulder replacement allows other muscles — such as the deltoid — to do the work of the damaged rotator cuff tendons.
Reverse total shoulder replacement may be recommended if you have:
The components of a reverse total shoulder replacement include the metal ball that is screwed into the shoulder socket, and the plastic cup that is secured into the upper arm bone.
This procedure to replace your shoulder joint with an artificial device usually takes about 2 hours. Your surgeon will make an incision either on the front or the top of your shoulder. He or she will remove the damaged bone and then position the new components to restore function to your shoulder.
Reverse total shoulder replacement is a highly technical procedure. Your surgeon will evaluate your particular situation carefully and discuss the risks of surgery with you.
Risks for any surgery include bleeding and infection. Complications specific to a total joint replacement include wear, loosening, or dislocation of the components. If any of these occur, the new shoulder joint may need to be revised, or re-operated on.
A typical follow-up x-ray of a reverse total shoulder replacement.
After rehabilitation, you will most likely be able to lift your arm to just above shoulder height and bend your elbow to reach the top of your head or into a cupboard. Reverse total shoulder replacement provides outstanding pain relief and patient satisfaction is typically very high.
Early studies of the results of this surgery have been very promising, but currently no long-term studies exist. This is an area for future research.
The following information will help you prepare for your shoulder replacement surgery. It is important that you understand and follow the rehabilitation guidelines to give yourself the best chance of recovery from surgery. If you have any concerns or questions at any time, please discuss these with me or your therapist.
Things You Should Know: