Our knowledge of orthopaedics. Your best health.

Osteoarthritis

Also known as "wear-and-tear" arthritis, osteoarthritis is a condition that destroys the smooth outer covering (articular cartilage) of bone. As the articular cartilage wears away, it becomes frayed and rough, and the protective space between the bones decreases. During movement, the bones of the joint rub against each other,  causing pain; this is often referred to as "bone on bone" arthritis.

Osteoarthritis usually affects people over the age of 50 and is more common in the acromioclavicular joint than in the glenohumeral shoulder joint.

(Left) An illustration of damaged cartilage in the glenohumeral joint. (Right) This X-ray of the shoulder shows osteoarthritis and a decreased joint space.

(Left) Reproduced with permission from JF Sarwark, ed: Essentials of Musculoskeletal Care, ed 4. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2010. 

Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic disease that attacks multiple joints throughout the body. 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 — called 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 an autoimmune disease. This means that the immune system attacks its own tissues. In RA, the defenses that protect the body from infection instead damage normal tissue (such as cartilage and ligaments) and soften bone.

Rheumatoid arthritis is equally common in both joints of the shoulder.

Posttraumatic Arthritis

Posttraumatic arthritis is a form of osteoarthritis that develops after an injury, such as a fracture or dislocation of the shoulder.

Rotator Cuff Tear Arthropathy

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 their arm away from the side.

Rotator cuff arthropathy.

Avascular Necrosis

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.

Avascular necrosis develops in stages. As it progresses, the dead bone gradually collapses, which damages the articular cartilage covering the bone and leads to arthritis. At first, AVN affects only the head of the humerus, but as AVN progresses, the collapsed head of the humerus can damage the glenoid socket.

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.

Medical History and Physical Examination

After discussing your symptoms and medical history, your doctor will examine your shoulder.

During the physical examination, your doctor will look for:

• Weakness (atrophy) in the muscles
• Tenderness to touch
• Extent of passive (assisted) and active (self-directed) range of motion
• Any signs of injury to the muscles, tendons, and ligaments surrounding the joint
• Signs of previous injuries or surgeries
• Involvement of other joints (an indication of rheumatoid arthritis)
• Crepitus (a grating sensation inside the joint) with movement
• Pain when pressure is placed on the joint

X-Rays

X-rays are imaging tests that create detailed pictures of dense structures, like bone. They can help distinguish among various forms of arthritis.

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).

This X-ray shows severe osteoarthritis of the glenohumeral joint.

Reproduced with permission from Crosby LA (ed): Total Shoulder Arthoplasty. Rosemont, IL, American Academy of Orthopaedic Surgeons, 2000, p 18. 

To confirm the diagnosis, your doctor may inject a local anesthetic into the joint. If it temporarily relieves the pain, the diagnosis of arthritis is supported.

Nonsurgical Treatment

As with other arthritic conditions, initial treatment of arthritis of the shoulder is nonsurgical. Your doctor may recommend the following:

• Rest or change in activities. You may need to change the way you move your arm to avoid provoking pain.
• Physical therapy exercises may improve the range of motion, strength, and function in your shoulder. 
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin, ibuprofen, or naproxen, may reduce inflammation and pain. These medications can irritate the stomach lining and cause internal bleeding. They should be taken with food. Consult with your doctor before taking over-the-counter NSAIDs if you have a history of ulcers or are taking blood thinning medication.
• Corticosteroid injections in the shoulder can dramatically reduce the inflammation and pain. However, the effect is often temporary.
• Moist heat may provide temporary relief.
• Icing your shoulder for 20 to 30 minutes two or three times a day to reduce inflammation and ease pain.
• If you have rheumatoid arthritis, your doctor (typically a rheumatologist) may prescribe a disease-modifying drug, such as methotrexate.
• Dietary supplements, such as glucosamine and chondroitin sulfate may help relieve pain. (Note: There is little scientific evidence to support the use of glucosamine and chondroitin sulfate to treat arthritis. In addition, the U.S. Food and Drug Administration does not test dietary supplements. These compounds may cause negative interactions with other medications. Always consult your doctor before taking dietary supplements.)

Surgical Treatment

Your doctor may consider surgery if your pain causes disability and is not relieved with nonsurgical treatment.

Arthroscopy. Cases of mild glenohumeral arthritis may be treated with arthroscopy, During arthroscopy, the doctor inserts a small camera, called an arthroscope, into the shoulder joint. The camera displays pictures on a video monitor, and the doctor uses these images to guide miniature surgical instruments.

Because the arthroscope and surgical instruments are thin, the surgeon can use very small incisions rather than the larger incision needed for standard, open surgery.

During the procedure, your doctor can debride (clean out) the inside of the joint. Although the procedure provides pain relief, it will not eliminate the arthritis from the joint. If the arthritis progresses, further surgery may be needed in the future.

Shoulder joint replacement (arthroplasty). Advanced arthritis of the glenohumeral joint can be treated with shoulder replacement surgery. In this procedure, damaged parts of the shoulder are removed and replaced with artificial components, called a prosthesis.

Replacement surgery options include:

• Hemiarthroplasty. Just the head of the humerus is replaced by an artificial component.
• Total shoulder arthroplasty. Both the head of the humerus and the glenoid are replaced. A plastic cup is fitted into the glenoid, and a metal ball is attached to the top of the humerus.
• Reverse total shoulder arthroplasty. In a reverse total shoulder replacement, the socket and metal ball are opposite a conventional total shoulder arthroplasty. The metal ball is fixed to the glenoid, 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 — not the rotator cuff — to move the arm.

(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. 

Resection arthroplasty. The most common surgical procedure used to treat arthritis of the acromioclavicular joint is a resection arthroplasty. Depending on your specific situation, this procedure may be performed either arthroscopically or through traditional open surgery.

In this procedure, the doctor removes a small amount of bone from the end of the collarbone, leaving a space that gradually fills in with scar tissue.

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. Other factors, such as comorbidities (other medical conditions, such as high blood pressure or diabetes), smoking, and depression, can also affect outcomes after surgery.

Pain management. After surgery, you will feel some pain. This is a natural part of the healing process. Your doctor and nurses will work to reduce your pain, which can help you recover from surgery faster.

Medications are often prescribed for short-term pain relief after surgery. Many types of medicines are available to help manage pain, including opioids, non-steroidal anti-inflammatory drugs (NSAIDs), and local anesthetics. Your doctor may use a combination of these medications to improve pain relief, as well as minimize the need for opioids.

Be aware that although opioids help relieve pain after surgery, they are a narcotic and can be addictive. Opioid dependency and overdose have become critical public health issues in the U.S. It is important to use opioids only as directed by your doctor and to stop taking them as soon as your pain begins to improve. Talk to your doctor if your pain has not begun to improve within a few days of your surgery.

Complications. As with all surgeries, there are some risks and possible complications. Potential problems after shoulder surgery include infection, excessive bleeding, blood clots, and damage to blood vessels or nerves.

Your doctor will discuss the possible complications with you before your operation.