Bones and Joints

You may think of your shoulder as a single unit, but this joint is actually made up of three bones—the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone)—and three joints. The acromioclavicular joint is between the tip of the shoulder blade (acromion) and the collarbone. The scapulothoracic joint is between the shoulder blade and the thorax (rib cage), and the glenohumeral joint, commonly called the shoulder joint, is between the glenoid cavity (shoulder socket) and the head of the humerus. The shoulder is a ball-and-socket–type joint that permits a wide range of motion. In fact, the shoulder is the most movable—and, because of this, the most unstable—joint in the body.

Shoulder Dislocation
Shoulder dislocation occurs when the humerus (upper arm bone) comes out of the shoulder joint. The bone is usually displaced in front of and below the shoulder. Ligaments and other connective tissues are stretched or torn. In severe cases, nerves and blood vessels also may be damaged. The injury is caused by falling onto an outstretched hand or arm or onto the shoulder itself. It also may be caused by a powerful direct blow to the shoulder. Shoulder dislocation is sometimes accompanied by a fracture (search fractures for more info).

Symptoms of shoulder dislocation include severe pain in the shoulder accompanied by swelling and bruising. The shoulder also may look misshapen.

To reduce pain and swelling, place an ice pack on the injured area immediately after the injury occurs. Then see your doctor or go to a hospital emergency department without delay. (With a recurring dislocation, you may be able to “pop” the shoulder back into place.) To immobilize the shoulder and to aid healing, the doctor may place your arm in a sling or strap your arm to your chest. He or she may prescribe an analgesic (pain-relieving) medication such as codeine with aspirin or acetaminophen. The doctor also may prescribe a nonsteroidal anti-inflammatory drug such as aspirin or ibuprofen to relieve pain and reduce swelling. (Warning: Do not take these medications at the same time unless your doctor tells you to do so.)

You should avoid athletic activities until after the injury has healed. Your doctor will probably recommend that you apply an ice pack to the injured area for 20 to 30 minutes three or four times per day for 2 to 4 days to reduce swelling and inflammation. After the swelling has gone down, apply a heating pad to your shoulder to increase circulation to the injured area and speed healing. (Warning: Apply heat only after swelling has subsided, or swelling in the injured area may increase. Be careful when using a heating pad; too much heat can cause tissue damage or burns.)

Once you have had a shoulder dislocation, you are at risk for a recurrence of the injury. Raising your arm over your head or sleeping with your arm above your shoulder could cause another dislocation. Your doctor may recommend that you work with a physical therapist or an athletic trainer on exercises that will stabilize the ligaments and tendons, strengthen the shoulder muscles, and help prevent another dislocation. A shoulder dislocation is usually a more serious injury than a shoulder separation (see below).

Shoulder Separation
Shoulder separation occurs when the ligaments that attach the clavicle (collarbone) to the scapula (shoulder blade) are torn. The injury is caused by falling onto an outstretched hand or arm or onto the shoulder itself. It also may be caused by a direct blow to the shoulder. Symptoms include severe pain, swelling, and bruising. There may be limited movement in the shoulder. In some cases the collarbone is pushed out of its normal position and sticks up under the skin. Also, the shoulder may look misshapen.

To reduce pain and swelling, place an ice pack on the injured area immediately after the injury occurs. If symptoms persist, see your doctor as soon as possible, or go to a hospital emergency department. To immobilize the shoulder and to speed healing, the doctor may place your arm in a sling or strap your arm to your chest. A nonsteroidal anti-inflammatory drug such as aspirin or ibuprofen will help reduce pain and inflammation. In severe cases, surgery to repair the damaged ligaments may be required.

You should avoid athletic activities until after the injury has healed. Your doctor probably will recommend that you apply an ice pack to the injured area for 20 to 30 minutes three or four times per day for 2 to 4 days to reduce swelling and inflammation. Use a heating pad on the injured area once the swelling has gone down, to increase circulation and speed healing. (Warning: Apply heat only after swelling has subsided, or swelling in the injured area may increase. Be careful when using a heating pad; too much heat can cause tissue damage or burns.) Ask your doctor if he or she has a list of recommended exercises or if you should work with a physical therapist or an athletic trainer on exercises that will stabilize the ligaments and tendons and strengthen the shoulder muscles. Shoulder separation usually does not cause any lasting adverse effects.

The elbow is a hinge joint between the humerus (upper arm bone) and the ulna and radius. The elbow allows you to bend and straighten your arm and to rotate your forearm without moving your upper arm. Your biceps muscle bends the forearm, while your triceps muscle straightens the forearm. The bony projection that forms the point of the elbow is the olecranon. Popularly known as the “funny bone,” because bumping the nerve (the ulnar nerve) that passes over it produces a familiar tingling sensation, the olecranon prevents overextension of the elbow.

Epicondylitis
Tendons attach the forearm muscles to the elbow at bony outgrowths called epicondyles. These tendons can become inflamed and painful, especially with repetitive motions of the forearm (such as using a manual screwdriver, washing windows, or swinging a baseball bat). This inflammation is called epicondylitis. The two types of epicondylitis are called tennis elbow (the outer tendons are inflamed) and golfer’s elbow (the inner tendons are inflamed).

The usual treatment for these disorders includes ice packs, rest, nonsteroidal anti-inflammatory medications such as aspirin or ibuprofen, or, in severe cases, corticosteroid injections. In some cases, surgery may be necessary.

Trapped Nerve
A trapped ulnar nerve is another common injury that occurs when the nerve that crosses the point of the elbow is compressed or pinched. This causes numbness, tingling, weakness, and pain in the forearm and hand. Rest, ice, and avoiding reinjury can relieve symptoms and help the damaged nerve heal. Surgery to reposition the ulnar nerve may help prevent repeated compression.

Other possible elbow disorders include bursitis, fractures, and osteoarthritis.

A joint is the point at which two or more bones meet. It is made up of the bones and muscles brought together at the joint, the ligaments (which connect bone to bone), the tendons (which connect muscle to bone), the bursae (which cushion the joint), and cartilage. The cartilage permits smooth movement of the joint and acts as a shock absorber between the bones. The entire joint is enclosed in a fibrous capsule with a special lining (the synovium) that produces fluid to reduce friction within the joint. Inflammation of or damage to any of these components affects the entire joint. This section describes some common problems that can affect the joints.

Osteoarthritis
Arthritis is a general term that refers to inflammation of one or more joints. There are more than 100 arthritic disorders. Osteoarthritis, which most people refer to as simply arthritis, is a chronic joint disease that affects many middleaged and older Americans. Osteoarthritis that has no obvious cause is called primary arthritis. Osteoarthritis that results from damage to the cartilage that covers the ends of the bones in a joint is called secondary arthritis. Injury and obesity are two factors that may be involved in the development of osteoarthritis. Heredity may also be a factor.

The symptoms of osteoarthritis include pain, tenderness, swelling, redness, and loss of motion or strength in the affected joint or joints. The pain tends to worsen toward the end of the day. In some people the joint may make cracking sounds when it is in motion. In osteoarthritis, joint cartilage gradually wears away, allowing adjoining bones to rub against each other. Painful outgrowths of bone (spurs) also may develop. Although symptoms usually do not appear until middle age, they can begin as early as between ages 20 and 30. Among adults under age 55, men and women are affected equally; after age 55, the incidence of osteoarthritis is higher in women. Joints in the hips, knees, spine, big toe, and fingers are most commonly affected.

Osteoarthritis is diagnosed based on your symptoms and the results of a physical examination. X rays usually are taken to confirm the diagnosis. There is no cure for osteoarthritis. Your doctor probably will prescribe a nonsteroidal anti-inflammatory drug to relieve symptoms. Severe episodes of inflammation
may be treated by injecting a corticosteroid drug directly into the affected joint. Massage, heat treatments, and warm baths may help relieve symptoms. Regular, gentle exercise (such as walking or swimming) will help your joints stay flexible. Maintaining a healthy weight (search healthy weight for more info) will reduce the strain on your joints. For some people doctors may recommend joint replacement.

Rheumatoid Arthritis
Rheumatoid arthritis is a chronic autoimmune disease in which the immune system attacks the synovial tissue, the membrane that lines the joints. It is the second most common form of arthritis and usually appears between ages 20 and 40. Although the cause of rheumatoid arthritis is unknown, there is a genetic component: if a close relative is affected, you are more likely to develop the disease. There is no known cure.

In rheumatoid arthritis, the fluid that lubricates the joints contains irritating chemicals that attack and damage the surfaces of the joints. The inflamed membrane swells and thickens, causing a wearing away of the joint cartilage, which leads to erosion of the bone and weakening of supporting tendons, ligaments, and muscles. The small joints in the hands, wrists, feet, ankles, and neck are most frequently affected, but the hips and the knees also can be affected. In most cases, more than one joint is affected and usually the same joints are affected on both sides, such as both hands.

Rheumatoid arthritis alternates between periods during which symptoms are present and periods with no symptoms. These periods can vary in length. When the disease is active, it causes redness, warmth, swelling, tenderness, pain, and stiffness in the affected joints. The severity of symptoms can vary from person to person. The joint damage resulting from the disease is not reversible; in advanced cases, the joints can become deformed.

A diagnosis of rheumatoid arthritis is based on the symptoms and an examination of the joints. The doctor also can use X rays to detect damage—such as erosion of cartilage and bone—in the affected joints. A blood test also may be performed to check for a specific protein (an antibody called rheumatoid factor) that is present in most people who have rheumatoid arthritis.

Treatment of rheumatoid arthritis is similar to the treatment of osteoarthritis. If treatment with nonsteroidal anti-inflammatory drugs is not effective, the doctor may prescribe other medications, including gold compounds such as auranofin and aurothioglucose, and oral corticosteroids such as prednisolone and triamcinolone. The doctor also may prescribe antirheumatic drugs such as hydroxychloroquine and penicillamine. In severe cases, medications such as azathioprine, cyclophosphamide, cyclosporine, and methotrexate sometimes are prescribed to suppress the inappropriate immune response.

For most people with rheumatoid arthritis, regular exercise can help maintain flexibility and strength in the joints. Your doctor can recommend suitable exercises and also may recommend that you work with a physical therapist to maintain or restore movement in your joints. For some people, surgery to remove the affected joint lining (a procedure called synovectomy) may provide relief. For severely damaged joints, a total joint replacement can reduce pain and restore movement, allowing a person to return to an active life.

Joint Replacement Because of engineering and medical advances, surgeons can now replace certain joints and restore their normal function. Joint replacement (called arthroplasty) has been used on the ankles, hands, wrists, and toes, but it is most often performed on the knee and the hip. With total joint replacement, the bone ends and cartilage are replaced with metal and plastic joint components. The metal component is inserted into the canal inside each long bone involved, while the plastic part covers or receives the metal “bone ends” as a cartilagelike cushion, where bone meets bone. The joint components are usually attached to the bone tissue with an acrylic cement.

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In hip replacement surgery, the end of the femur is replaced with a metal ball, and a plastic cup is cemented into the pelvis where the acetabulum (pelvic socket) would normally receive the end of the femur. In many patients, particularly younger ones, the plastic cup is not cemented into place to give time (with limited activity) for the natural bone to grow and attach to it. In the knee, damaged bone ends are replaced with metal ends covered with plastic that can permit the same range of motion as a normal knee joint.

Joint replacement surgery lasts approximately 2 to 4 hours and requires a lengthy, structured recuperation period. The amount of recovery time required in the hospital depends on the nature of the surgery, your overall health, and whether you have any complications (such as infection, joint dislocation, or blood clots). You may be walking with support within a day of surgery, and you will start physical therapy immediately. You will probably be hospitalized for about a week, although full recovery can take up to 6 months. It is vital to maintain an appropriate exercise and stretching program after the surgery to keep your new joint in good working order. Although replacement joints usually last at least 20 years, younger and more active patients may need to undergo revision surgery (surgery to repair or replace the artificial joint). Joint replacement surgery has an excellent success rate.

Gout
Gout is a metabolic disorder that results from high levels of uric acid (a waste product of cell metabolism) in the blood. The condition can lead to joint inflammation, deposits of uric acid in and around the joints, reduced kidney function, and sometimes the development of kidney stones.

Gout is nine times more common in men than in women. Risk factors for gout include obesity, moderate to heavy alcohol consumption, high blood pressure, and kidney disorders. Certain drugs (such as aspirin) can worsen gout, and certain diseases that affect kidney function (such as diabetes and sickle-cell disease) can be a factor. Acute attacks of gout can be brought on by dehydration, joint injury, fever, large meals, high alcohol intake, stress, or recent surgery. Certain foods, such as shellfish, sardines, and organ meats, also may trigger attacks.

The small joint at the base of the big toe is the most common location for an acute gout attack. Other joints affected may include the ankles, knees, wrists, fingers, and elbows. An acute gout attack often begins at night, with severe pain and sometimes a fever. The attack may subside in several hours or several days but usually recurs at irregular intervals.

The symptoms alone usually are sufficient to diagnose gout, but your doctor can confirm the diagnosis by examining your blood for elevated uric acid levels and your joint fluid for signs of uric acid crystals.

Future attacks can be prevented by increasing fluid consumption (at least eight 8-ounce glasses every day), losing weight, reducing alcohol intake, modifying your diet, and taking nonsteroidal anti-inflammatory drugs (such as ibuprofen) to relieve the pain and inflammation and medications (such as allopurinol or probenecid) to lower blood levels of uric acid.