The Many Causes of Joint Pain

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1 I n t r o d u c t i o n The Many Causes of Joint Pain there are about a hundred different forms of arthritis, an umbrella term for diseases with symptoms that include joint and musculoskeletal pain. And if you live long enough, you can pretty much count on developing symptoms of one of them a touch of osteoarthritis, at the very least. In fact, more than 50 percent of people over age sixty-five have clinical signs of arthritis, meaning that an estimated seventy million Americans suffer from the disease. As the life expectancies for men and women continue to increase, Americans over the age of sixty-five will continue to be the most rapidly growing segment of the population. Consequently, according to even the most conservative estimates, the number of patients suffering from arthritis will nearly double by the year 2030 (a statistic that includes not only forms that emerge in the later years, but also those variations that affect young children, or adults in their prime). And osteoarthritis, the most prevalent form of arthritis, is the most common chronic disease affecting older individuals today. Given this growing prevalence of osteoarthritis, it is not surprising that the health-care industry, which encompasses both traditional and unconventional modes of research and treatment, is rushing to develop and propose miracle cures and that seniors who are confronted with arthritis can be all too ready to try them. After all, although Americans today look forward to living into and past their seventies and eighties, none imagine 1

2 2 i n t r o d u c t i o n COPYRIGHTED MATERIAL Almost everybody experiences joint pain at some point in their lifetime. their golden years crippled with arthritis or envision their independence and quality of life hampered by other causes of joint pain. Our hope is that this book will help you become an educated health-care consumer one who can easily distinguish among effective mainstream treatments, reasonable alternative treatments, and outright scams. In addition, while medical and surgical advances have given new hope to millions of joint pain and arthritis sufferers, this book will also stress the importance of arthritis prevention for readers who understand that early steps to avoid disease are always the best cure. Anatomy of a Joint Human beings have more than one hundred joints connecting over two hundred bones, most of which are specifically designed to allow a broad range of motion. There are many different kinds of joints: ball-and-socket joints (think hips and shoulders), saddle joints (which connect thumb to hand), hinge joints (like those in your fingers and knees), or pivot joints (your wrists, for example). In its simplest form, a joint is a connection between two or more bones and is made up of the ends of the bones; tough, rubbery cartilage that wraps around the ends of the two bones and that also functions as a shock absorber; a fluid-filled capsule that surrounds the bone ends and cartilage; and various ligaments and tendons that provide both stability

3 i n t r o d u c t i o n 3 Arthritis Facts According to the Centers for Disease Control and Prevention, one in three adults in the United States suffers from arthritis or chronic joint pain. Almost twice as many women as men suffer from arthritis. Arthritis accounts for nearly forty million doctor visits and more than half a million hospitalizations. Osteoarthritis is the most common form of arthritis, afflicting more than twenty million Americans. Rheumatoid arthritis and gout are the second and third most common causes of arthritis. While rheumatoid arthritis strikes mostly women, gout tends to afflict men. Gout is twice as likely to strike African-American men as Caucasian men. This may be because more African- American men suffer from hypertension and take medication to lower their blood pressure. Some of these antihypertensive drugs can increase production of uric acid the substance that crystallizes and then deposits in gouty joints. An astonishing 285,000 children under age seventeen have arthritis, including 50,000 who have juvenile rheumatoid arthritis. and movement. Inside the joint capsule a special lining the synovial membrane, or synovium makes a slick liquid called the synovial fluid that lubricates the joint. In many forms of arthritis, the synovium becomes inflamed and thickened, producing extra fluid containing inflammatory cells. Under the right circumstances, these inflammatory cells can then attack and damage the cartilage and the bone underlying it. Although scientists researching arthritis have come a long way toward understanding how joints work, we still don t know exactly what causes arthritis. Even so, prevention, early detection, and appropriate medical and surgical treatment can help most arthritis sufferers.

4 Bone is a living and dynamic organ. Anatomy of a normal joint.

5 i n t r o d u c t i o n 5 Different types of joints in your body. A joint with osteoarthritis. Common Forms of Arthritis: An Overview Osteoarthritis, the most common form of arthritis, occurs when joint cartilage breaks down, exposing bone ends and allowing them to rub together. The result can be pain, stiffness, loss of movement, and, sometimes, swelling. Osteoarthritis is most often found in the weight-bearing joints such as the hips, knees, ankles, and spine. There are many causes of osteoarthritis, including trauma, obesity, genetics, and other factors. Rheumatoid arthritis is the second-most-common form of arthri-

6 6 i n t r o d u c t i o n COPYRIGHTED MATERIAL A joint affected by rheumatoid arthritis. Typical joint destruction caused by gout. tis, and it occurs when the immune system turns against the body. The faulty immune system causes inflammation and swelling that begins in the joint lining and spreads to the cartilage and the bone. Rheumatoid arthritis tends to affect joints symmetrically in other words, it tends to affect the same joint on both sides of the body (for example, both hands or both wrists). Gout is caused by the buildup of uric acid, which forms crystals that deposit in the joint. These needlelike crystals cause inflammation

7 i n t r o d u c t i o n 7 Ankylosing spondylitis leads to loss of normal spine curvature. leading to severe pain and are most commonly found in the knees, the wrists, and the big toe. Heredity, diet, and certain drugs may cause or exacerbate gout. Pseudogout occurs when calcium crystals deposit within joints. The symptoms are similar to those of gout, but, unlike gout, pseudogout is not caused or exacerbated by dietary habits. Ankylosing spondylitis is a chronic inflammation of the spine that causes the vertebrae to eventually fuse together, giving the spine a very rigid appearance. Although the cause is unknown, genetics is thought to play a large role. Infectious arthritis occurs when bacteria, viruses, or fungi enter the body, settle in the joints, and cause fever, inflammation, and joint destruction. Juvenile arthritis encompasses different kinds of arthritis that strike children under the age of sixteen, the most common of which is juvenile rheumatoid arthritis. Pain or swelling in the shoulders, elbows, knees, ankles, or toes; chills; a reappearing fever; and sometimes a body rash are many of the common symptoms. The cause remains unknown. Psoriatic arthritis occurs in conjunction with the inherited skin condition psoriasis, which causes scaly, red, rough patches on the neck, elbows, and knees. Psoriatic arthritis often afflicts the joints of the fingers and toes, causing the digits to swell.

8 8 i n t r o d u c t i o n COPYRIGHTED MATERIAL Typical appearance of a hand afflicted with psoriatic arthritis. The Many Causes of Joint Pain Whether arthritis has developed because of genetic factors or, far more commonly, torn cartilage, sprains, and dislocations, joint pain is a condition that can be most effectively treated and prevented when its causes are understood. Osteoarthritis As mentioned earlier, osteoarthritis, which is sometimes called degenerative arthritis or degenerative joint disease, is the result of the breakdown of cartilage inside the joint. When the cartilage that cushions bone ends no longer does its job, the bone ends can t slide easily across each other within the joint. That s when the pain and stiffness begin. What Is Cartilage? Three different types of cartilage are found in the body. The smooth articular, or hyaline, cartilage covers joint surfaces. Its function is to provide a low-friction surface to help the joint withstand the stress and strain that occurs with daily weight-bearing activities such as walking, stair climbing, and exercise. The ultrastrong fibrocartilage is found in the knee and

9 i n t r o d u c t i o n 9 Our joints are complex structures that on a microscopic level involve the intricate interaction of cells (chondrocytes), water, collagen, and various proteins such as proteoglycans. within the vertebral disks and is used to help connect bones. And the stiff but soft elastic cartilage, which is used to keep open passageways in the body, is found in such places as the ear canals and the throat. Cartilage is made up of four ingredients: 1. Water. Most of cartilage, percent, is water, which lubricates the joints, cushions bones, and absorbs shock. 2. Collagen. The joint gains elasticity and the ability to be a shock absorber from collagen, a connective tissue that is arranged in a meshlike framework and holds bones and muscles together. 3. Proteoglycans. The large molecules called proteoglycans embed themselves securely into the collagen mesh and soak up water like a sponge (they can also release water). The proteoglycans allow cartilage to expand and contract, molding to the shape of the joint as the pressure within the joint capsule changes with activity. 4. Chondrocytes. The important chondrocyte cells break down and get rid of old proteoglycan and collagen molecules, forming new ones to take their place.

10 10 i n t r o d u c t i o n COPYRIGHTED MATERIAL How Osteoarthritis Starts Osteoarthritis occurs when the articular cartilage within the joint becomes disrupted (from a variety of reasons). These articular cartilage injuries can occur as a result of a sudden injury (such as a car accident or sports injury) or from ordinary wear and tear. Depending on the extent of the damage and the location of the injury, articular cartilage can sometimes heal itself, but complete restoration is difficult because articular cartilage has no direct blood supply. (Perhaps surprisingly, an injury that involves the bone beneath the cartilage has a better chance of healing despite being a deeper injury, because the underlying bone will provide some blood for the cartilage to renourish and possibly heal itself.) Osteoarthritis generally develops in three stages. First, there is a loss of cartilage or an injury to the cartilage within the affected joint. Second, the body tries to repair the cartilage and is unsuccessful; and third, the bone beneath the cartilage becomes sclerotic, meaning that it becomes abnormally thickened or hardened. Once your cartilage is damaged, the tissue that is laid down to try to repair the injury is always biomechanically inferior to articular cartilage. In addition, injured cartilage will occasionally lay down bone instead of cartilage in its attempt to heal itself, forming an irregular surface that doesn t glide smoothly against the cartilage on the opposing bone end. Sometimes, too, the cartilage doesn t try to repair itself at all. Pieces of loose cartilage and/or bone may break off and float freely around the joint (these are called loose bodies, or joint mice, and can sometimes cause the joint to lock). Now the bone ends are no longer well padded, and they start to rub against each other and begin to develop bony spurs (osteophytes). The joint space narrows, and the entire shape of the joint begins to change. All this from a little damaged cartilage. Signs and Symptoms of Osteoarthritis How do you know whether the joint pain you re suffering from is the result of osteoarthritis? Most of those with the disease have at least one of the following symptoms: Joint pain. Most people experience joint pain as a deep-seated ache. The feeling is different from a muscular ache and may come and go according to changes in the weather. People sometimes say, I can feel it in my bones when it s going to rain. The pain is