Living Well with Arthritis: A Sourcebook For Understanding And Managing Your Arthritis

In my years in practice as a rheumatologist, I have noted that among patients and the medical community alike, there are some major misconceptions about arthritis.

The most common misconception may have come from the slogan “Arthritis: there is no cure.” Many equate the slogan to “Arthritis: there is no treatment.” Time and again, I have seen patients who have been told, “It’s arthritis and nothing can be done, so go home and live with it.”

The most dangerous misconception is that arthritis is not a serious disease. In fact, arthritis is the number one cause of disability in North America and affects people of all ages: it is not only a disease of the old.

It is also not true that all arthritis is the same: there are approximately 100 forms of arthritis. The most common form is osteoarthritis, which affects approximately 55 percent of us by age 65. Rheumatoid arthritis is less common, but does affect approximately 1 percent of the population; most of these people begin to be affected between the ages of 30 and 50.

What Is Arthritis?

Arthritis is derived from the Greek arthron (joint) and itis (inflammation). Therefore, arthritis by this definition would mean inflammation within a joint.

A joint is the structure that connects two bones. The joint is held together by ligaments and tendons and a capsule. The ends of the bones are covered with cartilage and the capsule is lined by a synovial membrane (see illustration below).

Cartilage is the white glistening stuff you have probably seen at the end of a chicken bone. It allows bones to glide smoothly over each other, with synovial fluid acting as a lubricant, and also absorbs the forces that impact on the joints. Cartilage is made up of collagen (protein fibres), water, chondrocyctes (the cartilage cells), and pro­teoglycans. Normal cartilage is essential to a well-functioning joint.

In arthritis, the cartilage may have become damaged. It may have thinned and eventually disappeared, leading to bone rubbing on bone. The damage to cartilage can occur in different ways, and this is why we have different forms of arthritis. The two major types of arthritis are degenerative (wear and tear) and inflammatory.

Degenerative arthritis is known as osteoarthritis. In this form of arthritis, the primary problem occurs in the cartilage. The cartilage may be damaged by a previous injury to the joint, or by a chronic stress on the joint (as in osteoarthritis in the knees of obese females). The cartilage itself may be abnormal because of a genetic defect that can lead to premature osteoarthritis in whole families. Degenerative arthritis used to be referred to as “non-inflammatory arthritis,” however, researchers have become increasingly aware that inflammation is an important factor in the progression of osteoarthritis.

In inflammatory arthritis, the inflammation in the joint causes the damage. The signs of inflammation are redness, heat, swelling, and pain. In the joint, this leads to loss of function. An example of an inflammatory arthritis is rheumatoid arthritis, in which the immune system is overactive, leading to inflammation mainly (but not always) in the synovium and the joint fluid. The inflammation itself causes pain and a poorly functioning joint, but ultimately, the cartilage is damaged and the joint is finished. Rheumatologists want to treat the inflammation before this happens.

Other conditions such as bursitis or tendonitis are not arthritis. They do not occur in the joint. They are referred to as soft tissue rheumatism, and are discussed in Chapter 2, “Not All Musculoskeletal Pain Is Arthritis.”

Osteoarthritis

Osteoarthritis is a common disease characterized by pain in the joint, stiffness, and loss of movement. It is also referred to as degenerative joint disease and osteoarthrosis. It is a slowly evolving disease that is part of the aging process. Autopsy studies have shown that by age 40, 90 percent of all persons have changes in the weight bearing joints (knees, hips) although, of course, all of these people did not have symptoms. By age 65, approximately 60 percent of us will have symptoms of osteoarthritis.

Not only is osteoarthritis common, but it has been around for a long time: dinosaur bones and Egyptian mummies all show evidence of osteoarthritis. Yet we still understand very little about this disease and specific treatment has eluded us.

Osteoarthritis is classified as a non-inflammatory arthritis. This implies that there is no inflammation, but recent research shows that this is not true. The factors that cause the disease (which starts in the cartilage) are not completely known. It is known that early on, although there is no inflammation yet, the cartilage starts to wear away and fragment, and the bone under the cartilage thickens. Loose pieces of cartilage cause an immune response and inflammation, which is known to be responsible for some of the progression of the disease. As the disease evolves, the cartilage thins and disappears. As well, new bone is formed at the joint edges (this is referred to as an osteophyte) and the bone under the cartilage continues to thicken.

Dr. Stein discusses in detail some of the causes of osteoarthritis in Appendix I, “Heredity and Environment,” but we will summarize some of the causes here:

•   Trauma may lead to osteoarthritis (whether this is sudden, severe trauma, or a repetitive strain such as seen in obese females and osteoarthritis of the knees).

•   The tendency to develop osteoarthritis can also be passed from parent to child in the genes, as we see with congenital hip dysplasia or erosive osteoarthritis of the hands (which seems to be passed from mother to daughter most commonly).

Classification of Osteoarthritis

Generally, osteoarthritis is divided into primary and secondary forms: primary osteoarthritis has no underlying cause; secondary osteoarthritis may be a result of trauma, previous inflammatory diseases such as rheumatoid arthritis, or crystal induced diseases.

Primary osteoarthritis is further broken down into the subsets of generalized osteoarthritis, erosive osteoarthritis, diffuse idiopathic skeletal hyperostosis, and chondromalacia patellae. These are discussed below.

Generalized osteoarthritis

Generalized osteoarthritis refers to osteoarthritis that affects the DIP (distal interphalangeal), PIP (proximal interphalangeal), and CMC (carpometacarpal) joints of the hands, but may also involve the neck, low back, hips, knees, and big toes (see illustration on page 5). There is usually a period where the joints are inflamed. Generalized osteoarthritis occurs primarily in middle-aged women.

Erosive osteoarthritis

This particular variant, which is usually inherited, involves the DIP and PIP joints and is associated with swollen, painful finger joints. The X-rays show erosions in the bone.

Diffuse idiopathic skeletal hyperostosis (DISH, or Forestier’s disease)

This is arthritis in the spine, in which huge flowing bone spurs (osteophytes) can be seen on X-ray between the vertebrae of the thoracic spine. Large bony spurs can also occur elsewhere, such as on the heels. Stiffness of the spine is the predominant symptom and pain may be surprisingly minimal.

Chondromalacia patellae

This is a condition seen in teenage girls, and more commonly in those who have had repeated trauma to the knee. They have knee pain that is made worse with squatting, kneeling, and going down stairs. What has happened is that the cartilage behind the kneecap has softened and split into fibres, and the kneecap has been allowed too much sideways...