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| Osteoarthritis |
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How does it affect the joints?
Osteoarthritis is the most common form of arthritis. Almost half of all people over the age of 60 and virtually all over the age of 80 will have osteoarthritis. Osteoarthritis has been called "wear and tear" or "degenerative" arthritis and there is growing understanding that it is an inflammatory arthritis. It occurs as a result of mechanical breakdown in the structures affecting the joints. This happens most often in the large weight bearing joints - the knees, hips and spine. It often occurs in the hands, but rarely in the feet or ankles apart from the big toe. Except as a result of injury or stress, osteoarthritis seldom affects the wrist, elbow, shoulder or jaw. How does it affect the joints?In a normal joint a firm rubbery material called cartilage covers the end of each bone. This joint cartilage acts as a cushion, or shock absorber, providing a smooth, slippery surface between the bones. The bones in the joints are held together by ligaments and tendons, which act as strong flexible cables and allow movement in the right directions. All of these are completely enclosed in a capsule and the joint is lined by a thin synovial membrane which releases a slippery fluid into the enclosed joint space. The first major change in a joint with osteoarthritis is that the smooth cartilage surface softens and becomes pitted and, with time, sections of cartilage may be worn away completely, leaving the ends of the bones unprotected.(diag) Without their normal gliding surface, joints become painful and difficult to move. As the cartilage breaks down further, the joint loses its shape, the bone underneath thickens and grows out at the sides (like spurs) further reducing movement.
What causes osteoarthritis?For years osteoarthritis has been considered a result of normal wear and tear during a person's lifetime. But researchers now recognise that several factors lead to its development rather than one single cause. These are:
Although it seems that only those 'over the hill' get osteoarthritis, it has been detected in some people before they reach 21 years old! It may be more common in older people, but age is definitely only one of the causes. An injury such as a fracture or torn cartilage may result in osteoarthritis later in life. It may follow unusual or prolonged strain on a joint either in work or sport. Being overweight over a long period of time is also considered to speed up the process. Some forms of osteoarthritis do run in families, especially those that affect the small joints of the fingers. In general heredity is not a major reason for having osteoarthritis. However, the precise causes of mechanisms leading to osteoarthritis are still unknown and research is continuing. New Zealand is leading the world in researching the cells within cartilage which first break-down, leading to osteoarthritis. Osteoarthritis is not caused by bacteria or poisons in the blood, acids in the body, diet deficiencies or excesses, gland abnormalities, the weather, exercise or sudden shock, although some of these may influence the pain due to osteoarthritis. Symptoms of osteoarthritis
Osteoarthritis is often very mild and does not always have many symptoms even though xrays may show joint changes. Most older people will experience some twinges of joint pain which will soon go away or which are fully eased by rest and a little warmth. Sometimes, however, the symptoms are more pronounced and may include any one, or all of the following: Pain and stiffnessPain in a joint tends to increase with use and to decrease with rest. Stiffness, however, usually occurs when the joint has been rested. SwellingThis occurs when irritation of the synovial membrane causes an outpouring of extra joint fluid - just as your eye produces tears when irritated. But in the joint, the extra fluid cannot escape as easily. This occurs, most often, in the weight bearing joints of the hips, knees and spine. Bony growthsA fairly common complication of osteoarthritis is the appearance of bony growths (called nodes) in the finger joints. These occur more commonly in women and sometimes occur as early as age 40. Sudden redness, swelling, tenderness and aching may be noticed. Although these nodes may make the finger joints painful, most people continue to have good use of their hands. The pain can be relieved by appropriate treatment in the early stages. Some people do not feel any pain with these nodes and many people with this kind of osteoarthritis may never have serious problems with any other joints.
DiagnosisThere are no specific blood tests for osteoarthritis although sometimes these are taken to exclude other forms of arthritis. The doctor will ask you to describe possible physical stress or injury that may have led to your pain. A physical examination will be carried out with close attention to your affected joints. X-rays will be helpful in the diagnosis, but these are not a good guide as to the severity of future symptoms. They may show extensive change, but this does not always mean pain or disability. TreatmentTreatment cannot reverse the changes that have already taken place in the joints, but there is still a lot that can be done to slow down the disease process, and control the symptoms. It is important to gain proper medical attention so the most disabling effects of the disease can be avoided. Neglect and delay are the worst enemies in overcoming osteoarthritis. Your doctor is likely to advise a variety of treatments that take into account the severity of the disease, what joints are affected, your symptoms, other medical problems, your age, occupation and every day activities. These may include:
Each of these treatments is discussed in more detail in other sections of this web-site. Osteoarthritis can have a big impact on your lifestyle but you can make a big difference in how you manage day to day activities. Your occupational therapist, physiotherapist and other allied health workers can support you with a programme of exercise, aids and appliances and helpful guidance which will make a difference. |
