Your GP will probably be able to diagnose Osteoarthritis if you present with these symptoms and signs. Your GP may examine your joints to check for tenderness, swelling and bony growths and may want to see if your movement is restricted. Your GP may also ask if your joints ‘creak’ or ‘crunch’ when you move them and may suggest a blood test to rule out other inflammatory forms of arthritis, such as RA. An x-ray may be requested to confirm OA, because it shows changes to the bone caused by cartilage thinning, calcification and bony outgrowths on the joints. However, an x-ray can’t predict the level of pain and disability you might experience. Occasionally an MRI scan may be used - this shows the soft tissues such as cartilage, muscles and tendons that don’t show up on an x-ray.
What causes osteoarthritis?
There is no single cause of OA, but there are several factors that can raise the risk of developing it.
Although OA can sometimes develop in young people, it more commonly develops from the late 40s onwards. This is probably down to changes in the body that tend to develop as the body ages, such as the muscles weakening, weight gain and a reduction in the body’s ability to self-heal. However, OA is not an inevitable part of ageing: keeping your weight down, remaining active and avoiding joint strain can all help to keep symptoms at bay.
Before the age of 45, OA is more common in men. However, among the over 55s, women are more likely to be affected, which suggests a link with the menopause; some research suggests that oestrogen protects cartilage from inflammation and this effect is lost after the menopause. Another factor that has been suggested is that women’s tendons are more elastic than men’s to enable them to give birth; this means that their joints are less stable and more prone to injury. Some experts link it to female anatomy; women’s hips are wider than men’s to make pregnancy and childbirth easier, which means their knees are not quite as aligned with their hips and this puts more strain on the knee joints. It may also be because women have smaller, weaker bones than men, which are less able to withstand wear and tear.
According to Arthritis Research UK, twice as many women as men develop OA in their hands and four times as many women as men have OA in their knees. Equal numbers of men and women develop OA in their hips.
Being overweight puts extra strain on the weight-bearing joints, especially the hips, spine and knees, and not only greatly increases your chances of developing OA, but also makes it worse once it has developed.
Joint overuse or stress
If a joint is overused, or put under stress – for example through bad posture, repetitive use of the finger joints whilst using a keyboard at work, or through participating in a sport, it is more likely to develop OA at some point.
If you injure a joint, for example whilst playing sport, or through an accident, OA may develop in the affected area later on in life.
Other forms of arthritis
Having another form of arthritis, for example arthritis of the knee or gout, increases the risk of developing OA.
Nerve conditions such as peripheral neuropathy, which affects the nerves in limbs, may raise the risk of developing OA. Peripheral neuropathy can be caused by other health problems, such as diabetes or alcoholism.
Some rare forms of OA that develop in young people and affect the production of collagen (a major component of cartilage) have been linked to particular genes. A form of arthritis known as nodal osteoarthritis, which tends to affect the hands of middle-aged women, has a strong genetic link. However, in general, heredity plays a minor role, compared to the other factors mentioned above.