Osteoarthritis

Osteoarthritis (OA) is probably the most common cause of limb joint and spine arthritis in the human race. The prevalence of OA is in the region of 10-20% of the adult population. In the United States it has been estimated that more than one billion US dollars are spent annually on surgery of joint disease, the majority of these are due to OA. Similarly the health and economic impact in other countries are as dramatic. Our own gradually ageing population is not spared. The most common form of OA in Malaysia is knee OA.

What causes OA?

OA can be easily defined as joint failure. Most of the time doctors are unable to determine the exact cause of the disease. This is because there are many factors which influence whether an individual will get OA. However, in certain situations, OA can develop secondary to an illness. Examples of these are as a consequence of
1. Football injury
2. Rheumatoid arthritis
3. Infective arthritis.
People who are older and overweight are more prone to knee OA. Women tend to get it earlier and more severely than men and in some cases, OA may run in families.
What are the main symptoms?

OA is caused by mechanical failure of the joint probably due to repeated damage over time. The cartilage, which is responsible for providing the cushion for weight bearing, wears down and there is exposure of the underlying bony surface to direct pressure. The other structures around the joint are also affected. There is bony overgrowth, swelling of the joint with fluid and there will eventually be damage to the supporting ligaments and weakening of the muscles. Because of the above gradual changes to the joint the patient may experience initially a sense of unease when using the joint. It has been described as stiffness or gelling. There may be feeling of instability or insecurity on walking. Then there may be pain. The degree and duration of pain varies but in general, the pain of OA is worse on using or stressing the joint. This pain may be only present a few hours during waking hours or it may be present throughout. The common sites of OA are in the hands, knees and hips. Hand OA most often affects the base of the thumb and the joints at the end of the fingers. At times these joints become red, swollen and tender, especially when the condition first appears. Gradually, over several years, firm knobby swellings form on the side of the joints, called Heberden’s nodes. In hip OA, the pain is usually felt mainly in the front of the groin, but can be sometimes around the thigh, buttock or down to the knee. There will be discomfort on walking. In knee OA, the pain is often aggravated by use. The knee can often feel stiff, for example, after resting or first thing in the morning. Walking for a few minutes usually eases the stiffness. The pain can vary – there may be good days or bad days for no apparent reason.

How do I know if I have OA?

If you have pain or insecurity when you use your joints (especially knee joint) which has been present for more than 6 months, there is a high chance that you suffer from OA. You should consult your doctor who will examine you and this may be followed with an X-ray. Usually these steps should be enough to diagnose OA. Occasionally, it may be necessary to subject a patient to more sophisticated testing to find out more about the disease by using MRI, ultrasound, bone radiograph and arthroscopy. Sometimes a blood test may be useful even if only to exclude other conditions.

What treatment is there for OA?

Doctors usually use one of the many types of painkillers to relief pain. The ideal painkiller is that which provides pain relief with minimal side effects. Simple analgesics like paracetamol have passed the test of time to have the ability to alleviate pain without any serious adverse effects. However, other agents work on the prostaglandin system like non-steroidal anti-inflammatory drugs (NSAIDs), may also provide pain relief with easier dosing. One of the common adverse effects of NSAIDs is it may cause stomach irritation or stomach ulcer. COX II inhibitors are the newer NSAIDs with minimal stomach adverse effect. However, caution is needed to avoid the possible heart and kidney problem related to the long term use of these drugs. It is still preferable that pain relieving medication in OA be used “as and when required” rather than constantly.

In knee OA it is important to lessen the mechanical burden on the joint. Weight reduction is essential if the patient is overweight. Muscle strengthening (quadriceps strengthening) is important to retard the progression of knee OA, it is useful to get help from a physiotherapist who is able to advise on muscle exercises and knee protection aids.

Sometimes when there is a lot of built up fluid in the joint, it is useful to remove the fluid and inject the joint with an anti-inflammatory agent like triamcinolone. Other injections that have been used in knee OA are those that contain hyaluronic acid (this method is called viscosupplementation), a substance that is naturally produced in the fluid present in joints. Viscosupplementation can ease mechanical pain related to knee OA in some patients; this treatment however has to be repeated when it is needed as the good effect is not permanent.

If the above measures fail to control pain or improve disability, some patients are referred for surgery. The surgeon can remove loose cartilage fragments or perform a knee washout for symptomatic relief. Joint replacement surgery can be offered to patients who are still getting severe pain despite other treatments. In these cases, it is remarkably effective in relieving pain and increasing mobility.

Over the last few years there have been several promising agents may help to retard the progression of OA, in particularly knee OA. Glucosamine sulfate, chondroitin sulfate and diacerein are agents with the ability to provide pain relief in knee OA; in some cases, they may slow down the progression of cartilage degradation. But however, none of the existing agents can build cartilage and they should be used to supplement the non-drug measures such as weight reduction and quadriceps exercise.
Exercises to help your knees.

These exercises should be performed 20 times each, twice a day.

Strengthening Thigh Muscles

	1. Sit with your legs straight on the floor, bed or couch. Pull the foot up towards you and then press the knee against the floor, tightening the thigh muscles. Hold this for a count of live, and then fully relax.
	2. Repeat as above, then lift the leg off the floor keeping the knee straight and raise it two or three inches only. Hold for a count of five.
	3. Repeat as above but put a rolled towel under the knee. Straighten the knee, hold it straight for a count of five. This is the only time a support is permitted under the knee. (Never sleep with a towel under the knees. Although this may be more comfortable, the likelihood of increasing deformity is high.)
	4. Sit with knees bent over the edge of the bed, then fully straighten the knee and hold for a count of five. When proficient at these exercises, add a slight amount of weight to the foot. Oven gloves or socks tied together hung over the ankles with small weights in them might be a good starting point. Any increase in weight should be gradual.

Can OA be prevented?

This is a mainly hypothetical question. However, certain modifications in lifestyle early in life may prevent people from suffering the severe effects of OA in later life. If one is overweight, weight reduction through sensible dieting and regular exercise are important. The key emphasis is good health rather than absolute weight loss. If a certain weight bearing joint is damaged, care must be taken to rest the joint when it is acutely sore and then rehabilitate it through expert advice.

There are certain activities or occupations which make someone more likely to develop OA. Knee bending activities like stair climbing have been shown to increase the likelihood of one developing knee OA. Farmers in Britain are more prone to develop hip OA. Soccer players are more likely to suffer from knee OA if they had meniscal injuries during their careers. There also appears to be an association of knee OA with flat-footedness and knock-knees. Though research is needed in this area, correct and supportive footwear from early and throughout life may well delay the development of unequal biomechanics which may lead to OA. Examples include the use of medial arch supports and wedge heels.

Common questions regarding OA

Can I play sports if I have OA?

In general, good physical health and muscle conditioning are good for the joints. Patients with OA are encouraged to exercise but where possible to avoid contact sports and high impact ones. Swimming and walking are excellent forms of exercise for the joints.

What about diet and arthritis?

There is little evidence that diet makes a difference. Patients are advised to avoid putting on weight as this puts pressure on the joints concerned.