Osteoarthritis

This article was last reviewed on

23 April 2018.

This article waslast modified on 5 February 2019.

What is it?

Osteoarthritis (OA) is a common joint disease due to wear and tear of joint cartilage. The joints most commonly affected are those of the hips, knees, hands, big toe, and spine..Osteoarthritis (OA) is the most common form of arthritis, affecting around 8 million people in the UK. Anyone can get OA however it is more common in women, those over 40 and if you are overweight. It is also more common if you have a manual job where you do repetitive movements or lift heavy objects which can put excess strain on the joints. Additionally, OA is more likely if there has been a previous injury to that joint or if the joint was damaged by another disease. This includes diseases such as gout or rheumatoid arthritis but also congenital defects of the joint (i.e. defects you are born with) or joint diseases that develop in childhood e.g. Perthes’ disease of the hip.

Genetic factors also play a role in OA therefore it is more common in those with a family history of OA. Genetic factors seem to be more common in those with a form of OA of the hands called nodal osteoarthritis which is more common in women. This causes nodules in the hands that are often very painful. There is also some evidence to show that rarer forms of arthritis that start at an earlier age may be related to genetic defects in collagen (one of the key components of cartilage). Genetic factors play a smaller, but still significant, part in osteoarthritis of the hip and knee also.

OA is a chronic, progressive disease. The joints usually have cartilage, a protective lining called synovium and a fluid called synovial fluid. These provide a smooth, low-friction surface between the ends of bones. When cartilage loses its elasticity and wears down, joint movement becomes less smooth. Eventually, cartilage can completely erode and the opposing bone ends rub together. This can cause the formation of new bone spurs called osteophytes at the edges of the joints. The synovium can also swell and thicken causing swelling of the joint. In addition the ligaments and connective tissue around the joint can thicken and contract as they try to stabilise the joint.

In view of these changes the most common symptoms of OA are pain usually at the end of the day or when moving the joint; stiffness that is worse in the morning and/or after rest and joint swelling. The wearing down of the bones if cartilage is lost, and the bony spurs, can also cause the shape of the joint to change. This will then affect its function. Therefore, in addition to pain and stiffness, the joint may not move as well or as far as normal. The muscles around the joint may also appear thin and wasted. This may cause the joint to “give way” or collapse when using it. The pain with OA may be intermittent but may become constant. In addition some people report that their pain is worse with cold or damp weather or if they have done a lot of exercise or activity.

About Osteoarthritis

Tests
Blood tests are not used to diagnose the disease but may be used to monitor side effects of various treatments and help differentiate osteoarthritis from other forms of arthritis such as rheumatoid arthritis. The diagnosis of OA is usually based on someone’s personal and family medical histories and a physical examination.

Signs that your doctor may look for on a physical examination are:

tenderness over the joint

cracking or grating of the joint (crepitus)

swelling or fluid in the joint ( effusion)

bony deformities of the joint

inability to move the joint to properly or pain when moving

muscle wasting around the joint

In the case that the joint is swollen with fluid sometimes a small sample of fluid from the joint may be taken to help exclude other conditions. It is not necessary for the diagnosis of OA however.

Imaging

Usually the diagnosis of OA is based on the clinical findings from the history and examination. Occasionally x-rays may be used to help in the diagnosis.
X-rays of the affected joints mayshow loss of cartilage and a narrowing of the joint space. It may also show bony spurs (osteophytes).

MRI imaging may also be used, typically in knee symptoms, to show cartilage and soft tissue damage that cannot be seen on a standard x-ray. This can help differentiate osteoarthritis from other conditions such as a torn cartilage that can also cause knee pain. It may also be helpful in some people with back symptoms.

It is important to realise that x-rays and MRIs are not always helpful or necessary in the diagnosis. As these techniques involve a dose of radiation to a patient which itself can cause a risk (albeit small) it would only be requested if it will change the management of that patient. In addition the findings on x-rays do not always correlate to the level of pain a patient reports. Therefore a patient with severe pain may only have mild changes on an x-ray and vice versa. Therefore usually the decision on how to treat a patient mostly depends on the symptoms the patient is experiencing and not on the imaging result.

In view of this, if the diagnosis is clear, or if the result would not change the treatment of the patient (e.g. if the management would just involve painkillers in any case based on the severity of the patient’s symptoms) it may not be requested. However, if the symptoms are severe and/or are in a joint that could be operated on (e.g. hip or knee) imaging may be requested to assess how badly the joint is damaged to see if surgery could be an option.
Treatments

Osteoarthritis may cause very little symptoms for some and severe symptoms for others. People often worry that the condition may worsen in time causing them severe symptoms or disability in the future. It is impossible to predict how osteoarthritis will progress in each individual. It can develop quickly sometimes and cause a lot of damage to a joint in a short space of time in some. However it can also develop more slowly and the changes to the joint can be more subtle, which is more common. In some patients the symptoms become a lot worse in time and progress but in others the symptoms can deteriorate slightly and then remain the same or even improve.

Unfortunately OA cannot be cured unless the affected joint is replaced by an artificial joint and not all joints can be replaced. Even if a joint is replaced it has a limited life span and therefore this is usually done as a last case resort in severe cases. The goals of treatment for osteoarthritis (OA) therefore are to relieve pain, maintain and improve joint mobility, and to minimise further joint damage.

Exercise

Being completely inactive can cause further muscle wasting and make the stiffness in your joints worse. Therefore exercise is one of the best therapies for those with OA. This should involve strengthening exercises for the muscles around the joint and aerobic exercise. Your doctor may refer you to a physiotherapist to have specific muscle strengthening exercises or may give you an exercise leaflet themselves. Aerobic exercise can help you lose weight, taking some stress off the joints. Weight loss if you are overweight is an important management plan in OA. However aerobic exercise also releases chemicals that can reduce pain such as endorphins and is good for your general wellbeing so it is also recommended for these reasons.

It is important to achieve a balance in OA between resting and exercising so that you are still active but do not do so much as to cause unnecessary pain. It is recommended that you do a small amount of exercise often. Low impact exercises (as opposed to high impact exercises involving running or jumping) are preferable to avoid any further damage to the joints. Therefore swimming where the weight of the body is supported by the water is often recommended. There is also evidence that Tai Chi can help reduce pain levels in patients with OA.

Other non-pharmacological therapies

Heat therapy with a hot water bottle or heat pad as well as cold therapies with an ice pack can also help with the pain of OA. Massage can also help relax any stiff muscles around the joint. Knee braces can also sometimes help with the pain of OA of the knee. The dietary supplements glucosamine and chondroitin are available 'over-the-counter' in many pharmacies. These are compounds usually found in joint cartilage but the studies as to whether they help or not have been conflicting.Acupuncture can also help with the pain of some forms of OA, in particular osteoarthritis of the knee. Chiropractors and osteopaths can sometimes help with OA pain in the neck and the back. If choosing these therapies it is important to ensure you choose a practitioner who is registered with the appropriate regulatory body.

Medications

Pain killers are commonly used to alleviate the pain with OA. It is best to use them occasionally when the pain is very bad or if you will be doing a lot of activity such as exercise where possible.

Paracetamol, which can be bought over the counter, is probably the safest one to use. Anti-inflammatory drugs (NSAIDS) such as ibuprofen, which can also be bought over the counter, can also be helpful. NSAIDS however can have side effects especially with long term use so if you need to take them for more than a week it is best to consult a doctor before continuing with this long term.

Anti-inflammatory gels such as ibuprofen gel are an excellent option causing fewer side effects than anti-inflammatories taken in tablet form. These can also be bought over the counter and rubbed into the affected joint. Because of this they are mostly effective for OA of the hands and knees where the gel can penetrate the joint easily and not for deep joints such as the hip. A cream called capsaicin cream can also be used in this way although it is only available on prescription.

Other painkillers such as codeine can occasionally be used for pain. However these can be addictive and cause side effects so long term use should be under supervision of a doctor. They tend to be used less often due to these reasons.

Other treatments such as steroid injections directly into the affected joint can also help relieve pain. However, they are not suitable for all and only certain joints can be treated in this way. In addition the pain relieving effects are not permanent and the injections may have to be repeated.

Surgery

In cases where the symptoms are very severe and the joint is severely damaged, surgery may be recommended. This may include key-hole surgery where any fluid in the joint can be drained and any debris removed. It may also include more complex surgery such as joint replacement. However, not all joints can be treated in this way. Occasionally joints may be fused together to stop any movement. Although this limits the pain caused by the movement of the damaged joint it will obviously result in further loss of movement so is not always ideal.