Osteoarthritis, also known as degenerative joint disease, is a condition that causes the joints to become painful and stiff. It is the most common type of arthritis, and occurs when the cartilage (a smooth, cushioning substance) on the end of bones becomes permanently damaged.
Cartilage helps to protect the ends of the bones where they meet to form joints. It also allows joints to move smoothly. When cartilage is damaged it loses its smooth surface and becomes rough or uneven, leading to problems in the affected joints.
Osteoarthritis can affect any joint in the body, but most commonly affects the knees, hips, hands, big toes and spine. Osteoarthritis affects around 1.8 million Australians.
The symptoms of osteoarthritis will vary from person to person, and may depend on which joints are affected.
The most common osteoarthritis symptoms include:
- Painful joints: pain often worsens during or after movement, or after periods of inactivity.
- Stiff joints: these may be worse first thing in the morning and after periods of inactivity or towards the end of the day.
- Loss of flexibility: the affected joints may not be able to move as far as they used to.
- Grating feeling or crackling sounds in the joints.
- Change in appearance: affected joints may appear slightly larger than they used to (swollen joints) or develop hard bumps on them; some joints start to look like they are bending sideways e.g. the finger joints and the base of the big toe. Bony enlargement of the small joint at the end of the fingers is called a Heberden’s node. Bony enlargement of the middle joint of the finger is called a Bouchard’s node. Osteoarthritis of the joint at the base of the big toes leads to the formation of a bunion.
- Weakness or wasting of the muscles around the affected joints.
Which joints are affected by osteoarthritis?
The joints most commonly affected by osteoarthritis are: the hands; the spine in the neck region (cervical spine); the lumbar spine (lower back); the knees and the hips.
Osteoarthritis develops when the cartilage at the ends of bones becomes permanently damaged. The joints are constantly exposed to low levels of stress and damage throughout life, and the body can usually repair minor damage without any problems. However, sometimes the damage can’t be fully repaired, leading to a permanent breakdown of the cartilage.
Several factors – or a combination of these – may increase the risk of osteoarthritis, for example:
- Joint injuries: e.g. sporting injuries, accidents or joint surgery
- Overuse of joints: osteoarthritis is more common in people who have jobs that place repeated stress on the joints e.g. lifting heavy loads, kneeling or squatting; overusing a joint that has been injured and is not fully healed can also increase the risk of osteoarthritis.
- Obesity: excess body weight puts added stress on the joints in the legs, hips and spine. And, in addition to the wear-and-tear on joints that occurs from carrying excess weight, fat cells release chemicals that promote inflammation and can damage the joints. A high level of inflammatory chemicals in the body is associated with loss of cartilage. So, recent research is showing that just the very state of being overweight or obese can cause damage to your joints, which may explain why joints that aren’t weight bearing, such as in the hands can also be affected by arthritis.
- Family history: osteoarthritis can run in families and some types have a strong genetic component.
- Age: the risk of developing osteoarthritis increases with age (but osteoarthritis is not actually a normal part of getting older).
- Female gender: Being female carries a higher risk of getting osteoarthritis than being male.
- Other medical conditions: joints that have been damaged by other conditions such as rheumatoid arthritis are more likely to develop osteoarthritis (this is often known as secondary arthritis). Some people are born with abnormalities of the joints — for example, Perthes’ disease of the hips — that cause early joint degeneration leading to osteoarthritis.
Who gets osteoarthritis?
Osteoarthritis can affect people of any age but it is more common in people aged over 40 years or those who have had joint injuries. If you have a family history of arthritis, you will be more likely to get it yourself.
There is no one test for osteoarthritis. A doctor will diagnose osteoarthritis based on the symptoms and a physical examination of the joints. A doctor may suspect a person has osteoarthritis if they are aged over 40 years and have pain that gets worse with activity, and joint stiffness in the mornings that lasts less than 30 minutes (although some people with osteoarthritis may not have any joint stiffness). Joint stiffness that lasts for a longer time may indicate another joint problem, such as rheumatoid arthritis. [link out]
A doctor may or may not order X-rays. Cartilage is not visible on normal X-rays, but when cartilage is damaged the space between the bones may be narrower. X-rays may also show any bony protrusions (bone spurs) that can develop with osteoarthritis. However, if joint damage is seen on an X-ray it does not mean a person has or will have a lot of pain and stiffness; and people with a lot of pain and stiffness may not have any changes visible on X-ray.
Blood tests do not diagnose osteoarthritis, but may be done to rule out other diseases.
Because osteoarthritis is a degenerative disease – it will worsen over time and can cause disability and difficulty carrying out normal daily activities.
There is no cure for osteoarthritis, but treatment can help to control the symptoms, such as pain and stiffness, and prevent disability from developing. Arthritis treatment may include:
- Weight loss: In people who are overweight or obese, losing weight can be very helpful in reducing arthritis symptoms such as pain and strain on the joints and reducing the release of inflammatory chemicals from fat cells, which cause deterioration of the joints. Obesity is the most important risk factor for arthritis that can be changed. Even losing 6kg over a year can make a big difference in reducing pain and improving mobility in people with knee osteoarthritis.
- Exercise: Regular exercise is one of the most important treatments for someone with osteoarthritis. An exercise program should be developed with a health professional e.g. a physiotherapist, and be tailored to your situation, ability and interests. The programme should include both strengthening and flexibility exercises. Exercise has been proven to reduce arthritis symptoms such as pain and improve the function of knee and hip joints with osteoarthritis. Flexibility and stretching exercises can increase the range of motion in your joints, making them more flexible.
- Medicines: Pain relieving medicine is often required. Unfortunately, despite being the first choice of medicine for arthritis for some time, paracetamol (e.g. Panadol) has been shown not to be effective for managing osteoarthritis pain and only marginally better than placebo (dummy drugs). Non-steroidal anti-inflammatory drugs (NSAIDs) reduce pain and swelling but may only be used for short-term relief (e.g. diclofenac, ibuprofen). NSAIDs are available as rub-on creams (topical NSAIDs), as well as tablets, but you should use one or the other, not both together as this raises the risk of problems. It is important for people to be aware that NSAIDs are not suitable for everyone and may cause other problems. Stronger medicines may be prescribed for people with severe pain.
- Corticosteroid injections: Corticosteroid is a type of medicine that can reduce pain and swelling. People with severe osteoarthritis may need an injection of corticosteroid into the joint, which can provide a few weeks of relief from pain and improve the function of the joint.
- Hyaluronan injections: Also known as viscosupplementation, these are injections of a type of natural joint lubricant into the affected joint. The hyaluronan allows the surfaces of the joint to move more smoothly against each other. Results from using these injections have been mixed.
- Topical capsaicin: Capsaicin is a compound derived from hot pepper plants. Capsaicin creams can be rubbed into the affected joint a few times a day and provide pain relief for some people. They can be bought from the pharmacy and don’t need a prescription. Some people can’t tolerate the cream on their skin due to allergy or burning.
- Devices: braces, walking sticks (used in opposite hand to affected hip or knee), special shoe insoles or splints may be helpful.
- Physical therapy: a physiotherapist can help to ease joint stiffness and pain, and provide exercises that strengthen the muscles around the joints.
- Heat or cold packs: applying heat or cold packs may help pain and stiffness in some people, especially during a flare up.
- Acupuncture: this may provide some relief from arthritis pain.
- TENS (transcutaneous electrical nerve stimulation): TENS machines, which send electrical pulses to the nerve endings in the skin, work by interfering with the pain signals in your body. Some people find them effective for relief of arthritis pain, but the evidence is not clear.
- Glucosamine and chondroitin: most key bodies, such as the Australian Rheumatology Association, do not recommend the use of glucosamine or chondroitin to treat osteoarthritis. The weight of evidence is that they do not work, other than a placebo effect for some people. There is the potential for severe allergic reactions in people with shellfish or seafood allergy.
- Fish oil: it is conditionally recommended against for osteoarthritis as the quality of evidence is very low.
- Surgery: some people with osteoarthritis may eventually need joint replacement surgery, such as a hip replacement or knee replacement.
- Stem cells: companies are offering stem cell treatments in Australia for osteoarthritis, but these have not been properly evaluated and the Federal Government has issued warnings that patients who undergo experimental treatments may be at risk of serious injury.
You may be able to reduce your risk of developing osteoarthritis by:
- Maintaining a healthy weight or losing weight if you are overweight or obese.
- Exercising to keep your joints healthy, and maintaining good alignment when you are exercising.
- Keep your muscles strong – they will help support your joints.
Living well with osteoarthritis
Most people with osteoarthritis can live healthy and active lives by:
- Learning about osteoarthritis: find out more about the condition and what may help arthritis symptoms. People should talk to a health professional about where to find reliable and accurate sources of information.
- Taking an active role in treatment: it’s important to do regular exercise, maintain a healthy weight, eat well, get plenty of rest and follow advice from health professionals.
- Looking after their joints: avoid or modify things that place a lot of stress on the joints (e.g. someone with osteoarthritis in the knees or hips may find swimming or cycling is more appropriate than running).
- Talking to other people: many people with osteoarthritis find it helpful to talk to others who have the same condition. This may be through support groups, patient organisations or individual friends.