Osteoarthritis | Pona ngoikore

Also known as OA, degenerative arthritis or degenerative joint disease

Osteoarthritis (pona ngoikore) is the most common form of arthritis. It causes pain, swelling, and reduced movement in the joints.

On this page, you can find the following information:

Key points

  1. Osteoarthritis is a condition affecting joints. Changes affect all parts of the joint including cartilage (the slippery tissue that covers the ends of bones), joint linings and ligaments and muscles. 
  2. Osteoarthritis can occur in any joint, but the most common joints to be affected are hands, fingers, knees, hips, spine (neck and lower back).
  3. Osteoarthritis is more common in people who are older but can also affect younger people, it has been found in some people under the age of 21. 
  4. You are more at risk for osteoarthritis if you are overweight or have had a joint injury.
  5. Exercise and weight loss (if required) in conjunction with other treatments can help to improve mobility and daily functioning, reduce pain and flares, and prevent your osteoarthritis from worsening.
  6. Not everyone who has early osteoarthritis will develop severe osteoarthritis.

Image: 123rf

How does osteoarthritis affect joints?

Changes with osteoarthritis affect all parts of a joint. Cartilage is a firm rubbery material that covers the end of each bone and provides a smooth, slippery surface for movement. With osteoarthritis the cartilage can become softer, then pitted, and eventually be lost from the bone ends. Bone can become thicker and spurs can form at joint margins, often where tendons or ligaments attach. Joint linings can become inflamed and thickened. Muscles around the joint can become weaker and nerves can become more sensitive. These changes can reduce movement and result in pain.

Osteoarthritis most commonly affects the knee joint, followed by the hip, and then other joints such as the small joints of the hands and the spine.

What causes osteoarthritis?

Previously osteoarthritis was thought to be a result of normal wear and tear during a person’s lifetime. But researchers now recognise that several factors lead to its development, including:

  • Being overweight over a long period of time.
  • Damage by joint injury, such as a fracture or torn cartilage.
  • Infection in the joint or bone.

Some forms of osteoarthritis do run in families, especially the form that affects the finger joints. However, in general, heredity is not a major reason for having osteoarthritis. The precise causes and mechanisms leading to osteoarthritis are still unknown.

What are the symptoms of osteoarthritis?

Osteoarthritis progresses slowly and develops over many years. It is often very mild and does not always have many symptoms even though x-rays may show joint changes. Sometimes, however, the symptoms are more pronounced and may include any or all of the following:

Symptoms Description
Pain and stiffness
  • Joint pain can increase with use of the joint. It does not indicate increased damage to the joint.
  • Stiffness usually occurs when the joint has been rested.
  • Swelling occurs when irritation of the synovial membrane (joint lining) 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, and so it causes swelling.
  • This most often occurs in the knees.
Creaking or cracking
  • Creaking or cracking sensations with joint movement may reflect a loss of the cartilage and the smooth gliding movement of the joint that cartilage should provide or soft tissues moving past each other.
Bony growths
  • As a result of the changes in the affected joint, the ends of the bones can change shape, forming bony spurs called osteophytes.
  • These may be felt as hard and bony swellings. They are especially apparent when osteoarthritis affects the finger joints.
Muscle weakness
  • The joint may feel unstable as if it is about to give way.

These symptoms can make it difficult for people with osteoarthritis to carry out many of their regular activities and can cause sleep problems, anxiety, depression, tiredness or fatigue.

If you are concerned about symptoms of osteoarthritis, see your doctor without delay. The sooner osteoarthritis is diagnosed the sooner treatment can be begun to help reduce pain, maintain mobility and prevent damage from getting worse.

See your doctor immediately if you develop any of the following:
  • Sudden pain, redness, swelling, and tenderness in a joint.
  • Pain in the joint following an injury.
  • Pain in the joint that continues (is persistent) despite resting the joint.
  • Pain in the joint that is so severe that you cannot weight bear on the joint such as when standing or walking.

These symptoms could be signs of more serious conditions such as fracture, infection in the joint or bone, or other forms of arthritis such as rheumatoid arthritis.

How is osteoarthritis diagnosed?

Your doctor will ask what you are able to do and what makes your pain worse. A physical examination will be carried out with close attention to your affected joints. There are no specific blood tests for osteoarthritis, but tests may be made to exclude other forms of arthritis.

X-rays are not needed to diagnose osteoarthritis but can be helpful in some instances. X-ray findings are not a good guide to how severe symptoms may become and X-ray findings do not correlate with the amount of pain or impairment someone experiences.

How is osteoarthritis treated?

Treatments for osteoarthritis cannot cure the condition, but can help with:

  • reducing the pain
  • maintaining your ability to work or do activities you enjoy
  • reducing how often your joints become more inflamed and painful (flares)
  • preventing joint changes from getting worse.

Your doctor or physiotherapist is likely to advise a treatment that takes into account the severity of the disease, what joints are affected, your symptoms, other medical problems, your age, occupation and everyday activities.

Changes to your lifestyle

How you manage day-to-day activities can make a big difference in the impact osteoarthritis has on your lifestyle. Most of the loss of mobility in the early stages of osteoarthritis can be reversed with a programme of exercises and losing weight if necessary.

  • Regular exercise is one of the best treatments to reduce pain and stiffness, reduce your usage of medicines, improve muscle strength, balance, mood and quality of life.
  • If you are overweight, weight loss of approximately 10% can result in symptom improvement comparable to the effect of joint replacement surgery.
  • Read more about exercise and weight loss.


Medication for osteoarthritis focuses mainly on pain relief. Usually, the approach is to try the milder pain relief medications first, such as paracetamol and gels or sprays, and if that does not provide relief, move to the stronger pain relief medications such as NSAIDs, or steroid injections in some cases. This approach reduces the risk of side effects.

  • Paracetamol: is recommended as the pain reliever to try first. It is best taken regularly and not just when pain is present.
  • Gels or sprays (also called topical agents): are useful for people with mild-to-moderate pain, especially when the pain is limited to a few joints or to a specific area such as the knee or finger joints. Examples include ibuprofen gel, diclofenac gel or spray and capsaicin cream.
  • Non-steroidal anti-inflammatories (NSAIDs): are useful for people with ongoing pain and discomfort despite treatment with paracetamol, in people with severe symptoms or during a flare. They are not suitable for everyone and are usually not recommended as a long-term treatment but some people may need to take them on an ongoing basis. They can cause serious side effects such as stomach bleeding, increased risk of heart attacks and stroke and kidney problems. Common examples of oral NSAIDs include ibuprofen (Ibugesic®, I-Profen®, Nurofen®), diclofenac (Voltaren®), naproxen (Noflam®, Naprosyn®) and celecoxib (Celebrex®).
  • Steroid injections: are given into the painful joint to reduce inflammation. These are reserved for extremely painful osteoarthritis and used for treating flares.
  • Read more about medications for osteoarthritis.

Complementary or alternate therapies 

Complementary or alternative treatments are not usually recommended in the treatment of osteoarthritis, due to a lack of quality evidence or evidence that they are ineffective. Some people may find them beneficial, possibly due to a placebo effect. Examples of therapies include:

  • acupuncture
  • heat or cooling, such as a hot bath or cooling pack on the affected joint. There is little evidence regarding whether these methods are effective but they are often used because they have a low risk of adverse effects.
  • TENS (transcutaneous electrical nerve stimulation) may be helpful if given in a healthcare setting but the use if TENS machines at home has not proven to be helpful.
  • Glucosaminechondroitin and fish oil have been suggested for use in osteoarthritis. The evidence shows that glucosamine and fish oil probably does not reduce symptoms, and that chondroitin might reduce pain a little. 

If you are considering the use of complementary or alternative treatments, it is important to consider the risks, benefits and costs. Read more about the considerations if you are using complementary or alternative therapy.


If joint changes, pain and disability are all severe and a comprehensive management programme including the above measures is not helping, a joint replacement may be necessary. See: Knee replacementHip replacement 

Learn more

The following links have more information about osteoarthritis. Be aware that websites from other countries may have information that differs from New Zealand recommendations.

Osteoarthritis management – a team approach NPS MedicineWise, Australia, 2017
Osteoarthritis Arthritis NZ, 2014
Arthritis - exercises to keep you moving Arthritis NZ, 2014
NZSL videos about osteoarthritis Platform Trust, in partnership with Deafradio and Health Navigator NZ, 2022


  1. Managing pain in osteoarthritis – focus on the person BPAC, NZ, 2018
  2. Towheed T, Maxwell L, Anastassiades TP, Shea B, Houpt J, Welch V, Hochberg MC, Wells GA. Glucosamine therapy for treating osteoarthritis. Cochrane Database of Systematic Reviews (2005)
  3. Singh JA, Noorbaloochi S, MacDonald R, Maxwell LJ. Chondroitin for osteoarthritis. Cochrane Database of Systematic Reviews (2015)
  4. Symptomatic management of osteoarthritis, Best Practice Advisory Centre, NZ, 2008

Reviewed by

Dr Ben Darlow is a musculoskeletal physiotherapy specialist in private practice in Wellington and a senior lecturer and researcher in the Department of Primary Health Care and General Practice at the University of Otago, Wellington. 
Credits: Health Navigator Editorial Team. Reviewed By: Dr Ben Darlow, Musculoskeletal Physiotherapy Specialist Wellington, Senior Lecturer and researcher, Department of Primary Health Care and General Practice, University of Otago, Wellington (June 2018) Last reviewed: 18 Jun 2018