Osteoarthritis is the most common form of arthritis. It is a long-term condition that causes the gradual breakdown of soft tissue in certain joints, such as knees, hips and fingers.
Symptoms include pain, stiffness, and swelling, while treatment will focus on reducing pain and disability through lifestyle changes (diet, exercise), physical and occupational therapies, medication, and (in some cases) surgery.
About one in ten adult New Zealanders is affected by the condition.
Cartilage is a firm rubbery substance that covers the end of bones and acts as a cushion or shock absorber between bone ends. Osteoarthritis causes the progressive breakdown and wearing away of the cartilage, leaving the bone ends unprotected. As this occurs, the joint can become painful, stiff, difficult to move and eventually, swollen.
Osteoarthritis can be classified as primary or secondary. Primary osteoarthritis has an unknown cause but is generally associated with ageing. It is sometimes referred to as “wear and tear” arthritis.
Secondary osteoarthritis is the destruction of cartilage from a known cause. Conditions that lead to cartilage loss include joint injury, obesity, gout, infection, congenital abnormalities (abnormalities present at birth), and joint surgery.
Osteoarthritis can occur at any time of life but the incidence increases with age.
Osteoarthritis usually occurs in the hands and weight-bearing joints such as hips, knees, feet, and spine. Osteoarthritis of the neck is called cervical spondylosis.
Osteoarthritis does not usually affect the shoulder, wrist, elbow, or jaw unless as a result of unusual stress or injury.
Common risk factors for developing osteoarthritis include:
- Older age.
- Being overweight – extra body weight increases the stress on weight-bearing joints, such as the knees and hips, and fat tissue produces inflammatory substances that harm joints
- Female gender – osteoarthritis is more common and more severe in women.
- Heredity – osteoarthritis, particularly where it affects the hands and fingers, tends to run in families.
- Joint injuries – sports or other accidental injuries can increase the risk of developing osteoarthritis later in life.
Some occupations that involve repetitive heavy activity may damage joints and make them more prone to osteoarthritis later in life.
Signs and symptoms
The most common signs and symptoms of osteoarthritis include:
- Pain is the most common symptom of osteoarthritis. It is usually made worse by moving the joint or placing weight on it, and it is usually relieved by rest. As the condition progresses and inflammation develops, pain may become constant.
- Stiffness of the affected joint is often noticed first thing in the morning, and after resting.
- Swelling, which is sometimes warm to touch, may be noticeable in an arthritic joint.
- Deformity can occur with osteoarthritis due to bone growths (bone spurs) and cartilage loss. Degeneration of knee cartilage can result in the outward curvature of knees (bow-leggedness).
- Creaking and cracking (a crackling sound or grating feeling) may be noticed when an arthritic joint is moved. This is caused by bone rubbing against bone or roughened cartilage.
- Loss of flexibility makes it more difficult to move an arthritic joint through its full range of motion.
Osteoarthritis is often able to be diagnosed by its characteristic symptoms of pain, decreased movement, and/or deformity.
Osteoarthritis may be confirmed with an x-ray or MRI (magnetic resonance imaging) scan. Common findings include narrowing of the joint space between bones, a loss of cartilage, and bone spurs or bone growths.
Blood tests may be used to exclude other possible conditions but they cannot diagnose osteoarthritis. Joint fluid tests (in which fluid is drawn from an affected joint and analysed) may be used to determine whether joint pain is caused by gout or an infection rather than osteoarthritis.
There is no cure for osteoarthritis but the progression of the disease can be slowed and pain and disability reduced. Treatment will depend on the nature and severity of the condition and treatment will be tailored to the individual. Treatment options include:
Healthy body weight
Maintaining a healthy body weight will reduce stress on weight-bearing joints like hips and knees.
Exercise can assist with weight loss and the maintenance of muscle strength and the mobility of arthritic joints. Activity at a level that does not cause pain is not thought to worsen osteoarthritis. Non-weight-bearing exercises such as swimming or aqua jogging in a heated pool may be beneficial, as may gentle forms of exercise or stretching such as yoga and tai chi.
Physiotherapists can advise on appropriate exercises to improve mobility, increase muscle strength, and decrease pain with the aim of improving function and maintaining independence. Heat or ultrasound treatment may also be used to relieve pain and relax muscles.
If activities of daily living become difficult, occupational therapists can provide advice on suitable home adaptations and special devices. These may include handrails, tap or bottle turners, large pegs, tongs, or other gadgets. Equipment to assist mobility may include a walking stick or walking frame.
Medications can play an important role in the management of pain caused by osteoarthritis. There are different classes of medications that have proven useful. These include simple pain relievers (eg: paracetamol), non-steroidal anti-inflammatory drugs (NSAID's: eg: ibuprofen) and oral corticosteroids (eg: prednisone).
A class of NSAID called COX-2 inhibitors, eg: celecoxib (Celebrex), has proven effective in the management of osteoarthritis pain. However, some medications in this class have been linked to an increased risk of heart attacks and stroke. For advice on suitable pain relief medications please consult a medical practitioner who can prescribe and monitor appropriate medication.
Supplements such as glucosamine sulphate and chondroitin sulphate have been reported to relieve the pain of osteoarthritis in some clinical studies but not others. It is advisable to consult a medical practitioner before taking these supplements.
Alternative therapies such as acupuncture and massage may relieve symptoms in some people.
It is recommended that a healthy balanced diet is followed as this can assist with overall wellbeing and with maintaining a healthy body weight.
Synovial fluid (lubrication) injections
Synovial fluid is a clear, sticky, viscous solution that lubricates, protects, and supports joints. In osteoarthritis this fluid does not function effectively. Injections of a substance similar to synovial fluid, into an arthritic knee joint may provide some pain relief in some people.
Injections of corticosteroid medications into an arthritic joint can relieve pain and increase range of movement temporarily. This procedure is usually reserved for very painful osteoarthritis and is limited to three or four injections per year because corticosteroids can worsen joint damage over time.
When osteoarthritis has caused extensive joint damage and produces severe pain and restriction of movement, joint replacement surgery may be necessary. The most common procedures are hip joint replacement and knee joint replacement.
However, partial or complete replacement of the shoulder, elbow, wrist, finger, ankle, and toe joints are also possible in some cases. The surgery is performed by an orthopaedic surgeon and can greatly reduce the symptoms of osteoarthritis in the affected joint. This allows greater mobility and an improved quality of life.
Because an artificial joint does not last forever, joint replacement is often delayed in very young people to minimise the need for repeated replacements.
In osteoarthritis of the knee, if one side of a knee joint has more damage than the other, a bone realignment (knee osteotomy) might be helpful. In this procedure, a surgeon cuts across the bone either above (thigh bone) or below (shin bone) the knee, and either removes or adds a wedge of bone. A knee osteotomy shifts a person’s body weight off the damaged part of the knee.
For further information and support contact:
Arthritis New Zealand
Phone: 0800 663 463
E-mail: [email protected]
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University of Otago (2019). Burden of knee osteoarthritis costs predicted to almost double to $370 million (Web Page). Dunedin: University of Otago. https://www.otago.ac.nz/news/news/otago719478.html [Accessed: 14/01/20]
Last Reviewed – January 2020