What is osteoarthritis?

Osteoarthritis is the most common type of arthritis. It is a degenerative disease that affects the joints, particularly those in the thumb and fingers, big toes, knees, hips and spine.

Causes

Osteoarthritis is commonly attributed to ageing. However, it is a complex condition with multiple contributing factors such as lifestyle factors and genetic susceptibility. It may also result from other causes or underlying diseases such as physical injury, calcium accumulation, septic arthritis and avascular necrosis.

It leads to the gradual erosion of cartilage in joints. Cartilage is the tissue that cushions your joints. If the cartilage breaks down, the bones start rubbing against one another, causing pain, stiffness, swelling and limited movement. The ligaments that connect muscle to bone may also become weaker as a result.

Osteroarthritic bone.Osteoarthritis affects the cartilage in the joints. 

Septic arthritis

An infection of a joint, often causing it to be red, hot and painful.

Avascular necrosis

Refers to death of bone tissue due to a lack of blood supply.

Risk factors

Risk factors of osteoarthritis include:

  • Age - the risk of osteoarthritis increases with age;
  • Gender - women are slightly more likely than men to get osteoarthritis;
  • Family history and genetics - several genes have been implicated in osteoarthritis;
  • Obesity - excess body weight puts mechanical pressure on joints, such as the knees and hips;
  • Occupations or sports that involve a lot of physical exertion can cause excessive pressure on joints;
  • Bleeding disorders, such as haemophilia, that can result in bleeding in the joint;
  • Disorders such as avascular necrosis that block blood supply to a joint, and;
  • Having other types of arthritis such as rheumatoid arthritis, or chronic gout.

Genes

A unit of inheritance (heredity) of a living organism. A segment of genetic material, typically DNA, that specifies the structure of a protein or related molecules. Genes are passed on to offspring so that traits are inherited, making you who you are and what you look like.

Avascular necrosis

Refers to death of bone tissue due to a lack of blood supply.

Haemophilia

A rare, inherited blood disorder that leads to individuals being prone to severe (usually internal) bleeding.

Signs and symptoms

Sometimes there are no symptoms, despite X-rays showing signs of osteoarthritis. When they occur, signs and symptoms of osteoarthritis vary from person to person, but commonly include:

  • Joint stiffness, usually when you first wake up;
  • Joint pain that often gets worse throughout the day when you are active, and;
  • Muscle weakness.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Methods for diagnosis

A diagnosis of osteoarthritis can be suggested based on symptoms and physical examination findings, such as a crackling sound (crepitus), swelling, tenderness and/or a limited range of motion in joints. X-rays may show loss of joint space, worn-down bones and bone spurs. Ultrasound, bone scans or magnetic resonance imaging (MRI) scans may support the diagnosis if changes cannot be seen with an X-ray.

Sometimes, if there is fluid accumulation within a joint (effusion), a sample of the fluid can be extracted using a needle for further testing. This fluid can be helpful in distinguishing between certain types of arthritis, such osteoarthritis, infection and gout.

Magnetic resonance imaging

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

Ultrasound

A scan that uses high-frequency soundwaves to produce images of the body’s internal structures.

X-rays

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

Treatment cannot cure osteoarthritis, but it can slow its progress. Treatment options initially include losing weight if overweight, pain-relief medications, such as paracetamol and ibuprofen, and regular, gentle exercise. It is also important to maintain a healthy diet.

With progressive symptoms, corticosteroid injections into the affected joint are sometimes used, especially during flare-ups to reduce inflammation. An occupational therapist may be able to provide mobility aids and strategies to assist with living with the condition.

Other therapies that may be considered, but have mixed results, include intra-articular hyaluronate injections, glucosamine and chondroitin, and colchicine. Hyaluronate injections are similar to joint fluid and are aimed at reducing friction between joints, and thus may alleviate pain. Glucosamine and chondroitin are chemicals naturally found in joint cartilage, however, daily supplements of these chemicals have not shown to reduce the progression of osteoarthritis. Furthermore, glucosamine should be avoided if you have a severe seafood allergy. Colchicine, a drug normally used in gout, has been shown to be effective for certain cases of osteoarthritis.

If other treatment options have been exhausted and your osteoarthritis is resulting in debilitating pain or disability, surgery may be required. Types of surgery include:

  • Fusion - bones can be fused at the joint. This is done in cases of severely damaged joints for which replacement is not an option;
  • Realignment - this fixes bones and other structures that have become misaligned;
  • Joint replacement - damaged joints may need to be replaced to improve range of motion and quality of life, and;
  • Cartilage grafting - new cartilage cells can be grafted into damaged areas of joints, only in cases where the damage is minor and the damaged area is surrounded by healthy cartilage.

Allergy

A harmful, hypersensitive immune reaction to usually innocuous environmental substances.

Occupational therapist

A healthcare professional trained to deliver occupational therapy, which involves teaching a person self care, work and play activities to promote independence and reduce disability.

Potential complications

Treatment side effects

  • Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, may cause stomach ulcers and bleeding, impaired kidney function, liver damage, and heart problems;
  • Corticosteroid injections can damage joints if used too often, and;
  • Surgery carries the risk of several complications, including infection, joint dislocation and blood clots.

Osteoarthritis progression

As osteoarthritis progresses, pain worsens and movement can become increasingly limited.

Prognosis

As osteoarthritis is a generally progressive disease, over time symptoms can become worse. Movement of affected joints may become more limited and everyday chores may become more challenging.

Prevention

Although it cannot be prevented, not overusing painful joints at work or during other activities can help delay the onset or slow the progression of osteoarthritis. Maintaining a healthy weight, eating a healthy diet, performing strengthening exercises and keeping generally fit may also help slow the onset and progression of symptoms.