Osteoarthritis

Osteoarthritis is a joint condition in which the cartilage deteriorates in quality and thickness. The term ‘wear and tear’ is often incorrectly used. ‘Wear and tear’ suggests that movement is bad for the joint, which it is not.

What is osteoarthritis?

The parts of the bones that together form a joint are covered with cartilage. Together with joint fluid, called synovial fluid, cartilage allows the bone ends to glide smoothly over each other. In osteoarthritis, this layer of cartilage disappears. This prevents the joint from functioning properly. Examples include osteoarthritis of the knee, hip, shoulder, and hand.

In addition to the loss of cartilage, more changes occur around the joint. Bone at the joint margins remodels. These 'bony overgrowths' are called osteophytes and cause the joint to widen and movement to become more difficult.

The bone tissue beneath the cartilage also changes in structure, becoming denser and harder. This is called sclerosis. Osteoarthritis generally progresses, meaning the cartilage deteriorates further over time.

Cause

The exact cause of osteoarthritis is not yet known. However, several factors increase the risk. Osteoarthritis can occur in anyone, but women and older adults are at higher risk. Being overweight, (long-term) overuse or underuse, or previous injuries to a joint also increase the likelihood of osteoarthritis. It is more common in certain families, suggesting that heredity also plays a role.

Symptoms

About 10% of people over the age of 55 have symptoms due to osteoarthritis. This percentage increases with age.

As cartilage quality declines and disappears, symptoms may develop over time. The most common symptoms are pain and stiffness. This stiffness is especially present in the morning or when getting moving again after a period of inactivity. This is known as 'morning and start-up stiffness' and usually disappears or is greatly reduced within half an hour. In general, this stiffness and pain decrease with movement. 

Crepitus (crackling sounds) may also be heard during joint movement. In addition, an inflammatory reaction can cause a joint to swell and feel warmer.

Diagnosis

An X-ray is often taken to assess the joint. This may show a narrowing of the joint space, which occurs when the layer of cartilage between the bones becomes thinner or disappears completely. It can also show whether osteophytes have formed and whether the joint has been deformed by osteoarthritis.

Osteoarthritis does not always lead to pain or limitations. Sometimes considerable osteoarthritis is visible on an X-ray with few to no symptoms. The reverse can also occur.

The degree of osteoarthritis visible on an X-ray is indicated by the Kellgren-Lawrence scale. This scale says nothing about the severity of symptoms someone experiences.

• 0 (No osteoarthritis)= No cartilage abnormalities.
• 1 (Possible osteoarthritis)= Doubtful joint space narrowing and possible early osteophyte formation.
• 2 (Minimal osteoarthritis)= Osteophyte formation and possible joint space narrowing.
• 3 (Moderate osteoarthritis)= Multiple osteophytes, joint space narrowing, bony sclerosis, and possible bone deformity.
• 4 (Severe osteoarthritis)= Multiple large osteophytes, marked joint space narrowing, severe bony sclerosis, and bone deformity.

Treatment

There are many ways to address problems caused by osteoarthritis. The main goals are to slow down deterioration, reduce pain, and improve joint function.

It is important to get moving and stay active. The joint needs movement to lubricate and nourish the cartilage. Without movement, a joint becomes stiff and muscle strength and fitness decline, which leads to more symptoms. Exercise therapy under the guidance of a physical therapist can help.

Using a crutch or cane and/or pain medication can reduce pain, making movement easier. Weight loss, if overweight, is also important. Contact a physical therapist to treat the symptoms.

When osteoarthritis causes severe symptoms and therapy does not provide sufficient results, surgery may be considered. There are several options. A localized cartilage injury can be treated by cleaning the joint, replacing a loose cartilage fragment, or stimulating the joint to repair damaged cartilage itself.

The alignment of the joint can also be adjusted so the cartilage is loaded more favorably. The (partial) replacement of a joint is also possible. For example, someone may receive a 'new knee', also known as a knee prosthesis.

A more drastic option is to fuse the joint completely. This eliminates movement but significantly reduces pain. This is relatively common in joints of the spine or foot.