Osteoarthritis (OA), also known as degenerative arthritis or degenerative
joint disease is the most common type of arthritis. Although OA can develop at any age, it usually develops after the
age of 45, affecting both men and women equally.
Joints are located between 2 bones. The ends of each bone are covered by
a tough, elastic material called cartilage. Cartilage protects the ends
of the bones from damaging each other when they move.
In OA, the cartilage deteriorates, leading to joint damage, pain, and stiffness.
OA is often referred to as a "wear and tear" disease, because over time, cartilage
can weaken and break down, sometimes developing cracks and holes. Pieces of
damaged cartilage can break off and irritate the joints or the tissues nearby.
The joint pain and swelling caused by OA can make it painful and difficult to
move.
Although any joint can be affected in OA, weight-bearing joints of the hips,
knees, feet and spine are the most common. Those less commonly affected
are the nonweight-bearing joints of the fingers and the joint at the base of
the thumb. Other joints are not usually affected by OA, unless they have been
either injured or have experienced unusual stress.
What causes pain in OA?
Since there are no nerve endings in cartilage, the cartilage itself doesn't
actually hurt. However, all the surrounding tissues such as tendons (inflexible
cords that connect muscle to bone or other tissue) and ligaments (slightly
elastic band of tissue which connects the ends of bones and prevents excessive
movement of the joint) as well as bone can become inflamed (swollen,
irritated, and painful). As the cartilage damage progresses, movements become
more difficult and the other tissues such as tendons and ligaments must work
harder to help keep the joints moving. Because tendons and ligaments are not
designed to do this work, they become overworked, resulting in more inflammation
in the joint. Eventually, the wearing of the cartilage may cause the bones to
rub together, causing more pain. Bony growths (called spurs or osteophytes)
which form as the bone thickens, also rub together, causing additional pain.
This is especially common in weight-bearing joints like the hips, knees, and
spine.
What are the usual symptoms of OA?
Will they get worse over time? The most common symptoms of OA are joint
pain, swelling, and stiffness. These symptoms last for at least 2 weeks.
In addition to the most commonly affected joints of the hips, knees, feet, and
spine, smaller joints such as those of the fingers and thumbs can also develop
OA.
OA is a progressive disease, and symptoms usually develop slowly, commonly
involving the area around the joint. Over time, as the damage progresses, it
may become painful to move the joint. It is common to hear grating sounds as
the roughened surfaces of the cartilage rub together, creating bumps or swelling,
especially in the small joints of fingers and feet.
What causes OA?
Although the exact cause is unknown, the older you are, the greater your
chances of having OA. Heredity also may play a role, since some people
who have OA also have other family members with it. Since being overweight
can put stress on joints, it can increase your chances of getting OA, especially
in the weight-bearing joints such as hips and knees. Overuse of the joint
or repeated injury from work or sports can cause excessive or unusual wear
and damage of their joints, and cause OA to develop. Joint damage from other
types of arthritis, such as rheumatoid arthritis, can also increase the risk
of OA.
How might OA affect my daily activities?
In addition to pain, inflammation, and visible joint deformities, joint damage
from arthritis can make everyday activities such as walking, using a computer
keyboard or brushing your teeth a challenge.
Is there a cure for OA?
There is no cure for OA and treatments vary depending on the location and
severity of the disease. The available treatments can help manage the condition,
to reduce pain and stiffness and improve joint mobility. Treatments include
medications, physiotherapy, exercise, weight loss, and surgery. Medications
used for osteoarthritis include painkillers (analgesics) such as acetaminophen,
nonsteroidal anti-inflammatory drugs, corticosteroid injections
into the joint, and capsaicin cream. Surgery is a last resort, and it is usually
reserved for severe cases where the entire joint (often a hip or a knee) is
worn, and needs replacement.