National Institute of Arthritis and Musculoskeletal and Skin Diseases
How Does Osteoarthritis Affect People? continued...
Osteoarthritis affects different people differently. Although
in some people it progresses quickly, in most individuals joint damage develops
gradually over years. In some people, osteoarthritis is relatively mild and
interferes little with day-to-day-life; in others, it causes significant pain
While osteoarthritis is a disease of the joints, its effects
are not just physical. In many people with osteoarthritis, lifestyle and
finances also decline.
Lifestyle effects include
- feelings of helplessness
- limitations on daily activities
- job limitations
- difficulty participating in everyday personal and family joys and
Financial effects include
- the cost of treatment
- wages lost because of disability.
Fortunately, most people with osteoarthritis live active,
productive lives despite these limitations. They do so by using treatment
strategies such rest and exercise, pain relief medications, education and
support programs, learning self-care, and having a “good attitude.”
Osteoarthritis Basics: The Joint and Its Parts
A joint is the point where two or more bones are connected.
With a few exceptions (in the skull and pelvis, for example), joints are
designed to allow movement between the bones and to absorb shock from movements
like walking or repetitive motions. These movable joints are made up of the
Cartilage: a hard but slippery coating on the
end of each bone. Cartilage, which breaks down and wears away in
osteoarthritis, is described in more detail on the next page.
Joint capsule: a tough membrane sac that
encloses all the bones and other joint parts.
Synovium (sin-O-vee-um): a thin membrane
inside the joint capsule that secretes synovial fluid.
Synovial fluid: a fluid that lubricates the
joint and keeps the cartilage smooth and healthy.
A Healthy Joint
In a healthy joint, the ends of bones are encased in smooth
cartilage. Together, they are protected by a joint capsule lined with a
synovial membrane that produces synovial fluid. The capsule and fluid protect
the cartilage, muscles, and connective tissues.
A Joint With Severe Osteoarthritis
With osteoarthritis, the cartilage
becomes worn away. Spurs grow out from the edge of the bone, and synovial fluid
increases. Altogether, the joint feels stiff and sore.
Ligaments, tendons, and muscles are tissues that surround the
bones and joints, and allow the joints to bend and move. Ligaments are tough,
cord-like tissues that connect one bone to another. Tendons are tough, fibrous
cords that connect muscles to bones. Muscles are bundles of specialized cells
that, when stimulated by nerves, either relax or contract to produce
Cartilage: The Key to Healthy Joints
Cartilage is 65 to 80 percent water. The remaining three
components – collagen, proteoglycans, and chondrocytes – are described
(KAHL-uh-jen): A family of fibrous
proteins, collagens are the building blocks of skin, tendon, bone, and other
(PRO-tee-uh-GLY-kanz): Made up of
proteins and sugars, strands of proteoglycans interweave with collagens and
form a mesh-like tissue. This allows cartilage to flex and absorb physical
(KAHN-druh-sytz): Found throughout
the cartilage, chondrocytes are cells that produce cartilage and help it stay
healthy as it grows. Sometimes, however, they release substances called enzymes
that destroy collagen and other proteins. Researchers are trying to learn more