WHAT
IS Osteoarthritis?
Osteoarthritis
(OA) is the most common form of arthritis. In OA, there
are changes in the cartilage and bone of joints. These changes lead to pain, stiffness,
swelling and limitations in the use of joints.
Risk
factors for OA include being over weight; joint injury; muscle weakness; having
other forms of arthritis; and heredity.
OA
can affect any joint, but it occurs most often in knees, hips, lower back and
neck, small joints of the fingers, and the base of the thumb and big toe. It rarely
affects other joints, except as a result of joint injury of unusual stress on
the joint.
Nearly
21 million people in the United States have OA; however, not everyone has joint
symptoms because of it. OA can be serious, but it may be prevented and effectively
treated. It is important to see your doctor to get the correct diagnosis and treatment
plan.
Osteoarthritis
(OA)
- Most
common type of arthritis.
- Primarily
affects cartilage, the tissue that cushions the ends of bones within the joints.
- May initially
affect joints asymmetrically
- Affects
hands and weight bearing joints
- Can
cause joint pain and stiffness
- Usually
develops slowly over many year
WHAT
HAPPENS IN OSTEOARTHRITIS?
In
normal joints, a firm, rubbery material called cartilage covers the end of each
bone. Cartilage provides a smooth, gliding surface for joint motion and acts as
a cushion between the bones. In OA, the cartilage covering the ends of bones breaks
down. This leads to symptoms such as pain and swelling and problems using the
joint.
There
are several phases in OA:
Cartilage
loses its elasticity and is more easily damaged by injury or excessive use. The
timing and extent to which these changes occur also is influenced by heredity,
trauma to the joint and other factors. As the cartilage breaks down, changes occur
in the underlying bone. The bone becomes thickened and fluid-filled cysts form
under the cartilage. Bony growths called spurs develop at the bone surface at
the margins of the joint.
Bits
of bone or cartilage may float loosely in the joint space.
Finally,
the membrane lining the joint (the synovium) becomes inflamed because of the cartilage
breakdown.
Along
with this inflammation, cytokines (inflammatory proteins) and enzymes that may
damage the cartilage further are produced.
Read
more on "Arthritic Diseases"
