The knee is a complicated hinge joint. It is made
up of bones, muscles tendons and ligaments. These components in combination
enable us to stand, sit pivot and walk up and down stairs.
The most common disease to the knee joint is Arthritis.
There are several forms of Arthritis. Osteoarthritis is the most
common form, and the knee is the most common joint affected.
When the knee joint has been
damaged by trauma or a disease such as Arthritis, degeneration of its
bony surfaces will occur. The surfaces are covered with a protective
layer called articulating cartilage. It is this protective coat that
wears and causes raw bone to rub on raw bone.
Over time the joint slowly erodes
until the underlying bone is exposed. Exposed bone results in a painful
joint when it moves and bears weight.
For the individual the knee becomes painful. This
can cause limping, swelling, instability, and discomfort.
x-ray on the left shows a normal knee. On the right is an x-ray
of a knee with arthritis.
that protects the ends of the bones does not appear on the x-rays.
Thus the space between the bones on the left.
cartilage has worn away in the right x-ray, revealing how raw bone
now rubs against raw bone.