Osteoarthritis is the most common form of arthritis
and is associated with the aging process.
Image shows two pairs of legs from above the knee down.
Even from the outside,
you can see that the knee of an older person
looks considerably different than that of a younger person.
The image zooms in on the right knee of each pair of legs.
The knee with the more saggy skin is labeled “Older person’s knee”.
The other knee, which is more muscly, is labeled “Younger person’s knee”.
Let's take a look at the joint itself to see the differences.
The skin of both knees becomes translucent to reveal the underlying bone and cartilage.
The older person’s cartilage is more deteriorated than that of the younger person’s.
Osteoarthritis is a chronic disease,
a disease that persists for a long time.
It causes the deterioration of the cartilage within a joint.
For most people, the cause of osteoarthritis is unknown,
but metabolic, genetic, chemical,
and mechanical factors play a role in its development.
Symptoms of osteoarthritis include loss of flexibility,
limited movement, and pain and swelling within the joint.
The condition results from injury to the cartilage,
The skin of the knees disappears and only the bone and cartilage are visible.
A label which reads “Cartilage” points to the white
tissue between the two leg bones of the younger person’s knee.
This cartilage is smooth.
The older person’s knee has deteriorated cartilage and lumps on the bone.
which normally absorbs stress and covers the bones, so they can move smoothly.
The cartilage of the affected joint is roughened and becomes worn down.
As the disease progresses, the cartilage becomes completely worn down
and the bone rubs on bone.
Bony spurs usually develop around the margins of the joint.
A label which reads “Bone spur” points to the lumps on the older person’s bones.
Part of the pain results from these bone spurs,
which can restrict the joint's movement as well.