What is Osteoarthritis?
by: Arlene Gentallan
What is Osteoarthritis?Osteoarthritis (also known as degenerative joint disease) is the most prevalent type of arthritis. It is marked by articular cartilage destruction / degeneration leading to joint pain and decreased range of motion.
What is an articular cartilage?Articular cartilage is the pearly white membrane that covers the end of bones where they meet to form a joint. The articular cartilage protects the bone ends of a joint when we move and lift weight. It provides a smooth surface so bone ends will not be damaged by friction when they slide against each other during a movement.
A joint capsule holds and surrounds the articular cartilages where they form a joint. The joint capsule has a cavity filled with synovial fluid which serves as a lubricant to prevent excessive friction when bone ends (covered with articular cartilage) move against each other.
Cartilage is composed of:
• Collagen - makes the cartilage tough
• Proteoglycan - enables the cartilage to spring back to it's original shape after being stretched or squeezed (like when we are doing heavy lifting)
The composition of the cartilage makes it an excellent shock-absorber. However, it is worth knowing that cartilage has no blood supply so they heal slowly when damaged.
What happens to the articular cartilage when you have osteoarthritis?• Proteoglycan and collagen diminishes.
• Articular cartilage turns from shiny white to dull yellow / brown.
• Articular cartilage's surface peels off while deeper layers cracks, leading to eventual cartilage lost.
• Cartilage at the center of the bone end is lost while there are new formation of cartilage along the edges, giving the bone an irregular contour (making it hard and painful to move leading to movement limitation.)
• Articular cartilage is no longer able to protect bone ends.