How does osteoarthritis (OA) damage your knee?

How does Osteoarthritis damage the knee?

Normally, smooth, firm tissue called cartilage covers and protects the ends of your bones. The fluid in the joint contains a substance called hyaluronate. This fluid acts as a "shock absorber" and lubricant so that the knee joint can work properly.

When you have OA of the knee:

  • The joint fluid may lose its ability to protect the joint
  • Smooth cartilage that normally protects the ends of the knee bones may lose its cushioning effect or become pitted and frayed. Large areas of cartilage may even wear away completely, so the bones scrape painfully over each other
  • Cartilage breakdown may cause the joint to lose its shape, and the bone ends may thicken and form bony spurs
  • Fragments of bone or cartilage may float in the joint space, causing further damage and pain
  • For this and other information please see
Risk Factors
  • Age
  • Obesity
  • Injury or overuse
  • Genetics or heredity
  • Muscle weakness
  • Other diseases and types of arthritis


if you think you have OA of the knee