A healthy knee has linings of cartilage and lubricating joint fluid (i.e. synovial fluid) to protect and cushion between the main leg bones, allowing for pain-free knee movements. However, in Knee Osteoarthritis, the cartilage lining gradually wears out and the synovial fluid loses its shock-absorbing qualities. This produces the symptoms of Knee Osteoarthritis.
Doctors grade the severity of Knee Osteoarthritis by a combination of the symptoms including pain, stiffness, swelling, or loss of range of motion and X-ray appearance of the knee.
