Arthritis knee improved just after one session of stem cells and PRPOsteoarthritis (also known as OA) is a type of arthritis and one of the most common cause... As a degenerative disease of the knee joint, it is more common in females older than 40 years. It is due to their physique that leads to a gradual deterioration of the cartilage in the bones, reducing their shock-absorbing qualities of joints.