KNEE OSTEOARTHRITIS - Knee osteoarthritis is defined by degeneration in knee’s cartilage, the flexible, slippery material that normally protects bones from joint friction and impact. The condition also involves changes to the bone underneath the cartilage and can affect nearby soft tissues.The most commonly reported symptom of knee osteoarthritis is knee pain. The description of the pain will depend on the patient’s condition and situation. Knee arthritis pain usually gets worse with certain activities that place additional strain on the joint, such as when squatting or walking up stairs. Knee joint swelling makes the knee feel stiff. Some people may only experience knee stiffness for few minutes in the morning or after sitting for a long period. Stiffness may or may not be accompanied by visible swelling or a reduced range of motion.