Since the knees are the largest joint in the body, it is also one of the easiest areas to injure. Knee pain is one of the most common reason people visited their doctor.1
Worldwide approximately 355 million2 people suffer from some kind of arthritis. Degenerative knee pain is generally gradual rather than sudden. Degenerative disorders progress slowly and are usually marked by the gradual erosion of the articulating cartilage lining the knee joint. Types of degenerative disorders include osteoarthritis, rheumatoid arthritis, and traumatic arthritis (an old knee injury). Sudden knee pain usually occurs as a result of a traumatic injury sustained during an accident, or while playing sports, for example.
1 American Academy of Orthopedic Surgeons (AAOS)
2 Orthopedic Industry Annual Report 2012