The categorization of people by social strata occurs in all societies, ranging from the complex, state-based societies to tribal and feudal societies, which are based upon socio-economic relations among classes of nobility and classes of peasants.
Knee replacement, also known as knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability. It is most commonly performed for osteoarthritis,[1] and also for other knee diseases such as rheumatoid arthritis and psoriatic arthritis.
During the knee replacement procedure, the entire joint is replaced with an artificial prosthesis. The end of the femur is replaced with a metal shell, while the end of the tibia is fitted with a plastic cup and metal stem that fit into the shell.