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.
A new total knee replacement that saves all of the ligaments can make a personâs knee feel and move just like the original. During a traditional total knee replacement, the surgeon must remove the island of bone to which the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL) are attached. The new knee features a shape that protects that island of bone and saves the ligaments.