Standard library functions. The standard library functions are built-in functions in C programming to handle tasks such as mathematical computations, I/O processing, string handling etc. These functions are defined in the header file. When you include the header file, these functions are available for use.
Knee replacement. 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.
It is important to realize that a knee 'replacement' is actually just a resurfacing of the knee joint. The femur or thigh bone is covered with a metal covering and plastic is placed on the tibia so that instead of irregular arthritic surfaces, one has metal and plastic articulating which produces a smooth non-patent surface.