This book serves the objective of providing an understanding of the current state of arthroplasty. Success of Sir Charnley's total hip arthroplasty has inspired many researchers to study this subject in detail and analyze its various aspects. Arthroplasty basically deals with joints of upper extremity and spine. However, any foreign design brought to the human body could lead to complications. The book discusses the topic of infections which includes complete analysis, detailed description and management of this difficult condition. It also talks about immune system and how it is challenged with big amounts of micro-particles from the tribology code. Thus, it discusses the problem of aseptic loosening along with the information regarding materials presently accessible for arthroplasty.