The reader is enthusiastically encouraged to tackle this second edition text in two ways. The first is simply to scan chapters with their introductions, summaries and conclusion points. Second, is to delve into those sections of seeming greater interest depending upon one’s s- cialty and role. The expansion and quality of this material speak to the success of the first edition by these editors and many similar authors. In addition, the continued and enlarged interest in computer assisted Orthopedic surgery indicates the relevance and enduring importance of this advance in our field of musculoskeletal surgery. I suggest that no other discipline in surgery is so appropriately suited to computer assistance including robotic performance. Orthopedics has always seemed unique to this author in that it focuses more than any other medical field on gross physical, mechanical structure. We deal nearly exclusively in physical repair of broken elements, rearrangement of deformed ones, and resurfacing or refurbishing those that are diseased in a way that has altered their mechanical integrity, shapes, and other structural aspects.