The field of hip preservation surgery has evolved over the past decade as our understanding of hip pathomechanics and pathomorphology has expanded. The published literature on non-arthritic hip pathology, for example, has grown exponentially. The topics of controversy in the past decade have been answered in some cases, but new questions have also arisen. In addition to the 99 chapters in the original edition   most of which will be retained and updated as applicable   there will be over 30 brand new chapters focusing on new and more sophisticated techniques from authors that have been the pioneers of the field.