A half century ago, orthopedic surgeons needed to specialize in only the pathophysiology and treatment of the neuromuscular and skeletal systems in order to treat patients. However, since then, surprising progress has been made in medicine, and through the limitless avenues for research orthopedics is now divided into many subspecialities, with terms such as orthopedic pathology, orthopedic oncology, orthopedic rheumatology, and orthopedic traumatology becoming commonplace. Interdisciplinary studies in this and other related fields are now indispensible. As a result, the half-life of the information accumulating yearly has been estimated at five years. In times such as these, if one stubbornly adheres to treatment alone, progress comparable to that in other fields will not be made. If one opens an orthopedic textbook, it is easy to see that there are still many diseases of undetermined etiology; in the last quarter of a century, there has been no evidence of even one of these diseases' etiology having been resolved internationally. This is a direct result of the ineptitude of basic orthopedic research. Therefore, recently in the United States, Japan and Canada, orthopedic research institutes and associations have been established, and SIROT has been organized internationally. This book contains the manuscripts presented by international and Japanese speakers at the 5th Annual Meeting of the Orthopedic Research Society of the Japanese Orthopedic Association, and the Second Inter­ national Cherry Blossom Conference of Rheumatology.