In 2%-7% of all bone fractures, union is delayed or fails. Nonunions of the bones represent a challenge for orthopedic surgeons and can have a severe psychological impact on these patients. Moreover, the social cost of managing these lesions, often requiring multiple procedures, may be very high, and complications related to improper treatment are not rare. This text is based on the development over many years of the devices and operative techniques of monofocal, bifocal, and multifocal compression-distraction osteosynthesis, in cooperation with the CITO Institute of Moscow and the LNIITO Institute of Riga, and on hundreds of operative procedures on noninfected and infected nonunions personally performed by the authors both in the former Soviet Union, Russia and Italy. The primary purpose of this book is to discuss currently available tools for diagnosing long bone nonunions, to illustrate the means of prevention, and to specify the indications for management using compression-distraction techniques.