This book presents a comprehensive classification of fractures of all long bones. The fundamental principle of this classification is the division of all fractures of a bone segment into three types and the further subdivision into three groups and their subgroups. The groups are arranged in an ascending order of severity according to the morphologic complexitites of the fractures, the difficulties inherent in their treatment, and the prognosis. Thus once a surgeon classifies a fracture, he will have determined its severity and will have a guide to its best possible treatment. This system of classification is based on the AO classification in use since 1979 and on over 150,000 documented cases on file in the AO Documentation Center in Berne. The diagnosis of a fracture is expressed by combining the numerical code of its location with the alpha- numeric code of its morphological characteristics. This alphanumeric code has been designed to facilitate computer storage and retrieval; it will greatly assist computerized documentation.