It is to the great and lasting credit of LORENZ BOHLER and his school that they have in the last decade developed and demonstrated so thoroughly the techniques for the conservative management of fractures. Nevertheless there have always been many, including some from BOHLER'S school, who have found considerable place for surgical management, and with the significant progress in general surgery seen in postwar years, a new stimulus has been given to this part of traumatic surgery, especially since bone injuries have become more complex and frequent. The concept of internal fixation is not new. The serious criticisms that have been levelled at it retain today their basic significance. Progress in the fields of asepsis, corrosion-free metal implants, operative experience and postoperative care has diminished the dangers but has not relieved the surgeon of responsibility. The Association for the Study of the Problems of Internal Fixation (AO) has devoted itself over a number of years to the basic principles and best methods of open treatment of fractures by means of extended clinical and scientific studies in order to determine in each individual case the most promising line of treatment. At the same time a well designed and tested instrument set has been developed with precise instructions for the appropriate techniques. As a result, the new observations about primary bone healing which have emerged from the practice of rigid internal fixation are as interesting as the uses to which they can be put in allowing early mobilization.

The German edition of our book entitled "Operative Frakturen behandlung" by M. E. MUELLER, M. ALLGOEWER and H. WILLENEGGER (Springer, Berlin . Goettingen . Heidelberg, 1963) has been out of print now for more than three years. We are planning a new edition which will deal with the collective experience of 14,000 new cases, all treated by internal fixation, and will include the newest developments in the field of internal fixa tion. However, it will be some time before this new edition can be published. Increasing demands for a description of the AO technique of internal fixation has stimulated us to publish this manual. In it we shall describe in a comprehensive but somewhat apodictic mann er the principles and techniques of the AO methods of fracture treatment and reconstructive surgery, which in our hands, have stood the test of time. The book is written in a somewhat abbreviated style. It cor responds in subject matter to the teaching given at the AO courses in Davos, but deals with each subject more thoroughly. We have dispensed with pictures of the instruments, as these may be found in the Synthes Catalogue *. This manual should be regarded as the product of collective experiencc, containing new thoughts and new discoveries from basic research. In considering the risks of mistakes and dangers, we can only reiterate what we have already stated in "Technique of Internal Fixation of Fractures": "Open treatment of fractures is a valuable but difficult method which involves much responsibility.

The first part of this manual deals with the experimental and scientific basis and the principles of the AOjASIF method of stable internal fixation. It deals with the function and main use of the different AO implants, the use of the different AO instruments, and with the essentials of the operative technique and of postoperative care. It also discusses the handling of the most important postoperative complications. The second part deals at length with the AO recommendations for the operative treatment of the most common closed fractures in the adult. This has been organized in anatomical sequence. The discussion of the closed fractures is followed by a discus sion of open fractures in the adult, then by fractures in children and finally by pathological fractures. The third part presents, in a condensed fashion, the application of stable internal fixation to reconstructive bone surgery. 1 GENERAL CONSIDERATIONS 1 Aims and Fundamental Principles of the AO Method The Chief Aim of Fracture Treatment is the Full Recovery of the Injured Limb In every fracture there is a combination of damage to both the soft tissues and to bone. Immediately after the fracture and during the phase of repair, we see certain local circulatory disturbances, certain manifestations of local inflammation, as well as pain and reflex splinting. These three factors, that is, circulatory disturbances, inflammation and pain, when combined with the defunctioning of bone, joints and muscle, result in the so-called jl'acture disease.

1m allgemeinen Teil dieses Manuals sollen experimentelle und wissenschaftliche Grund lagen und Prinzipien der stabilen Osteosynthese nach der AO-Methode, Funktion und Hauptindikation der verschiedenen AO-Implantate, Handhabung des Standardin strumentariums der AO sowie einige wesentliche Gesichtspunkte der Operationstechnik und der Nachbehandlung dargestellt werden. Auch die Behandlung der wichtigsten postoperativen Komplikationen wird besprochen. 1m spe:: iellen Teil werden die von der AO befolgten Richtlinien fur die operative Behandlung der haufigsten geschlossenen Frakturen beim Erwachsenen nach anatomi schen Regionen eingehend erortert. Es folgen dann die Behandlung der offenen Fraktu ren beim Erwachsenen, der Frakturen bei Kindern und beim alten Menschen sowie der pathologischen Frakturen. In einem drittel1 Teil wird die Anwendung der stabilen Osteosynthese bei Wiederher stellungseingriffen am Knochen zusammenfassend dargestellt. R T IL LL MI 1 Ziele, Grundlagen und Prinzipien der AO-Technik Hauptziel jeglicher Knochenbruchbehandlung ist die Wiederherstellung der vol/en Funk tion der verletzten Extremitat. Jede Fraktur stellt eine Kombination von Weichteil-und Knochenschaden dar. Sofort nach der Fraktur und im Laufe der Reparationsvorgange treten lokale Zirkulationssto rungen, entziindliche Erscheinungen und Schmerz mit reflektorischer Immobilisierung auf. Diese drei Faktoren fiihren in Verbindung mit dem Ausfall funktioneller Beanspru chung von Knochen, Gelenken und Muskeln zur sog. Frakturkrankheit, d.h. chroni scher Odembildung, Atrophie der Weichteile, Knochenabbau (Osteoporose) und Ge lenksteifen. Jede Behandlung einer Fraktur muS deshalb sowohl den Bruch an sich als auch die damit in Verbindung stehenden lokalen Reaktionen des Organismus beriicksichtigen."