6 Better tolerated, more elastic metallic fixation through titanium.
7 More advanced external fixation techniques utilizing Ilizarov principles for lengthening, segment transport, and deformity correction in fresh fractures and non-unions.
8 New techniques, instruments, and implants for the treatment of human pelvis, acetabulum, hand, feet, and spine fractures. In addition, computer and robotic-assisted surgery as well as special implants to fit the varied sizes and shapes of animal bones.
9 Better bone-grafting techniques including allografts and bone substitutes.
10 Extensive classification of fractures and soft tissue injuries; and newer techniques for computer documentation.
11 More careful postoperative management to ensure return of function and prevent loss of the race between implant failure and fracture healing.
A great many of these newer advances and techniques are applicable to large animals and are incorporated in PEOS. The work encompasses the more extensive large animal osteosynthesis applications and techniques that were developed in the 5 years since the publication of EBEQOS. Finally, the most innovative and exciting change in PEOS is its refinement of the electronic format utilizing CD-ROM for a true multimedia approach to teaching equine fracture treatment. With simple commands the reader can switch from text to figures, to animation, to videos. Indeed this pioneering computerization is to be a template for the upcoming human manual—another first for veterinary orthopedics and the authors!
PEOS has two additional chapters: on humeral fractures encompassing better compression technology, and on documentation including the AO Vet Equine Documentation System itself. There have also been added full length videos on the use of the dynamic condylar screw plate (DCS/DHS) systems in the treatment of short oblique distal fractures of the adult radius.
The bibliography style has been changed to the one adopted by AO Publishing to be utilized in the books to be published in the future.
This edition also encompasses newer concepts, advances, and techniques, seeking the true etiologies of conditions we deal with—such as biomechanics and tissue growth factors. Newer implants and instruments are shown, but biologic fixation will be stressed where applicable in large animals. Local antibiotics via loaded polymethylmethacrylate (PMMA) beads, more constructive use of allografts, and expanded use of nuclear scintigraphy, MRI, and CT scanning for better and earlier diagnosis and more effective intervention have also been incorporated.
Finally, the greater use of electronic technologies in everyday practice and teaching, utilizing documentation and computer-aided learning methods, have been given an impetus by this book, propelling these advances well into the new millennium.
It is still strongly suggested that the user complement the book's informative guidance through equine osteosynthesis by obtaining specialized practical training at an AO course or at a school where these exacting techniques can be practiced on plastic bones and/or cadavers. To insure the best possible clinical results, however, careful soft tissue handling, aseptic operating room conditions and good preoperative and postoperative management should be practiced, in addition to the proposed osteosynthesis.
In conclusion, I wish all the practitioners and students who utilize the AO techniques promulgated in this exciting new work the best of luck in obtaining excellent functional results following their repair of equine fractures. I also congratulate the authors, editors, and publishers once again on a job well done.
David M. Nunamaker
1.3 Precise anatomic reconstruction
1.5 Soft tissue considerations
1.1 Introduction
Goal of AO fracture treatment: Functional fracture treatment with early joint mobility and gradually increasing weight bearing.
A full fifteen years after the publication of the Manual of Internal Fixation in the Horse by Springer Verlag, the principles of internal fixation using AO techniques remain intact. New techniques have expanded the capabilities of the surgeon, and experience with established techniques has added a perspective that was not present a decade ago. Immediate full weight bearing following fracture fixation remains a goal that cannot always be achieved in the horse. Functional fracture treatment with early joint mobility and gradually increasing weight bearing as tissue healing progresses are admirable goals. In the horse, early or immediate full weight bearing is a necessity difficult or impossible to side-step. The use of casts and splints to protect internal fixation devices from failure, and techniques such as plate luting that increase the fatigue life of those implants can combine to significantly improve results [1, 2].
Successful internal fixation allows sharing of loads between bone and implants.
Successful internal fixation starts with the anatomic reconstruction of bone and joint surfaces that allows the sharing of loads between the reconstructed bone and the implants. Anatomic reconstruction can be accomplished by screws alone or screws combined with a plate. Interfragmentary compression is absolutely essential for maintaining bone contact between fragments to protect the relatively weak implants. Orthopedic implants by themselves are not able to withstand the full force of weight-bearing without failure.
1.2 Surgical approaches
Accurate alignment of fracture fragments is made possible by surgical approaches that allow adequate visualization.
Incisions into badly bruised skin with subcutaneous hemorrage carry a high risk of infection.
The accurate alignment of fracture fragments and the perfect reconstruction of joint surfaces is made possible by surgical approaches that allow adequate visualization. Perfect reduction cannot be ensured if the joint surfaces are reduced without direct vision, and inadequate exposure of shaft fractures may not allow reduction of overriding fracture fragments or proper placement of plates or screws. Surgical approaches should also be designed to maintain vascular integrity and to avoid areas of compromised soft tissues. Evaluation of compromised skin may be difficult, and decisions need to be modified based upon the amount of time which has elapsed since the injury. In general, incisions into badly bruised skin with subcutaneous hemorrhage carry a high risk of subsequent infection. Devitalized skin may mean delaying open reduction and internal fixation. External skeletal fixation alone may be considered or in combination with minimal internal