Practical Biomechanics for the Orthopedic Surgeon, 2d ed.

The first edition of this book was published in 1979. In the preface to this second edition, the authors note that since 1979, "Newton's laws of mechanics have not changed but the practice of orthopedics has." This observation is particularly apt with respect to some of the implants used by orthopedic surgeons. Advances in materials, techniques, and designs have had a noticeable impact in the areas of internal fixation devices and total joint replacements. In addition to these improvements in hardware, the field of orthopedic biomechanics has evolved significantly during the past decade. This book is an attempt to communicate to the orthopedic surgeon some of the important biomechanical issues that play an ever-increasing role in clinical orthopedics.

Like its predecessor, this book is divided into five chapters: "Biomechanics of the Spine," "Mechanics of Fracture and Fracture Fixation," "Biomechanics of Sports Injuries," "Mechanics of Joint Degeneration," and "Joint Replacements." The generous use of figures is one of the strong points of this book. In the 199 pages that comprise chapters 1 through 5, there are 217 figures. These figures serve as an indispensable aid in understanding the numerous mechanical and biomechanical concepts addressed.

In each chapter, the authors introduce biomechanical concepts in a specific clinical context. In this way, the reader is not overwhelmed by definitions and mechanics in an abstract setting. In chapter 1, for example, compression, tension, and shear forces are illustrated using the spine. The explanations are clear, and the line drawings of the spine showing the various forces and resulting deformations are informative and uncluttered.

In chapter 2, fracture and fracture repair are addressed. Although there is an obvious bias in this chapter toward nonconservative techniques for fracture treatment (open reduction and internal fixation), the biomechanics of plates, screws, nails, and other devices have been extensively studied. These devices represent important components in the armamentarium of the modern orthopedic trauma specialist, and an understanding of their mechanics is essential if these devices are to be used successfully.

Less than 25 pages long, chapter 3 is the shortest chapter in the book. It covers some of the basic mechanisms of sports injuries. This is also the weakest chapter in the book, and readers with a background in sports medicine will more than likely know of more comprehensive texts. The chapter does, however, offer a fair description of the mechanics (eg, deceleration, energy dissipation, impact, shock absorption) that are important for understanding the causes of skeletal injuries.

In chapter 4, the authors address cartilage and joint degeneration. The authors restrict their attention to the so-called "wear and tear" type of osteoarthritis, in which the cause is presumed to be mechanical in origin. Their presentation includes well-balanced coverage of cartilage stresses, lubrication, friction, and wear. Some of the time-proven treatment modalities, both nonsurgical and surgical, are outlined along with the biomechanical principles that underlie each approach.

Chapter 5 deals with joint replacements. As the authors note in the preface, the area of total joint arthroplasty has changed significantly since 1979. It is not surprising, therefore, that chapter 5 has undergone extensive revision from the first edition. This chapter is restricted to an examination of the hip and knee joints. This should not be considered as a limitation, but merely as an indication of the importance of these two joints in the history of total joint arthroplasty. Nearly two thirds of the chapter is devoted to the hip joint. The authors present a very comprehensive description of the forces and stresses that act on the femur both before and after total hip replacement. A somewhat less comprehensive section is devoted to knee replacements. As a whole, this chapter is very well written and should be enjoyable reading for anyone interested in the biomechanics of total hip or knee arthroplasty.

One organizational improvement from the first edition is a consolidated glossary of engineering terms that now appears at the back of the book. As anyone working in a multidisciplinary field knows, learning the terminology can be a difficult task. The glossary should serve as an invaluable resource for the orthopedic specialist, for whom some of the engineering terms can be intimidating.

The book has a few minor shortcomings. Unlike the first edition, this edition does not include a bibliography or a list of selected readings. Whereas such references are often somewhat dated, a list of selected readings would have provided a starting point for the reader who desires more depth or a different perspective on a particular topic. In terms of the book's scope, the upper-limb joints and ankle are virtually ignored. This is perhaps related to the fact that the biomechanics of these joints is much less advanced than it is for the hip and knee. Although some progress has been made in these areas in the past 10 years, the neglect of these "minor joints" is no doubt primarily related to the clinical interests of the authors. The book also contains several outdated statements. The authors state, for example, that comminuted fractures of long bones frequently cannot be stabilized with rods. In the past 5 years, new designs of locking intramedullary nails have greatly expanded the clinical indications for using such devices. As a result, locking nails can be used even when some comminution is present.

In summary, this book is well written, generously illustrated, and very reasonably priced. The book should appeal to a variety of readers. First and foremost, it would make a valuable addition to a library for the orthopedic rehabilitation specialist who wishes to know more about the biomechanics of orthopedic rehabilitation. It would also be very useful for the student who might desire an introduction to the field of orthopedic biomechanics. Finally, the book should be of value to the generalist physical therapist and occupational therapist working with patients with orthopedic conditions. An understanding of the biomechanics of the spine and lower limb often plays an important role in treatment strategies.