THE COMPREHENSIVE (M«LLER/AO) CLASSIFICATION OF FRACTURES AND ITS IMPORTANCE IN DECISION MAKING

Abstract

Introduction The unique aspects of the Comprehensive AO classification is discussed.

Methods The unique feature of this system of classification is that it’s principles and the classification itself are not based on the regional features of a bone or its fracture patterns. It is not bound by convention of usage or the popularity of an eponym. It is generic and applies to the whole skeleton. It’s guiding philosophy is that a classification is worthwhile only if it helps in evolving the rationale of treatment and in the evaluation of the outcome of that treatment. The classification must therefore indicate the severity of the fracture, which in this case indicates the morphological complexity of the fracture, the difficulties to be anticipated in treatment, and it’s prognosis. This has been accomplished by formulating the classification on the basis of repeating triads of fracture types, their goups and subgroups and by arranging the triads and the fractures in each triad in an ascending order of severity. Thus there are three fracture types A, B, and C in an ascending order of severity. Each fracture type has three groups and each group three subgroups. The identification of the Type indicates immediately the severity. The classification considers a long bone to have a diaphyseal segment and two end segments. It makes use of the rule of squares to define the end segments with great precision. The location of the fracture has also been simplified by noting the relationship which the center of the fracture bears to the segment. A new terminology has been developed. In order to provide a check list of essential data which must be available before a fracture can be classified, the Comprehensive Classification System has a system of binary questions which allow the classifier to determine precisely whether all the essential data necessary is available. If not, further imaging may be necessary. To facilitate computer entry and retrieval of the cases, an alphanumeric code has been created. The diagnosis of a fracture is given by coupling the location of the fracture with its morphologic complexity.

Results The developed terminology is so precise that it is now possible to describe a fracture verbally with such accuracy that it’s pictorial representation is superfluous.

Conclusions Once the surgeon has accurately classified the fracture, he can, basing himself on information available from the literature and on his own experience make proper decision regarding it’s treatment.