Condylar Fractures of the Humerus
Most fractures of the lower humerus can be classified into three main groups: the supracondylar, the condylar, and the epicondylar (Fig. 1); other varieties such as the diacondylar and the T or Y fractures are much less common. Only condylar fractures* will be discussed here because their treatment involves several peculiar problems which are not always handled to the best advantage of the patient. To understand these problems one must have a clear conception of the difference between a supracondylar and a condylar fracture and the anatomy and epiphyseal development of the lower humerus.
In the usual supracondylar fracture, the lower fragment is pulled up and back by the triceps muscle, but it is not tilted significantly because the attached muscles (the flexors to the internal condyle and the extensors to the external condyle) pull evenly and symmetrically. Consequently, by manipulating the forearm one can gain satisfactory control over the fragment, disengage it, and accomplish reduction by a fairly simple, well-standardized maneuver.
An entirely different situation exists when a single condyle is broken. Such a condyle forms a small triangular fragment to which is attached a single set of powerful muscles which produce a displacement that is in many cases characteristic. The condyle is not only pulled down but also twisted on itself so that its fractured surface faces outward instead of inward. This is not always apparent on casual inspection of the roentgenogram, but careful “three-dimensional” reconstruction will reveal it with great regularity (Figs. 4,C and 5,C). From a. . .