Supracondyloid Fracture. (Child, nine years old.) Union with deformity, fragment so joined to lower end of shaft of humerus at an angle that when forearm is completely flexed upon this fragment it yet is only at right angle with the arm. Operation indicated. (X-ray picture.)
The external condyle when fractured is displaced by muscle pull; when the internal condyle is broken the tendency is to backward displacement of the fragment and widening of the joint.
Fracture of the internal condyle is often an exceedingly serious matter, because it is so often associated with more or less dislocation and with permanent deformity, as a result of inattention to the anatomical relations of the bones. The ulna sustains peculiar relations to the inner condyle; at its upper end it is wrapped around the process, holding it much as a monkey-wrench can be made to seize an ordinary object, and being held to it by the internal lateral ligament. Herein lies the secret of success or failure in treatment, for the fragment, being so fixed to the ulna, should be controlled by it, i. e., the position of the ulna is the most essential feature of the treatment of the fracture. The forearm makes an angle with the arm proper, by which a considerable degree of divergence is maintained. This has been alluded to by Allis and others as the “carrying function.” It can only be estimated in the extended position, and be accurately judged by comparison with the other arm. If the arm be flexed all possibility of estimating it is lost; therefore to dress such a fracture in the right-angle position is bad practice ([Fig. 292]). The only position in which the carrying function can be preserved is the extended, or one a little short of it for the purpose of comfort. If the ulna is put in the proper position the fragment will be held equally so or as nearly as possible ([Fig. 294]).
Fig. 293
Fracture of external condyle. (Lejars.)
In the treatment of fractures of the inner condyle the patient, if a child, should be anesthetized, the upper part of the body exposed, both arms extended, and the injured arm made to correspond exactly with the other so far as concerns the angle of divergence. Upon the arm so placed an anterior plaster-of-Paris molded splint should be carefully applied, extending from axilla to wrist, and then lightly secured with bandages, the surgeon holding the arm in the proper position until the plaster is sufficiently hardened to permit no displacement. The arm should be kept in this position for at least ten days, after which the splint may be removed and gentle motion practised. It may then be reapplied for two or three days, after which we may begin to flex the arm, applying either a new plaster splint or any other that seems suitable, and in such a way that at the expiration of another week the forearm is brought to a comfortable position of right angle, where it may be maintained with a light splint or simply with a sling, according to the age and tractability of the patient. [Fig. 294] illustrates the splint and the position, which is the only one in which the surgeon maintains his own security and can properly estimate the carrying function. The mistake has been in dressing this fracture, like most others at the elbow, in the right-angle position.
In fractures of the outer condyle these anatomical conditions do not prevail, and these may be dressed in whatever position best meets the indications of comfort and accurate reduction. Intercondyloid fractures are subject to the same conditions as those of the internal condyle, plus others which are added, and should therefore be dressed in the same position.
Fig. 294