It is also a striking fact that the most common and troublesome complication of wounds of the chest, hæmothorax, was usually the result of the wound of the chest-wall and not of the lung. I preface these remarks to the detailed account of the thoracic injuries, because I think the favourable course usually taken by patients with wounds of the lung has been accorded somewhat greater prominence than the circumstances warranted.
Non-penetrating wounds of the chest-wall.—Surface wounds were not very common, and were chiefly of interest in so far as they illustrated the very superficial course that may be occasionally taken by a bullet without breach of the integument, and as sometimes affording opportunity for the exercise of diagnostic skill when the track traversed the axilla.
The most common situation for tracks taking a long course on the surface of the thoracic skeleton was the back. Such wounds were usually received while the patients were prone on the ground; thus I might instance a case in which the bullet entered the posterior aspect of the shoulder 3 inches above the spine of the scapula, passed downwards, pierced that process, and emerged 2 inches below the inferior angle of the bone. Wounds of a similar nature coursing in transverse and oblique directions, and not implicating bone, were also seen. Those implicating the vertebræ have been already dealt with. The scapular region was also a favourite one for the lodgment of retained bullets, some resting in the supra- and infra-spinatus muscles, others lying beneath the bone itself.
On the anterior aspect of the chest, bullets coming from the front sometimes traversed and fractured the clavicle, and then took a short course downwards, emerging over the ribs or sternum. Figure 81 represents a particularly long track in this region. In other cases the precordial region was crossed, but I never witnessed any serious effect on the heart's action in any such injury at the time the patients came under my notice.
Wounds received with the arm outstretched and traversing the axilla sometimes gave considerable trouble in excluding with certainty a perforation of the thoracic cavity. Thus a bullet entered below the centre of the right clavicle and emerged 2½ inches below, above the angle of the scapula, at its axillary margin. The arm was outstretched at the moment of the reception of the injury; but when the wound was viewed with the limb placed alongside the trunk, it seemed almost impossible that the chest cavity could have escaped. In some cases of this kind the difficulty was at once cleared up by noting evidence of injury to the axillary nerves.
A word will suffice as to the treatment of these wounds. The only special indication was to keep the scapula at rest for a sufficient period. I have dealt with the anatomy of them at such length only because in their extreme form they are so highly characteristic of the nature of the injuries which may be produced by bullets of small calibre.
Penetrating wounds of the chest.—Tracks crossing the thoracic cavity in every direction were common. When the erect attitude was maintained, frontal and sagittal wounds, pure or oblique, were received; when the prone position was assumed, longitudinal tracks, either purely or obliquely vertical, were the rule. Experience of wounds of the latter class was extensive in the present campaign, from the fact that so many of the advances were made in prone or crawling attitudes. The vertical and transverse tracks each possessed the special characteristic of frequently implicating both the thoracic and abdominal cavities, but the vertical were often prolonged into the neck, or even downwards through the pelvis. The vertical wounds in addition sometimes exhibited one very important feature, the fracture of several ribs from within, often at a very considerable distance from the aperture of either entry or exit.
Fig. 81.—Superficial Track in anterior Wall of Trunk
Characters of the apertures of entry and exit.—As has already been mentioned, the chest-wall was one of the situations in which the aperture of entry was often large, and the oval form due to obliquity of impact on the part of the bullet was particularly well marked. The exit wounds were often smaller than those of entry, especially if the bullet emerged by an intercostal space; even when the ribs were comminuted, the fragments were, as a rule, too small to occasion more than a slightly enlarged and irregular aperture. Taken as a class, however, and putting aside explosive exit wounds, wounds of the chest afforded more numerous examples of irregular outline and variation in size than were met with in any other region of the body.