Surgical Experiences in South Africa, 1899-1900. George Henry Makins
applied to it, but it would be more correct to reverse the term to 'punched in,' since the appearance is really most nearly simulated by a hole resulting from the driving of a solid punch into a soft structure enveloped in a denser covering. The loss of substance, moreover, in the primary stage is not actually so great as appears to be the case, fragments of contused tissue from the margin being turned into the opening of the wound track. The true margin therefore is not sharp cut, and the nature of the line differs somewhat according to the structure of the skin in the locality impinged upon. Thus the granular scalp and the comparatively homogeneous skin of the anterior abdominal wall will furnish good examples of the nature of the slight difference in appearance. From the first the margin is also often somewhat discoloured by a metallic stain, similar to that seen when a bullet is fired through a paper book. This ring is, however, narrow, and not likely to be noticeable when the bullet has passed through the clothing. In any case it is subsequently obscured by the development of a narrow ring of discoloration due to the contusion. This latter varies in width, and still later a halo of ecchymosis half an inch or more in diameter surrounds the original wound.
Diagram enlarged to actual size from case shown in fig. 24, p. 64.
With increasing degrees of obliquity of impact more and more pronounced oval openings of entry result, culminating in an actual gutter such as is seen in fig. 17.
In all oval openings the loss of substance is more pronounced at the proximal margin, while the wound is liable to undergo secondary enlargement at the distal margin, since in the former the epidermis is mainly affected, while in the latter the epidermis is spared as an ill-nourished bridge, the deeper layers of the skin suffering the more severely. When the wound occurs in regions, such as the chest-wall or over the sacrum, where the skin is firmly supported, the oval openings are often very considerable in size, reaching a diameter at least double that of the circular ones. In the case of the oval openings the depression of the margins is not such a well-marked feature as in wounds resulting from rectangular impact of the bullet, since the distal margin is really lifted.
Oval Entry Wound over third sacral vertebra. Exit wound, anterior abdominal wall. Slightly starred variety. Diagram made on second day
Aperture of exit.—The wound of exit in normal cases offers far more variation in appearance than that of entry, this variation depending on several circumstances: first, the want of support to the skin from without, and such other factors as the degree of velocity retained by the travelling bullet, the locality of the opening, and the density, tension, and resistance offered by the particular area of skin implicated.
When the range has been short and the velocity high, it is often difficult to discriminate between the two apertures. Both may be circular and of approximately the same size, and the only distinguishing characteristic, the slight depression of the margin of the wound of entrance, may be absent if any time has elapsed between the infliction of the injury and examination by the surgeon. One very strong characteristic if present is the general tendency of the margins, and even the area surrounding the exit wound itself, to be somewhat prominent. Fig. 16 shows this point, although the wound from which it was drawn had been produced thirty-six hours before death. The specimen was then hardened in formalin and still preserves its original aspect. This character is, however, more frequently displayed in wounds received at mean, or longer, ranges. In wounds produced by bullets travelling at the highest degrees of velocity it is often absent.
Circular Entry back of arm; exit (bird-like) in anterior elbow crease
Circular Entry over patella. Starred exit of elongated form in popliteal crease
When the range of fire has been greater and the velocity retained by the bullet lower, slit wounds are common, or some of the slighter degrees of starring. Actual starring I never saw, but reference to figs. 20 and 21 will show a tendency in this direction, also a close resemblance to the starred wounds resulting from perforations by large leaden bullets. Such wounds, I believe, are usually the result of a somewhat low degree of velocity.
Slit exit wounds may be vertical or transverse (fig. 20) in direction, and the production of these is dependent on the locality in which they are situated, the thickness, density, and tension of the skin, and the nature of the connection of the latter with the subcutaneous fascia in the locality. Thus in wounds of different parts of the hairy scalp, so little variation exists in the relative density and structure of the skin, that, in spite of the want of external support at the aperture of exit, it is often difficult to discriminate offhand the two apertures, if neither bone nor brain débris occupies that of exit.
If, however, a wound crosses from side to side a region such as the thigh where well-marked differences exist in the subjacent support, thickness, and elasticity of the skin implicated in the apertures, the wound of entry, if in the thick skin of the outer aspect, was usually circular, while the exit in the thin elastic skin of the inner aspect was either slit-like or starred. The difficulty in laying down any general rule as to the occurrence of circular or slit apertures of exit in any definite region is, however, great, as may be seen by reference to the accompanying diagrams taken from two patients wounded at Paardeberg (figs. 22 and 23).
In fig. 22 the bullet entered the outer and posterior aspect of the left buttock, crossed the limb behind the femur, and emerged at the inner aspect by a vertical slit: the bullet then entered the scrotum by a vertical slit, and emerged by a typical circular aperture; re-entered the right thigh by a transverse slit aperture, and, striking the femur in its further course, underwent deformation, and finally escaped by an irregular aperture ¾ of an inch in diameter. The occurrence of exit slits in the adductor region is common, and to be explained by the tendency of the comparatively thin elastic skin to be carried before the bullet; the slit entry in this position must, I suppose, be explained by the comparatively slight support afforded by the underlying structures, which are often in a condition of hollow tension. The scrotal wounds are perhaps more difficult to account for, but in this case the fact of the distal aperture being directly supported by the right thigh is a ready explanation of the circular exit, while the skin corresponding to the slit entry was no doubt carried before the bullet, and finally gave way in the line of a normal crease.
Entry and Exit Wounds in both thighs and scrotum.
From right to left: 1. Circular entry in left buttock behind trochanter. 2. Vertical slit exit in adductor region. 3. Slit entry in scrotum (probably inverted before bullet broke the surface, and then a slit occurred in a normal crease). 4. Circular exit in scrotum (here supported by surface of right thigh). 5. Transverse slit entry in right adductor region. 6. Irregular 'explosive' exit, the bullet having set up on contact with the front surface of the femur, but without having caused solution of continuity of the bone
In fig. 23 all the wounds are circular except the final exit, which was irregular as a result of the bullet in this case also having struck the femur in the second thigh. Considerable variation also exists in the size of the circular apertures; this illustrates the secondary enlargement often occurring in such wounds, and most marked at the apertures of entry, as the more contused. Both diagrams were made from patients eight days after the reception of the wounds.
Wound of both Thighs. First and second entry typical circular wounds. First exit a small circular wound; the bullet 'set up' on contact with the femur