Surgical Experiences in South Africa, 1899-1900 / Being Mainly a Clinical Study of the Nature and Effects of Injuries Produced by Bullets of Small Calibre

by George Henry Makins

The aseptic nature of the wounds, and the slight and localised character of the bone lesions, have in fact justified the opinion previously expressed by Von Coler, that these injuries in the future would be less feared than fractures of the diaphyses of the bones.

Not less important than the localised character of the bone lesion itself is the fact that the accompanying wounds of the soft parts retain the small or type forms. Thus I occasionally observed more troublesome results from minor shell wounds in the neighbourhood of joints, but not implicating the synovial cavity, than in actual perforating injuries produced by bullets of small calibre.

Vibration synovitis.—Before proceeding to the consideration of wounds of the joints, a short account is necessary of a condition of some importance which is, I believe, more or less special to injuries from bullets of small calibre travelling at high rates of velocity. This condition, if not novel, at any rate excited little comment in the descriptions of the older forms of injury, although this may have depended on the more serious nature of the primary local lesions accompanying wounds from the larger bullets, among which it formed a comparatively unimportant element.

The condition referred to was the occurrence of considerable synovial effusion into the joints of limbs in which the articulation itself was primarily untouched. These effusions sometimes occurred even when the soft parts alone were perforated, especially when the wounds were situated above or below the knee-joint. They were apparently the direct result of vibratory concussion of the entire limb dependent on the blow received from the bullet.

The effusions were most strongly marked in cases of fractures of the diaphyses, although this was more noticeable in some situations than others. Thus with fractures of the shaft of the femur anywhere below the junction of the upper and middle thirds of the bone, and in some cases even higher, effusion into the knee-joint was very common, and sometimes extreme. On the other hand, similar effusions into the hip-joint were less marked, since I failed to determine their existence in the majority of cases. I am inclined to ascribe this to the different anatomical arrangement of the two joints, particularly to the fact that the head of the femur is included in a bony cup, into the hollow of which it is accurately fixed by the resilient cotyloid fibro-cartilage. The latter by its firm grasp of the head allows of little play in the joint; hence vibrations are conveyed directly to the acetabulum in continuous waves, and rocking of the articular surfaces is prevented. Beyond this no doubt the difficulty of detecting small effusions in this joint is an element which must be taken into consideration.

I do not think that wrenches of the knee-joint in the act of falling can be suggested as an explanation of the frequency of effusions into that articulation, since the fractures of the femur were not always received while the erect position was maintained, and effusion was most marked when the diaphysis was the part affected, the latter point illustrating the greater resistance offered by compact bone. Again, when fracture had taken place, the solution of continuity rendered the directly injured point the most mobile, and tended to prevent lateral strain from falling on the joints.

Effusion into the knee or ankle, or sometimes both joints, was common in fractures of the shaft of the tibia.

In the articulations of the upper extremity the condition was also common, but somewhat less marked than in the lower limb. Effusions into the shoulder or elbow occurred. In the former these were less striking; again, perhaps, as a result of the difficulty of detecting small effusions in this situation. The elbow was to a certain extent protected by the possession of a degree of fixity somewhat resembling that already mentioned in the case of the hip-joint, although here depending on the conformation of the bones alone. I think this explained the absence of free effusion in many cases of fracture of the humeral shaft, but when the latter affected the lower third effusion into the elbow was usually abundant.

The lighter weight and greater mobility of the upper extremity as a whole, as decreasing the resistance to the bullet, were also probably an element in the fact that these effusions were less severe than those in the joints of the lower limb.

The nature of the effusions was apparently simple, since they were rapidly reabsorbed, and little thickening of the synovial membrane remained to suggest either a marked degree of inflammation, or the deposition of blood-clot on the inner aspect of the same.