Part 20 (1/2)

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 sh.e.l.l 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 ill.u.s.trating 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.

The only treatment indicated was a short period of rest, accompanied in the early stages by pressure and slight fixation, followed later by ma.s.sage and movement if necessary.

Before dismissing this subject, I should like to particularly emphasise the fact, that in the cases described there was no reason to suspect the extension of fissures from the point of fracture in the shafts into the articular ends of the bones. This was as far as possible excluded by clinical examination, and in the cases where wounds of the soft parts only were present, the rapid return of the patients to active duty, with absence of remaining joint trouble, negatived the possibility of such fractures.

I only saw one case in which a longitudinal fracture actually extended for any considerable distance into a neighbouring joint. In this a comminuted fracture occurred just above the centre of the shaft of the humerus. At the time of examination and putting up of the fracture there was considerable swelling of the whole arm, and nothing special was noticed about the shoulder-joint. Three weeks later, however, when the fracture was consolidating, difficulty in abduction of the shoulder was noted, and the arm could not be placed closely in contact with the trunk. There was no evident displacement of the head of the humerus forwards. A skiagram, which I much regret I have not been able to insert, showed that a longitudinal fissure extended from the seat of fracture upwards in such a manner as to divide the upper fragment into two parts, of which the outer bore the greater tuberosity, the inner the articular surface of the head. The latter fragment had become somewhat displaced downwards, and had united in such a manner that the head rested on the lower part of the glenoid cavity. Abduction of the limb therefore brought the greater tuberosity into contact with the acromion process, and movement was checked. This case pa.s.sed out of my observation shortly afterwards, and I have no knowledge of the final result as to movement.

Fractures of the bony processes surrounding the elbow-joint, and of the malleoli of the tibia and fibula, were not infrequent, but offered no special features.

One other form of injury indirectly affecting the joints is perhaps worthy of mention, but I observed it only once, and that in the case of the shoulder, the only joint where it is likely to be marked. I refer to the displacement of the head of the humerus by the force of gravity, when the circ.u.mflex nerve is injured. In the instance I refer to, a fracture of the surgical neck of the humerus was accompanied by complete motor paralysis of the deltoid and very rapid wasting of the muscle. Circ.u.mflex sensation was impaired, but not absent at the time the condition of the muscle was noted--a favourable prognostic sign of much importance. At the end of five weeks, when the fracture of the bone was consolidated, the head of the humerus had dropped vertically at least an inch, but could be replaced with ease. Shortly afterwards an improvement in the condition of the muscle commenced, and with this the head of the humerus was gradually raised. This patient later recovered his power in great part, but not completely.

In a few cases bullets lodged in the neighbourhood of joints in such positions as to limit movement by mechanical impact with the bones. Thus I saw one case in which a bullet lay between the radius and ulna just below the lesser sigmoid cavity; in another the bullet lay in front of the ankle-joint, and limited the possibility of flexion; and in a case related to me by Mr. Bowlby, a bullet was removed by him from the wall of the acetabulum where it was tightly fixed in the substance of the bone. In two other cases I saw bullets lying deeply on the anterior surface of the hip capsule and so limiting flexion. In all such cases the indication for removal of the bullet was sufficiently strongly marked.

WOUNDS OF THE JOINTS

These may be divided into several cla.s.ses, varying much in comparative severity, and in prognostic importance.

1. The comparatively rare instances in which a wound implicated a joint cavity, without accompanying lesion of any bone.

2. Perforating wounds in which the bullet was retained within the articular cavity. These were also rare.

3. Wounds of the joints accompanied by grooving of the articular extremities of the bones.

4. Complete perforating tracks through the articular ends of the bones, crossing the joint cavity in various directions.

5. Comminuted fractures of the terminal parts of the diaphyses extending into joints.

Of these several cla.s.ses, the first was of the least prognostic importance. In the absence of bone injury the wounds usually healed without any obvious ill effect beyond the transient effusion into the joints of a mixture of blood and synovial fluid. When suppuration of the wound in the soft parts occurred, however, the remarks made as to the injuries cla.s.sed under the third heading also apply here in a lesser degree.

With regard to the retention of the bullet, in the case of bullets of small calibre this was a distinctly rare occurrence. I never happened to see an instance of retention of either a Mauser or Lee-Metford bullet in an articulation. It is only possible with bullets practically spent, or travelling at a very low rate of velocity and making irregular impact.

The influence of both volume and velocity of flight was well ill.u.s.trated by my own small experience of retained bullets. In one case a Martini-Henry was found impacted between the femoral condyles, having slipped in beneath the margin of the patella. It caused a semiflexed position to be a.s.sumed by the joint, and was removed by Mr. Brown in No.

1 General Hospital at Wynberg. The second instance I saw in the Portland Hospital at Bloemfontein in a patient of Mr. Bowlby's. The bullet was a Guedes, a form which has been already described as possessing low velocity and deficient power of penetration; beyond this, in the particular instance irregular impact was evidenced by the presence of a large irregular contused wound of entry over the tuberosity of the tibia.

The presence of the bullet in the knee-joint was later determined by the X-rays, and Mr. Bowlby removed it successfully. Seven months later the range of movement was nearly normal.

I may add that I saw several instances of large leaden bullets lodging in the popliteal s.p.a.ce, and a comparatively insignificant number of bullets of small calibre in the same situation. This was very striking, in view of the immense relative frequency of use of the latter forms.