The commencement of an incomplete groove extending from the anterior margin is seen, resembling the groove of the humerus, fig. 58.]

1. _Stellate comminuted fractures._--A shows the primary nature of the lesion in all comminuted fractures of compact bone, consisting in the production of a number of radiating fissures, which a.s.sume a stellate form of which the point of impact corresponds to the centre. B shows an incomplete development of this form, the fragments being simply displaced laterally with slight loss of substance, so as to simulate a real punctured fracture. An ill.u.s.tration of this fracture produced by a bullet travelling at a low degree of velocity is seen in plate XXIII., which also shows the unaltered bullet lying in close proximity to the injured fibula.

The degree of comminution in these fractures depends first on the range of fire and consequent striking force retained by the bullet, a high degree of velocity producing extreme comminution of compact bone. The severity of the latter again may be influenced by the measure of resistance dependent on the density and brittleness of any individual bone, or on the possession of the same characters as a special property by the tissues of the man struck. Thus plate IV. shows a fracture of the humerus produced by a bullet shot from a short range, and the fragments are comparatively large and of even dimensions, while plate XIV. shows extreme comminution of the portion of the femur exposed to direct impact, with elongated large fragments at the sides of the track. Plate XIX. shows less extreme comminution and less separation of the fragments, and was probably produced by a bullet from a longer range of fire.

The separation of elongated lateral fragments is a special feature, and best marked when the portion of bone struck is considerably wider than the bullet, as in the case of the shaft of the femur. These fragments correspond in the method of their production to those seen in the wedge fractures described below, while their separation leaves a pointed extremity to either segment of the shaft. This fracture in its purest type is, I believe, spoken of as the 'b.u.t.terfly fracture.'

With regard to the spread of the fissures in the long axis of the bone into neighbouring articulations I think fractures produced by bullets of small calibre differ considerably from those produced by larger projectiles, in that their general tendency is not to extend beyond the commencement of the cancellous bone forming the joint end. This is perhaps capable of explanation on several grounds: first, the smaller area of impact results in the a.s.sumption of a strongly marked stellate figure, the radiating fissures of which rapidly reach the lateral limits of the shaft, producing a solution of continuity in the bone which interrupts the continuance of the action of the wedge represented by the bullet. Secondly, the small size of the wedge itself is opposed to the wide separation of the parts directly implicated, which is necessary for the continued progress of the process of fissuring, and again the rapidity of pa.s.sage minimises the period during which the force is exerted. It is in these points that I believe the chief differences between the modern and old gunshot fractures find their explanation, since with the larger bullets fractures extending from some distance into the joints were a somewhat special feature. In addition it is probable that the alteration in structure at the junction of the shafts with the cancellous ends also tends to check the regular extension of the fissures, as a similar limitation is ill.u.s.trated even in some fractures by Snider bullets. Fig. 51 of the lower end of the femur ill.u.s.trates a not uncommon lower limit to a comminuted injury in this region.

[Ill.u.s.tration: FIG. 51.--Lower end of Femur. From Case needing amputation. It shows the usual tendency of the fissures to stop short of the articular ends of the long bones]

The degree and nature of the comminution also vary with the directness of impact on the part of the bullet. The more nearly this approaches at a right angle, the more severe is the local comminution, but probably a lesser area of the shaft is implicated. Plate V. shows an example of this: all trace of continuity is lost, a wide gap separates the bone ends, while the fragments themselves have been for the most part driven altogether out of the wound. Oblique impact, on the other hand, may widen the comminuted area at the point of impact, while, if the bullet retains sufficient force and regularity of outline, it may then travel 'cutting its way' through the remainder of the bone in an oblique direction. It will be of course recognised that the exact impact of the bullet depends not alone on the direction of the projectile, but also on the nature of the slope offered by the surface of bone struck.

2. _Wedge fractures._--This form (C and D, fig. 50) is equally characteristic of gunshot injury with pure perforation; it is met with in two varieties. C ill.u.s.trates the more strongly marked type; in it the bullet makes pa.s.sing lateral impact with the shaft, and from the point struck radiating fissures extend to the opposite margin, so that a wedge-shaped piece of bone often secondarily comminuted is separated from the remainder of the shaft; see plate X. of the radius.

The second variety, D, is an incomplete development of the stellate fracture in which the fissures pa.s.s to one margin of the bone only. The explanation of this variation is probably to be sought in the direction of impact on the part of the bullet, since the main fissure is often accompanied by secondary lines which run a somewhat parallel course to the main one, and suggest the dispersion of the force in the form of concentric waves. Such fractures were most strongly marked in the tibia, the breadth of the surfaces of this bone presenting especially favourable conditions for their production.

3. _Notched fractures._--These may be a slight degree of the form of wedge fracture last described; such a one is depicted in plate XXII.

where a portion of the spine of the tibia has been carried away by a pa.s.sing bullet. Other notched fractures approximate themselves more nearly to perforations, the notch being a groove secondary to the opening up of such a track as is shown in the ill.u.s.tration of a perforation of the lower third of the shaft of the tibia (fig. 57 on p.

219). Notching or grooving is naturally much more common in the cancellous portions of bones.

4. _Oblique fractures._--These also occur in two varieties: the first has been already alluded to; in it the bullet actually cuts an oblique track in the bone; the main line of fracture is often considerably comminuted, usually at the proximal end of the track (see plates XV. and XIX.).

The second variety (E, fig. 50) is less common; in it two of the main limbs of the simple stellate figure are suppressed, while the remaining two form a continuous line from one margin of the shaft to the other, the point of impact lying approximately in the centre of the line of fracture. Such a fracture is ill.u.s.trated by the skiagram of a femur in plate XVI. in which the bullet traversed the soft parts transversely at the level of the centre of the fracture, which was 9 inches in length.

In another case the line of fracture occupied the lower third of the femur, pa.s.sing from the inner border of the shaft, the lower end of the upper fragment was formed by the compact tissue forming the outer wall of the external condyle. This latter perforated the vastus externus and lay beneath the skin; as it could not be disentangled, an incision was made over it, and the fragments when reduced were screwed together by Mr. S. W. F. Richardson. In neither fracture was there any comminution.

Such fractures most nearly resemble the oblique or spiral ones met with in civil practice as the results of falls. In all the instances I observed the patients were supported on the lower extremities at the time of the accident, and one can only a.s.sume that a twist of the trunk consequent on the fall of the body diverts the most forcible vibrations resulting from the impact of the bullet into one line, and thus produces a solution of continuity of a simple oblique nature. In both the cases mentioned above the bullet was probably travelling at a low degree of velocity; in the first it was a ricochet and was retained. I never saw one of these fractures in the upper extremity.

Plate XXI. affords an excellent example of this mechanism. The patient was standing when struck, and then fell backwards. An incomplete fissure 7 inches in length is seen to extend from an otherwise pure perforation of the shaft of the tibia.

5. _Transverse fractures._--Throughout these were of very rare occurrence. Plate XX. ill.u.s.trates a pure transverse fracture produced by pa.s.sing contact of a bullet probably fired at a distance not exceeding 400 yards, and which subsequently struck the fibula plumb and produced considerable comminution. No fissure extended into the ankle-joint.

Comminutions such as that ill.u.s.trated by plate V. more or less simulated transverse fractures, but I saw no examples of transverse tracks comparable to the oblique ones described above 'cut through' the shaft of a bone.

6. _Perforations._--Although these were common in cancellous bone, they were comparatively rare in the compact shafts. I saw, however, complete pure perforations of the shafts of the tibia, femur, clavicle, and other bones. These perforations were, I believe, always the result of low degrees of velocity, and they took the place of simple transverse fractures of the 'cut' variety. The apertures of entry and exit in the bones resembled in character those seen in the soft parts, or in the bones of the skull in low-velocity injuries (see figs. 71 and 72, p.

261). The entry was more or less cleanly cut, while at the exit a plate of bone was raised, and either separated or turned back on a hinge by the bullet (fig. 52), (plate XVII.) Such a projecting hinged fragment was sometimes a source of some trouble; thus in a case of postero-anterior perforation of the lower third of the shaft of the femur, the long exit fragment projected into the substance of the quadriceps extensor muscle, and interfered with flexion of the knee-joint. Fig. 57 of a superficial tunnel of the lower third of the tibia is especially interesting as bringing such injuries of the long bones into line with fractures of the flat bones of the skull, such as are ill.u.s.trated in fig. 68, p. 259.

Plate XXI. affords an excellent example of perforation of the shaft of the tibia, although complicated by the secondary fissure.

Plates XXIII., VIII., and III., of the fibula, humerus, and clavicle, exhibit examples of what may be called spurious perforations of the shafts of bones, since comminution or loss of continuity accompanies all three.

Subsequently to writing the above paragraphs, I took the opportunity of re-examining the magnificent series of gunshot fractures collected during the Franco-German campaign by Sir William MacCormac, and afterwards presented by him to the museum of St. Thomas's Hospital.

The close approximation in type between the main features in these and those in the fractures produced by the modern bullet is very striking.

In the case of the shafts of the long bones, the same stellate, oblique, wedge-shaped, and even perforating injuries are ill.u.s.trated on a coa.r.s.er scale. In a specimen of a patella, a perforation of the lower half, implicating also the tendon of the quadriceps muscle is, though large, almost as pure as a Mauser perforation.

The difference in the nature of the lesions of the bones is seen to be, firstly, one of pure magnitude, corresponding to the size of the large Snider bullet by which they were produced. Thus the fragments generally are larger, and occupy a wider area of the shafts, the first character depending on the lesser degree of velocity of the bullet, the latter on its volume and weight. Fine comminution, however, the most striking feature of the modern injury, is throughout absent.

The effect of the larger size of the wedge provided by the bullet in increasing the length of secondary longitudinal fissures is well marked, and for the same reason the perforations are usually accompanied by fissures of considerable extent. It is interesting to note, however, that even in the case of the large bullets, and the special tendency shown by them to cause the extension of fissures into the joints, one or two specimens still show that these fissures incline to stop short when the point of junction between the portion of the shaft occupied by the medullary ca.n.a.l and that built on a foundation of cancellous tissue is reached.

LESIONS OF THE SHORT AND FLAT BONES

The above types of fracture are those common to the shafts of the long bones, but the difference in structure of the articular ends and the short and flat bones endows lesions of these with somewhat different characters, the nature of which varies between grooving, perforation, and great comminution.

The most typical injury consists in the production of a clean perforation of the cancellous bone; this was common both in the articular ends and in the short bones. The tunnel differed little in character from those already described, a tendency always existing to the lifting of a lid of compact tissue at the exit end of the track.

For the production of the cleanest forms of injury I believe high rates of velocity were distinctly favourable, although I am unable to maintain this statement by proof in the case of injuries received at the shortest ranges of fire. When the velocity was lower, yet with force still sufficient to produce a perforating injury, the separation of an extensive scale of bone at the exit aperture was a marked feature not seen in perforations produced by higher degrees of velocity. Fig. 52, of a perforation of the lower end of the femur, well exhibits this feature; but it must be borne in mind in this case that the ill.u.s.tration is not a pure one, both shaft and epiphysis taking part in the walls of the track, and the exit opening is in the former, where a thicker layer of compact bone exists than would cover any epiphysis, and hence the fragment is larger. I use the example, however, because it so forcibly ill.u.s.trates the effect of increased resistance on the part of the bone struck in widening the area of the lesion. When the track was entirely limited to the articular ends the small amount of damage at either aperture was shown by clinical evidence in the rarity of subsequent limitation of joint movements due to bony deformity.

[Ill.u.s.tration: FIG. 52.--Oblique perforation, implicating both epiphysis and diaphysis. Large fragment detached at exit aperture. Caused by a bullet travelling at a low rate of velocity. Compare with figs. 71 and 72 of a skull fracture. The dotted lines indicate the course of the track]

Again, it was rare for fissuring to extend from these tunnels to the articular surfaces; thus many instances could be given of perforation of the head of the humerus, the olecranon, or the femoral condyles, in which no evidence of joint fissure was discoverable. The slight amount of resistance offered by the cancellous ends was also clinically ill.u.s.trated by the absence of severe synovial effusions when they were struck. When the joint cavity was not crossed, slight effusion only resulted, while in the case of fractures of the femoral shaft great effusion into the knee-joint, resulting from the forcible vibration transmitted to the limb, was a common feature, even when the point fractured was situated above the centre of the bone. Again, when the joint cavity was crossed a moderate degree only of haemarthrosis was the most common result.

With regard to the implication of joints, either primary or secondary, in connection with fractures of the articular ends, I am inclined to place the lesions of the upper end of the tibia in a more important position than those of any other bone. Evidence of this implication was in my experience more frequent here than in any other situation. This may in part be attributable to the complexity of structure of this epiphysis, and perhaps more correctly to the influence of its irregular outline in favouring lateral forms of impact on the part of the bullet and consequent increase in the area of damage.

Next to tunnelling, grooving was the most common form of injury to the short bones. In the case of superficial tracks the compact tissue might be considerably comminuted, but not, as a rule, over a width greatly exceeding the calibre of the bullet.

Comminution and crushing of a single or several bones were rare in proportion to the occurrence of similar injuries produced by Martini-Henry or large leaden bullets. When the condition was produced by bullets of small calibre, I believe it was in the majority of cases the result of irregular impact on the part of the projectile. In support of this view it may be added that such injuries were most common in the bones of the tarsus, bones especially liable to be struck by ricochet bullets.

It was generally believed that bullets travelling at a very high degree of velocity were liable to cause severe comminution of the short bones, but I never saw any cases supporting this opinion; in point of fact, all the short-range lesions of this nature that I saw were of the clean perforating variety. I believe that this is capable of satisfactory explanation on the ground of the thin character of the layer of compact tissue which for the most part ensheaths the short bones; this decreases the resistance offered to the bullet and so tends to localise the lesion. This statement may be supported by two observations with regard to the long and flat bones. First, if the shaft of a long bone be hit above the junction of diaphysis and epiphysis, the cancellous tissue in and extending from the medullary cavity is pulverised, and examination of fragments from such fractures gives the impression of the inner aspect having been sc.r.a.ped clean. Secondly, I saw one fracture of the ilium produced by a bullet taking a course between its compact layers for 3 inches from the notch between the anterior superior and anterior inferior spines; the bone to the extent of 2-1/2 square inches was pulverised, the cancellous tissue blown away as dust, and the compact tissue only represented by scales still adhering by their periosteum to the muscles attached to the two surfaces of the bone. This injury was produced from a rifle fired at five yards distance, and was an extreme example; but, on the other hand, it ill.u.s.trates only what we are thoroughly well acquainted with in the case of flat bones, such as those of the cranium, where the compact element is abundant in comparison with the cancellous, and the resistance offered to the bullet is consequently great.

Some remarks on transverse fractures of the patella will be found under the heading devoted to that bone.

Lesions of the flat bones are considered at some length in Chapter VII., which deals with injuries to the head, and their special features are there described; some further remarks on these injuries will be found under the headings of the individual bones.

_Special characters of the symptoms observed, and of the course of healing of the fractures._--Peculiarities in the initial signs may be rapidly pa.s.sed over. The first depended on the large number of lesions of the bone which were unaccompanied by loss of continuity. In the case of perforations attention to the course of the track, external palpation, and possibly the detection of bone dust in the aperture of exit, were usually sufficient to indicate injury to the bones. When these did not suffice the introduction of a probe would usually set the question at rest; but this is always to be avoided if possible, as adding a fresh item of risk to the wound. The X rays were not always to hand, and are not always capable of giving reliable information in the matter of perforations, although very useful in detecting grooves or notching. The latter injuries are those in which information as to the condition of the bones is often of most interest in view of the characters of the external wounds.

Fractures with solution of continuity were, as a rule, easy of detection, but the relative prominence of the cla.s.sical signs varied somewhat from what we are accustomed to see in civil practice.

The first striking peculiarity noted in comminuted fractures of the long bones was the degree of local shock; the limbs were often quite powerless, the muscles flaccid, and common sensation lowered. This was of importance in two ways; firstly, shortening of the limb was often absent as a sign, and, secondly, pain was sometimes not at all p.r.o.nounced even when the patient was moved. The primary absence of shortening, even persisting for the first two or three days, was a phenomenon always important to bear in mind, as it affected the degree of extension needed in the treatment of the fracture, which, if sufficient at the moment, often proved quite inadequate with the return of tone in the muscles. Secondly, abnormal mobility was usually strongly marked, and this sometimes without very definite crepitus, as a result of the fine nature of the comminution and the displacement of the small fragments.

During the course of healing some other peculiarities are worthy of mention. First of all, union was tardy and often not strong. On the other hand, an abundance of provisional callus was common, which formed large swellings apt to implicate neighbouring nerves, and sometimes to interfere with the movements of joints. The slowness of healing was particularly noticeable in those cases where the degree of local shock had been marked, and was probably to some extent dependent on disturbance of the general nutrition of the tissues of the affected limb. Beyond this, however, it was in many cases a direct result of the degree of comminution and displacement of the fragments, which necessitated the formation of a large amount of provisional callus, and time for the proper consolidation and contraction of the same. In many cases a large ball-like ma.s.s of callus surrounding the fragments was developed, into which the actual ends of the broken bone only dipped, and hence union was weak and insecure. As to those cases in which the wounds closed by primary union, we must bear in mind in this relation the tardy union often observed in civil practice, when the irritation of suppuration and consequent inflammation are absent.

Another peculiarity of a similar nature was the occasional late necrosis of fragments; the wounds apparently healed well, only to break down weeks or months later for the discharge of a sequestrum. Such cases were quite distinct from those in which primary suppuration had occurred. I saw one or two instances in fractures of the humerus, the trouble arising with commencing use of the limb, and I suppose that fragments which suffered death at the time of the injury had been enclosed, and only caused irritation as foreign bodies when the muscles again came into action. In the absence both of evident necrosis and suppuration, however, in some cases the exit portion of the track in the soft parts was extremely slow in healing. Although no discharge beyond a small quant.i.ty of blood-tinged serum escaped, the wounds remained open for many weeks, even when the fracture consolidated well. I ascribed this to slow separation of aseptic sloughs, a point which has already been mentioned under the heading of wounds in general.

Superabundance of callus, as far as I had an opportunity of judging, comparatively seldom gave rise to permanent mechanical trouble. This was no doubt due to the infrequency of extension of the comminuted fractures beyond the junction of diaphysis and epiphysis.

Lastly, with regard to suppuration, only a small proportion of the fractures, accompanied by the presence of large wounds, escaped infection. When infection did occur, the results offered some special features dependent on the small relative amount of damage to the soft tissues, compared with that suffered by the bone. In an ordinary compound fracture, such as we meet with in civil practice, whether the result of direct or indirect violence, a considerable amount of contusion or laceration, as the case may be, accompanies the injury to the bone. The result of this is a widespread effusion of blood into the limb, which tears and strips up the various layers of soft parts, and opens up the way to the spread of infection, often into the whole length of the segment of the limb affected. In fractures produced by bullets of small calibre, even when the exit portion of the track is large, the injury to the soft parts is far more localised, except in extreme cases, while the bone itself is the tissue which has suffered the most severe violence and contusion. When infection occurred, its spread corresponded with this anatomical feature of the lesion, and the bone itself and its immediate neighbourhood suffered the most severely.

At the present day one is naturally not very familiar with a large series of suppurating compound fractures, but during my whole experience I have never seen so many cases of what might be regarded as fairly pure instances of acute osteo-myelitis. The symptoms corresponded with the main seat of the suppuration; only moderate swelling of the limbs occurred, this mainly consisting in soft superficial oedema; often there was no redness, and fluctuation was difficult to determine. At the same time symptoms of const.i.tutional infection, such as continued fever, rapid pulse, restlessness, loss of strength, progressive anaemia, and emaciation, were marked. Pyaemia, as evidenced by secondary deposits, was, however, rare; I only saw two cases, both in fractures of the femur; in both recovery followed secondary amputation.

_Prognosis._--This depended almost entirely on the nature of the injury to the soft parts; given moderate injury to these, and the preservation of the wound from infection, scarcely any degree of injury of the bones precluded recovery, even if this were slow and prolonged. The existence of perforations scarcely increased to an important extent the gravity of a wound of the soft parts alone; in fact, this injury could not be regarded as more severe than an ordinary surgical osteotomy, putting the risks of infection of the wound under the special circ.u.mstances on one side.

With regard to the functional results, these depended on the degree of comminution; when this was extreme, union was slow and for a time weak, and shortening was often considerable, but a fair result was as a rule obtained.

Suppuration and osteo-myelitis were the dangerous features when they occurred; still, even in the presence of these, I never saw a fatal result in an upper extremity fracture, although in the lower extremity a considerable mortality followed fractures both of the leg and thigh, the deaths being most commonly from septicaemia, or from a combination of this with secondary haemorrhage.

_Treatment._--The general treatment was of a simple character. The perforations may be at once dismissed, since nothing more was needed than what has been already described under the heading of wounds of the soft parts. Again, with regard to the co-existence of vascular injury, or injury to the soft parts generally, the ordinary rules guiding us in civil practice were followed.

The first point of importance, and needing consideration in the treatment of severely comminuted fractures, was as to whether in these it was better simply to try to obtain union of the wound with as little disturbance as possible, or to anaesthetise the patient and explore the wound, removing such fragments as were free or widely displaced. I think the answer to this question depends entirely on the nature of the external wounds. If these be of the small type forms, or if the exit aperture is, at any rate, of only moderate size, a strictly conservative att.i.tude is the better when the risk of making an exploration under the circ.u.mstances is borne in mind, the more so as an exploration, to be safe and useful, ought to be done at once. If the exit wound is of the large or explosive type, on the other hand, there is no doubt that the best results are to be obtained by early exploration and the removal of all loose fragments. I saw several excellent results obtained in this way, even when the patients had to undergo the risk of transport shortly, in some cases the very next day, after the operation. The loose fragments are an immediate source of danger, and later may interfere with the healing of the fracture, even if suppuration does not occur. In all the cases that I saw the exit wound was dressed, but left freely open, and I do not think any attempt to close it should ever be made.