Thus the time required for the consolidation of the fractured segments is divisible into two distinct periods. In the first they are surrounded by an external bony ring, and the medullary cavity is closed by a bony plug or stopper, const.i.tuting the period of the provisional callus. This is followed by the period of permanent callus, during which the process of converting the cartilaginous into the osseous form is going forward.

The restorative process is sooner completed in the carnivorous than in the herbivorous tribes. In the former the temporary callus may attain sufficient fineness of consistency for the careful use of the limb within four weeks, but with the latter a period of from six weeks to two months is not too long to allow before removing the supporting apparatus from the limb.

This, in general terms, represents the fact when the resources of nature have not been thwarted by untoward accidents, such as a want of vigor in the const.i.tution of the patient or a lack of skill on the part of the pract.i.tioner, and especially when, from any cause, the bony fragments have not been kept in a state of perfect immobility and the constant friction has prevented the osseous union of the two portions. Failures and misfortunes are always more than possible, and instead of a solid and practicable bony union the sequel of the accident is sometimes a false joint, composed of mere flexible cartilage, a poor pseudarthrosis.

The explanation of this appears to be that, first, the sharp edges of the ends of the bone disappear by becoming rounded at their extremities by friction and polishing against each other. Then follows an exudation of a plastic nature which becomes transformed into a cartilaginous layer of a rough, articular aspect. In this bony nuclei soon appear, and the lymph secreted between the segments thus transformed, instead of becoming truly ossified, is changed into a sort of fibrocartilaginous pouch, or capsular sac, in which a somewhat alb.u.minous secretion, or pseudo-synovia, permits the movement to take place. Most commonly, however, in our animals, the union of the bony fragments is obtained wholly through the medium of a layer of fibrous tissue, and it is because the union has been accomplished by a ligamentous formation only that motion becomes practicable.

_Prognosis._--The prognosis in a case of fracture in an animal is one of the gravest vital import to the patient, and therefore of serious pecuniary concern to his owner. The period has not long elapsed when to have received such a hurt was quite equivalent to undergoing a sentence of death for the suffering animal, and perhaps to-day a similar verdict is p.r.o.nounced in many cases in which the exercise of a little mechanical ingenuity, with a due amount of careful nursing, might secure a contrary result and insure the return of the patient to his former condition of soundness and usefulness.

_Treatment._--Considered per se, a fracture in an animal is in fact no less amenable to treatment than the same description of injury in any other living being. But the question of the propriety and expediency of treatment is dependent upon certain specific points of collateral consideration.

(1) The nature of the lesion is a point of paramount importance. A simple fracture occurring in a bone where the ends can be firmly secured in coaptation presents the most favorable condition for successful treatment. If it is that of a long bone, it will be the less serious if situated at or near the middle of its length than if it were in close proximity to a joint, from the fact that perfect immobility can rarely, in the latter case, be secured without incurring the risk of subsequent rigidity of the joint.

A simple is always less serious than a compound fracture. A comminuted is always more dangerous than a simple, and a transverse break is easier to treat than one which is oblique. The most serious are those which are situated on parts of the body in which it is difficult to obtain perfect immobility, and especially those which are accompanied with severe contusions and lacerations in the soft parts; the protrusion of fragments through the skin; the division of blood vessels by the broken ends of the bone; the existence of an articulation near the point to which inflammation is liable to extend; the luxation of a fragment of the bone; laceration of the periosteum; the presence of a large number of bony particles, the result of the crushing of the bone--all these are circ.u.mstances which discourage a favorable prognosis, and weigh against the hope of saving the patient for future usefulness.

Fractures which may be accounted curable are those which are not conspicuously visible, as those of the ribs, where displacements are either very limited or do not occur, the parts being kept in situ by the nature of their position, the shape of the bones, the articulations they form with the vertebra, the sternum, or their cartilages of prolongation; those of transverse processes of the lumbar vertebra; those of the bones of the face; those of the ilium; and that of the coffinbones. To continue the category, the following are evidently curable when their position and the character of the patient contribute to aid the treatment: Those of the cranium, in the absence of cerebral lesions; those of the jaws; of the ribs, with displacement; of the hip; and those of the bones of the leg in movable regions, but where their vertical position admits of perfect coaptation.

On the contrary, a compound, complicated, or comminuted, fracture, in whatever region it may be situated, may be counted incurable.

In treating fractures time is an important element and "delays are dangerous." Those of recent occurrence unite more easily and more regularly than older ones.

(2) As a general rule, fractures are less serious in animals of the smaller species than in those of more bulky dimensions. This influence of species will be readily appreciated when we realize that the difficulties involved in the treatment of the latter cla.s.s have hardly any existence in connection with the former. The difference in weight and size, and consequent facility in handling and making the necessary applications of dressings and other appliances for the purpose of securing the indispensable immobility of the parts, and usually a less degree of uneasiness in the deportment of the patients are considerations in this connection of great weight.

(3) In respect to the utilization of the animal, the most obvious point in estimating the gravity of the case in a fracture accident is the certainty of the total loss of the services of the patient during treatment--certainly for a considerable period of time; perhaps permanently. For example, the fracture of the jaw of a steer just fattening for the shambles will involve a heavier loss than a similar accident to a horse. Usually the fracture of the bones of the extremities in a horse is a very serious casualty, the more so proportionately as the higher region of the limb is affected. In working animals it is exceedingly difficult to treat a fracture in such manner as to restore a limb to its original perfection of movement. A fracture of a single bone of an extremity in a breeding stallion or mare will not necessarily impair the value of the animal as a breeder. Other specifications under this head, though pertinent and more or less interesting, may be omitted.

(4) Age and temper are important factors of cure. A young, growing, robust patient whose vis vitae is active is amenable to treatment which one with a waning const.i.tution and past mature energies would be unable to endure, and a docile, quiet disposition will act cooperatively with remedial measures which would be neutralized by the fractious opposition of a peevish and intractable sufferer.

The fulfillment of three indications is indispensable in all fractures.

The first is the reduction, or the replacement, of the parts as nearly as possible in their normal position. The second is their retention in that position for a period sufficient for the formation of the provisional callus, and the third, which, in fact, is but an incident of the second, the careful avoidance of any accidents or causes of miscarriage which might disturb the curative process.

In reference to the first consideration, it must be remembered that the accident may befall the patient at a distance from his home, and his removal becomes the first duty to be attended to. Of course, this must be done as carefully as possible. If he can be treated on the spot, so much the better, though this is seldom practicable, and the method of removal becomes the question calling for settlement. But two ways present themselves--he must either walk or be carried. If the first, it is needless to say that every caution must be observed in order to obviate additional pain and to avoid any aggravation of the injury. Led slowly, and with partial support, if practicable, the journey will not always involve untoward results. If he is carried, it must be by means of a wagon, a truck, or an ambulance; the last being designed and adapted to the purpose, would, of course, be the most suitable vehicle.

As a precaution which should never be overlooked, a temporary dressing should first be applied. This may be so done as for the time to answer all the purposes of the permanent adjustment and bandaging. Without thus securing the patient, a fracture of an inferior degree may be transformed to one of the severest kind, and, indeed, a curable changed to an incurable injury. We recall a case in which a fast-trotting horse, after running away in a fright caused by the whistle of a locomotive, was found on the road limping with excessive lameness in the off fore leg, and walked with comparative ease some 2 miles to a stable before being seen by a surgeon. His immediate removal in an ambulance was advised, but before that vehicle could be procured the horse lay down, and upon being made to get upon his feet was found with a well-marked comminuted fracture of the os suffraginis, with considerable displacement. The patient, however, after long treatment, made a comparatively good recovery and though with a large, bony deposit, a ringbone, was able to trot in the forties.

The two obvious indications in cases of fracture are reduction, or replacement, and retention.

In an incomplete fracture, where there is no displacement, the necessity of reduction does not exist. With the bone kept in place by an intact periosteum, and the fragments secured by the uninjured fibrous and ligamentous structure which surrounds them, there is no dislocation to correct. Reduction is also at times rendered impossible by the seat of the fracture itself, by its dimensions, alone, or by the resistance arising from muscular contraction. That is ill.u.s.trated even in small animals, as in dogs, by the exceeding difficulty encountered in bringing together the ends of a broken femur or humerus, the muscular contractions being even in these animals sufficiently forcible to renew the displacement.

It is generally, therefore, only fractures of the long bones, and then at points not in close proximity to the trunk, that may be considered to be amenable to reduction. It is true that some of the more superficial bones, as those of the head, of the pelvis, and of the thoracic walls, may in some cases require special manipulations and appliances for their retention in their normal positions; hence the treatment of these and of a fractured leg can not be the same.

The methods of accomplishing reduction vary with the features of each case, the manipulations being necessarily modified to meet different circ.u.mstances. If the displacement is in the thickness of the bone, as in transverse fracture, the manipulation of reduction consists in applying constant pressure upon one of the fragments, while the other is kept steady in its place, the object of the pressure being the reestablishment of the exact coincidence of the two bony surfaces. If the displacement has taken place at an angle it will be sufficient in order to effect the reduction to press upon the summit, or apex, of the angle until its disappearance indicates that the parts have been brought into coaptation. This method is often practiced in the treatment of a fractured rib. In a longitudinal fracture, or when the fragments are pressed together by the contraction of the muscles to which they give insertion until they so overlap as to correspond by certain points of their circ.u.mference, the reduction is to be accomplished by effecting the movements of extension, counter extension, and coaptation. Extension is accomplished by making traction upon the lower portion of the limb.

Counter extension consists in firmly holding or confining the upper or body portion in such manner, that it shall not be affected by the traction applied to the lower part. In other words, the operator, grasping the limb below the fracture, draws it down or away from the trunk, while he seeks not to draw away, but simply to hold the upper portion still until the broken ends of bone are brought to their natural relative positions, when the coaptation, which is thus effected, has only to be made permanent by the proper dressings to perfect the reduction.

In treating fractures in small animals the strength of the hand is usually sufficient for the required manipulations. In the fracture of the forearm of a dog, for example, while the upper segment is firmly held by one hand the lower may be grasped by the other and the bone itself made to serve the purpose of a lever to bring about the desired coaptation. In such case that is sufficient to overcome the muscular contraction and correct the overlapping or other malposition of the bones. If, however, the resistance can not be overcome in this way, the upper segment may be committed to an a.s.sistant for the management of the counter extension, leaving to the operator the free use of both hands for the further manipulation of the case.

If the reduction of fractures in small animals is an easy task, however, it is far from being so when the patient is a large animal whose muscular force is largely greater than that of several men combined. In such case resort must be had not only to superior numbers for the necessary force, but in many cases to mechanical aids. A reference to the manner of proceeding in a case of fracture with displacement of the forearm of a horse will ill.u.s.trate the matter. The patient is first to be carefully cast, on the uninjured side, with ropes or a broad, leather strap about 18 feet long pa.s.sed under and around his body and under the axilla of the fractured limb and secured at a point opposite to the animal and toward his back. This will form the mechanical means of counter extension. Another rope will then be placed around the inferior part of the leg below the point of fracture, with which to produce extension, and this will sometimes be furnished with a block and pulleys, in order to augment the power when necessary; there is, in fact, always an advantage in their use, on the side of steadiness and uniformity, as well as of increased power. It is secured around the fetlock or the coronet or, what is better, above the knee and nearer the point of fracture, and is committed to a.s.sistants. The traction on this should be firm, uniform, and slow, without relaxing or jerking, while the operator carefully watches the process. If the bone is superficially situated he is able, by the eye, to judge of any changes that may occur in the form or length of the parts under traction, and discovering, at the moment of its happening, the restoration of symmetry in the disturbed region he gently but firmly manipulates the place until all appearance of severed continuity has vanished. Sometimes the fact and the instant of restoration are indicated by a peculiar sound or "click"

as the ends of the bones slip into contact, to await the next step of the restorative procedure.

The process is the same when the bones are covered with thick muscular ma.s.ses except that it is attended with greater difficulties from the fact that the finger must be subst.i.tuted for the eye and taxis must take the place of sight.

It frequently happens that perfect coaptation is prevented by the interposition, between the bony surfaces, of such substances as a small fragment of detached bone or a clot of blood; sometimes the extreme obliquity of the fracture, by permitting the bones to slip out of place, is the opposing cause. These are difficulties which can not always be overcome, even in small-sized animals, and still it is only when they are mastered that a correct consolidation can be looked for. Without it the continuity between the fragments will be by a deformed callus, the union will leave a shortened, crooked, or angular limb, and the animal will be disabled.

If timely a.s.sistance can be obtained, and the reduction accomplished immediately after the occurrence of the accident, that is the best time for it, but if it can not be attended to until inflammation has become established and the parts have become swollen and painful, time must be allowed for the subsidence of these symptoms before attempting the operation. A spasmodic, muscular contraction which sometimes interposes a difficulty may be easily overcome by subjecting the patient to general anesthesia, and need not, therefore, cause any loss of time. A tendency to this may also be overcome by the use of sedatives and antiphlogistic remedies.

The reduction of the fracture having been accomplished, the problem which follows is that of retention. The parts which have been restored to their natural position must be kept there, without disturbance or agitation, until the perfect formation of a callus, and it is here that ample lat.i.tude exists for the exercise of ingenuity and skill by the surgeon in the contrivance of the necessary apparatus. One of the most important of the conditions which are available by the surgeon in treating human patients is denied to the veterinarian in the management of those which belong to the animal tribes. This is position. The intelligence of the human patient cooperates with the instructions of the surgeon, in the case of the animal sufferer there is a continual antagonism between the parties, and the forced extension and fatiguing position which must for a considerable period be maintained as a condition of restoration require special and effective appliances to insure successful results. To obtain complete immobility is scarcely possible, and the surgeon must be content to reach a point as near as possible to that which is unattainable. For this reason, as will subsequently be seen, the use of slings and the restraint of patients in very narrow stalls is much to be preferred to the practice sometimes recommended of allowing entire freedom of motion by turning them loose in box stalls. Temporary and movable apparatus are not usually of difficult use in veterinary practice, but the restlessness of the patients and their unwillingness to submit quietly to the changing of the dressings render it obligatory to have recourse to permanent and immovable bandages, which should be retained without disturbance until the process of consolidation is complete.

The materials composing the retaining apparatus consist of oak.u.m, bandages, and splints, with an agglutinating compound which forms a species of cement by which the different const.i.tuents are blended into a consistent ma.s.s to be spread upon the surface covering the locality of the fracture. Its components are black pitch, rosin, and Venice turpentine, blended by heat. The dressing may be applied directly to the skin, or a covering of thin linen may be interposed. A putty made with powdered chalk and the white of egg is recommended for small animals, though a mixture of sugar of lead and burnt alum with the alb.u.men is preferred by others. Another formula is spirits of camphor, Goulard's extract, and alb.u.men. Another recommendation is to saturate the oak.u.m and bandages with an adhesive solution formed with gum arabic, dextrin, flour paste, or starch. This is advised particularly for small animals, as is also the silicate of soda. Dextrin mixed while warm with burnt alum and alcohol cools and solidifies into a stony consistency, and is preferable to plaster of Paris, which is less friable and has less solidity, besides being heavier and requiring constant additions as it becomes older. Starch and plaster of Paris form another good compound.

In applying the dressing the leg is usually padded with a cushion of oak.u.m thick and soft enough to equalize the irregularities of the surface and to form a bedding for the protection of the skin from chafing. Over this the splints are placed. The material for these is, variously, pasteboard, thin wood, bark, laths, gutta-percha, strips of thin metal, as tin or perhaps sheet iron. They should be of sufficient length not only to cover the region of the fracture but to extend sufficiently above and below to render the immobility more nearly complete than in the surrounding joints. The splints, again, are covered with cloth bandages--linen preferably--soaked in a glutinous mixture.

These bandages are to be carefully applied, with a perfect condition of lightness. They are usually made to embrace the entire length of the leg in order to avoid the possibility of interference with the circulation of the extremity as well as for the prevention of chafing. They should be rolled from the lower part of the leg upward and carefully secured against loosening. In some instances suspensory bandages are recommended, but except for small animals our experience does not justify a concurrence in the recommendation.

These permanent dressings always need careful watching with reference to their immediate effect upon the region they cover, especially during the first days succeeding that of their application. Any manifestation of pain, or any appearance of swelling above or below, or any odor suggestive of suppuration should excite suspicion, and a thorough investigation should follow without delay. The removal of the dressing should be performed with great care, and especially so if time enough has elapsed since its application to allow of a probability of a commencement of the healing process or the existence of any points of consolidation. With the original dressing properly applied in its entirety in the first instance, the entire extremity will have lost all chance of mobility, and the repairing process may be permitted to proceed without interference. There will be no necessity and there need be no haste for removal or change except under such special conditions as have just been mentioned, or when there is reason to judge that solidification has become perfect, or for the comfort of the animal, or for its readaptation in consequence of the atrophy of the limb from want of use. Owners of animals are often tempted to remove a splint or bandage prematurely at the risk of producing a second fracture in consequence of the failure of the callus properly to consolidate.

The method of applying the splints which we have described refers to the simple variety only. In a compound case the same rules must be observed, with the modification of leaving openings through the thickness of the dressing, opposite the wound, in order to permit the escape of pus and to secure access to the points requiring the application of treatment.

FRACTURE OF CRANIAL BONES.

Fractures of the cranial bones in large animals are comparatively rare, though the records are not dest.i.tute of cases. When they occur, it is as the result of external violence, the sufferers being usually run-aways which have come in collision with a wall or a tree or other obstruction, or it may occur in those which in pulling upon the halter have broken it with a jerk and been thrown backward, as may occur in rearing too violently. Under these conditions we have witnessed fractures of the parietal, of the frontal, and of the sphenoid bones. These fractures may be of both the complete and the incomplete kinds, which indeed is usually the case with those of the flat bones, and they are liable to be complicated with lacerations of the skin, in consequence of which they are easily brought under observation. When the fact is otherwise and the skin is intact, however, the diagnosis becomes difficult.

_Symptoms._--The incomplete variety may be unaccompanied with any special symptoms, but in the complete kind one of the bony plates may be so far detached as to press upon the cerebral substance with sufficient force to produce serious nervous complications. When the injury occurs at the base of the cranium hemorrhage may be looked for, with paralytic symptoms, and when these are present the usual termination is death. It may happen, however, that the symptoms of an apparently very severe concussion may disappear, resulting in an early and complete recovery, and the surgeon will therefore do well to avoid undue haste in venturing upon a prognosis. In fractures of the orbital or the zygomatic bones the danger is less pressing than with injuries otherwise located about the head.

_Treatment._--The treatment of cranial fractures is simple, though involving the best skill of an experienced surgeon. When incomplete hardly any interference is needed; even plain bandaging may usually be dispensed with. In the complete variety the danger to be combated is compression of the brain, and attention to this indication must not be delayed. The means to be employed are the trephining of the skull over the seat of the fracture and the elevation of the depressed bone or the removal of the portion which is causing the trouble. Fragments of bone in comminuted cases, bony exfoliations, collections of fluid, or even protruding portions of the brain substance must be carefully cleansed away and a simple bandage so applied as to facilitate the application of subsequent dressings.

FRACTURES OF THE BONES OF THE FACE.

In respect to their origin--usually traumatic--these injuries rank with the preceding, and are commonly of the incomplete variety. They may easily be overlooked, and may even sometimes escape recognition until the reparative process has been well established and the wound is discovered owing to the prominence caused by the presence of the provisional callus which marks its cure. When the fracture is complete it will be marked by local deformity, mobility of the fragments, and crepitation. Nasal hemorrhage, roaring, frequent sneezing, loosening or loss of teeth, difficulty of mastication, and inflammation of the cavities of the sinuses are varying complications of these accidents.

The object of the treatment should be the restoration of the depressed bones as nearly as possible to their normal position and their retention in place by protecting splints, which should cover the entire facial region. Special precautions should be observed to prevent the patient from disturbing the dressing by rubbing his head against surrounding objects, such as the stall, manger, rack, etc. Clots of blood in the nasal pa.s.sages must be washed out, collections of pus removed from the sinuses, and, if the teeth are loosened and liable to fall out, they should be removed. If roaring is threatened, tracheotomy is indicated.

FRACTURES OF THE PREMAXILLARY BONE.

These are mentioned by continental authors and are usually encountered in connection with fractures of the nasal bone, and may take place either in the width or the length of the bone.

The deformity of the upper lip, which is drawn sidewise in this lesion, renders it easy of diagnosis. The abnormal mobility and the crepitation, with the pain manifested by the patient when undergoing examination, are concurrent symptoms. Looseness of the teeth, abundant salivation, and entire inability to grasp the feed complete the symptomatology of these accidents. In the treatment splints of gutta-percha or leather are sometimes used, but they are of difficult application. Our own judgment and practice are in favor of the union of the bones by means of metallic sutures.

FRACTURES OF THE LOWER JAW.

A fracture here is not an injury of infrequent occurrence. It involves the body of the bone, at its symphysis, or back of it, and includes one or both of its branches, either more or less forward, or at the posterior part near the temporomaxillary articulation, at the coronoid process.

Falls, blows, or other external violence, or powerful muscular contractions during the use of the speculum, may be mentioned among the causes of this lesion. The fracture of the neck, or that portion formed by the juncture of the two opposite sides, and of the branches in front of the cheeks, causes the lower jaw, the true dental arch, to drop, without the ability to raise it again to the upper, and the result is a peculiar and characteristic physiognomy. The prehension and mastication of feed become impossible; there is an abundant escape of fetid and sometimes b.l.o.o.d.y saliva, especially if the gums have been wounded; there is excessive mobility of the lower end of the jawbone; and there is crepitation, and frequently paralysis of the under lip. Although an animal suffering with a complete and often compound and comminuted fracture of the submaxilla presents at times a serious aspect, the prognosis of the case is comparatively favorable, and recovery is usually only a question of time. The severity of the lesion corresponds in degree to that of the violence to which it is due, also to the resulting complications and the situation of the wound. It is simple when at the symphysis, but becomes more serious when it affects one of the branches, and most aggravated when both are involved. Fracture of the coronoid process becomes important princ.i.p.ally as an evidence of the existence of a morbid diathesis, such as osteoporosis, or the like.

The particular seat of the injury, with its special features, will, of course, determine the treatment. For a simple fracture, without displacement, provided there is no laceration of the periosteum, an ordinary supporting bandage will usually be sufficient, but when there is displacement the reduction of the fracture must first be accomplished, and for this special splints are necessary. In a fracture of the symphysis or of the branches the adjustment of the fragments by securing them with metallic sutures is the first step necessary, to be followed by the application of supports, consisting of splints of leather or sheets of metal, the entire front of the head being then covered with bandages prepared with adhesive mixtures. During the entire course of treatment a special method of feeding becomes necessary. The inability of the patient to appreciate the situation, of course, necessitates a resort to an artificial mode of introducing the necessary feed into his stomach; this is accomplished by forcing between the commissures of the lips, in a liquid form, by means of a syringe, the milk or nutritive gruels selected for his sustenance until the consolidation is sufficiently advanced to permit the ingestion of feed of a more solid consistency. The callus will usually be sufficiently hardened in two or three weeks to allow of a change of diet to mashes of cut hay and scalded grain, until the removal of the dressing restores the animal to its old habit of mastication.

FRACTURES OF VERTEBRae.

These are not very common, but when they do occur the bones most frequently injured are those of the back and loins.