Part 48

DISEASES OF MUSCLES AND TENDONS.

SPRAINS.

This term expresses a more or less complete laceration or yielding of the fibers of the muscles, tendons, or the sheaths surrounding and supporting them. The usual cause of a sprain is external violence, such as a fall or a powerful exertion of strength, with following symptoms of soreness, heat, swelling, and a suspension of function. Their termination varies from simple resolution to suppuration, and commonly fibrinous exudation difficult to remove. None of the muscles or tendons of the body are exempt from liability to this lesion, though naturally from their uses and the exposure of their situation the extremities are more liable than other regions to become their seat. The nature of the prognosis will be determined by a consideration of the seat of the injury and the complications likely to arise.

Treatment.—The treatment will resolve itself into the routine of local applications, including warm fomentations, stimulating liniments, counterirritation by blistering, and in some cases even firing. Rest, in the stable or in a box stall, will be of advantage by promoting the absorption of whatever fibrinous exudation may have formed, or absorption may be stimulated by the careful persevering application of iodin in the form of ointments of various degrees of strength.

There are many conditions in which not only the muscular and tendinous structures proper are affected by a strain, but, by contiguity of parts, the periosteum of neighboring bones may become involved, with a complication of periostitis and its sequelae.

LAMENESS OF THE SHOULDER.

The frequency of the occurrence of lameness in the shoulder from sprains entitles it to precedence of mention in the present category, for, though so well covered with its muscular envelope, it is often the seat of injuries which, from the complex structure of the region, become difficult to diagnosticate with satisfactory precision and facility. The flat bone which forms the skeleton of that region is articulated in a comparatively loose manner with the bone of the arm, but the joint is, notwithstanding, rather solid, and is powerfully strengthened by tendons passing outside, inside, and in front of it. Still, shoulder lameness or sprain may exist, originating in lacerations of the muscles, the tendons or the ligaments of the joint, or perhaps in diseases of the bones themselves. "Slip of the shoulder" is a phrase frequently applied to such lesions.

The identification of the particular structures involved in these lesions is of much importance, in view of its bearing upon the question of prognosis. For example, while a simple superficial injury of the spinatus muscles, or the muscles by which the leg is attached to the trunk, may not be of serious import and may readily yield to treatment, or even recover spontaneously and without interference, the condition is quite changed in a case of tearing of the flexor brachii, or of its tendons as they pass in front of the articulation, or, what is still more serious, if there is inflammation or ulceration in the groove over which this tendon slides, or upon the articular surfaces or their surroundings, or periostitis at any point adjacent.

Causes.—The frequency of attacks of shoulder lameness is not difficult to account for. The superficial and unprotected position of the part and the numerous movements of which it is capable, and which, in fact, it performs, render it both subjectively and objectively preeminently liable to accident or injury. It would be difficult and would not materially avail to enumerate all the forms of violence by which the shoulder may be crippled. A fall, accompanied with powerful concussion; a violent muscular contraction in starting a heavily loaded vehicle from a standstill; a misstep following a quick muscular effort; a jump accompanied with miscalculated results in alighting; a slip on a smooth, icy road; balling the feet with snow; colliding with another horse or other object—indeed, the list may be indefinitely extended, but without profit or utility.

Symptoms.—Some of the symptoms of shoulder lameness are peculiar to themselves, and yet the trouble is frequently mistaken for other affections—navicular disease more often than any other. The fact that in both affections there are instances when the external symptoms are but imperfectly defined, and that one of them especially is very similar in both, is sufficient to mislead careless or inexperienced observers and to occasion the error which is sometimes committed of applying to one disease the name of the other, erring both ways in the interchange. The true designation of pathological lesions is very far at times from being of certain and easy accomplishment, and, owing to the massive structure of the parts we are considering, this is especially true in the present connection. Still there are many cases in which there is really no reasonable excuse for an error in diagnosis by an average practitioner.

Shoulder lameness will, of course, manifest itself by signs and appearances more or less distinct and pronounced, according to the nature of the degrees and the extent of the originating cause. We summarize some of these signs and appearances:

The lameness is not intermittent, but continued, the disturbance of motion gaging the severity of the lesion and its extent. It is more marked when the bones are diseased than when the muscles alone are affected. When in motion the two upper bony levers—the shoulder blade and the bone of the upper arm—are reduced to nearly complete immobility and the walking is performed by the complete displacement of the entire mass, which is dragged forward without either flexion of extension. The action of the joint below, as a natural consequence, is limited in its flexion. In many instances there is a certain degree of swelling at the point of injury—at the joint, or, more commonly, in front of it, or on the surface of the spinatus muscle. Again, instead of swelling there will be muscular atrophy, though, while this condition of loss of muscular power may interfere with perfect locomotion, it is not in itself usually a cause of shoulder lameness. "Sweenied" shoulders are more often due to disease below the fetlock than to affections above the elbow.

During rest the animal often carries his leg forward, somewhat analogous to the "pointing" position of navicular disease, though in some cases the painful member drops at the elbow in a semiflexed position. The backing is sometimes typical, the animal when performing it, instead of flexing his shoulder, dragging the whole leg without motion in the upper segment of the extremity.

The peculiar manner in which the leg is brought forward in the air for another step in the act of walking or trotting is in some instances characteristic of injuries of the shoulder. The lameness also manifests itself in bringing the leg forward with a circumflex swinging motion and a shortening in the extension of the step. The foot is carried close to the ground and stumbling is frequent, especially on an uneven road.

With the utmost scrutiny and care the vagueness and uncertainty of the symptoms will contribute to perplex and discredit the diagnosis and embarrass the surgeon, and sometimes the expedient is tried of aggravating the symptoms by way of intensifying their significance, and thus rendering them more intelligible. This has been sought by requiring the patient to travel on hard or very soft ground and compelling him to turn on the sound leg as a pivot, with other motions calculated to betray the locality of the pain.

Treatment.—It is our conviction that lameness of the shoulder will in many cases disappear with no other prescription than that of rest. Provided the lesions occasioning it are not too severe, time is all that is required. But the negation of letting alone is seldom accepted as a means of doing good, in the place of the active and the positive forms of treatment. This is in accordance with a trait of human nature which is universal, and is unlimited in its applications; hence something must be done. In mild cases of shoulder lameness, then, the indications are water, either in the cold douche or by showering, or by warm fomentations. Warm, wet blankets are of great service; in addition, or as alternative, anodyne liniments, camphor, belladonna, either in the form of tincture or the oils, are of benefit, and at a later period stimulating friction with suitable mixtures, sweating liniments, blistering compounds, subcutaneous injections over the region of the muscle of 1-1/2 grains of veratrin (the variety insoluble in water) mixed in 2 drams of water, etc., will find their place, and finally, when necessity demands it, the firing iron and the seton.

The duration of the treatment must be determined by its effects and the evidence that may be offered of the results following the action of the reparative process. But the great essential condition of cure, and the one without which the possibility of relapse will always remain as a menace, is, as we have often reiterated in analogous cases, rest, imperatively rest, irrespective of any other prescriptions with which it may be associated.

SPRAIN OF THE ELBOW MUSCLES.

Causes.—This injury, which fortunately is not very common, is mostly encountered in cities among heavy draft horses or rapidly driven animals which are obliged to travel, often smooth shod, upon slippery, icy, or greasy pavements, where they are easily liable to lose their foothold. The region of the strain is the posterior part of the shoulder, and the affected muscles are those which occupy the space between the posterior border of the scapula and the posterior face of the arm. It is the muscles of the olecranon which give way.

Symptoms.—The symptoms are easily recognized, especially when the animal is in action. While at rest the attitude may be normal, or by close scrutiny a peculiarity may perhaps be detected. The leg may seem to drop; the elbow may appear to be lower than its fellow, with the knee and lower part of the leg flexed and the foot resting on the toe, with the heel raised. Such an attitude, however, may be occasionally assumed by an animal without having any special significance, but when it becomes more pronounced in motion the fact acquires a symptomatic value, and this is the case in the present instance. A rapid gait becomes quite impossible, and the walk, as in some few other diseases, becomes sufficiently characteristic to warrant a diagnosis even when observed from a distance. An entire dropping of the anterior part of the trunk becomes manifest, and no weight is carried on the disabled side in consequence of the loss of action in the suspensory muscles. There are often heat, pain, and swelling in the muscular mass at the elbow, though at times a hollow, or depression, may be observed near the posterior border of the scapula, which is probably the seat of injury.

These hurts are of various degrees of importance, varying from mere minor casualties of quick recovery to lesions which are of sufficient severity to render an animal useless and valueless for life.

Treatment.—The prime elements of treatment, which should be strictly observed, are rest and quiet. Prescriptions of all kinds, of course, have their advocates. Among them are ether, chloroform, camphor, alcoholic frictions, warm fomentations, blisters, setons, etc. Unless the conclusions of experience are to be ignored, my own judgment is decisive in favor of rest, judiciously applied, however, and my view of what constitutes a judicious application of rest has been more than once presented in these pages. There are degrees of this rest. One contemplates simple immobility in a narrow stall. Another means the enforced mobility of the slings and a narrow stall as well. Another a box stall, with ample latitude as to posture and space, and option to stand or lie down. As wide as this range may appear to be, radical recovery has occurred under all of these modified forms of letting our patients alone.

HIP LAMENESS.

The etiology of injuries and diseases of the hip is one and the same with that of the shoulder. The same causes operate and the same results follow. The only essential change, with an important exception, which would be necessary in passing from one region to the other in a description of its anatomy, its physiology, and its pathology would be a substitution of anatomical names in reference to certain bones, articulations, muscles, ligaments, and membranes concerned in the injuries and diseases described. It would be only a useless repetition to cover again the ground over which we have so recently passed in recital of the manner in which certain forms of external violence (falls, blows, kicks, etc.) result in other certain forms of lesion (luxation, fracture, periostitis, ostitis, etc.), and to recapitulate the items of treatment and the names of the medicaments proper to use. The same rules of diagnosis and the same indications and prognosis are applicable equally to every portion of the organism, with only such modifications in applying dressings and apparatus as may be required by differences of conformation and other minor circumstances, which must suggest themselves to the judgment of every experienced observer when the occasion arrives for its exercise.

An exception is to be made, while considering the subject in connection with the region now under advisement, in respect to the formidable affection known as morbus coxarius, or hip-joint disease; and leaving the detail of other lesions to take their place under other heads, that relating to the shoulder, for instance, we turn to the hip joint and its ailments as the chief subject of our present consideration.

Symptoms.—In investigating for morbus coxarius, let the observer first examine the lame animal by scanning critically the outlines of the joint and the region adjacent for any difference of size or disturbance of symmetry in the parts, any prominence or rotundity, and on both sides. The lame side will probably be warmer, more developed, and fuller, both to the touch and to the eye. Let him then grasp the lower part of the leg (as he would in examining a case of shoulder lameness) and endeavor to produce excessive passive motion. This will probably cause pain when the leg is made to assume a given position. Let him push the thigh forcibly against the hip bone, and the contact will again probably cause a manifestation of pain. If the horse is trotted, the limited action of the hip joint proper and the excessive dropping and rising of the hip of the opposite side will be easily recognized. Usually the animal does not extend the foot so far as customarily and picks it up much sooner.

The abductive or circumflex motion observed in shoulder lameness is also present in hip lameness, but under special conditions, and the test of the difficulty, either by traveling on soft ground or in turning the horse in a circle, may here also contribute to the diagnosis, as in testing for lameness in the anterior extremity.

Prognosis.—The prognosis of hip lameness is at times quite serious, not only on account of the long duration of treatment required to effect good results, and because of the character which may be assumed by the disease, but of the permanence of the disability resulting from it. Exostosis and ulcerative arthritis are sequelae which often resist every form of treatment.

Treatment.—As before intimated, this is little more than a repetition of the remarks upon the lameness of the shoulder, with slight modifications occasioned by the muscular structure of the hip, and we are limited to the same recommendations of treatment. The advantages of rest must be reaffirmed, with local applications, of which, however, it may be said that they are more distinctly indicated and likely to be more effective in their results than in shoulder lameness, and may be more freely employed, whether in the form of liniments, blisters (singly or repeated), firing, or setoning.

SPRAINS OF SUSPENSORY LIGAMENTS AND OF FLEXOR TENDONS OR THEIR SHEATHS.

The fibrous structure situated behind the cannon bones, both in the fore and hind legs, is often the seat of lacerations or sprains resulting from violent efforts or sudden jerks.

Cause.—The injury may be considered serious or trifling, according to the circumstances of each case as judged by its own history. Among the predisposing causes are a long, thin fetlock and a narrow knee or hock as viewed from the side, with the flexor muscles tied in just below the joint. The longer and more oblique the pastern the greater is the strain on the flexor tendons and suspensory ligaments; hence a low quarter, a toe calk, and no heel calks, or a thin calk placed at the tip under the toe, and leaving the quarters long abnormally stretches the back tendons and causes a great strain upon them just before the weight is shifted from the foot in locomotion. In runners and hunters the disease is liable to be periodic. In driving horses it is most common in well-bred animals of nervous temperament. Draft horses suffer most frequently in the hind legs.

Symptoms.—The injury is readily recognized by the changed aspect of the region and the accompanying local symptoms. The parts which in health are well defined, with the outlines of the tendons and ligaments well marked, become the seat of a swelling, more or less developed, from a small spot on the middle of the back of the tendon to a tumefaction reaching from the knee down to and even involving the fetlock itself. It is always characterized by heat, and it is variously sensitive, ranging from a mere tenderness to a degree of soreness which shrinks from the lightest touch. The degree of the lameness varies, and it has a corresponding range with the soreness, sometimes showing only a slight halting and at others the extreme of lameness on three legs, with intermediate degrees.

The lameness is always worse when the weight is thrown on the foot and is most marked toward the end of the phase of contact with the ground. Either passive irritation of the leg or turning the animal in a circle causes pain as in diseases of the joints. Sometimes the horse likes to get the heels on a stone or some elevation so as to relieve the weight from the flexor tendons. Finally, in cases of long standing, a shortening of the tendons occurs, resulting in the abnormal flexion of the foot known by horsemen as "broken down," or a more upright position of the foot may follow, producing perhaps knuckling or the so-called clubfoot.

Prognosis.—It may be safely assumed on general principles that a leg which has received such injuries seldom returns to a perfect condition of efficiency and soundness, and that as a fact a certain absolute amount of thickening and deformity will remain permanent, even when the lameness has entirely disappeared.

Treatment.—The injured member should receive the earliest attention possible, not only when the inflammatory condition is present, but when it is subsiding and there is only the thickening of the ligaments, the tendons, or the sheath.

The most important remedy is rest, and the shoes should always be removed. During the first three days cold in the form of immersion or continuous irrigation is indicated. Then warm moisture and continuous pressure are advised. The latter is best applied by placing two padded splints about the thickness of the thumb along the two sides of the tendon and binding them in place with even pressure by bandage. Frequent bathing with warm soap suds is also beneficial. The absorption of the exudate may be promoted and the work of restoration effected by frictions with alcohol, tincture of soap, spirits of camphor, mild liniments, strong, sweating liniments, and blisters. An excellent ointment to apply with massage consists of equal parts of blue ointment and green soap, with double the quantity of vaseline. The action of blisters in these cases depends chiefly upon the massage used in applying them and upon the continuous pressure of the swollen skin on the inflamed tendons. In old cases more beneficial results will follow line firing. In these cases shoeing is very important. Leave the quarters long, shorten the toe, give the shoe rolling motion, and either put short heel calks on the branches or thicken the branches. Although this line of treatment is efficacious in many cases, there are others in which the thickening of the tendons refuses to yield and the changed tissues remain firmly organized, leaving them in the form of a thick mass resting upon the back part of the cannon bone.

KNUCKLING OF FETLOCK.

As a consequence of the last-mentioned lesion of the tendons, a new condition presents itself in the articular disposition, constituting the deformity known as the knuckling fetlock. (See also p. 400.)

By this is meant a deformity of the fetlock joint by which the natural angle is changed from that which pertains to the healthy articulation. The first pastern, or suffraginis, loses its oblique direction and assumes another, which varies from the upright to the oblique, from before backward, and from above downward; in other words, forming an angle with its apex in front.