Lameness of the Horse / Veterinary Practitioners' Series, No. 1

by John Victor Lacroix

Sheaths may be opened surgically by means of a knife, and the removal of a portion of the wall of distended and atonic tendon sheaths is possible. These operations belong to the realm of surgery and are not properly a part of this treatise. However, in passing, it may be said that if a perfect technic is possible in doing the last named operation, a permanent recovery is the outcome.

Fracture of the Metacarpus.

Etiology and Occurrence.—As the result of all sorts of violence, such as falls and injuries in accidents of various kinds wherein the metacarpals are subjected to contusions, fractures may result. In the horse it is unusual for fracture of one of the small metacarpal bones to take place without there being at the same time a fracture of the third (large) metacarpal bone.

Classification.—Fractures of the metacarpal bones as they occur, are as likely to be compound as simple, and the multiple and comminuted varieties are occasionally observed. The manner in which the third (large) metacarpus is fractured, largely determines the outcome in any given case.

Symptomatology.—Abnormal mobility of the broken parts of bone and crepitation mark fracture of the metacarpus, and the condition is easily diagnosed. In many instances, when compound fracture exists, broken ends of bone are protruding through the skin. No weight is borne upon the fractured member ordinarily, although during the excitement occasioned by runaways, horses are sometimes seen to support weight with a broken leg even when the protruding bone is sunk into the ground in so doing.

Prognosis.—Generally speaking, fractures other than the simple-transverse in young animals, are considered unfavorable cases. With the metacarpus, however, there are instances where compound fracture occurs in colts that justify treatment. But in all cases of compound fracture, the element of infection in addition to the increased difficulty in maintaining immobility of the broken bone, creates almost insuperable difficulties in the average instance. And unless the practitioner distinctly explains to his client the various reasons which make treatment an economic impracticability, dissatisfaction is likely to follow if treatment is instituted without such an understanding.

Treatment.—Perfect apposition of the broken ends of bone is easily effected and less difficulty is encountered in maintaining such relations in metacarpal fractures than in fractures of the radius. However, reduction and immobilization of this as in all fractures, must be done without delay. In simple fracture, the metacarpus is covered with enough cotton to pad the parts, and this is retained in position by bandages. Splints of heavy leather or of thin pieces of tough flexible wood are placed on each side of the leg and firmly held in position with bandages. Bandages may be put on in layers and a coating of glue applied over each layer if this is thought necessary. The advantage gained in using glue or other adhesive materials is that the cast thus formed is more rigid than where such material is not employed. On the other hand, all elasticity is lost as soon as the cast adapts itself to the contour of the extremity, and because of this rigidity, it is doubtful if anything is gained by the incorporation of glue, except in the way of added strength of the cast. Since the animal does not walk upon the broken leg, it is possible to employ splints of suitable materials which are retained in position without glue and frequent readjustment of a part of the immobilizing apparatus is possible. This is impossible with casts.

In compound fractures, provision ought to be made for dressing the wound of the soft structures. This entails adjusting the splints in such manner that one splint may be retained and others removed for dressing the wound and readjusted as often as wound dressing is necessary.

Splints.

By this term is meant a condition where there exists an exostosis which involves usually the second (inner small) and third (large) metacarpal bones. While an exostosis involving any one of the splint bones, even when directly caused by an injury, is called a "splint," the term is employed here, in reference to exostoses not due to direct injury such as in contusions.