[Illustration:  Fig. 10—­Contraction of carpal flexors, “knee sprung.”]

Where inflammation is caused by a puncture wound and subfascial infection occurs, there is evident manifestation of pain.  No weight is supported by the affected member and because of the pressure, occasioned by the swollen muscles confined within the non-yielding brachial fascia, there exists marked supersensitiveness of the affected parts.  Flexion of the elbow is avoided because contraction of the biceps brachii (flexor brachii) or the extensors, which are antagonists of the flexors of the carpus, tenses the carpal flexors and pain is thereby increased.

However, in most instances, the practitioner’s attention is not directed to typical and uncomplicated cases, but to subacute or chronic inflammations which are often attended with contraction of the tendinous parts of the carpal flexors, and in such cases carpitis is present.  Animals so affected have lost the rigidity which characterizes the normal carpal joint when the leg is a weight bearing member, and because of its sprung condition, the leg trembles when supporting weight.

Treatment.—­Acute inflammation is treated by means of local application of cold or hot packs until the pain and acute stage of inflammation has subsided and later stimulating liniments are indicated.  Absolute quiet must be enforced.  Especially where the carpus is involved must the subject be kept quiet until all evidence of inflammation has subsided.

The application of vesicants or line-firing is beneficial in subacute inflammation of the tendons of the carpal flexors.  Where contraction of tendons exists and no osseous or ligamentous change prevents correction of the condition, tenotomy is necessary.  The reader is referred to Merillat’s “Veterinary Surgery"[17] for a good description of the technic of this operation.

In all serious cases of inflammation of the carpal flexors, whether tenotomy has been performed or not, the subject needs a long period of rest subsequent to treatment.  In fact, three or four months at pasture is necessary to permit of recovery and this where no congenital deformity has predisposed the subject to such affection of the flexors.  Return to work must be gradual and the character of the work such as to enable the animal to become inured to service without a recurrence of the trouble if possible.

It follows then, that tenotomy, here as in other cases, is not practical from an economic viewpoint, unless the animal be of sufficient value to justify the long period of rest for recovery.  Tenotomy is not of practical benefit unless ample time is allowed for regeneration of divided tendinous tissue.

Fracture and Luxation of the Carpal Bones.

Etiology and Occurrence.—­Fracture of the carpal bones is of infrequent occurrence in horses and, when it does occur, it is usually due to injuries, and because of their nature (resulting as they generally do from heavy falls or in being run over by street cars or wagons), a comminuted fracture of one or more bones exists.  The accessory carpal bone (trapezium) is said to be fractured at times without being subjected to blows or like injuries, but this is exceptional.