Page 194 - WSAVA2018
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 25-28 September, 2018 | Singapore
Treatment Options
External coaptation
In case of minimal deformity and minimal or no displacement, treatment consist of a combination of some form of external immobilization, rest and exercise restriction by cage confinement for 3 to 5 weeks.
Coaptation after traction and reduction can yield to good results for suitable diaphyseal fractures.
Cast or splinted bandages require a diligent management to decrease the potential for complications. Depending on the stage and speed of growth of the patient, the cast or splint will require frequent checks and revisions, up to once a week in a very young animal.
Unfortunately, the indications for external coaptation are limited to fractures below the elbow and stifle.
Inappropriate application and incorrect management of external coaptation can lead to a very high rate of complications.
Complete immobilization of the knee in young dogs can result in stiffening of the joint secondary to adhesion formation and quadriceps contracture.
Fracture disease is a syndrome characterized by joint stiffness or laxity, periarticular fibrosis, degeneration of the joint cartilage, osteopenia and muscle atrophy.
Other adverse effects of improperly placed limb splintage are valgus and rotational deformity. Immobilization of the stifle joint should be avoided, particularly in cases of distal femoral fractures to avoid the risk of devastating complications like quadriceps contracture and genu recurvatum. Prolonged immobilization of the hind limb in a non-weight bearing position causes coxa valga and increased anteversion. Unfortunately, the last two conditions are not reversible.
Coaptation of the antebrachiocarpal joint typically causes palmar carpal ligament laxity and consequent carpal hyperextension. This problem is commonly seen in large breeds and usually resolves spontaneously with controlled exercise. The application of any form
of supporting bandages, in the attempt of correcting the hyperextension are inappropriate and should be avoided.
Frequent radiographic monitoring of the healing process is advisable. As soon as radiographic signs of clinical union are visible, coaptation should be removed.
Surgical Options
Early recognition of fracture is essential for a successful treatment of this injuries. Delayed repair will necessitate reduction manoeuvres that can damage the blood supply and disrupt the early callus. The goal of the repair of diaphyseal fractures is normal alignment, whereas anatomic apposition is not a priority because of the potential for compensatory remodelling.
Although fractures in immature skeleton can be treated for the most part as fractures in adults, it is mandatory to bear in mind the associated effects on further growth. Intramedullary pins, cross pins, Rush pins, plates, screws or external skeletal fixation, should be applied as to not interfere or restrict the normal growth at the physes.
Intramedullary Pin (IM pins)
The use of intramedullary pins is generally limited to femural, humeral and tibia fractures.
IM nailing in immature animals, is favored by the high proportion of cancellous bone present in the medullary cavity. IM pins should be smooth and relatively smaller in diameter than those used in adults. They should not occupy more than 25% of the physeal cross sectional area and should be inserted perpendicular to the physis to not disturb the growth potential.
Classic IM pinning of the femur through the inter- trochanteric fossa has been associated with serious alterations as malformations of the femoral head and neck ,coxa valga, hyper anteversion and coxo-femoral subluxation.
External Fixator (ESF)
The principles of application of external skeletal
fixation in immature animals follows the same general principles as in the adults. However, the intrinsic stability and rapid healing of the of the fractures of immature animals, favour the use of fixators with a low stiffness configuration.
The thin and relatively soft cortices of immature animals, compromise the bone-implant interface for the fixation pins. Fortunately, this do not generally represent a concern as clinical union usually occurs before the ESF failure. Major recommendation in the insertion of the fixator pins are: never bridge a physis, avoid thermal necrosis during insertion, avoid insertion into fissures along the bone. For mechanical and biological reasons, the use of external fixation is poorly suited for the treatment of femoral shaft fractures. Due the anatomical characteristics of the region, the external fixator frame will result in a position, far from the neutral axis of the femur. this remote position will accentuate the bending stresses at the pin bone interface. The biological consideration is that the transfixion of the muscle groups of the lateral aspect of the tight generate pain, decrease the range of motion and can result in quadriceps contracture.

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