Page 239 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

214 CHAPTER 1

VetBooks.ir 1.409 than 200 kg with a displaced fracture. Successful
repair of diaphyseal or proximal physeal fractures
has been achieved only in foals and small ponies,
and distal physeal fractures have been successfully
treated in yearlings. Internal fixation of diaphyseal
fractures requires double plating, and full fracture
healing is expected in 50% of cases. The advent
of locking compression plates (LCPs) has made
the plate and screw construct stronger but double
plating is still required (Fig. 1.409). Distal phy-
seal fractures can be more difficult to repair due
to the smaller distal part of the bone restricting
screw placement. In these cases, a single special
plate may be used. Conservative management of
a minimally displaced distal physeal fracture may
result in a satisfactory result; however, although
a similar approach to the treatment of diaphyseal
fractures may lead to healing, complications such
Fig. 1.409 The femoral fracture of the horse in
1.405 was successfully repaired with two locking as limb shortening, rotational deformity and con-
compression plates. tralateral varus deformity are common. A variety
of surgical techniques and implants can be used to
repair proximal physeal fractures, but the prog-
Management nosis is guarded as significant complications such
Treatment depends on a variety of factors such as as OA of the coxofemoral joint, unstable fixation
location, type and severity of the fracture, degree and necrosis of the femoral head are common.
of soft-tissue damage, temperament of the horse Conservative management of these fractures is
and financial constraints. The most important fac- best avoided as it is unlikely to result in a comfort-
tor to consider is the size of the affected animal, able horse. Box rest is the treatment of choice for a
and euthanasia is warranted for horses heavier fractured greater or third trochanter.

COXOFEMORAL JOINT

INJURIES AND JOINT DISEASE to a lesser extent, by other smaller ligaments. The
rare instances of round ligament rupture/partial tear
Definition/overview without joint dislocation result in instability and/or
The hip joint is rarely a cause of lameness in the horse. subluxation of the coxofemoral joint and rapid devel-
Conditions involving this joint include fractures of the opment of OA. Luxation results from damage to the
femoral head and neck (see p. 212), fracture involving supporting ligaments, unstable fracture of the ilial
the coxofemoral joint, coxofemoral joint subluxation shaft or articular fracture of the acetabulum follow-
and luxation, partial tear and rupture of the round ing a fall, violent overextension or severe abduction
(teres) ligament, OA, OCD and hip dysplasia. or adduction of the limb. The femur most commonly
displaces in a craniodorsal direction and the greater
Aetiology/pathophysiology trochanter of the femur may appear higher on the
Fractures and damage to the round ligament are the limb. Luxation can also occur after application of a
result of trauma to the region, commonly after a fall. full-limb cast and, occasionally, it is manifested as
The coxofemoral joint is predominantly maintained a complication of upward fixation of the patella or
in position by the round (accessory) ligament and, it accompanies this condition. Hip dysplasia occurs