Page 590 - Adams and Stashak's Lameness in Horses, 7th Edition

556 Chapter 4

Treatment tablished by securing dorsal 4.5‐mm cortical screws into
the sesamoid bones from adjacent to the plate for avul-
Treatment should be considered for horses that are to
VetBooks.ir be used for breeding or when there is sentimental value. the sesamoid bones. For injuries without intact sesamoid
sions proximal to the sesamoid bones or of the apex of
Management of the horse on the racetrack is critical for
bones or with disruption of the DSLs, a tension band wire
success in treatment. Emergency crews must immediately
restrain the horse and apply secure splints, such as a cast must be placed around the palmar surface of the joint. 14
or the Kimzey Leg Saver® to permit transport of the
horse to a facility for radiographs. Immediate immobili- Prognosis
zation of the affected limb is required to decrease the The prognosis appears to be good for pasture and
chances of further injury to the soft tissue as well as the breeding soundness with preselection of cases. With
vascular supply. Maintenance of the splint for a 4‐ to arthrodesis, 32 of 54 horses with arthrodesis of the fetlock
5‐day period prior to the selection of the final treatment survived and were eventually allowed unrestricted activ-
permits the horse to acclimate to the immobilization and ity. The prognosis is better for horses in which fetlock
14
recover from the trauma and allows definition of the arthrodesis was elected as the primary treatment rather
extent of skin necrosis and loss of vascular supply accom- than as a last resort and was better for horses in which
panying the injury. The fetlock arthrodesis procedure does fusion was elected for OA rather than rupture of the sus-
not need to be performed immediately, and the soft tissue pensory apparatus. In one report, 4 of 6 Thoroughbreds
injury and permanent deficit and risk of infection must be with breakdown injuries treated with fetlock arthrodesis
evaluated to properly predict the outcome with surgery. with the locking compression plate survived. 21
Treatments include casting, splinting, and fetlock
arthrodesis (Figure 4.136B). 14,21,100 Casting and splinting
are aimed at supporting and immobilizing the fetlock LUXATION OF THE METACARPOPHALANGEAL/
until soft tissues have healed sufficiently to support METATARSOPHALANGEAL JOINT (FETLOCK
body weight. The use of a fetlock sling shoe can work in
partial breakdown injuries. The Kimzey Leg Saver splint LUXATION)
is not as rigid as a cast, but allows cleaning and treat- Lateral and medial luxation of the fetlock joint occurs
ment of soft tissue injuries and is designed to assist with uncommonly, but is a recognized syndrome that can
fetlock joint support in suspensory apparatus injuries. affect all ages and breeds of horses. Usually, either the
Arthrodesis with implants and bone graft can be used to lateral or medial collateral ligament is ruptured, creating
achieve a pain‐free stable fusion of the fetlock joint if an obvious varus or valgus deformity of the fetlock
the soft tissues are intact and risk of infection is mini- region. 88,109 Occasionally, avulsion fractures associated
mal. Supporting limb laminitis of the unaffected foot is with the insertion of these ligaments or joint capsule may
a common sequela to this injury; therefore, the con- occur and be noted on the radiograph proximal to the
tralateral foot should be supported to distribute loading joint space. Articular fractures of the palmar/plantar
along the sole. eminence may also accompany the luxation. Both fore-
43
Casting the limb in flexion can immobilize the fetlock limbs and hindlimbs can be affected, and the joint was
until healing has occurred, but may be complicated with open in half of 10 reported cases. The diagnosis is usu-
109
severe pressure sores over the sesamoids that may result ally quite obvious because an angular deviation of the
in septic osteomyelitis requiring euthanasia. Casting is fetlock joint is present. Occasionally the luxation will
100
also expensive and labor intensive due to the multiple reduce spontaneously, and only a lateral or medial swell-
cast changes required and the prolonged duration for ing will be noticed. Immediately after the injury, if the
fusion. After 8 weeks in a cast, the limb is supported in luxation is reduced, some horses will be minimally lame
a bulky bandage, and a special shoe is applied to elevate and appear sound at the walk. Re‐luxation can occur if
the heel. Other methods of supporting the limb with the joint is not adequately stabilized. Physical manipula-
weight‐bearing on the toe (splints) and with sling sup- tion of the fetlock in these cases clarifies the suspicion of
port shoes can be successful, but continual monitoring luxation. Typically, the joint re‐luxates when it is flexed
and aftercare is required for an extended duration. Of 25 and abducted away from the side of injury.
cases managed conservatively, 15 survived. Complications
82
were similar to those from surgical techniques and
included pressure sores, osteomyelitis, avascular necro- Etiology
sis, and supporting limb laminitis. 82 This injury frequently occurs when the horse steps in
Surgical arthrodesis of the fetlock should be consid- a hole or gets a foot caught between two immovable
ered in acute cases with intact skin that have not devel- objects. The luxation results while the horse attempts to
oped wounds during the initial management of the soft break free. Owners frequently relate the history of find-
tissues. It is also recommended in chronic cases that fail to ing the horse caught in this situation. Occasionally
ankylose or in those horses that have chronic joint pain. horses spontaneously luxate their fetlock during high‐
The most popular method to achieve fetlock arthrodesis speed activities (e.g. racing, rodeo eventing) or after run-
is use of a single 14‐hole broad plate secured with 5.5‐ ning into an object. 88
and 4.5‐mm cortical screws spanning the dorsal surface
of the metacarpus, fetlock joint, and proximal pha- Clinical Signs
lanx. 14,21 If the suspensory apparatus is disrupted, the pal-
mar tension band must be reestablished or the plate will The clinical signs are usually obvious and are helpful
bend when loaded. The palmar tension band can be rees- in differentiating this injury from a fracture. However,