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perpendicular to the ground. The limb should be held slightly caudal to the contralateral limb thereby extending slightly tarsal and stifle joints. It is then tightly secured to the limb with nonelastic tape or tightly pulled elastic tape. Both techniques can be resented strongly by horses
which, despite painful fractures, will make exaggerated movements and kick with the splinted limbs sufficiently vigorously to fall. This particularly can happen with the board splint. All associated personnel should be warned with respect to personal safety and the inherent risks to the horse. Firm decisive handling is critical.
Tarsal luxation and subluxation This is a rare racetrack injury. Most occur through the tarsometatarsal or talocalcaneal-centroquartal (proximal intertarsal) joint; the fourth tarsal bone bridges the centrodistal joint and interdigitation of the tibial malleoli and distal intermediate ridge with the talus provides osseous support to the remaining joints (Moll et al. 1987). Collateral and short intertarsal ligament disruption is inevitable and most are also accompanied by marginal fragmentation of tarsal bones. Complete or partial reduction is often spontaneous. The limb is most comfortable and stable when loaded. Ideal support is a tarsal cast extending from the distal
third of the crus/tibia to the proximal-middle third junction of the metatarsus and applied with the horse standing and limb loaded (Fig 18). Sedation is advisable. The author’s preference is for six rolls of 10 cm plaster of Paris followed by two rolls of 7.5 cm and two rolls of 12.5 cm fibreglass casting tape. ‘Doughnuts’ of adhesive orthopaedic foam placed over the tibial malleoli reduce impingement sores over these prominences. Most horses tolerate the cast well although many will, on their first movement, as tarsal flexion is restricted, lift the limb in a high abducted arc with a degree of panic. Firm handling by experienced personnel is critical as, if not controlled, the horse can become sufficiently
unbalanced to fall away from the affected/immobilised limb. Such behaviour generally subsides. Fixing the tarsus as described can result in rupture of the peroneus tertius. The author has experienced this only in recovery from general anaesthesia and not in horses in which the cast was applied standing.
Fractures of the tarsus that do not jeopardise axial stability Fractures of the tarsus that occur during training and racing but which do not jeopardise axial stability of the limb include fractures of the tibial (usually lateral) malleoli, fractures of the trochlear ridges of the talus, parasagittal fractures of the talus and slab fractures of the central or third tarsal bones. The latter are seen in all forms of racing while the others are most commonly the result of falls and therefore are most frequent in jump racing. Although fractures of the lateral malleolus of the tibia frequently will disrupt the majority of the short lateral collateral ligaments, they rarely extend sufficiently proximad to compromise significantly the long lateral collateral ligament and therefore tarsal stability. Attempts at immobilisation almost always are counterproductive. However, the horse’s comfort level may be improved and surgical condition of the soft tissues enhanced by use of a light, conforming bandage. Proprietary, tailored elasticated zip up bandages (Pressage3) are ideal and generally are well tolerated by the horse.
Stifle fractures Fractures involving the stifle joints are invariably of a traumatic nature and therefore principally involve horses in jump racing although even in these sports such fractures are rare. Fractures of the patella and tibial tuberosity are impact injuries. Fractures of the tibial eminences, most commonly the medial eminence, can result from falls but commonly represent only part of a more complex injury, which may include sufficient ligamentous disruption to result in femorotibial instability. There is no adequate immobilisation for such cases.
Fig 18: Immobilisation of the tarsus in a weight bearing position with a cast extending from the junction of the middle and distal one-thirds of the crus to the junction of the proximal and middle one-thirds of the metatarsus.
© 2016 EVJ Ltd
Fractures of the femur Fractures of the femur that present on the racetrack are most commonly diaphyseal, complete and displaced (I.M. Wright, unpublished observations). Limb shortening (greater trochanter to patella distance) due to overriding of fragments and rotational instability are common. Marked haemorrhage frequently follows as the femoral artery and/or major emergent vessels are lacerated by fracture fragments. The animal’s thigh may be seen to enlarge visibly minute by minute. The prognosis generally is hopeless and pain and anxiety are usually inadequately controlled. Horses with evidence of haemorrhage should be moved as little as possible and, as soon as a confident diagnosis is reached, the animal should be subjected to euthanasia on humane grounds to avoid the potential of painful and distressing exsanguination. Fractures which are suspected but which do not exhibit marked acute haemorrhage may be moved for further evaluation. The femur is surrounded by muscle and cannot be stabilised by any temporary immobilisation technique (Bramlage 1983, 1996; Furst 2006; Mudge and Bramlage 2007). Fractures of the greater trochanter occasionally are encountered but exhibit few reliable clinical signs in the
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