Page 173 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

148 CHAPTER 1

VetBooks.ir 1.271 1.272

Fig. 1.271 The complete displaced mid-
diaphyseal fracture in 1.266 post double-plate
internal fixation.

Fig. 1.272 The incomplete, non-displaced,
articular proximal fracture in 1.267 managed
conservatively.

Distal physeal fractures in foals can be managed Aetiology/pathophysiology
conservatively in young foals (less than 6 weeks Bone is a dynamic tissue and responds to stress
old) with casting for 2–3 weeks followed by ban- (Wolff’s law). With cyclic loading, bone remodelling
daging. In older foals or with unstable fractures, leads to deposition in areas of tension, resulting in
internal fixation is recommended. thickening and reduction in the inertial properties
of the bone. The porous bone is replaced by second-
Prognosis ary osteons and successful remodelling leads to bone
Prognosis for return to athletic use following a adaptation. If bone remodelling does not keep up
fracture involving the third metacarpal/ metatarsal with increased stress (e.g. increased training level),
bone is dependent on the type of fracture ( articular/ then a painful periosteitis occurs (‘sore or bucked
non-articular, simple/comminuted, open/closed, shins’). This problem tends to occur in 2-year-old
complete/incomplete, displaced/non-displaced), racehorses with a recently increased exercise level.
presence of contamination, soft-tissue/vascular The following year, as 3 year olds, some of these
compromise and finally size, age and temperament horses can develop dorsal cortical ‘stress’ fractures.
of the patient. Published figures suggest 70–80% of
racehorses return to function following management Clinical presentation
of non-displaced lateral condylar fractures, with a Horses present with pain/heat or swelling over the
reduction in prognosis to around 50% if displaced. dorsal (often dorsomedial) aspect of the metacarpus
(Fig. 1.273). Lameness is uncommon, but horses
DORSAL METACARPAL DISEASE may present with reduced performance or an unwill-
ingness to train.
Definition/overview
Dorsal metacarpal disease covers the ‘sore’ or ‘bucked Differential diagnosis
shin’ complex and dorsal cortical stress fractures. Exostosis; local trauma.