Page 186 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.4 The forelimb 161

VetBooks.ir Management Diagnosis
Clinical signs are usually clear, although radiogra-
Debridement of torn fibrils at the time of arthros-
phy is important to confirm the level of the luxation
copy is recommended.
and the presence of additional carpal bone fracture(s)
Prognosis (Fig. 1.301).
Prognosis depends on the degree of concurrent car-
pal pathology present. Management
Initial management requires assessment and stabilisa-
CARPAL SUBLUXATION tion. Subluxations where the bony column is intact and
stable may respond to a full-limb cast. For cases where
Definition/overview instability is present, partial or pancarpal, arthrodesis
Subluxation of the carpal joint(s). may be considered. Where carpal collapse and insta-
bility is present due to concurrent carpal bone frac-
Aetiology/pathophysiology tures, euthanasia should be considered.
Subluxation of the carpus is usually due to a trau-
matic incident (e.g. high-speed fall or kick) and can Prognosis
also be seen with multiple carpal bone fractures. Prognosis is guarded. Marked periarticular fibrosis
Luxation can occur at any level of the carpus. and carpal OA are common sequelae, with loss of
function of the carpal joint(s) affected.
Clinical presentation
Horses are usually severely lame with overt ana- OSSEOUS CYST-LIKE LESIONS
tomical deviation of the carpal region. Palpation and
manipulation usually show gross instability. Definition/overview
The carpus is an unusual site for OCD. OCLLs can
Differential diagnosis occur in the small carpal bones, particularly the
Proximal metacarpal, carpal or radial fracture; ulnar carpal bone (Fig. 1.302), and they also have
severe soft-tissue injury; severe OA. been described in the distal radius (Fig. 1.303), C2
and the proximal part of the second metacarpal bone.

Fig. 1.301 Dorsopalmar 1.301 1.302
radiograph of the carpus
showing subluxation of the
antebrachiocarpal joint sustained
following anaesthetic recovery.
This horse had been managed
for a chronic wound involving
the common digital extensor
tendon sheath, with a bony
sequestrum on the dorsal lateral
aspect of the distal radius.

Fig. 1.302 Dorsolateral/
palmaromedial oblique
radiograph showing a well-
circumscribed radiolucency in
the distal aspect of the ulnar
carpal bone, with an area of
surrounding sclerosis.