Page 216 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.5 The hindlimb 191

VetBooks.ir 1.366 1.367

Fig. 1.366, 1.367 Dorsoplantar (1.366) and lateromedial (1.367) radiographs showing luxation of the
proximal intertarsal joint following entanglement of the limb in a horse walker.

to non-weight bearing according to the extent of 1.368
damage to the structures within and around the
hock. Mild chronic lameness may precede an acute
onset of severe lameness. Lameness caused by frac-
ture of the small tarsal bones may diminish after
rest but will return when work commences. Horses
affected by bilateral fracture of the third tarsal bone
may be presented for poor performance rather than
hindlimb lameness. Depending on the nature of the
injury, palpation may reveal heat, soft-tissue swell-
ing, synovial effusion, crepitation and pain. Horses
suffering from fractures of the calcaneus will have
a dropped-hock appearance caused by the loss of
function of the gastrocnemius muscle. Luxation
of the tarsal joints may be presented as abnormal
deviation of the limb at the tarsus, and instability
may be identified.

Differential diagnosis
Synovial sepsis; OCD; peritarsal cellulitis; other
soft-tissue injuries. Spurs or fragments associ- Fig. 1.368 Stressed dorsoplantar radiograph of the
ated with the distal end of the medial trochlear hock demonstrating widening of the tarsometatarsal
ridge are a common incidental finding and do not joint following rupture of the medial collateral
require any treatment. ligament and subluxation.