Page 234 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.5 The hindlimb 209

VetBooks.ir in horses engaged in jumping/hunting activity Differential diagnosis
OCD; septic arthritis; rupture of the origin of the
after hitting a hard object while jumping. They
can also occur following a kick injury or a foreign
femoral fractures.
body penetration. Fractures of the lateral troch- long digital extensor tendon and peroneus tertius;
lear ridge and, less commonly, the medial troch-
lear ridge may occur either alone or concurrently Diagnosis
with patellar fractures. Fractures of the tibial The reciprocal apparatus coordinates the movement
tuberosity vary in size and may be displaced by the of the whole limb and therefore it is impossible to
pull of the patellar ligaments (avulsion fracture). localise gait abnormalities to the stifle. Clinical find-
Occasionally, these fractures are intra-articular. ings at the level of the stifle may point to this region
Fracture of the intercondylar eminence of the tibia as the potential site of pain, but careful examina-
is thought to be a sequela to lateral impingement tion of the rest of the limb is still mandatory. Where
of the medial condyle on the eminence rather than palpable abnormalities are insufficient to indicate
an avulsion. the cause of lameness, intra-articular analgesia may
prove useful, although in some cases only a partial
Clinical presentation improvement in lameness may be evident. If lame-
Horses that have suffered fractures associated ness is severe, local analgesia should be avoided.
with the stifle are lame, with the chronicity and Radiography and ultrasonography may identify the
the location of the fracture affecting the degree injury (Figs. 1.398–1.402). Additional views, such
of lameness. Affected horses will find flexion of as a skyline view of the patella, flexed lateromedial
the limb very painful and in some injuries, joint and oblique views at different angles, are sometimes
instability may be felt. In the acute stages the stifle required in addition to the routine radiographs of the
region will be generally swollen and painful but stifle. Scintigraphy is indicated in acutely lame horses
with time, joint effusion, often very pronounced, when a fracture is suspected but the location is not
is the most significant palpable abnormality. identified. CT of the stifle under general anaesthesia
Evidence of external injury or wounds may be is possible in some countries and may provide further
present. information on fracture location and configuration.

1.398 1.399

Figs. 1.398, 1.399 Caudocranial (1.398) and caudolateral/craniomedial oblique (1.399) radiographs showing
a fracture of the medial intercondylar eminence of the tibia sustained spontaneously during exercise. (Photos
courtesy Graham Munroe)