Page 715 - Adams and Stashak's Lameness in Horses, 7th Edition

Lameness of the Proximal Limb 681

severe with significant soft tissue swelling and palpable as it can be very painful to the horse. Luxations need to
instability and crepitus. The diagnosis is normally not be carefully evaluated for vascular injury to the arterial
VetBooks.ir Luxation of the TC joint is often accompanied by a management.
supply to the distal limb before moving forward with
difficult and is substantiated through radiographs.
Treatment usually requires first aid to safely trans-
severe angular limb deformity centered at the affected
articulation of the tarsus. Traumatic luxations of the port the horse to a surgical facility for reduction and
other joints of the tarsus usually occur at either the TMT stabilization in some fashion. TC joint luxation with
19
joint or the PIT joint presumably because of the stabi- intact CLs can be difficult to reduce, and manipulation
lizing effect of the fourth tarsal bone (Figure 5.82). of the tarsus with the limb in a flexed position may help
Clinical diagnosis is not difficult, but it is best to verify to facilitate reduction (Figure 5.83). A decision about
the injury through diagnostic imaging (radiographic and repairing the injury should be made quickly and
ultrasonographic examination). Stress radiographs of attempted during the same anesthetic period. While lux-
the tarsus can be helpful to demonstrate abnormal hock ation through the TMT or PIT joints can be repaired,
motion (in a sagittal plane) not easily seen with conven- these injuries usually significantly compromise athletic
tional radiography. Specific stress maneuvers can include soundness. Treatment is aimed at reestablishing com-
traction, axial rotation (clockwise and counterclock- fortable weight‐bearing. Reduction of the luxation with
wise), hyperextension, hyperflexion, and fulcrum‐ either cast stabilization or surgical repair should be per-
assisted medial and lateral flexion. Each maneuver is formed, and an assisted recovery performed if available.
designed to demonstrate instability in a particular part Tarsal luxations in the absence of significant fractures
of the tarsus and, in the process, to identify damage to can be treated with a full‐limb cast for 2–3 months. Full‐
one or more specific ligaments. Some luxations and sub- limb cast application should extend from the foot to the
luxations of the tarsus may reduce spontaneously, but level of the tibial tuberosity. Cast immobilization of a
they can still be demonstrated with stressed dorsoplan- hindlimb is not without problems and can often be asso-
tar radiographs. The presence of fracture(s) associated ciated with significant complications. The most com-
with a luxation generally decreases the chances for suc- mon cast complications included pressure sores, cast
cessful treatment. General anesthesia is usually required breakage, and secondary fractures. To minimize the risk

A B

Figure 5.82. A stressed lateromedial radiograph (A) used to aspect of the TMT joint (arrow). A medial plate was used to stabilize
help demonstrate opening of the joint surface in this horse with a the luxation and arthrodese the distal tarsal joints concurrently.
PIT joint luxation. This horse was maintained in a full‐limb cast. Source: Courtesy of Dr. Gary Baxter.
Dorsoplantar radiograph (B) of a foal with luxation of the medial