Page 76 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.2 The foal and developing animal 51

VetBooks.ir In the fetlock joint the degree of angulation is more 1.93
critical to the prognosis. Any concurrent malforma-
tion or injury to the distal physis and/or epiphysis and
to bones making up the articulation should also be
evaluated. This can affect the treatment selected and
the prognosis (e.g. Salter–Harris type V or VI injury
to the physis may lead to premature closure and loss
of major growth potential on the affected side).

Management
Conservative
Conservative management is more effective in early
cases, and exercise restriction (e.g. box rest and
daily in-hand short walking, or small-yard rest [not
a paddock]) is a crucial part of this. Corrective foot
trimming to alter the mediolateral foot balance (e.g.
lowering the lateral wall for carpal valgus, lower-
ing the medial wall for fetlock varus) is essential in Fig. 1.93 Solar view of a foal’s foot after composite
early cases. In addition, decreasing the toe length has been moulded and attached to the medial wall
and squaring the toe of the hoof off will encour- to create an extension for the treatment of a carpal
age symmetrical breakover. The use of glue-on valgus. (Photo courtesy Graham Munroe)
shoes or composite application to the hoof for more
advanced cases (e.g. medial extension for carpal val-
gus/lateral extension for fetlock varus) can be very Hemicircumferential periosteal transection and
effective, although contraction of the hoof capsule elevation (periosteal stripping) aims to accelerate
can occur if these are fitted for long periods (Fig. growth on the concave side of the affected limb (e.g.
1.93). The diet of the foal and lactating broodmare lateral distal radius for carpal valgus and medial
will require manipulation to reduce excessive pro- distal third metacarpus for forelimb fetlock varus).
tein and decrease growth rate, and it is important Note that concurrent transection of the remnant
to assess the diet for any deficiencies or excesses of ulna in the radius, or fibula in the tibia, is necessary
trace elements and minerals and to balance these to maximise the effect of this procedure for valgus
by the use of supplements. Monitoring these cases deviations of the carpus and tarsus, respectively. It
frequently (e.g. every 7–10 days) is advisable to fol- has been suggested that this sort of surgery has lim-
low their progression and to respond with different ited value, despite its continued use in many clin-
treatments if the foal is not steadily improving. ics. In fact there is little evidence that it significantly
The application of shock-wave therapy to retard improves an angular deformity to a greater extent
growth on the convex side of various ALDs has than using conservative management.
recently been described, but is controversial. Three In unresponsive cases, severe angular deformi-
to five sessions at weekly intervals were used concur- ties or if the window of opportunity for correction
rently with the use of corrective farriery techniques, is limited (i.e. close to functional physeal closure),
with comparable results to surgical correction. temporary transphyseal bridging should be used.
This involves bridging the physis on the convex
Surgical side of the deformity, using screws and wires, sta-
Surgical treatment is used when conservative treat- ples or a single transphyseal screw. For the car-
ment is unsuccessful, the condition is worsening or pus and fetlock, a single cortical screw is inserted
the deviation is severe at the outset. Surgery is aimed proximal to distal across the ipsilateral side of the
at manipulating growth acceleration and/or growth physis only. In cases of tarsal valgus, the screw
retardation of the physis and epiphysis. is inserted from distal to proximal through the