SARCOI DS
Veterinary surgeon
Peter Bakonyi
XLEquine practice
Chapelfield Veterinary
Partnership Ltd
Surgical feature:
Management of angular limb
deformities
Although most foals have less than ideal conformation at birth, the
majority of angular limb deformities (ALD) resolve with conservative
management. Some more severely affected foals or foals failing to
respond to conservative treatment methods are candidates for
surgical intervention.
Figure 1:
Intraoperative radiograph of the
temporary transphyseal bridging technique
with screws and cerclage wires in place.
Valgus deformity of the knee.
Peter Bakonyi DrMedVet MRCVS,
Chapelfield Veterinary Partnership Ltd
SPRING 2015 ISSUE
ALD SURGI CAL
Growth plates are a highly specialised
region at the end of long bones and
have a crucial role in bone development.
This narrow cartilaginous zone can adapt
and respond to weight loading be it
normal or uneven and it is responsible for
longitudinal bone growth. However, at
a well-defined time which is specific to
each region it mineralises and hence
growth stops. In general, the further down
the limb the growth plate is located, the
sooner it will become functionally
inactive, making correction of ALD's of the
fetlock and pastern more important early
in life than those of the knee or hock.
Bone development
Surgical treatment of foals with ALD's is
directed towards accelerating growth on
the concave side (outside of an outward
deviated limb) or slowing growth on the
convex (inside of an outward deviated
limb) side of the limb. The opposite is the
case in deformities with inward deviation.
Surgical treatment options
This technique is performed on the concave
aspect of the limb on the side where the
growth plate is growing too slowly.Cutting
the periosteum (fibrous membrane covering
bones) releases tension across the growth
plate allowing it to catch-up with the
opposing side. It should be undertaken
between four-six weeks old for the fetlock
and before six months old for the knee.
Periosteal transection - growth
acceleration
This technique retards growth on the
more active side of the growth plate. It
is used in the fetlock from one-three
months old, while on the knee or hock
it may be performed at a later stage
i.e. from around four and six months of
age respectively.
The surgery involves placing a staple
above or cortical screws on both sides
of the growth plate under general
anaesthesia. The screws are then
connected with a wire (Fig. 1.). As the
wire is tightened the pressure created
retards the growth plate below allowing
the opposite (less active) side to
‘catch-up’. The implant is left in place
until the required angulation of the limb
is achieved. A second surgery is needed
for implant removal.
The post-operative care for both
techniques involves two-three weeks
of box rest while the surgical site is
covered with a bandage. During this
period corrective hoof trimming should
be performed.
Temporary transphyseal
bridging – growth retardation
In older foals where growth plates
become inactive or in the case of a
crushed growth plate their surgical
manipulation would be ineffective,
corrective osteotomy has been adapted
to horses from human orthopaedic
surgery. This technically challenging
procedure is less often performed.
Other surgical treatments
Prognosis
Surgical correction of mild to moderate ALD's carries a good prognosis.
However, it should be carried out in a timely fashion while the window
of opportunity is still open.
EQUINE MATTERS
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