Page 54 - Manual of Equine Field Surgery

CHAPTER 7

Transphyseal Bridging

Rick D. Howard

INDICATIONS periosteal transection and elevation. Lateral re-

cumbency is used for unilateral cases not requir-

Transphyseal bridging is performed alone or ing periosteal transection and elevation,

in combination with periosteal transection and

elevation for the treatment of angular limb de-

formities associated with the carpus, tarsus, meta- ANATOMY

carpophalangeal, or metatarsophalangeal joints

in young foals ( <3 months of age) with severe Regardless of the technique used, transphyseal

angular limb deformity or in foals with clinically bridging requires the placement of an orthopedic

significant deformity after the potential for rapid implant in the epiphysis of the operated bone. The

growth has passed: 2 months for the distal 3rd surgeon should become familiar with the size a11d

metacarpal, 3rd metatarsal, and proximal 1st contour of the epiphyses of commonly operated

phalangeal physes; 4 months for the distal tibial bones to avoid inadvertent damage to the articu-
lar surfaces of the adjacent joint. Because of the

physis; and 6 months for the distal radial physis.1•2
irregular shape and narrow proximal-to-distal

dimension of the distal tibial epiphysis, radi-

ographic guidance is essential to avoid the risk of
EQUIPMENT

errant placement of the implant into the tibio-

tarsal joint. Radiographic confirmation of correct

An AO-ASIF 4.5-n1m or 5.5-mm screw set, instru- screw placement is recommended for transphy-

mentation for placement and removal of screws, seal bridging at all locations.

and orthopedic wire are required. Alternatively,

self-tapping screws may be used, reducing the

required orthopedic equipment to a drill, an PROCEDURE

appropriate-size drill bit, screwdriver, self-tapping

screws, and orthopedic wire. Equipment for ob- Transphyseal bridging is performed on the medial

taining intraoperative radiographs is also neces- aspect of the limb for the treatment of valgus

sary.
deformities and on the lateral aspect of the limb

for the treatment of varus deformities. Periopera-

tive antibiotics are administered, the foal is anes-

POSITIONNG thetized and positioned, and the surgical site is
I

prepared aseptically for surgery. A curvilinear

Dorsal recumbency is preferred for bilateral pro- incision is made i11 the skin and subcutaneous

cedures or when performed concurrently with tissues oriented along the long axis of the radius

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