Page 103 - Manual of Equine Field Surgery

Deep Digital Flexor Tenotomy 99

flex.ion. The incision for mid metacarpal deep
ANATOMY digital flexor tenotomy is located above the prox-

imal extent of the digital flexor tendon sheath and
The heads of the DDFT originate from the medial is typically below the distal check ligament inser-

epicondyle of the humerus, olecranon, and caudal tion. At this level, the neurovascular bundles lie

radius and insert as a single tendon on the palmar directly over and slightly dorsal to the DDFT. Care

surface of the third phalanx. 'Transecting the must be taken to not exteriorize or transect these

DDFT eliminates the pull of the deep digital flexor with the tendon (Figure 16-4).

muscle on the coffin bone, reducing shearing

forces between the dorsal coffin bone and hoof

wall and essentially eliminating coffin joint PROCEDURE

A 3-cm incision is made over the DDFT iI1 the

middle third of the metacarpus, avoiding the

flexor tendon sheath, which extends proximally to

the level of the second and fourth metacarpal

bones (Figure 16-5). The palmar fascia is incised,

and blunt dissection is used to create a space

between the superficial digital flexor tendon and

the DDFT. A space is then created between the

DDFT and the suspensory ligament (interosseous

medius tendon). The bent knife with the larger

curvature is slid on the palmar surface of the
Figure 16-3 Bent table knives are useful during iso-

lation and transection of the deep digital flexor tendon. DDFT, and the bent knife with the smaller curva-

The curvature of the top instrument i~ greater than that ture is slid on the dorsal surface of the DDFT until

of the bottom instrument. the instruments overlap (Figure 16-6). Slight

Lateral digital

extensor tendon -1-.?"'1

11.

f

I

. l

Dorsal br.

~~. of ulnar n.
1;.. ' .
.. . .

,. ,

Lateral palmar a.v.

(palmar common

digital a. v. 111)
Medial palmar n.

Lateral palmar n.

SOFT
DDFT

~~~~

Figure 16-4 Cross sectional anatomy of the deep digital flexor tendon and mid metacarpal region.