Page 113 - Manual of Equine Field Surgery
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Palmer-Plantar Digital Neurectomy 109
nerve (Figure 18-3, B). Identification of the nerve years, the reported soundness rate is 63°/o. 1
is confirmed by its appearance (smooth, white, Reasons for lameness vary and may be directly
and glistening), by the crimped appearance of the related to surgical complications, reinnervation,
nerve after it has been stretched and released, and or secondary lameness in the limb.
by palpating longitudinal fibers when the nerve is
stretched over the smooth portion of an instru-
ment (Figures 18-3, C and D). When isolation of COMPLICATIONS
the nerve is confirmed, a 2- to 3-cm section of the
nerve is freed from the surrounding tissues. The Progression of the underlying problem may occur.
nerve is stretched, and the proximal end is tran- In severe cases of navicular disease, progression
sected sharply with a new blade as proximal as can result in DDFT rupture or navicular bone
possible. The distal portion is then transected fracture. To decrease the incidence of these com-
sharply (Figure 18-3, E). The surgical site is eval- plications, we generally avoid performing neurec-
uated for accessory nerve branches. If identified, tomy in horses with erosion of the flexor cortex of
they are transected in a similar manner. Subcuta- the navicular bone or extremely large medullary
neous closure is optional. The skin is closed with cavity cysts (Figure 18-4). If neurectomy is per-
a continuous or interrupted pattern using No. formed in horses with flexor cortex lesions, the
2-0 suture material. horse should be shod with moderate to significant
heel elevation and activity should be limited. I11
all cases of navicular disease, corrective shoeing
POSTOPERATIVE CARE for navicular disease should be continued postop-
eratively.
Postopei;ative C@re Undetected foot abscesses may occur from lack
.. . . . '. . .
of sensation, and the foot should be examined
Bandaging: A sterile dressing is placed over the
incisions, and a limited-pressure bandage is daily for evidence of puncture. Reinnervation can
applied over the incision sites using folded gauze occur within months of the surgery, and treat-
sponges and 3-inch Elasticon. A half limb bandage ment options are limited to repeat neurectomy
is then applied. The initial bandage is changed 24 at a more proximal location. Neurectomy above
hours after surgery and replaced without the pres- the dorsal branch of the palmar digital nerve
sure bandage. Subsequent bandage changes are is not recommended. Painful neuroma formation
performed at 4- to '5-day intervals or more fre- is somewhat unpredictable.3 Its occurrence is
quently if indicated. Bandaging is applied for a thought to increase when excessive inflammation
minimum of 3 weeks.
Exercise Restridions: Stall rest is provided
for 4 weeks. After l O days, handwalking is al-
lowed. After 4 weeks, the horse may resume
normal activity.
Medications: Phenylbutazone is administered at
4.4 mg/kg BID for the first· 24 hours and 2.2
mg/kg BID for an additional 5 days.
Suture Removal: Skin sutures are removed 12
days postoperatively.
Other: When performed for navicular disease,
corrective shoeing to decrease the biornechanical
forces on the navicular bone should be continued.
The bottom of the foot should be checked daily
for puncture wounds, or the horse should be shod
with pads.
EXPECTED OUTCOME
Figure 18-4 Horse with large medullary cavity cyst.
Reported soundness rates 1 year after palmar This horse is at increased risk for deep navicular bone
digital neurectomy are 74o/o1 and 77%.2 After 2 fracture following neurectomy.
