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The great
toe has been harvested on its vascular
pedicle. The arterial system can
be dorsal or plantar dominant, although
occasionally both systems can have
adequate arterial caliber, as
represented in the schematic diagram
above. Two venous systems drain
the toe. The deep system is
present with the dorsal pedicle and
accompanies the artery as a venae
comitans. The other system is
subcutaneous, lying just under the skin,
and visible preoperatively as the veins
on the dorsum of the foot. This
system tends to be larger in caliber an
easier to work with.
The anatomy
of a recipient hand with a missing thumb
is outlined above. The palmar
surface is visible, and the deep palmar
structures are outlined. The
arterial inflow to the thumb is off the
palmar arch or the ulnar digital
artery.
Two digital
nerves must be repaired to supply the
pulp on the new thumb, and occcasionally
the dorsal nerve is repaired if
present. The thumb flexor and
extensor tendons can supply increased
range of motion that the thenar
musculature alone would not
supply. The artery is often
repaired to the ulnar digital artery if
the system is plantar dominant, or the
dorsal radial artery if the arterial
inflow is dorsal dominant. The
bony osteosynthesis can be performed
with wires, plates or screws.
Occasionally a composite joint from the
native metacarpal and the toe proximal
phalanx can be formed for
metacarpophalangeal range of motion.
The new
thumb is slightly larger than the
original native thumb. Usually
within six months to one year good
sensation and range of motion are
restored. Occasionally secondary
surgery is needed to improve tendon
glide or joint stiffness.
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