Tendon transfers in the foot and ankle is complicated. The
joints must be flexible and the muscle strength should be Grade IV or more for
a tendon transfer to achieve its effect. Here is the mnemonic to remember the
structures at the medial side of the ankle (Tom, Dick, and Harry): This
mnemonic (Tom, Dick, and Harry) contains the muscles that are the horsepower
for the tendon transfer in the foot and the ankle. The T, D, a, n, and H of Tom, Dick and Harry correspond to Tibialis posterior, flexor Digitorum longus, posterior tibial artery, tibial nerve and flexor Hallucis
longus. These three muscles, the flexor Hallucis longus, the flexor Digitorum
longus, and the tibialis posterior are very important tendons that can be used
for tendon transfers. The flexor halluces longus transfer can be used if there
is a large chronic defect that results from Achilles tendon tear, and if the
gap of the tear is 5 cm or more, then you transfer the flexor halluces longus
tendon. The flexor hallucis longus is next to the Achilles tendon, you can
transfer this tendon. The same concept may be done with the tibialis posterior
tendon tear (stage II), which means that is flexible and it may be treated with
a tendon transfer by the tendon that is next to the tibialis posterior, the flexor
digitorum longus tendon. You must add a bony realignment procedure such as
medial calcaneal displacement osteotomy. Lateral column lengthening is also
done if there is excessive forefoot abduction (too many toes), more than 40%
talonavicular uncoverage. When there is chronic tear of both peroneal tendons,
you will transfer the flexor hallucis longus when both tendons are involved and
this can be treated by tenodesis to the healthy tendon if only on tendon is
involved. You will use the girdle stone procedure, which is flexor to extensor
of the lesser toes for flexible hammer toe and claw toes. In
Charcot-Marie-Tooth disease, the patient will have varus of the hindfoot,
cavus, and plantar flexion of the first metatarsal. When the deformity of the
foot is flexible, you will do a soft tissue procedure. You will transfer the
peroneus longus tendon to the peroneus brevis tendon and this will eliminate
the strong plantar flexion of the first ray and this improves the eversion
power of the peroneus brevis muscle. Transfer of the tibialis posterior to the
dorsum of the foot through the interosseous membrane will decrease the varus
movement and it will assist in ankle dorsiflexion. Equinovaurs foot is the most common deficit
following a stroke or traumatic brain injury, this occurs due to over activity
of the tibialis anterior muscle. This condition can be treated with split
tibialis anterior tendon transfer (SPLATT) combined with Achilles tendon
lengthening or gastrocnemius recession. The deformity has to be flexible. Peroneal nerve palsy or foot drop: posterior
tibial tendon transfer through the interosseous membrane to the dorsum of the
foot. The chopart amputation is a partial foot amputation through the calcaneal
cuboid and talonavicular joints, transferring the tibialis and lengthening of
the Achilles tendon to avoid equinus deformity of the hindfoot. Dynamic
supination deformity in the swing phase can occur following Ponseti casting for
a club foot. This occurs due to the overpull of the tibialis anterior. This is
treated with a tibialis anterior tendon transfer to the lateral cuneiform.
