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Qiu et al. Plast Aesthet Res 2022;9:19 https://dx.doi.org/10.20517/2347-9264.2021.126 Page 11 of 17

An emerging technique is the Ninkovic transfer, which entails a neurotized transfer of the gastrocnemius to
[62]
the anterior compartment of the leg [Figure 7] . This requires the availability of a proximal peroneal nerve
[63]
stump, which is transferred to the tibial branch to the lateral gastrocnemius . The lateral gastrocnemius
tendon is then transferred and attached to the anterior tibialis. After reinnervation of the gastrocnemius
with the peroneal nerve, intuitive dorsiflexion with full excursion of the ankle can be obtained. Unlike
posterior tibialis transfers, this provides better muscle balance, synergism, and avoidance of hind foot valgus
deformity and flat foot deformity associated with sacrificing the tibialis posterior. Since its original
description, multiple variations have been described, such as transfer of the medial gastrocnemius to the
anterior compartment (the medial head provides greater muscular excursion than the lateral head of the
gastrocnemius) with or without transfer of the lateral gastrocnemius to the lateral compartment under its
native tibial innervation [63,64] . In Ninkovic’s largest series of 18 patients, nine underwent medial
gastrocnemius transfer, seven underwent lateral head transfer, and two underwent both. All patients
achieved full range of motion within 18 months and all walked without an ankle-foot orthosis. While its
outcomes require ongoing study with direct comparisons to other reconstructive options, the Ninkovic
transfer is currently our preferred method for surgical management of persistent foot drop.

Free functioning muscle transfers are another option for peroneal nerve and anterior compartment
deficits . Reliable options include gracilis and rectus femoris flaps, which can be taken with skin paddles.
[65]
Reinnervation can be achieved with peroneal or tibial branches, depending on what is available. Lin et al.
[66]
report on 17 patients with complex lower extremity defects who underwent anterior compartment
reconstruction with gracilis or rectus femoris flaps. All patients achieved independence from orthoses, and
10 patients achieved good or excellent functional outcomes by Stanmore criteria. Ultimately, we reserve
these for large composite defects of the leg that involve the posterior compartment or require significant soft
tissue coverage.

Reconstruction of tibial nerve injuries
Isolated injuries of the tibial nerve are rare, with traumatic and iatrogenic injuries occurring 2-3× less
frequently than CPN injuries [2,5,42] . However, the motor and sensory deficit associated with tibial nerve injury
can be very morbid. Although the tibial nerve is not critical to gait, it contributes to gait efficiency; paralysis
causes significant shortening of the contralateral step due to the inability to balance on the stance foot as the
[67]
center of gravity moves forward [Figure 2] . Loss of protective sensation predisposes the patient to injuries
and chronic wounds, and as such, restoration of protective sensation is an important goal of tibial nerve
reconstruction [Figure 8].

In most cases, primary neurorrhaphy or grafting can provide satisfactory results [Figure 9]. As reported by
[68]
[42]
Murovic and Kim et al. in a large series of lower extremity peripheral nerve trauma patients, outcomes
for nerve repair were better at the knee-to-leg level for the tibial nerve than for all other nerves and injury
levels. Primary suture or graft repair of the tibial nerve yielded 100% and 94% “good” or better outcomes,
respectively, indicating MRC grade 3 or better plantar flexion with intact light touch sensation. The success
of tibial nerve repair was attributed to the short regeneration distances to the calf muscles and the nerve’s
robust blood supply. It appears that outcomes are not affected by graft length up to 12 cm, but there is little
data to draw conclusions about graft length in tibial nerve repairs [68,69] . Interestingly, outcomes of tibial nerve
repair at the ankle were worse, yielding only 64% good outcomes. This was attributed to the tendency for
ankle-level injuries to be related to traction injuries propagated over a large distance which required
excision and long grafts. Nonetheless, repair of the tibial nerve should always be attempted even in very
delayed cases with large nerve gaps, as sensory recovery can be achieved even after complete loss of muscle
motor endplates occurs.