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Page 2 of 16 Garbuzov et al. Plast Aesthet Res 2023;10:9 https://dx.doi.org/10.20517/2347-9264.2022.51

[1]
experience chronic pain and require physical and occupational therapy . Therefore, proper diagnosis and
treatment are crucial for improving outcomes in these patients. Historically, more attention has been paid
to peripheral nerve reconstruction of the upper extremity, with less attention focused on the lower
extremity. The longer distances between nerves in the lower extremity make nerve transfers in the leg more
challenging. The increased distance required for regeneration can also lead to worse outcomes, as the target
[2]
muscle(s) may be atrophied by the time of regeneration . Research into nerve regeneration and factors that
improve outcomes is crucial for overcoming these obstacles.

There are various options for repair of lower extremity nerve injuries depending on the extent of nerve
damage and subsequent nerve gap. Direct repair is the preferred treatment modality in cases where a
[3]
tensionless repair is possible with a neglectable nerve gap . However, in cases of severe nerve damage, nerve
[3]
conduits are preferred for gaps less than 3 cm, and auto- or allografts are used for gaps of more than 3 cm .
However, the capacity for nerve regeneration and functionality can be limited after reconstruction by scar
[3]
formation, hemostasis, and infection . Interventions have been proposed to improve nerve regeneration,
including adipose-derived stem cells (ADSCs) , and electrical stimulation [8-10] . Although these
[4-7]
interventions have demonstrated potential for improving axonal regeneration and functional nerve
recovery, their use in clinical settings remains unclear.

In cases with significant scarring preventing nerve graft surgery, nerve transfers may be viable interventions
for restoring muscle function. Nerve transfers have the possibility of earlier reinnervation with restoration
of function . Anatomical and clinical studies have investigated new sites for nerve transfers and reported
[11]
promising results in traumatic cases [12-14] and patients with acute flaccid myelitis [15,16] . The variability of lower
extremity nerve injuries requires a personalized approach and understanding of each therapy’s unique
advantages and disadvantages. In this article, we will focus on the recent advances in nerve transfers and
provide additional details regarding interventions to improve axonal regeneration.

NERVE TRANSFER
In upper extremity injuries, nerve transfers have been increasingly performed to restore motor function .
[11]
Nerve transfers allow the surgeon to avoid operating in the zone of injury, which may have scarring .
[11]
Another advantage is the potential for faster recovery, due to a nerve coaptation site closer to the target.
Developments in nerve transfers for the lower extremity have lagged behind the upper extremity due to
inherent anatomical challenges, such as increased distance for nerve regeneration and fewer nerve branches
[2]
to serve as donor nerves following spinal cord injuries . Other advantages of nerve transfer surgery in the
lower extremity over nerve grafts arise because these injuries often require long nerve grafts, leading to a
degeneration of the target distal motor endplate before reinnervation can occur . Ambulation, as well as
[17]
bowel and bladder control, are priorities for lumbosacral plexus injuries . Examples of promising advances
[2]
have been reported and are discussed below [Table 1].

Femoral nerve repair
Femoral nerve is the major branch of the L2-L4 lumbar plexus and innervates the hip flexor and knee
extensor muscles. It also controls the sensory processing of the anteromedial thighs to the medial
compartment of the legs and feet. Injuries to the femoral nerve may result in significant functional
impairments depending on the anatomic location of the damaged nerve. Generally, femoral nerve injuries at
the pelvis level are classified as high femoral nerve injuries. The first successful employment of nerve
[18]
transfer for repair of high femoral nerve injury was reported in the study by Campbell et al. in 2010 . They
transferred the ipsilateral obturator nerve to the injured femoral nerve, which was damaged due to a
schwannoma . The impressive restoration of functional outcomes after this nerve transfer was the
[18]