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Page 2 of 10 Di Valerio et al. Plast Aesthet Res 2022;9:62 https://dx.doi.org/10.20517/2347-9264.2022.50

Conclusion: Included studies demonstrated TMR had lower maximal pain and pain intensity, behavior and
interference compared to the standard of care. Secondary TMR used to treat patients with established painful
neuromas also reported improvement in pain compared to baseline.

Keywords: Targeted muscle reinnervation, postamputation pain, neuroma pain, phantom limb pain, residual limb
pain

INTRODUCTION
Targeted muscle reinnervation (TMR) is a nerve transfer procedure originally pioneered to improve the
myoelectric control of upper limb prostheses by transferring residual mixed or sensory nerve ends from an
amputated limb to reinnervate target motor nerve units in denervated muscles . Once surgically relocated,
[1-3]
[4]
the fascicles of the transferred nerve will grow into the recipient muscle motor end plates . This procedure
allows the creation of additional signals that can be used to enhance myoelectric prosthetic control and
optimize function . In addition to more intuitive control of myoelectric prostheses, patients who
[5]
underwent TMR reported better outcomes with common amputation complications, particularly neuroma
pain. As a result, TMR has recently been adopted as an effective strategy for the management and
prevention of postamputation pain, including neuroma pain, phantom limb pain (PLP), and residual limb
[6,7]
pain (RLP) .

There are multiple distinct types of pain that a patient may experience postamputation. PLP is defined as
the perception of burning, tingling, discomfort, or electrical shooting pain in the missing portion of the
limb [6,8,9] . This pain may be localized to just one region of the missing limb or may extend over the entire
missing area. PLP typically occurs within the first 6 months postamputation, although its prevalence several
years after surgery has been reported to be as high as 85% [10-12] . RLP, also known as “stump” pain, is localized
to the portion of the limb remaining after the amputation. RLP is typically described as a sharp, electrical,
burning, or “skin-sensitive” pain that may be localized superficially at an incision or deep in the residual
limb. It can also encompass the entirety of the residual limb. The reported incidence of stump pain can be as
high as 74% and, like PLP, may persist for years after initial development [10-13] . RLP may also be driven by
terminal symptomatic neuromas that become irritated by pressure, light touch, and hot or cold
temperatures . Although neuromas may be a cause of RLP, neuroma pain is distinct from RLP and occurs
[8,9]
due to uncoordinated attempts of nerve fibers to regenerate, resulting in disorganized axons encased within
scar tissue at the site of nerve transection or injury. They are responsible for much of the RLP experienced
postamputation and may be difficult to treat with high recurrence rates .
[1]
Despite the increasing use of TMR for improvement of postamputation pain, there are few studies
comparing the functional outcomes of patients who underwent TMR procedures primarily for this purpose.
This study sought to perform a systematic review of the literature regarding the outcomes of
postamputation pain in patients who have undergone TMR procedures, including RLP, PLP, and neuroma
pain.

METHODS
This study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and
Meta-Analyses (PRISMA) guidelines . The PubMed database was queried for articles published in English
[14]
as the primary language in May 2021. A Boolean operator with the key term “targeted muscle
reinnervation” was employed to conduct the search. 588 articles were found and sorted using the “Best
Match” criteria. For each relevant article, additional articles were searched for using the “Similar Articles”