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Page 2 of 8 Bekisz et al. Plast Aesthet Res 2022;9:61 https://dx.doi.org/10.20517/2347-9264.2022.69

INTRODUCTION
Disabling upper extremity injuries encompass a broad spectrum of clinical conditions. These injuries have
devastating functional consequences for the patients who sustain them and present complex reconstructive
and rehabilitative challenges to the clinicians who treat them. Whether of a traumatic, congenital, ischemic,
or oncologic nature, the partial or complete loss of hand and upper extremity function brings with it
physical, psychological, and emotional barriers for patients and their providers to work through together.

Algorithmic approaches have been proposed for the initial management of serious traumatic upper
[1-4]
extremity injuries . However, the long-term restorative and rehabilitative management of each patient
represents a unique clinical situation and must be handled as such. Patients’ needs, desires, and abilities will
differ dramatically based on a host of patient-specific variables, as will the reconstructive options available
for a given injury and degree of functional loss.

Historically, the choices available to patients who sustained truly devastating hand and upper extremity
injuries were limited. Before the 1970s, problems such as amputations, devascularizing or denervating
trauma, or mangled bony and soft tissue injuries were either managed by formalized amputation and body-
[5]
powered or early electric prostheses or by limb salvage to heal wounds and fractures followed by
rehabilitation to attain the most meaningful possible use of the injured extremity. The 1960s saw the first
[6]
replantation of an upper extremity at the level of the shoulder by Ronald Malt in 1962 and the first
successful digital reattachment by Komatsu and Tamai in 1965 . The first successful microsurgical
[7]
transplant of a segment of omentum in a human by Harry Buncke and Donald McLean in 1969 opened the
door to an entirely new array of techniques involving free tissue transfer . Within the past few years, there
[8,9]
has been a considerable increase in the options within the armamentarium of the reconstructive upper
extremity surgeon. Improvements in prosthetic technology brought about with the advent of myoelectric
prostheses combined with progress in peripheral nerve surgery, such as regenerative peripheral nerve
[5]
interfaces [10-12] and targeted muscle reinnervation (TMR) [13-17] , have markedly improved the functional
outcomes following amputation . At the same time, widespread refinement of microsurgical techniques
[18]
has made possible the transfer of vascularized and neurotized muscle, termed free functional muscle
transfer (FFMT), with the aim of restoring specific upper extremity functions [19-23] . Furthermore, in the two
decades since the first successful hand transplant by Jean-Michel Dubernard in 1998 ushered in the era of
vascularized composite allotransplantation (VCA) , there have been significant advances in the availability
[24]
and feasibility of hand and upper extremity transplantation.

With the many novel and highly sophisticated reconstructive options now available as well as the rapid pace
at which technology is evolving and adapting, it can be challenging for surgeons, therapists, and prosthetists
alike to remain abreast of the most recent developments. This article explores three methods for
reconstruction and restoration of upper extremity function, namely, TMR and a myoelectric prosthesis
following traumatic or elective amputation, FFMT, and VCA. In reviewing them, the goals are to define
each modality and explore their benefits as well as current limitations.

TARGETED MUSCLE REINNERVATION
TMR refers to the surgical transfer of nerves, often following amputation of an extremity, to a new “target”
in the form of a remaining muscle. While the fundamental technique was successfully described as early as
1917 , the ability to harness its full potential has only recently started to be realized. TMR is now widely
[25]
performed in both the upper and lower extremities, given its proposed two-fold benefits of reducing post-
amputation neuroma pain and phantom limb pain and of facilitating improved control of a myoelectric
prosthesis . The mechanistic underpinnings of reduced residual limb pain result directly from guiding the
[26]