Regenerative Medicine Combat Injuries

179Regen. Med. (2014) 9(2), 179–190 ISSN 1746-0751
The purpose of this report is to describe regenerative medicine applications in the
management of complex injuries sustained by service members injured in support
of the wars in Afghanistan and Iraq. Improvements in body armor, resuscitative
techniques and faster transport have translated into increased patient survivability
and more complex wounds. Combat-related blast injuries have resulted in multiple
extremityinjuries,significanttissuelossandamputations.Duetothelimitedavailability
and morbidity associated with autologous tissue donor sites, the introduction of
regenerative medicine has been critical in managing war extremity injuries with
composite massive tissue loss. Through case reports and clinical images, this report
reviews the application of regenerative medicine modalities employed to manage
combat-related injuries. It illustrates that the novel use of hybrid reconstructions
combining traditional and regenerative medicine approaches are an effective tool in
managing wounds. Lessons learned can be adapted to civilian care.
Keywords: amputation • combat casualty care • extremity reconstruction • limb salvage
• regenerative medicine
Combat operations expose military service
members and civilians to the devastating
effects of high-energy munitions that often
lead to a complex pattern of injury (Figure 1).
For US service members, improvements in
personal protective gear and body armor, use
of tourniquets [1], rapid transport from the
battlefield to surgical stabilization [2,3], and
improvements in resuscitation [4] and hem-
orrhage control measures [5] have led to
increased patient survivability. The survival
rate of US service members injured in the
current conflict exceeds any other period of
conflict in history. These factors have con-
tributed to an increased number of service
members presenting to military treatment
facilities with complex wounds including
multiple extremity injuries and amputations
[6,7]. Through the early years of the current
conflicts in Iraq and Afghanistan, the multi
ple extremity amputation rate (18%) mir-
rored that of the Vietnam Conflict [8,9]. More
recently the rate of multiple extremity ampu-
tations sustained in combat has more than
doubled, likely secondary to changes in the
way operations are being conducted such as
increased foot patrols.
Concurrent with the increased multiple
extremity amputation rate has been a cor-
responding increase in extremity injuries
with composite tissue loss. Segmental bone
loss coupled with massive skin and soft tis-
sue deficits are commonplace in the blast-
injured service member [10]. Such injuries can
lead to severely compromised limb function
and adversely affect the quality of life. These
patients utilize a tremendous amount of med-
ical resources [11], and their resulting bone
and soft tissue losses lead to a major source of
disability [12]. Moreover, these injuries present
difficult clinical challenges not typically seen
in civilian trauma [13].
This complex injury pattern has initiated
efforts to create new and innovative tech-
niques in tissue regeneration. At our cen-
ter a multidisciplinary team has effectively
Mark E Fleming*,1,2
, Husain
Bharmal1,2
& Ian Valerio2,3
1
Department of Orthopaedics, Walter
Reed National Military Medical Center,
8901 Wisconsin Ave, Bethesda,
MD 20889, USA
2
Uniformed Services University of Health
Sciences, 4301 Jones Bridge Road,
Bethesda, MD 20814, USA
3
Plastic & Reconstructive Surgery Service,
Department of Surgery, Walter Reed
National Military Medical Center, 8901
Wisconsin Ave, Bethesda, MD 20889,
USA
*Author for correspondence:
Tel.: +1 301 295 2441
mark.e.fleming.mil@health.mil
Regenerative medicine applications in
combat casualty care
part of
Special Report
10.2217/RME.13.96
For reprint orders, please contact: reprints@futuremedicine.com

180 Regen. Med. (2014) 9(2)
adapted advanced reconstructive techniques merged
with regenerative medicine modalities to improve out-
comes in our combat casualties. These treatments com-
bine traditional reconstruction measures with regenera-
tive medicine applications and has been termed ‘hybrid
reconstructions’. The hybrid reconstruction model
aids in maximizing the function while minimizing the
disability and morbidity associated with traditional
reconstruction.
This article describes a single medical facilities appli-
cation of regenerative medicine modalities to manage
complex combat-related injuries. It is descriptive in
nature and does not attempt to define all of the out-
comes related to introducing regenerative medicine
modalities. The techniques employed by the authors
have been used in the civilian market with commer-
cially available products and are US FDA approved
for trauma indications. With regard to a comparative
analysis of methods and data on outcomes, that ques-
tion is beyond the scope of this current article, which
is descriptive in nature and not an outcomes article.
Follow on retrospective and prospective reviews will
analyze the outcomes utilized in these techniques.
Early management & evacuation
Early treatment of combat casualties includes the
battlefield (Level I) placement of tourniquets, gaining
of intravenous or intraosseus access, and the estab-
lishment or stabilization of a patent airway. Patients
are then transferred to a Level II or III facility, which
may be a mobile Army forward surgical team (FST),
US Marine Corps forward resuscitative surgical system
(FRSS) or a fixed medical treatment facility such as
a combat support hospital (CSH). Upon arrival to a
Level II or III facility, medical and surgical resuscita-
tion and stabilization is commenced. These facilities
have surgical and support capabilities to facilitate stabi-
lization of the wounded warriors who frequently arrive
in extremis (Figure 2).
Following the initial injury treatment and stabiliza-
tion at a Level III facility, patients are transported by
the aeromedical evacuation system for further care
in Landsthul (Germany; Level IV). There, patients
are optimized for uneventful evacuation to stateside
Level V facilities.
Level V facilities are stateside tertiary military medi-
cal centers that are designed to provide multidisci-
plinary definitive care including definitive stabilization,
reconstruction or amputation revisions of extremity
injuries [14]. Patients typically arrive at the Level V facil-
ities between 3 and 5 days after their initial battlefield
injury. Management of these patients requires a mul-
tidisciplinary approach including consultations from
general, orthopedic, plastic, neurology, ophthalmic and
urologic surgical services [15]. In addition, input from
the Anesthesia Acute Pain and Chronic Pain services,
physical therapy, occupational therapy, traumatic brain
injury (TBI), social work, case management, physiatrist
and other services is obtained for each wounded warrior
upon admission to the Level V facility.
Walter Reed National Military Medical Center
(WRNMMC) is one of the two major tertiary refer-
future science group
Special Report Fleming, Bharmal & Valerio
Figure 1. Complex battle injury with bilateral lower extremity amputations and significant composite soft
tissue loss.

www.futuremedicine.com 181
ral centers where the most severely injured patients
have been triaged. Over the past 12 years of war more
than 50% of all wounded warriors have been triaged
to WRNMMC to receive their definitive care. Defini-
tive management of these injuries typically requires a
prolonged hospital length of stay for extensive medi-
cal and surgical management. Approximately 25% of
wounded warriors with traumatic wounds receive sur-
gical management augmented with regenerative medi-
cine modalities or hybrid reconstructions. The resources
required to perform these reconstructions are extensive
and include significant personnel, long hospital length
of stay, extended periods of rehabilitation and expensive
materials that may be cost prohibitive in certain systems
or centers.
Challenges in the definitive management of
combat casualties
Profound shock should be expected upon presentation
in the blast-injured patient due to the complex nature of
the injuries and associated massive hemorrhage. Massive
transfusion protocols may be required to mitigate the
lethal triad of acidosis, hypothermia and coagulopathy
(Figure 3). A 1:1:1 ratio of packed red blood cells, fresh
frozen plasma and platelets [16] or fresh whole blood may
be beneficial to those requiring massive transfusions [17].
The initial goals of surgical management include
hemorrhage control, resuscitation, decontamination
and provisional fracture stabilization. A concomitant
goal is preservation of as much viable tissue as possible to
maximize the potential for limb salvage and soft
tissue
reconstruction [18].
The standard treatments for extremity injuries with
massive composite tissue loss (bone, skin, soft tissue,
nerves) require a spectrum of therapies. These therapies
include extremity amputation, limb-shortening to assist
Regenerative medicine applications in combat casualty care Special Report
Figure 2. Five levels (echelons) of care. (A) Buddy aid immediate first aid/life-saving measures at point of injury.
(B) US Marine Corps forward resuscitative surgical system (USMC FRSS)/US Army forward surgical team (USA FST)
– far forward surgical teams provide resuscitation. (C) Fleet hospital/combat support hospital (CSH) – increased
surgical capacity. (D) Landsthul Regional Medical Center (LRMC) – first facility outside theater to provide further
stabilization. (E) Stateside tertiary referral center provides definitive care and rehabilitation.
Casevac: Emergency evacuation by ground or air assets; evac: Evacuation.
Echelons of medical care
Tactical evac
Strategic evac
Casevac
Evac route
Surgical capability
Figure 3. Triad of death. Hypothermia, coagulopathy
and acidosis.
Triad of death
HYPOTHERMIA
COAGULOPATHY ACIDOSIS

182 Regen. Med. (2014) 9(2)
in residual limb soft tissue coverage, free tissue trans-
fers, pedicle flaps, local flaps, skin grafting, bone recon-
struction, nerve repair or reconstruction and vascular
repair. The traditional therapies may subtract from an
already decreased functional capacity and may result in
significant donor site morbidity. Revised amputations
may have nonpliable and/or nondurable surface areas
prone to erosive wear with prosthetic use. Furthermore,
the multiple limb injuries and amputations seen in
combat casualties typically involve expanded zones of
injury that extend beyond the directly affected extremi-
ties that can complicate reconstructive efforts. Further-
more, in the multiple extremity-injured service mem-
ber, the common accepted donor sites for autologous
tissues become increasingly limited (Figure 4). Conse-
quently, this has led to our adoption and increased use
of regenerative medicine modalities to enhance tissue
regeneration and improve reconstructive outcomes at
our center. The regenerative medicine products we
have employed have been used in the civilian market
to varying degrees and are FDA approved for trauma
indications. No compassionate use or emergency use of
products described in this paper has been performed,
but there has been consideration of such use in future
compassionate care cases.
Management of segmental bone defects
Historically, segmental bone defects were difficult to
manage and had unfavorably high rates of nonunion,
infection and poor outcomes that contributed to the
support for amputation of affected extremities. Several
methods have been described in the literature to address
many of the aforementioned issues in an attempt to
improve the outcomes of extremities with segmen-
tal bone defects. Techniques that have contributed to
improved outcomes to treat these bone defects include
bone transport (Figure 5) [19] or distraction osteogenesis,
autologous bone grafting, vascularized bone grafting,
bulk allograft and/or a combination of modalities [20].
While these techniques have proven useful in civilian
trauma, they may not be applicable in our patient pop-
ulation secondary to extended zones of injury, donor
site morbidity [21], as well as lack of tissue availability
as previously described (e.g., the bilateral lower limb
amputee without associated vascularized fibula bone
graft donor sites). A limitation of utilizing allografts for
segmental bone defects includes the size of the critical
defect. For defects greater than 5 cm in size, the chance
for healing is significantly diminished due to the inad-
equacy of blood vessel penetration. Clinical dilemmas
such as limited vascularized bone graft donor sites have
further necessitated the need for and use of regenerative
tissue options.
Recently, our reconstructive teams have adopted
the use of allograft mesenchymal stem cells (MSCs)
to address segmental bone gaps, both in combina-
tion with autologous bone grafts and in isolation
(Figure 6). MSCs, derived from adult bone marrow,
are multipotent stem cells capable of differentiating
along several lineage pathways [22]. MSCs are alloge-
neic, cadaveric and not cultured. The allogeneic MSC
product approved in the USA consists of a nonpuri-
fied population of allograft MSCs and demineralized
bone graft. The MSC product used is prepared as a
Figure 4. Multiple extremity injured patient from an improvised explosive
device with significant composite tissue loss. Representative injuries:
(A) mangled right upper extremity with massive soft tissue loss and
segmental nerve loss; (B) unstable pelvis fracture; (C) mangled left hand
with soft tissue loss; (D) right below knee amputation with full-thickness soft
tissue loss; and (E) left lower extremity >1000-cm2
full-thickness skin loss,
volumetric muscle loss and greater than 10-cm segmental tibial nerve loss.

cancellous bone allograft matrix. MSC do not express
MHC/HLA class II antigens and costimulatory mol-
ecules required to cause T-cell proliferation, and there-
fore do not induce a response [23]. Cell health and the
safety of Trinity Evolution™ (Orthofix, TX, USA)
are ensured by rigorous donor screening, meticulous
processing and microbial treatment of tissue, and pre-
clinical immunogenicity and biocompatibility testing.
In vitro studies have demonstrated that cells contained
within the matrix of Trinity Evolution are positive for
CD166, a marker for immunoprivileged MSCs and
osteoprogenitor cells (OPCs). They also stain positive
for osteocalcin, which verifies the presence of OPCs.
Theoretical advantages of MSC-based allografts
are that they contain the three essential components
for bone formation, including: the ability to serve as
an osteoconductive scaffold; they possess an osteo
inductive potential; and contain oteogenic cells [24].
An additional advantage is the lack of donor site
morbidity.
Several animal studies have demonstrated the feasi-
bility of the use of MSCs to enhance bone formation.
In addition, several human clinical studies have shown
efficacy in the use of culture-expanded, nongenetically
modified MSCs for bone formation [25].
The authors have not adopted the use of BMP-2
or similar products because of the documented con-
cerns related to these growth factor-containing grafts
including complications such as heterotopic ossifica-
tion, the potential for tumorgenicity, interaction with
exposed dura, systemic toxicity, reproductive toxicity,
immunogenicity, local toxicity, osteoclastic activation,
effects on distal organs, osteolysis, infection, arach-
noiditis, increased neurological deficits and retrograde
ejaculation [26–28].
While early results are promising, our reconstructive
team believes that further advancements in allograft
and autograft MSCs will continue to improve bony
reconstruction in certain combat casualties as well as
civilian trauma cases.
Management of soft tissue defect
The reconstructive ladder was a term coined by plastic
and reconstructive surgeons to describe levels of increas-
ingly complex management of soft tissue wounds [29].
Theoretically, the surgeon would utilize the lowest
rung of the ladder – that is, the simplest reconstruc-
tion technique – to address a clinical reconstructive
problem. The reconstructive surgeon would move
up the ladder as a more complex or suitable method
was required for a given reconstruction problem. We
propose a hybrid reconstructive ladder (Figure 7) that
augments the traditional reconstructive ladder with
regenerative medicine modalities. We theorize that
there may be improved outcomes at each rung on the
reconstruction ladder and these modalities may allow
for the expansion of indications for each rung on the
reconstruction ladder.
We have effectively employed dermal regenerates,
soft tissue regeneration techniques, biologic scaffolds,
fat grafting techniques and adipose-derived stem cells
in a number of reconstructions for combat casualties
in our center and elsewhere with promising results and
clinical outcomes.
An example of a recent reconstruction case is depicted
in Figure 8. This case represents the application of the
hybrid ladder to the surgical management of a degloved
tibia. Microvascular surgical techniques in the form
of a latissimus free muscle flap transfer were employed
for partial coverage of the proximal two‑thirds of the
Figure 5. Management of an open tibia fracture with segmental bone loss. (A) Anteroposterior x-ray of an open
tibia fracture in a soldier injured by a high-powered rifle. After initial irrigation, debridement, antibiotic bead
placement and stabilization with a monolateral external fixator, he had normal neurovascular function to the foot
and 12 cm of segmental bone loss. (B) Management via bone transport accomplished with a proximal corticotomy
and circular frame application. (C) Complete healing at 1 year postinjury.

184 Regen. Med. (2014) 9(2)
exposed bone and wound. The lower third of exposed
bone was effectively covered with the combination of
regenerative medicine products including porcine-
derived urinary bladder matrix (UBM) and a dermal
regenerative matrix. After 5 days, a suitable, viable and
durable tissue regenerate completely covered the soft
tissue-deficient bone, allowing for split-thickness skin
grafting and definitive wound closure. Such innovative
techniques in soft tissue coverage may provide a means
towards limb salvage in an injury that would have oth-
erwise been treated with amputation or multiple flaps
to facilitate soft tissue coverage.
For hypovascular or avascular surfaces that require
soft tissue coverage, we frequently employ UBM to
stimulate granulation tissue formation. UBM is a state-
of-the-art modality that has multiple applications in
wound care. By stimulating blood vessel formation and
chemotaxis of progenitor cells to the site of injury, it
promotes a unique healing environment favoring regen-
eration of native tissue over scar formation [30]. UBM is
an extracellular matrix (ECM) that consists of a com-
plex mixture of structural and functional proteins and
serves an important role in tissue and organ morpho-
genesis, maintenance of cell and tissue structure and
function, and in the host response to injury [31–33].
Dermal regenerative matrices are another modality
that is frequently employed to manage soft tissue loss
[34,35]. To manage complex combat-related soft tissue
wounds we regularly utilize bioartificial dermal sub-
stitutes combined with subatmospheric pressure (vac-
uum-assisted closure) dressings for wound preparation
prior to delayed split-thickness skin grafting [36]. The
dermal regenerative matrix we utilize is a bilaminar
membrane system consisting of porous bovine tendon
collagen and shark glycosaminoglycan (chondroitin-6-
sulfate) covered by a temporary epidermal substitute
made of silicone [37]. The collagen layer acts as a matrix
for the ingrowth of fibroblasts and endothelial cells,
and it is gradually replaced by the host collagen. Once
neovascularization is accomplished, split-thickness
skin grafts are employed [38].
Management of segmental nerve nefects
The standard treatment for large segmental peripheral
nerve injuries is the delayed grafting of autograft nerves
harvested from a less critical location, such as the sural
nerve [39], lateral antebrachial cutaneous nerve, anterior
division of the medial antebrachial cutaneous nerve,
dorsal cutaneous branch of the ulnar nerve, and super-
ficial sensory branch of the radial nerve [40]. Unfortu-
nately, given the nature of current injury patterns and
the high rates of multiple-extremity amputations and
injuries, the availability of suitable and sufficient nerve
autograft donor sites is severely limited.
Nerve regeneration repair techniques include decel-
lularized and sterile extracellular matrix, nerve grafts
Figure 6. Management of an open tibia fracture with mesenchymal stem cells. (A) Anteroposterior x-ray
of an open tibia fracture sustained as a result of a blast injury after irrigation, debridement, antibiotic bead
placement and stabilization with a ring fixator. (B) At 6 weeks postinjury, an allograft matrix that contains high
concentrations of allogeneic adult mesenchymal stem cells was grafted to the site. The allogeneic mesenchymal
stem cell product, approved in the USA, consists of a nonpurified population of allograft mesenchymal stem cells
and demineralized bone graft. The advantage of the matrix is that it contains all of the essential properties of an
ideal graft: osteoinductivity, osteoconductivity and high levels of osteogenic mesenchymal stem cells essential for
bone formation. (C) At 8 months postinjury, copious new bone formation can be seen.

processed from human peripheral nerve tissue, con-
duits and cadaveric nerve allograft transplantation.
Nerve conduits offer the benefit of being readily avail-
able, allow for decreased operative times as no need for
autograft nerve harvesting is necessary, and no donor
site morbidities [41]. The major disadvantage of nerve
conduits is that many of our nerve deficits exceed the
3-cm length that is the generally accepted upper limit
on nerve conduit length, as their reliability diminishes
above 3 cm [42].
Recently, processed nerve allografts have become our
alternative source for segmental peripheral nerve injury
reconstruction for defects up to 7 cm, although we have
performed reconstruction procedures on defects far
exceeding 7 cm (Figure 9). While not the gold standard
for the treatment of nerve deficits, processed allograft
nerve is an important alternative in these patients
with severely limited autologous nerve graft sources or
options [43]. Processed allografts have been shown to
have superior results for larger defects (28 mm) [44].
Fresh cadaveric allografts offer many of the same
advantages as processed allografts. The major disad-
vantage of cadaveric allografts is the requirement for
prolonged immunosuppression for the nerve to incor-
porate [45]. Immunosuppression is contraindicated
in many of the wounded warriors secondary to the
contaminated and often colonized wounds.
Discussion
Our center has performed over 500 reconstructive cases
that effectively employed novel regenerative medicine
therapies in combat casualty care. These cases included:
the utilization of high-concentration allogeneic MSCs
for segmental and severely comminuted osseous defi-
cits; dermal regeneration templates for preparation and
to improve the durability of wound beds for skin graft-
ing; biologic scaffolds such as urinary bladder matrix to
provide for soft tissue regeneration, surgical wound bed
preparation and muscle regeneration; and decelluarized
allograft nerves to serve as nerve regeneration templates
or conduits for segmental nerve defects in patients
lacking adequate autograft nerve sources.
The majority of our reconstructive cases have uti-
lized ‘hybrid reconstructions’, which refers to the com-
bination of novel regenerative medicine modalities with
traditional reconstructive surgery techniques (i.e., free
tissue transfers, regional flaps, skin grafting, and so
on). These hybrid reconstructions have transformed
the management of severe extremity injuries and have
offered the extension of indications for techniques
available to manage composite tissue loss. The applica-
tion of these techniques is continuing to evolve and may
become the standard of care for effective management
of composite tissue wounds in our combat casualties.
Our current application of regenerative medi-
cine therapies in the treatment of complex war inju-
ries has significantly aided in improving reconstruc-
tive outcomes at our institution. While there are not
retrospective case–controls as injury patterns change
throughout the conflict, anecdotal evidence from
clinical practice has shown that these regenerative
techniques are improving outcomes. Due to the size
and injury of blast injuries, traditional reconstructive
measures are typically inadequate to provide stable
and sufficient soft tissue coverage for these patients. In
many of these cases, the patients had failed traditional
reconstructive measures and these failures have been
addressed by these adjunctive regenerative medicine
therapies. The techniques that we outline for dermal
regenerates have reduced skin erosion rates compared
with those patients with skin grafting alone. It has
reduced wound healing issues surrounding the pros-
thetic wear sites by increasing durability. Orthopedic
union rates and nonunion rates have been reduced
by adjunctive use of these measures when compared
with traditional reconstructions without bony regen-
erates. These regenerative techniques have addressed
bony healing and wound healing as well as salvage
failed cases, which includes improving limb salvage
rates, amputation preservation of length, and carefully
selected cases. Even in patients with limb loss and mul-
tiple extremity amputations, using these modalities has
allowed residual limbs to be preserved at a length suit-
able for prosthetic fitting. These residual limbs would
have otherwise been suboptimal for prosthetic fitting.
Figure 7. Hybrid reconstructive ladder. This represents
the addition of regenerative medicine techniques that
may augment the various rungs on the ladder.
ECM: Extracellular matrix; UBM: Urinary bladder matrix.
UBM – ECM
Nerve conduits
Dermal
regeneration
matrix
External tissue
expansion
Nanotechnology

186 Regen. Med. (2014) 9(2)
Follow-on retrospective and prospective reviews will
analyze the outcomes utilized in these techniques.
The lessons learned from these challenging cases
may be adapted to certain civilian trauma and inju-
Figure 8. Management of a degloved tibia (including loss of periosteum) treated with a latissimus free flap for the proximal half
of the wound and the lower half with the combination of therapies including urinary bladder matrix, dermal regenerative matrix
and nanocrystalline silver dressings. (A) Degloved open tibia fracture with loss of soft tissue including periosteum. (B) Harvesting
of latissimus free flap. (C) Anastomosis and in-setting of latissimus free flap. (D) Post split-thickness skin grafting following dermal
regenerative matrix and extracellular matrix applications. (E) 1 year postreconstruction.

ries in an effort to provide better function and defini-
tive wound closure. Because of the severity of these
war-wounded injuries and the limitations with tradi-
tional reconstructive measures due to the massive size
and zones of blast injury, it may be extracted to treat
lesser severe injuries from trauma, burn or oncologic
cases using hybrid reconstructions. However, all the
mechanisms of injury are slightly different and must
be considered and extracted from our blast patients.
Our experiences will hopefully lead to further inno-
vations in the field as well as lay the groundwork for
future directions in novel breakthroughs to treat
our combat casualties as well as our civilian trauma
counterparts.
Soft tissue regeneration templates for skin and
muscle regeneration are of high interest and need for
the resulting massive soft tissue injury patient – both
in military and civilian trauma [46]. Large soft tis-
sue losses due to avulsion, burn or ballistic injuries
frequently present with volumetric or 3D defects,
and often leads to severely compromised extremity
function. The reconstruction options that currently
exist to treat such defects frequently fail to satisfac-
torily address the aesthetic and functional require-
ments of the resulting soft tissue defects. Continued
research and the development of strategies to address
volumetric muscle loss are of continued interest. The
utilization of biologic scaffolds may enhance the
musculotendinous repair process [47].
Given the limited autologous or donor source for
tissues and flaps in the polyextremity amputee or
injured service member, coupled with the compro-
mised tissues from extensive zones of injury, better
options for tissue regeneration and/or substitution
are important for the ultimate reconstruction and
recovery of combat-injured patients. Most traditional
reconstruction measures are very effective in the man-
agement of single-tissue soft tissue loss or address-
ing minor bone loss. However, composite tissue loss
typically results in severely compromised extremity
function. While a few functional muscle transfers are
available (e.g., functional free gracilis transfers), many
of our wound warriors lack appropriate donor tissues
and/or necessary nerves to be successful. As previ-
Figure 9. Management of a 7-cm segmental ulnar nerve injury. (A) A 7-cm ulnar nerve defect in an acute open wound.
(B) Anastomosis of the 7-cm processed peripheral nerve allograft to the native nerve. (C) Following anastomosis. (D) Wound closure
facilitated with an external tissue expander. (E) Complete wound closure. At 18 months postinjury the patient has regained sensation
to the level of the proximal interphalangeal joint and motor function to the flexor carpi ulnaris and ulnar-based flexor digitorum
profundus, confirmed by clinical examination and nerve conduction studies including electromyograph.

188 Regen. Med. (2014) 9(2)
ously discussed, in addition to the actual aesthetic
and functional reconstructive needs of the complex
wounds themselves, many complicated polyextremity
amputees have limited donor sites. Thus, regenerative
medicine therapies that could augment such deficits
would and are of great interest, utility, and need for
improving the aesthetic and functional outcomes of
the complex trauma reconstructive patient.
Future perspective
Future directions in each of the areas discussed are
promising in enhancing the management of complex
wounds. The future for large peripheral nerve defect
reconstruction include tolerance induction and mini-
mal immunosuppression for nerve allografting, cell-
based supportive therapies and bioengineering of
nerve conduits [48].
The future of dermal regenerates includes enhanc-
ing existing technologies and adapting them to sin-
gle-stage procedures to manage soft tissue avulsion
injuries. Spray skin technologies are being investi-
gated as a therapeutic measure to address significant
skin loss [49]. Spray skin technologies include the use
of nonculture autologous cells to promote wound
healing and reconstructive procedures. Other dermal
regenerate technologies that may have applications
in combat casualty care include allogeneic matrices
that are embedded with immortal keratinocytes,
which is a continuous cell line that is virus free and
nontumorigenic.
Future strategies that may enhance bone regenera-
tion include seeded matrices that will allow imme-
diate weight bearing, vascularized bioartificial bone
grafts [50,51] and gene therapy.
Vascularized composite tissue allograft transplan-
tation is another possible therapy that combat casu-
alties may benefit from [52]. Currently, the major
disadvantage of this modality is the life-long immu-
nosuppressant agents required. Finally, the use of
prefabricated composite tissue flaps in combination
with regenerative medicine applications is an option
that has yet to be fully tapped as a source for complex
soft tissue management [53].
In conclusion, the goal is to provide the best pos-
sible care to our combat casualties while developing
better techniques at tissue salvage for the benefit of
all patients, both active-duty and civilian.
Acknowledgements
The authors thank Nancy Lee (Walter Reed National Mili-
tary Medical Center Department of Orthopaedics Research
Coordinator) for her expertise and support in the editing of
this manuscript.
Disclaimer
The views expressed in this article are those of the authors
and do not reflect the official policy of the Department of
Defense, or US Government.
Financial & competing interests disclosure
The authors have no relevant affiliations or financial in-
volvement with any organization or entity with a financial
interest in or financial conflict with the subject matter or
materials discussed in the manuscript. This includes employ-
ment, consultancies, honoraria, stock ownership or options,
expert testimony, grants or patents received or pending, or
royalties.
No writing assistance was utilized in the production of
this manuscript.
Informed consent disclosure
Written informed consent has been obtained from the par-
ticipants involved in the study. Appropriate Institutional
Review Board clearance obtained.
Executive summary
Early management & evacuation
• Combat-related injuries are often devastating and require multiple resources to manage.
Challenges in the definitive management of combat casualties
• Resuscitation, decontamination and stabilization are the hallmarks of the initial management of
combat-related injuries.
Management of soft tissue defect
• Dermal regenerative matrices have proven beneficial in the management of burn patients and are proving
promising in the management of traumatic full-thickness wounds.
Management of segmental bone defects
• Mesenchymal stem cell-based therapy to replace segmental bone loss is a promising therapy for patients with
segmental bone loss.
Management of segmental nerve defects
• Expansion of indications for existing nerve conduits is needed for large segmental nerve defects.
Future perspective
• Cell-based therapies and allotransplantation will enable new pathways in reconstruction.

References
Papers of special note have been highlighted as: • of interest; •• of
considerable interest
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Support Hospital Research Group. Prehospital tourniquet
use in Operation Iraqi Freedom: effect on hemorrhage
control and outcomes. J. Trauma 64(2 Suppl.), S28–S37
(2008).
2 Beninati W, Meyer MT, Carter TE. The critical care air
transport program. Crit. Care Med. 36(7 Suppl.), S370–S376
(2008).
3 Morrison JJ, Oh J, Dubose JJ et al. En-route care
capability from point of injury impacts mortality after
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(2013).
4 Cap AP, Spinella PC, Borgman MA, Blackbourne LH,
Perkins JG. Timing and location of blood product
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5 Fox CJ, Starnes BW. Vascular surgery on the modern
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6 Andersen RC, Fleming M, Forsberg JA et al. Dismounted
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7 Belmont PJ Jr, McCriskin BJ, Sieg RN, Burks R, Schoenfeld
AJ. Combat wounds in Iraq and Afghanistan from 2005 to
2009. J. Trauma Acute Care Surg. 73(1), 3–12 (2012).
8 Potter BK, Scoville CR. Amputation is not isolated: an
overview of the US Army Amputee Patient Care Program
and associated amputee injuries. J. Am. Acad. Orthop. Surg.
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9 Stansbury LG, Lalliss SJ, Branstetter JG, Bagg MR,
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22(1), 43–46 (2008).
10 Owens BD, Kragh JF Jr, Macaitis J, Svoboda SJ, Wenke JC.
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11 Fleming M, Waterman S, Dunne J, D’Alleyrand JC,
Andersen RC. Dismounted complex blast injuries: patterns
of injuries and resource utilization associated with the
multiple extremity amputee. J. Surg. Orthop. Adv. 21(1),
32–37 (2012).
•• Describes a complex injury pattern sustained in combat
and reveals the extraordinary resources required to manage
these complex injuries.
12 Masini BD, Waterman SM, Wenke JC, Owens BD, Hsu
JR, Ficke JR. Resource utilization and disability outcome
assessment of combat casualties from Operation Iraqi
Freedom and Operation Enduring Freedom. J. Orthop.
Trauma 23(4), 261–266 (2009).
13 Belmont PJ Jr, Thomas D, Goodman GP et al. Combat
musculoskeletal wounds in a US Army Brigade Combat
Team during operation Iraqi Freedom. J. Trauma 71(1),
e1–e7 (2011).
14 Fang R, Pruitt VM, Dorlac GR et al. Critical care at
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Int. J. Crit. Illn. Inj. Sci. 1(1), 51–56 (2011).
17 Spinella PC, Perkins JG, Grathwohl KW et al. 31st CSH
Research Working Group. Fresh whole blood transfusions
in coalition military, foreign national, and enemy combatant
patients during Operation Iraqi Freedom at a U.S. combat
support hospital. World J. Surg. 32(1), 2–6 (2008).
18 Mamczak CN, Elster EA. Complex dismounted IED
blast injuries: the initial management of bilateral lower
extremity amputations with and without pelvic and perineal
involvement. J. Surg. Orthop. Adv. 21(1), 8–14 (2012).
19 Chaddha M, Gulati D, Singh AP, Singh AP, Maini L.
Management of massive posttraumatic bone defects in the
lower limb with the Ilizarov technique. Acta Orthop. Belg.
76(6), 811–820 (2010).
20 Gessmann J, Köller M, Godry H, Schildhauer TA, Seybold D.
Regenerate augmentation with bone marrow concentrate after
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21 Younger EM, Chapman M. Morbidity at bone graft donor
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23 Ryan JM, Barry FP, Murphy JM, Mahon BP. Mesenchymal
stem cells avoid allogeneic rejection. J. Inflamm. (Lond.) 2, 8
(2005).
•• Allogeneic mesenchymal stem cells avoid allogeneic rejection
in humans and in animal models. These finding are
supported by in vitro co-culture studies.
24 Rush SM. Trinity evolution: mesenchymal stem cell
allografting in foot and ankle surgery. Foot Ankle Spec. 3(3),
140–143 (2010).
25 Chatterjea A, Meijer G, van Blitterswijk C, de Boer J. Clinical
application of human mesenchymal stromal cells for bone
tissue engineering. Stem Cells Int. 11, 215625 (2010).
26 Poynton AR, Lane JM. Safety profile for the clinical use of
bone morphogenetic proteins in the spine. Spine (Phila. PA
1976) 27(16 Suppl. 1), S40–S48 (2002).
27 Epstein NE. Complications due to the use of BMP/INFUSE
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29 Levin LS. The reconstructive ladder. An orthoplastic
approach. Orthop. Clin. North Am. 24(3), 393–409 (1993).
•• Describes the reconstructive ladder used in complex injury
reconstruction. Serves as the foundation for the hybrid
reconstruction model described in this report.

190 Regen. Med. (2014) 9(2)
30 Mitchell KB, Gallagher JJ. Porcine bladder extracellular
matrix for closure of a large defect in a burn contracture
release. J. Wound Care 21(9), 454–456 (2012).
31 Badylak SF. The extracellular matrix as a scaffold for tissue
reconstruction. Semin. Cell Dev. Biol. 13(5), 377–383
(2002).
•• Summarizes the concept of extracellular matrices utilized
as a scaffold for tissue reconstruction.
32 Kruper GJ, Vandegriend ZP, Lin HS, Zuliani GF. Salvage of
failed local and regional flaps with porcine urinary bladder
extracellular matrix aided tissue regeneration. Case Rep.
Otolaryngol. 2013, 917183 (2013).
33 Remlinger NT, Gilbert TW, Yoshida M et al. Urinary
bladder matrix promotes site appropriate tissue formation
following right ventricle outflow tract repair. Organogenesis
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34 Demiri E, Papaconstantinou A, Dionyssiou D,
Dionyssopoulos A, Kaidoglou K, Efstratiou I.
Reconstruction of skin avulsion injuries of the upper
extremity with Integra(®)
Dermal Regeneration Template and
skin grafts in a single-stage procedure. Arch. Orthop. Trauma
Surg. 133(11), 1521–1526 (2013).
35 Graham GP, Helmer SD, Haan JM, Khandelwal A. The
use of Integra®
Dermal Regeneration Template in the
reconstruction of traumatic degloving injuries. J. Burn Care
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36 Helgeson MD, Potter BK, Evans KN, Shawen SB.
Bioartificial dermal substitute: a preliminary report on its use
for the management of complex combat-related soft tissue
wounds. J. Orthop. Trauma 21(6), 394–399 (2007).
• Demonstrates the successful application of bioartificial
dermal substitutes for the management of complex
combat-related wounds.
37 Moiemen NS, Staiano JJ, Ojeh NO et al. Reconstructive
surgery with a dermal regeneration template: clinical and
histologic study. Plast. Reconstr. Surg. 108, 93–103 (2001).
38 Stern R, McPherson M, Longaker MT. Histologic study of
artificial skin used in the treatment of full-thickness thermal
injury. J. Burn Care Rehabil. 11, 7–13 (1990).
39 Whitlock EL, Tuffaha SH, Luciano JP et al. Processed
allografts and type I collagen conduits for repair of peripheral
nerve gaps. Muscle Nerve 39(6), 787–799 (2009).
40 Matsuyama T, Mackay M, Midha R. Peripheral nerve repair
and grafting techniques: a review. Neurol. Med. Chir. (Tokyo)
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41 Rivlin M, Sheikh E, Isaac R, Beredjiklian PK. The role of
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42 Deal DN, Griffin JW, Hogan MV. Nerve conduits for nerve
repair or reconstruction. J. Am. Acad. Orthop. Surg. 20(2),
63–68 (2012).
43 Hudson TW, Zawko S, Deister C et al. Optimized acellular
nerve graft is immunologically tolerated and supports
regeneration. Tissue Eng. 10(11–12), 1641–1651 (2004).
44 Whitlock EL, Tuffaha SH, Luciano JP et al. Processed
allografts and type I collagen conduits for repair of peripheral
nerve gaps. Muscle Nerve 39(6), 787–799 (2009).
45 Mackinnon SE, Doolabh VB, Novak CB, Trulock EP.
Clinical outcome following nerve allograft transplantation.
Plast. Reconstr. Surg. 107(6), 1419–1429 (2001).
46 Ficke JR, Obremskey WT, Gaines RJ et al. Reprioritization
of research for combat casualty care. J. Am. Acad. Orthop.
Surg. 20(Suppl. 1), S99–S102 (2012).
• Discusses the research gaps and the need for
reprioritization of research in combat casualty care.
47 Turner NJ, Badylak SF. Biologic scaffolds for
musculotendinous tissue repair. Eur. Cell Mater. 25, 130–143
(2013).
48 Siemionow M, Uygur S, Ozturk C, Siemionow K.
Techniques and materials for enhancement of peripheral
nerve regeneration: a literature review. Microsurgery 33(4),
318–328 (2013).
•• Summarizes the regenerative medicine options for
peripheral nerve regeneration.
49 Tenenhaus M, Rennekampff HO. Surgical advances
in burn and reconstructive plastic surgery: new and
emerging technologies. Clin. Plast. Surg. 39(4), 435–443
(2012).
50 Kokemueller H, Spalthoff S, Nolff M et al. Prefabrication
of vascularized bioartificial bone grafts in vivo for segmental
mandibular reconstruction: experimental pilot study in sheep
and first clinical application. Int. J. Oral Maxillofac. Surg.
39(4), 379–387 (2010).
51 Kneser U, Polykandriotis E, Ohnolz J et al. Engineering
of vascularized transplantable bone tissues: induction
of axial vascularization in an osteoconductive matrix
using an arteriovenous loop. Tissue Eng. 12(7), 1721–1731
(2006).
52 Murphy BD, Zuker RM, Borschel GH. Vascularized
composite allotransplantation: an update on medical and
surgical progress and remaining challenges. J. Plast. Reconstr.
Aesthet. Surg. 66(11), 1449–1455 (2013).
53 Erkin UR, Kerem M, Tug M, Orbay H, Sensöz O.
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