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MANAGEMENT OF GUNSHOT WOUNDS
OF THE LIMBS
G. W. BOWYER,
INSTRUCTIONAL COURSE
LECTURE
N. D. ROSSITER
From the Royal Hospital, Haslar and the Royal Defence Medical College, Gosport, England
The incidence of bullet wounds in civilian trauma has
increased in many parts of the world, sometimes approach1
ing epidemic level. For surgeons with limited experience
there is a bewildering range of apparently contradictory
2-4
advice on management. An attempt to clarify this for
gunshot injuries of the limbs, without major vascular injury,
must include current concepts of ballistic wounding, the
pathology of soft-tissue wounds and fractures, and of bacterial contamination.
Advice on clinical practice and treatment options cannot
be prescriptive because of the wide range of injury patterns
and settings, but an understanding of the general principles
can guide clinical management.
WOUND BALLISTICS
5
The interaction of projectiles and biological targets should
not be considered merely in terms of the missile velocity or
its available energy. The important factor is its tissue
interaction: a ‘high-energy’ bullet may sometimes produce
6
a low-energy transfer wound.
Energy transfer. The available kinetic energy of a missile
depends on its mass (m) and velocity (v) according to the
2
equation E = 1/2 mv , but the tissues involved and other
projectile factors will determine the amount of energy
which is transferred ( E). The rate of energy transfer (dE/
dt) is also important; this may vary along the wound track
(dE/dx) and in terms of energy flux (E/cross-sectional
area). These unfamiliar terms are the major determinants of
G. W. Bowyer, MA, FRCS Orth, RAMC, Consultant Trauma and Orthopaedic Surgeon
The Royal Hospital Haslar, Gosport, Hampshire PO12 2AA, UK.
N. D. Rossiter, FRCS, RAMC, Specialist Registrar in Trauma and Orthopaedic Surgery
Royal Defence Medical College, Gosport, Hampshire PO12 2AB, UK.
Correspondence should be sent to Major G. W. Bowyer.
©1997 British Editorial Society of Bone and Joint Surgery
0301-620X/97/66977 $2.00
VOL. 79-B, NO. 6, NOVEMBER 1997
3,7
the pathological effects, and mean that wound management cannot be based on the characteristics of the weapon,
be it handgun, rifle, or shotgun. The key is to “treat the
4
wound, not the weapon”.
Soft-tissue wounds. A projectile produces a permanent
cavity containing fragments of necrotic muscle and clot.
Other tissues are stretched as they are thrown aside from
8-10
the path of the bullet, creating a temporary cavity
with
zones of contusion and concussion, some devitalised tissue,
11
and haemorrhage within and between muscle fibres. The
extent and shape of this temporary cavity are related to the
local transfer of energy (dE/dx). There is a transient low
pressure as this temporary cavity collapses, which may
12
draw contamination into the wound.
High-speed photographs of temporary cavitation in gela2,10
tin targets illustrate certain ballistic interactions.
Highenergy transfer may produce devastating effects (Fig. 1),
but a rifle bullet may travel some distance into a target
2,7,10,11
before it gives up its maximal energy.
For this
reason there may be less cavitation in the wound track
closest to the entry. Temporary cavitation does not always
cause a large zone of tissue damage, and skeletal muscle is
3
relatively tolerant, especially with low-energy transfer. For
this reason it may be unwise to try to excise all the tissue
2
which may have been affected by cavitation.
Fractures. Projectiles which cause a fracture will transfer
13
energy of the order of a few hundred Joules to the bone.
The pattern and comminution of the fracture will depend on
7
the rate of energy deposition (d/dtE) and energy flux.
Severe comminution may arise without high local energy
transfer, and may be due either to very fast transfer or to
concentration in a small area. The way in which the energy
is transferred therefore affects the fragmentation: a gunshot
fracture of the tibia, caused by a handgun with low- to
medium-energy transfer of a few hundred Joules, may be as
radiologically comminuted as a tibial ‘bumper’ fracture, but
in the latter the zone of soft-tissue injury will be much more
extensive and severe. A highly-comminuted gunshot fracture may have a relatively healthy soft-tissue envelope (Fig.
2), with its important implication for healing potential.
Bacterial contamination. A bullet is not sterilised by firing
12
and may carry viable bacteria into a wound. In addition,
clothing may distribute bacteria along the wound track
1031
1032
G. W. BOWYER,
Fig. 1a
N. D. ROSSITER
Fig. 1b
A high-energy transfer wound of the thigh. The extent of soft-tissue disruption is suggested on the radiograph (a). At operation,
much devitalised muscle was found and excised (b).
Fig. 2a
Fig. 2b
A gunshot fracture of the distal femur shows extensive comminution (a), but the soft-tissue wound was
small with low-energy transfer. Treatment by retrograde femoral nail resulted in bony healing in three
months (b), confirming the viability of the soft-tissue envelope.
from both the entry and exit wounds. Bacteria may be
drawn into the low pressure of the temporary cavity and
12
distributed along the wound track. Despite this, gunshot
fractures due to indirect interactions with the projectile may
have minimal disruption of the surrounding soft tissue and
14
periosteum with little or no contamination.
The bacterial flora of a gunshot wound changes with
time. The species causing infection in the first few days are
THE JOURNAL OF BONE AND JOINT SURGERY
MANAGEMENT OF GUNSHOT WOUNDS TO THE LIMBS
mainly commensals. The risk of florid infection, rather than
contamination, is related to the gross physical characteristics of the wound, the presence of fabric material and the
15
viability of the surrounding tissues.
WOUND MANAGEMENT
Initial management must identify and treat life-threatening
16
injuries by established resuscitation methods.
An
involved limb must be assessed and investigated for major
17
vascular injury. All findings must be recorded and should
be photographed when possible. In a civilian setting, foren5
sic evidence should be preserved.
Initial dressing and antibiotics. A sterile dressing cover
should be provided as soon as possible and left in place
until the wound can be inspected in an operating theatre.
Antibiotics play a part in preventing or delaying the onset
8,15,18,19
of infection in military ballistic wounds.
In the past,
clostridia and beta-haemolytic streptococci have caused the
major fatal infective complications of war wounds to limbs;
antibiotic prophylaxis therefore has tended to rely on benzylpenicillin as the mainstay of first-line treatment, partic15,18
Penicillin has been
ularly for soft-tissue injuries.
associated with a reduction in the morbidity and mortality
of war wounds and there is strong experimental evidence to
15,20-22
support its continued use.
A gunshot fracture carries a risk of staphylococcal osteomyelitis, and most pathogenic staphylococci are now resistant to penicillin. For this reason additional cover is needed
15
with flucloxacillin or a cephalosporin. A short course of
15,16
antibiotics is commonly advised,
but the need for this
in low- to medium-energy transfer wounds from handguns
23
in civilian practice has been debated.
Wound surgery. The traditional approach to the surgery of
gunshot wounds is based on the treatment of wounds
caused by the rifle or machine-gun bullets and large shell
fragments of the First World War. The Inter-Allied Surgical
24
Conference of 1917 emphasised the importance of excision of the skin margin, generous extension of the wound,
exploration of all layers and the excision of damaged
muscle. This advice has influenced the military management of war wounds for the remainder of this century, but
has now been amended.
Incision and irrigation. An incision should pass through
the skin wound, trimming only its grossly damaged edges,
and continue in the axis of the limb, crossing flexor
creases obliquely. Damaged subcutaneous fat and shredded fascia are removed. The deep fascia is incised for the
8,18
to allow exploration
length of the incision or beyond it,
and relieve pressure within the wound and associated
compartments. Irrigation with copious volumes of saline
is used to reduce the number of bacteria, and pulsating
16,22
high-pressure irrigation may be even more effective.
The addition of antiseptic agents or antibiotics remains
25
controversial. Any evidence of raised or increasing pressure in compartments is treated by complete fasciotomy
VOL. 79-B, NO. 6, NOVEMBER 1997
1033
16,22,25
by an open technique.
Excision. Muscle is assessed for colour, consistency, con9
tractility and capacity for bleeding. The criteria for exci26
sion or retention have been validated in war surgery and
should be applied in civilian trauma. Piecemeal excision of
muscle which fails to meet the criteria for viability ensures
that the remaining tissue will be capable of resisting infec3,9,11,22
tion from any residual bacteria in the wound.
Dressing and closure. Dressing the open wound with
fluffed-out gauze allows drainage with no need for a surgical drain. Primary closure over a drain is associated with an
22
unacceptable complication rate.
The principle of staged treatment, using delayed primary
suture (DPS) to close wounds with no excessive loss of
18,22
Wounds may be reinspected in
skin, is widely accepted.
an operating theatre at 48 hours, but closure should be
planned for four to five days after injury. Suturing is
appropriate only if all tissues appear healthy and the edges
of the skin and deeper tissues can be approximated without
undue tension.
Alternatives to DPS. A few areas of skin have sufficient
vascularity to allow immediate primary closure; the face,
neck, scalp and genitalia may be sutured, but only after
careful wound excision.
A larger skin deficit may be difficult to close without
tension. Split-skin grafting at four to five days may be used
over healthy granulation tissue but, as in all trauma surgery,
a large defect should be managed with the early help of a
25
27
plastic surgeon. The use of an antibiotic bead pouch is
16
a temporising measure to prevent wound desiccation and
28
maintain antibiotic levels until ‘second-look’ surgery and
planned cover.
Splintage. Even when there is no fracture, the injured limb
needs support and stabilisation by a plaster cast or back29
slab, to protect the soft tissues.
Non-operative management. In recent decades a much
less aggressive surgical approach with non-operative management for simple gunshot wounds has been reported from
30,31
a number of North American hospitals.
Soft tissues. Civilian experience has led to a concept of the
‘minor’ gunshot wound which is a low-energy transfer
injury of the soft tissues (Fig. 3). At some centres these
soft-tissue wounds have been treated on an outpatient basis
after wound irrigation. In one series of over 3000 patients
30
the overall infection rate was under 2%. About 40% of
these had antibiotic cover, but infection (mostly Staphylococcus aureus) was not significantly reduced by this. Risk
factors for infection in such wounds include undue delay
between wounding and treatment, the lack of basic wound
cleansing before attendance, a wound size of between 1 and
2 cm, and failure to comply with instructions on wound
care.
Fractures. Carefully selected gunshot fractures may also be
treated by early wound irrigation, dressing, antibiotics and
32
splintage. Many low- to medium-energy transfer wounds
involving fractures which do not need operative fixation are
1034
G. W. BOWYER,
Fig. 3a
N. D. ROSSITER
Fig. 3b
Fig. 3c
A low-energy transfer injury from a handgun bullet. The entry (a) and exit (b) wounds are small. There is little radiological
comminution (c) and this type of gunshot fracture is commonly managed non-operatively.
treated in this way at the Shock Trauma Centre in Balti33
more; infection rates are low, but follow-up is generally
poor (unpublished data).
In certain centres with great experience this non-surgical
approach may be a safe and efficient use of resources, but it
must be emphasised that proper assessment of soft-tissue
injuries may actually require surgical exploration. The indirect evidence inferred from the position, size and extent of
the entry and exit wounds, and the radiological appearance
may not be enough at centres without considerable experience. If there is any doubt about the amount of non-viable
tissue in the missile track, the safe management is by
operative exploration.
Military setting. In this situation the main problems arise
from high-energy transfer wounds, rather than the smaller
wounds seen in civilian practice. Small-fragment (‘shrapnel’) wounds, however, are now common in modern warfare and are similar to civilian low-energy transfer wounds.
This has led to the recognition that carefully selected soft34-39
tissue wounds may be treated without operation.
A
major concern in military surgery is how to distinguish
those wounds which can be managed by non-operative
treatment, with prompt antibiotic cover, from those which
require operation.
Treatment of fractures. There is still much debate over the
treatment of fractures caused by gunshot. A wide range of
methods ranging from the non-operative such as ‘low-tech’
splintage through external fixation to internal fixation or
intramedullary nailing, has been advised. The basic princi40
ples should be borne in mind. Does the wound need
exploration? Does the fracture need reduction? Will the
reduction be stable without fixation? What are the facilities
and expertise available for immediate after-care and for
follow-up?
Traditionally, the internal fixation of gunshot fractures
41
has been condemned, but several major trauma centres
have shown that intramedullary nailing of such fractures of
42
the femur gives a favourable outcome as does internal
43
fixation of other gunshot fractures. Many military medical services now recommend early external fixation for the
stabilisation of fractures. It is recognised that this is not
definitive treatment, but allows good management during
29
evacuation through later echelons of care. The use of
external fixation as definitive treatment has been associated
44,45
and it has been shown
with high rates of complication,
that femoral and humeral fractures can be well managed
even more simply by splintage or bracing in ‘third-world’
46
conditions.
In the choice of management it is important to remember
that, like any other compound fracture, a gunshot fracture
requires careful assessment, especially of the soft-tissue
injury, and the use of fixation methods which are appropriate to the fracture pattern, the associated envelope and
the expertise which is available.
CHOICE OF TREATMENT
Surgeons faced with a gunshot wound need to make carefully reasoned clinical decisions based on an understanding
of the mechanisms involved. Figure 4 shows a proposed
decision-making sequence which takes account of some of
the variables.
Neither bullet velocity nor available energy can provide
a guide to tissue damage in gunshot fractures; the surgeon
should not ‘treat the weapon’. The state of the soft-tissue
envelope and the fracture pattern are the key factors, and
are determined by energy transfer. The aim is the preservation of healthy soft tissue with minimal non-viable tissue
THE JOURNAL OF BONE AND JOINT SURGERY
MANAGEMENT OF GUNSHOT WOUNDS TO THE LIMBS
1035
Fig. 4
Algorithm for the management of gunshot fractures. This emphasises the stepwise approach and the importance
of soft-tissue management.
and contamination. This will allow fracture healing with
any of a variety of different methods of stabilisation appropriate to the fracture pattern. Especially for massive
wounds, a viable soft-tissue environment must be estabVOL. 79-B, NO. 6, NOVEMBER 1997
lished before addressing the bony problem. Treatment must
be based on careful assessment of the wound and available
expertise and facilities. There is no dogmatic ‘treatment of
choice’ for gunshot fractures.
1036
G. W. BOWYER,
N. D. ROSSITER
REFERENCES
1. Schwab CW. Violence: America’s uncivil war: Presidential Address,
sixth scientific assembly of the Eastern Association for the Surgery of
Trauma. J Trauma 1993;35:657-65.
2. Fackler ML. Wound ballistics: a review of common misconceptions.
JAMA 1988;259:2730-6.
3. Cooper GJ, Ryan JM. Interaction of penetrating missiles with tissues:
some common misapprehensions and implications for wound management. Br J Surg 1990;77:606-10.
4. Lindsey D. Editorial. The idolatry of velocity, or lies, damn lies, and
ballistics. J Trauma 1980;20:1068-9.
5. Swan KG, Swan RC. Principles of ballistics applicable to the
treatment of gunshot wounds. Surgical Clinics of North America 1991;
71:221-39.
6. Molde A, Gray R. High-velocity gunshot wound through bone with
low energy transfer. Injury 1995;26:131.
7. Sellier KG, Kneubuehl BP. Wound ballistics and the scientific
background. Amsterdam: Elsevier, 1994:
8. Ryan JM, Cooper GJ, Maynard RL. Wound ballistics: contemporary and future research. J R Army Med Corps 1988;134:119.
9. Ryan JM, Cooper GJ, Haywood IR, Milner SM. Field surgery on a
future conventional battlefield: strategy and wound management. Ann
R Coll Surg Engl 1991;73:13-20.
10. Thoresby FP. Cavitation: the wounding process of the high velocity
missile, a review. J R Army Med Corps 1966;112:89-99.
11. Bellamy RF, Zajtchuk R. The physics and biophysics of wound
ballistics. In: Bellamy RF, Zajtchuk R, eds. Textbook of military
medicine: conventional warfare: ballistic, blast and burn injuries.
Part 1. Vol. 3. Washington: Office of the Surgeon General, Department of the Army, 1991:107-62.
12. Thoresby FP, Darlow HM. The mechanism of primary infection of
bullet wounds. Br J Surg 1967;54:359-61.
13. Rossiter ND. Ballistic femoral fractures. J Bone Joint Surg [Br] 1996;
78-B:Suppl II and III:134.
14. Rossiter ND. Contamination of high energy transfer ballistic femoral
fractures. J Bone Joint Surg [Br] 1996;78-B:Suppl II and III:165.
15. Mellor SG, Easmon CSF, Sanford JP. Wound contamination and
antibiotics. In: Ryan JM, Rich NM, Dale RF, Morgans BT, Cooper GJ,
eds. Ballistic trauma. London: Edward Arnold, 1997;61-71.
16. Gustilo RB, Merkow RL, Templeman D. The management of open
fractures. J Bone Joint Surg [Am] 1990;72-A:299-304.
17. Barros D’Sa AAB. Complex vascular and orthopaedic limb injuries.
J Bone Joint Surg [Br] 1992;74-B:176-8.
18. Kirby NG, Blackburn G. Field surgery pocket book. London:
HMSO, 1981:
19. Mellor SG, Cooper GJ, Bowyer GW. Efficacy of delayed administration of benzylpenicillin in the control of infection in penetrating soft
tissue injuries in war. J Trauma 1996;40:128-34.
20. Thoresby FP, Matheson JM. Gas gangrene of the high velocity
missile wound. II: an experimental study of penicillin prophylaxis. J R
Army Corpos 1967;113:36-9.
21. Owen-Smith MS, Matheson JM. Successful prophylaxis of gas
gangrene of the high-velocity missile wound in sheep. Br J Surg
1968;55:36-9.
22. Bowyer GW, Ryan JM, Kaufmann CR, Ochsner MG. General
principles of wound management. In: Ryan JM, Rich NM, Dale RF,
Morgans BT, Cooper CJ, eds. Ballistic trauma. London: Edward
Arnold, 1997:
23. Dickey RL, Barnes BC, Kearns RJ, Tullos HS. Efficacy of antibiotics in low-velocity gunshot fractures. J Orthop Trauma 1989;
3:6-10.
24. Surgery. Volume XI. In: The Medical Department of the United States
Army in the World War. Washington DC: Government Printing Office,
1927:
25. Sanders R, Swiontkowski M, Nunley J, Spiegel P. The management
of fractures with soft-tissue disruptions. J Bone Joint Surg [Am] 1993;
75-A:778-89.
26. Scully RE, Artz CP, Sako Y. An evaluation of the surgeon’s criteria
for determining the viability of muscle during debridement. Arch Surg
1956;73:1031-5.
27. Henry SL, Ostermann PA, Seligson D. The antibiotic bead pouch
technique: the management of severe compound fractures. Clinical
Orthopaedics & Related Research 1993:54-62.
28. Bowyer GW. Antibiotic impregnated beds in open fractures: a report
on the technique and possible applications in military surgery. J R
Army Med Corps 1993;139:100-4.
29. Coull JT. War Injuries. In: Coombs R, Green S, Sarmiento A, eds.
External fixation and functional bracing. London: Orthotext 1979:
239-43.
30. Ordog GJ, Sheppard GF, Wasserberger JS, Balasubramanium S,
Shoemaker WC. Infection in minor gunshot wounds. J Trauma 1993;
34:358-65.
31. McAndrew MP, Johnson KD. Penetrating orthopedic injuries. Surg
Clin North Am 1991;71:297-303.
32. Hansraj KK, Weaver LD, Todd AO, et al. Efficacy of ceftriaxone
versus cefazolin in the prophylactic management of extra-articular
cortical violation of bone due to low-velocity gunshot wounds. Orthop
Clin North Am 1995;26:9-17.
33. Bowyer GW, Brown M, Marsicano J, Burgess AR. Civilian gunshot
wounds to the limbs: patterns of injury. Injury 1995;26:135.
34. Coupland RM. War wounds of limbs: surgical management. Oxford,
Butterworth Heineman, 1993.
35. Rowley DI. War wounds with fractures: a guide to surgical management. Geneva: International Committee of the Red Cross, 1996.
36. Gray R. War wounds: basic surgical management. International
Committee of the Red Cross, 1994.
37. Hoffer MM, Johnson B. Shrapnel wounds in children. J Bone Joint
Surg [Am] 1992;74-A:766-9.
38. Bowyer GW. Management of small fragment wounds in modern
warfare: a return to Hunterian principles. Ann R Coll Surg Engl 1997;
79:175-82.
39. Bowyer GW. Management of small fragment wounds: experience
from the Afghan border. J Trauma 1996;40:170-2.
40. Apley AG, Solomon L. Principles of fractures. In: Apley’s system of
orthopaedics and fractures. 6th edition. London: Butterworth Scientific 1982;333-68.
41. Farquharson-Roberts MA, Somerville DW, Rossiter ND. Limb
injury. In: Ryan JM, Rich NM, Dale RF, Morgans BT, Cooper GJ, eds.
Ballistic trauma. London: Edward Arnold, 1997:123-32.
42. Brien WW, Kuschner SH, Brien EW, Wiss DA. The management of
gunshot wounds to the femur. Orthopedic Clinics of North America
1995;26:133-8.
43. Brien EW, Long WT, Serocki JH. Management of gunshot wounds
to the tibia. Orthopedic Clinics of North America 1995;26:165-80.
44. Has B, Jovanovic S, Wertheimer B, Mikolasevic I, Grdic P.
Externalf fixation as a primary and definitive treatment of open limb
fractures. Injury 1995;26:245-8.
45. Reis ND, Zinman C, Besser MI, Shifrin LZ, Rosen H. A philosophy
of limb salvage in war: use of the fixateur extreme. Mil Med 1991;
156:505-20.
46. Rowley DI. The management of war wounds involving bone. J Bone
Joint Surg [Br] 1996;78-B:706-9.
THE JOURNAL OF BONE AND JOINT SURGERY