1.1

Weapons Effects and Parachute Injuries

Chapter 1

Weapons Effects

and Parachute Injuries

Just as with any medical topic, surgeons must understand the

pathophysiology of war wounds in order to best care for the patient.

Treat the wound, not the weapon.

Epidemiology of Injuries

 Weapons of conventional war can be divided into explosive

munitions and small arms.

ο Explosive munitions: artillery, grenades, mortars, bombs,

and hand grenades.

ο Small arms: pistols, rifles, and machine guns.

 Two major prospective epidemiological studies were

conducted during the 20th century looking at the cause of

injury as well as outcome.

ο During the Bougainville campaign of World War II, a

medical team was sent prospectively to gather data on the

injured, including the cause of injury. This campaign

involved primarily infantry soldiers and was conducted

on the South Pacific island of Bougainville during 1944.

ο US Army and Marine casualties from the Vietnam War

collected by the Wound Data and Munitions Effectiveness

Team (WDMET) in Vietnam.

US Casualties, Bougainville Campaign (WW II) and Vietnam

Weapon Bougainville % Vietnam %

Bullet 33.3 30

Mortar 38.8 19

Artillery 10.9 3

Grenade 12.5 11

Land mine/booby trap 1.9 17

RPG (rocket — 12

propelled grenade)

Miscellaneous 2.6 —
1.2

Emergency War Surgery

The most common pattern of injury seen on a conventional

battlefield is the patient with multiple small fragment wounds

of the extremity.

Anatomical Distribution of Penetrating Wounds (%)

Conflict Head and Thorax Abdomen Limbs Other

Neck

World War I 17 4 2 70 7

World War II 4 8 4 75 9

Korean War 17 7 7 67 2

Vietnam War 14 7 5 74 —

Northern Ireland 20 15 15 50 —

Falkland Islands 16 15 10 59 —

Gulf War (UK) ** 6 12 11 71 (32)*

Gulf War (US) 11 8 7 56 18+

Afghanistan (US) 16 12 11 61 —

Chechnya (Russia) 24 9 4 63 —

Somalia 20 8 5 65 2

Average 15 9.5 7.4 64.6 3.5

* Buttock and back wounds and multiple fragment injuries, not

included

+ Multiple wounds

** 80% caused by fragments; range of hits 1–45, mean of 9

Mechanism of Injury

 For missile injuries, there are two areas of projectile-tissue

interaction, permanent cavity and temporary cavity (Fig. 1-1).

 

Temporary Cavity

Permanent Cavity

Sonic

Shock

Wave

Fig. 1-1. Projectile–tissue interaction, showing components of tissue

injury.
1.3

Weapons Effects and Parachute Injuries

ο Permanent cavity. Localized area of cell necrosis,

proportional to the size of the projectile as it passes

through.

ο Temporary cavity. Transient lateral displacement of tissue,

which occurs after passage of the projectile. Elastic tissue,

such as skeletal muscle, blood vessels and skin, may be

pushed aside after passage of the projectile, but then

rebound. Inelastic tissue, such as bone or liver, may

fracture in this area.

 The shock (or sonic) wave (commonly mistaken for the

temporary cavity), though measurable, has not been shown

to cause damage in tissue.

Explosive munitions have three mechanisms of injury (Fig. 1-2):

Distance From Epicenter

Probability

Of

Injury

Ballistic

0

1.0

Blast

Thermal

Fig. 1-2. The probability of sustaining a given trauma is related to the

distance from the epicenter of the detonation.

 Ballistic.

ο Fragments from explosive munitions cause ballistic

injuries.

ο Fragments are most commonly produced by mortars,

artillery, and grenades.

ο Fragments produced by these weapons vary in size, shape,

composition, and initial velocity. They may vary from a

few milligrams to several grams in weight.

ο Modern explosive devices are designed to spread more

uniform fragments in a regular pattern over a given area.
1.4

Emergency War Surgery

ο Fragments from exploding munitions are smaller and

irregularly shaped when compared to bullets from small

arms.

ο Although initial fragment velocities of 5,900 ft/s (1,800 m/

s) have been reported for some of these devices, the

wounds observed in survivors indicate that striking

velocities were less than 1,900 ft/s (600 m/s). Unlike small

arms, explosive munitions cause multiple wounds.

 Blast (see Fig. 1-2).

ο The blast effects take place relatively close to the exploding

munition relative to the ballistic injury.

ο Blast overpressure waves, or sonic shock waves, are

clinically important when a patient is close to the exploding

munition, such as a land mine.

ο The ears are most often affected by the overpressure,

followed by lungs and the gastrointestinal (GI) tract hollow

organs. GI injuries may present 24 hours later.

ο Injury from blast overpressure is a pressure and time

dependent function. By increasing the pressure or its

duration, the severity of injury will also increase.

ο Thermobaric devices work by increasing the duration of a

blast wave to maximize this mechanism of injury. The

device initially explodes and puts a volatile substance into

the air (fuel vapor). A second explosion then ignites the

aerosolized material producing an explosion of long

duration. The effects from this weapon are magnified when

detonated in an enclosed space such as a bunker.

ο Air displaced on the site after the explosion creates a blast

wind that can throw victims against solid objects, causing

blunt trauma.

 Thermal.

ο Thermal effects occur as the product of combustion when

the device explodes. Patients wounded near exploding

munitions may have burns in addition to open wounds,

which may complicate the management of soft tissue injuries.
1.5

Weapons Effects and Parachute Injuries

Common Misconceptions About Missile Wounds

Misconception Reality

Increased velocity causes

increased tissue damage.

Projectiles yaw in flight,

which can create irregular

wounds.

Exit wounds are always

greater than entrance

wounds.

Full metal-jacketed bullets

do not fragment, except

in unusual circumstances.

All projectile tracts must

be fully explored, due to

the effects of the

temporary cavity.

Velocity is one factor in

wounding. An increase in

velocity does not per se

increase the amount of tissue

damage. The amount of tissue

damage in the first 12 cm of a

M-16A1 bullet wound profile

has relatively little soft tissue

disruption, similar to that of a

.22 long rifle bullet, which has

less than half the velocity.

Unless a projectile hits an

intermediate target, the

amount of yaw in flight is

insignificant.

This is untrue and has no

bearing on surgical care.

The M-193 bullet of the M-16A1

rifle reliably fragments at the

level of the cannulure after

traversing about 12 cm of

tissue in soft tissue only.

Elastic soft tissue (skeletal

muscle, blood vessels, and

nerves) generally heals

uneventfully and does not

require excision, provided the

blood supply remains intact.

Temporary cavity effects are

analogous to blunt trauma.
1.6

Emergency War Surgery

Antipersonnel Landmines

 There are three types of conventional antipersonnel

landmines available throughout the world: static, bounding,

and horizontal spray.

ο Static landmines are small, planted landmines (100–200 g

of explosive) that are detonated when stepped on, resulting

in two major areas of injury (Fig. 1-3).

Fig. 1-3. Mechanisms of injuries caused by antipersonnel land mines.

♦ Partial or complete traumatic amputation, most

commonly at the midfoot or distal tibia.

♦ More proximally, debris and other tissue is driven up

along fascial planes with tissue stripped from the bone.

♦ Factors influencing the degree of injury include size

and shape of the limb, point of contact with the foot,

amount of debris overlying the mine, and the type of

footwear.

ο Bounding mines propel a small explosive device to about

1–2 m of height and then explode, causing multiple small

fragment wounds to those standing nearby. These

landmine casualties have the highest reported mortality.
1.7

Weapons Effects and Parachute Injuries

ο Horizontal spray mines propel fragments in one direction.

This land mine can be command-detonated or detonated by

tripwire. The US Claymore mine fires about 700 steel spheres

of 3⁄4 g each over a 60° arc. Horizontal spray mines produce

multiple small-fragment wounds to those nearby.

 An unconventional weapon (improvised explosive device,

or IED) is a fourth type of antipersonnel landmine. Either

another piece of ordnance is used, such as a grenade or a

mortar shell, or the device is completely fabricated out of

locally available materials.

Small Arms

 Pistols, rifles, and machine guns.

 Trends for small arms since World War II include rifles that

have increased magazine capacity, lighter bullets, and

increased muzzle velocity.

 Below are some examples of the characteristics of commonly

encountered firearms seen throughout the world. The

illustrations are of the entire path of missiles fired consistently

at 5–10 m in range into ordnance gelatin tissue-simulant

blocks. Variations of range, intermediate targets such as body

armor, and body tissue will alter the wound seen.

ο The AK-47 rifle is one of the most common weapons seen

throughout the world. For this particular bullet (full metal

jacketed or ball) there is a 25 cm path of relatively minimal

tissue disruption before the projectile begins to yaw. This

explains why relatively minimal tissue disruption may be

seen with some wounds (Fig. 1-4).

Temporary Cavity

0 cm

Permanent Cavity AK-47 7.62 mm FMC

Vel - 2340 f/s (713 m/a)

Wt - 120.5 gr (7.89 gm)

5 10 15 20 25 30 35 40 45 50 55 60 65 70 74

Fig. 1-4. Idealized path of tissue disruption caused by an AK-47

projectile, (10% gelatin as a simulation).
1.8

Emergency War Surgery

ο The AK-74 rifle was an attempt to create a smaller caliber

assault rifle. The standard bullet does not deform in the

tissue simulant but does yaw relatively early (at about 7

cm of penetration).

ο The M-16A1 rifle fires a 55-grain full metal-jacketed

bullet (M-193) at approximately 950 m/s. The average

point forward distance in tissue is about 12 cm, after

which it yaws to about 90°, flattens, and then breaks at

the cannalure (a groove placed around the mid section

of the bullet). The slightly heavier M-855 bullet used

with the M-16A2 rifle, shows a similar pattern to the M193 bullet (Fig. 1-5).

5 10 15 20 25 30 35

Detached Muscles

22 Cal (5.6 mm) FMC

Wt. - 55 gr (3.6)

Vel - 3094 f/s 943 m/s

Final wt - 35 gr (2.3 gm)

Permanent Cavity 36% Fragmentation

Temporary Cavity

Bullet

Fragments

Fig. 1-5. Idealized path of tissue disruption caused by an M-193 bullet

fired from the M-16A1 rifle (10% gelatin as a simulation).

ο The 7.62 mm NATO rifle cartridge is still used in sniper

rifles and machine guns. After about 16 cm of penetration,

this bullet yaws through 90° and then travels base forward.

A large temporary cavity is formed and occurs at the point

of maximum yaw (Fig. 1-6).
1.9

Weapons Effects and Parachute Injuries

Fig. 1-6. Idealized path of tissue disruption caused by the 7.62 mm

projectile, (10% gelatin as a simulation).

Armored Vehicle Crew Casualties

 Since the first large scale use of tanks during WWI, injuries

to those associated with armored vehicles in battle have been

a distinct subset of combat casualties.

 Tanks, infantry fighting vehicles, armored personnel carriers,

armored support vehicles, and “light armored vehicles.”

ο Light armored vehicles tend to use wheels rather than

tracks for moving and have lighter armor. The main

advantage for these vehicles is to allow for greater mobility.

Compared to infantry, injuries to those inside or around

armored vehicles are characterized by:

 Decreased overall frequency.

 Increased severity of injury and mortality (up to 50%).

 Increased incidence of burns and traumatic

amputations.

 There are three main types of antiarmor weapons on the

battlefield today.

ο Shaped charge (Fig. 1-7a).

♦ The shaped charge or high explosive antitank (HEAT)

round consists of explosives packed around a reverse cone

of metal called a melt sheet or a liner. This is the principle

behind the warhead of the RPG.

7.62 mm NATO

Vel - 2830 f/s (862 m/a)

Wt - 150 gr (9.7 gm) FMC

Permanent

Cavity

Temporary

Cavity

0 cm 5 10 15 20 25 30 35 40 45 50 55 60 65
1.10

Emergency War Surgery

a

 

Spall Material

Jet

Explosive Melt Sheet Target Material

Fuse

Nose Cone

Armor

Exploding Charge

Gas and Fragments of

Melt Sheet

Fig. 1-7. (a) Disruptive mechanisms of the shaped-charge warhead,

(b) diagram taken from photograph of an actual detonation of shapedcharged warhead against armor plate caused by antitank land mines.

♦ Shaped charges range in diameter from the 85 mm

RPG-7 to the 6-in diameter tube launched, optically

tracked, wire guided (TOW) missile.

♦ If the armor is defeated by the shaped charge, there

are two areas of behind-armor debris.

◊ First, there is the jet of the shaped charge itself. This may

cause catastrophic wounds to soldiers who are hit, or it

may ignite fuel, ammunition, or hydraulic fluid.

◊ There is a second type of debris, called spall, which

is material knocked off from the inside face of the

armored plate. This produces a spray of small,

irregularly shaped fragments inside of the

compartment (Fig. 1-7b).

ο Kinetic energy round.

♦ The kinetic energy (KE) round contains an

aerodynamically shaped piece of hard metal (such as

depleted uranium or tungsten) shaped like a dart. The

metal is usually encased in a carrier or sabot that falls

away from the projectile after it leaves the barrel.

Fragments of depleted uranium should be treated during

initial wound surgery as any retained metal foreign body

should. There is a hypothetical risk, over years, that

casualties with retained depleted uranium fragments may

develop heavy metal poisoning. This concern by itself

does not justify extensive operations to remove such

fragments during initial wound surgery.

b
1.11

Weapons Effects and Parachute Injuries

♦ Injuries to those inside a vehicle are due to the direct

effects of the penetrator or from fragments knocked

off the inside face of the armored plate. The range of

fragment masses may be from a few milligrams to over

a kilogram.

ο Antitank landmines.

♦ Blast mines are those with a large explosive filler of 4–

5 kg. Injuries are often from blunt trauma due to

crewmembers being thrown around inside the vehicle

after it detonates the mine.

♦ Closed fractures of the upper and lower extremities and

spine are common (Fig. 1-8).

♦ A modification of the shaped charge is the MiznaySchardin antitank mine that creates a projectile or large

metal slug to cause damage to the vehicle. This is less

likely than a conventionally shaped charge to be broken

up by intermediate targets.

20.1% 13.5%

2.8%

63.6%

Fig. 1-8. Distribution of fracture

sites sustained within an

armored vehicle that had

detonated a land mine (Soviet

data from Afghanistan, early

1980s).
1.12

Emergency War Surgery

Mechanisms of Injury (Fig. 1-9)

 Ballistic injuries take place as the result of defeated armor as

described above.

Fig. 1-9. Injuries sustained as a result of defeated armor, (a) translational

blast injury, (b) toxic gases, (c) blast overpressure, (d) penetrating

missile wounds.

 Thermal. Burns occur because of ignited fuel, ammunition,

hydraulic fluid, or as the direct result of the antiarmor device.

ο Two large studies, one from British WWII tank crewmen

and one from Israeli casualties in Lebanon, showed that

about 1⁄3 of living wounded casualties have burns.

A B

Translational blast

injury

Blast overpressure

B Toxic gases Missiles

A

D

C

C

C

C

D
1.13

Weapons Effects and Parachute Injuries

ο The severity of burns range from a mild 1st degree burn to

full thickness burns requiring skin coverage. Most burns

are superficial burns to exposed skin, most often of the

face, neck, forearms, and hands. These are often combined

with multiple fragment wounds.

 Blast overpressure occurs from the explosion occurring

inside a confined space. One study from WWII showed 31%

of armored crewmen casualties had ear injury due to blast

overpressure, including ruptured tympanic membranes.

 Toxic Fumes are secondary to phosgene-like combustion

byproducts in Teflon coated interiors of armored vehicles

(antispall liners).

ο HCL is produced at the mucous membrane.

ο Treatment is supportive and may require IV steroids (1,000

mg methylprednisolone, single dose).

ο Surgical triage considerations. Emergent if pulmonary

edema, expectant if hypotensive and cyanotic. Reevaluate

nonemergent patients q 2 h.

 Blunt Trauma is due to acceleration mechanisms.

Unexploded Ordnance (UXO)

 UXOs are embedded in the casualty without exploding.

ο Rockets, grenades, mortar rounds.

ο Some UXO must travel a distance (50–70 m) in order to arm.

ο Fuses are triggered by different stimuli (impact,

electromagnetic, laser).

 Notify explosive ordnance disposal immediately!

 31⁄31 victims lived after removal (from recent review).

 The casualty should be triaged as nonemergent, placed far

from others, and operated on last.

 Preplan for how to handle both transport and operation.

ο Transport.

♦ If by helicopter, ground the casualty to the aircraft

(there is a large electrostatic charge from rotors).

ο Move into safe area.

♦ Revetment, parking lot, or back of building.

ο Operate in safe area, not in main OR area.

 Operative management.

ο Precautions for surgeon and staff.
1.14

Emergency War Surgery

♦ Sandbag operative area, use flak vests and eye protection.

ο Avoid triggering stimuli.

♦ Electromagnetic (no defibrillator, monitors, Bovie

cauterizer, blood warmers, or ultrasound or CT

machines).

♦ Metal to metal.

♦ Plain radiography is safe. It helps identify the type of

ammunition.

ο Anesthesia.

♦ Regional/spinal/local preferred.

♦ Keep oxygen out of OR.

♦ Have anesthesiologist leave after induction.

ο Operation: The surgeon should be alone with the patient.

♦ Employ gentle technique.

♦ Avoid excessive manipulation.

♦ Consider amputation if other methods fail.

♦ Remove en-bloc if possible.

 The decision to remove a chemical/biological UXO is a

command decision.

 Immediately after removal, hand to explosive ordnance

disposal (EOD) personnel for disposal.

Parachute Injuries

 Dependent on several factors: Weather (wind), day/night,

drop zone hazards/terrain, low drop altitude, and level of

opposition (enemy resistance) at the drop zone.

 Caused by improper aircraft exit, parachute malfunction,

hazards (including enemy) on descent or in the landing zone,

entanglements, or an improper parachute landing fall (PLF).

 Peacetime rate of injuries is 0.8%.

 Combat injury rate is historically higher (subject to above

listed factors).

ο As high as 30% overall.

ο Majority of injuries are minor.

ο 8% to 10% of total jumpers are rendered either combat

ineffective or significantly limited.
1.15

Weapons Effects and Parachute Injuries

Injury Site/Type % Injury Site/Type %

Ankle 20 Sprain/Strains 37.7

Back 11.1 Contusions 30.1

Knee 10.7 Lacerations 14.7

Head/Neck 8.7 Closed Fractures 11.1

Leg 8.3 Concussions 2.0

Open Fractures 2.0 — —

 Fractures result in a higher percentage of removal from

combat.

Fractures of the calcaneus are associated with fractures of

the axial skeleton (10%). Patients should be placed on spinal

precautions until such injuries are ruled out.
1.16

Emergency War Surgery