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Emergency War Surgery (2004) - page 1

Emergency

War Surgery

THIRD UNITED STATES REVISION

2004

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 20^th 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

—

1.1

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).

Permanent Cavity

Sonic

Shock

Wave

Temporary Cavity

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

injury.

1.2

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

1.0

Probability

Of

Injury

0

Ballistic

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.

1.3

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.

1.6

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 Permanent Cavity AK-47 7.62 mm FMC

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

Wt - 120.5 gr (7.89 gm)

0 cm 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).

1.7

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 M-

193 bullet (Fig. 1-5).

22 Cal (5.6 mm) FMC

Wt. - 55 gr (3.6)

Detached Muscles

Vel - 3094 f/s 943 m/s

Final wt - 35 gr (2.3 gm)

Permanent Cavity

36% Fragmentation

Temporary Cavity

Bullet

Fragments

5

10

15

20

25

30

35

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).

1.8

Weapons Effects and Parachute Injuries

Permanent

7.62 mm NATO

Cavity

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

Wt - 150 gr (9.7 gm) FMC

Temporary

Cavity

0 cm 5

10

15

20

25

30

35

40

45

50

55

60 65

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.

1.9

Emergency War Surgery

a

b

Explosive Melt Sheet

Nose Cone

Target Material

Fuse

Armor

Jet

Gas and Fragments of

Exploding Charge

Melt Sheet

Spall Material

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

(b) diagram taken from photograph of an actual detonation of shaped-

charged 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.

1.10

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 Miznay-

Schardin 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%

Fig. 1-8. Distribution of fracture

sites sustained within an

armored vehicle that had

detonated a land mine (Soviet

2.8%

data from Afghanistan, early

1980s).

63.6%

1.11

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