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Weapons Effects
Overview
• Epidemiology of Injuries• Mechanism of Injury• Antipersonnel Landmines• Small Arms
Epidemiology of Injuries
• Two Major Categories of Weapons– Explosives: artillery, grenades, mortars, bombs,
hand grenades– Small Arms Fire: pistols, rifles, machine guns
• Most common pattern or injury is multiple small fragment wounds of extremities
Mechanism of Injury: Projectiles
• There are two areas of projectile-tissue interaction– Permanent cavity: localized area of tissue injury that is proportional to
the size of the projectile
• Temporary cavity: Transient 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.
Mechanism of Injuries: Explosives
• Explosives have three mechanisms of injury:– Ballistic– Blast– Thermal
Mechanism of Injury
• Ballistic: – Injuries caused by fragments created by explosives– Typically cause multiple wounds
• Blast– This occurs more closely to the explosion compared to ballistic injury– The ears are most often affected by the overpressure, followed by lungs and
gastrointestinal organs. – The explosion creates a blast wind that can throw victims against solid objects,
causing blunt trauma.
• Thermal– The result of combustion, may cause burns
Antipersonnel Landmines
• Tree types of antipersonnel landmines– Static– Bounding– Horizontal spray
Antipersonnel Landmines
• Static: small landmines that detonate when stepped on and result in 2 types of injury• Partial or complete traumatic amputation• More proximally, tissue and other debris is pushed up
along fascial planes, stripping tissue from bone
Antipersonnel Landmines
• Bounding: a mine that is propelled to 1-2m in height and then explodes, causing multiple small fragment wounds. This type of mine is associated with the highest mortality.
• Horizontal spray mines: propel fragments in one direction, causing multiple small fragment wounds
Small Arms
• In the past, differentiation made between HI and LOW velocity weapons but now felt not to be totally different entities.
• Change to higher velocity weapons a result of change to smaller and lighter automatic weapons
• Automatic weapons more effectiveMost combat actions < 200 metersMost infantry not great marksman
• Smaller, lighter ammo developedLess recoil, better aimEach soldier can can carry more rounds
• To maintain wounding power, higher bullet velocities were necessary
• Higher velocities developed to increase FIREPOWER, not wounding power (same)
• Always potential for higher energy transfer with higher velocity, but this is not always the case
• Surgeon should always be concerned with the individual wound, rather than the “worst case scenario”
Small Arms (cont)
• Some missiles are designed to fragment or expandDum-dums, Hollow-points, Non-jacketed, Some fragments despite copper jacket (M-16)
• Fragments cause multiple tracts of permanent and temporary cavities
• Expansion makes the permanent cavity wider
Fragmentation/ Expansion
Yaw
• Yaw is the deviation in the longitudinal axis of the bullet from its line of flight (tumbling)
• Yaw is usually 180 degrees and can be caused by striking foliage or tissue
• It increases the area of permanent and temporary cavitation
• Important in the injuries caused by AK-47, AK-74
Shotgun Injuries
Shotgun shells have a big powder charge with a large mass of lead balls
• Destructive potential depends on range
• At close range, it can cause a large wound with severe disruption of anatomy by direct crush alone
• Long range (>25m) cause usually only skin wounds
• Wadding is a projectile too