Gunshot Wounds: Ballistics, Pathophysiology, and Management

Gunshot wounds (GSWs) represent complex traumatic injuries with highly variable clinical presentations. Their severity depends on ballistic characteristics, tissue interaction, and anatomical location. Understanding the physics of injury and evidence-based management principles is essential for optimal patient outcomes.

Ballistics and Classification

Velocity Categories

• Low-velocity (< 2,000 ft/s)
  • Typically handguns
  • Cause localized tissue damage
• High-velocity (> 2,000 ft/s)
  • Military and most hunting rifles
  • Produce extensive tissue destruction due to higher energy transfer

Shotgun Injuries

Wounding potential depends on:

• Choke (dispersion pattern)
• Load (pellet size)
• Distance from target (critical determinant of spread and penetration)

Energy Transfer and Wound Mechanics

The severity of a gunshot wound is governed by kinetic energy (KE):

KE=1/2*mv²

Where:

• m = mass of projectile
• v = velocity

Key Determinants of Energy Transfer

• Striking energy (energy at impact)
• Exit energy (residual energy after passage)
• Projectile behavior:
  • Tumbling
  • Deformation
  • Fragmentation

High-velocity projectiles transfer significantly more energy due to the squared relationship with velocity, resulting in disproportionately greater tissue injury.

Tissue Interaction and Cavitation

Permanent Cavity

• Direct tissue destruction along the bullet path
• Caused by crush injury
• Typically narrow and well-defined

Temporary Cavity

• Produced by shock wave and energy dissipation
• Causes radial tissue stretching
• Much larger in high-energy injuries

Tissue-Specific Effects

• High-density tissues (e.g., bone, liver) → greater damage
• Air-filled structures (e.g., lungs) → injury often limited to direct path
• Fluid-rich tissues (e.g., muscle, liver) → extensive cavitation and distant damage

A transient vacuum effect may draw debris (e.g., clothing, bacteria) into the wound, contributing to contamination.

See Also: Soft Tissue Injury

Clinical Evaluation

Management follows Advanced Trauma Life Support principles:

Primary Considerations

• Airway, breathing, circulation stabilization
• Hemodynamic assessment

Local Examination

• Neurovascular evaluation is critical

Wound Characteristics

• Entrance wound:
  • Small, circular
  • Surrounding abrasion ring
  • Possible soot, tattooing, or muzzle imprint
• Exit wound:
  • Larger, irregular
  • Stellate or slit-like appearance

Radiographic Evaluation

• Standard anteroposterior (AP) and lateral radiographs
• CT imaging if:
  • Complex fractures
  • Suspected vascular or visceral injury

Fracture Patterns

• Low-velocity injuries: nondisplaced or minimally displaced fractures
• High-velocity injuries: comminuted, unstable fractures

Orthopedic Treatment of Gunshot Wounds

A. Low-Velocity Injuries

Initial Management

1. First-generation cephalosporin antibiotics
2. Tetanus prophylaxis
3. Irrigation and local wound debridement

Indications for Operative Debridement

• Intra-articular involvement
• Vascular injury
• Gross contamination
• Compartment syndrome
• Retained fragments in critical locations (e.g., subarachnoid space)
• Severe soft tissue damage

Fracture Treatment

• Stable → conservative management
• Unstable → surgical fixation

B. High-Velocity and Shotgun Injuries

Managed as high-energy trauma:

1. Broad antibiotic coverage
2. Extensive and repeated surgical debridement
3. Fracture stabilization (external or internal fixation)
4. Delayed wound closure
   • Skin grafts
   • Flap reconstruction

Special Scenario: Abdominal Gunshot Wounds

• Require:
  • Debridement of missile tract
  • Broad-spectrum antibiotics (gram-negative + anaerobic coverage)

Complications

Retained Bullet Fragments

• Usually well tolerated
• Removal indicated if:
  • Symptomatic
  • Intra-articular
  • Infected
  • Located in palms/soles

Infection

• Not sterile injuries
• Sources:
  • Skin flora
  • Clothing debris
  • Gastrointestinal contamination

Complications include:

• Abscess
• Osteomyelitis

Neurovascular Injury

• More common in high-velocity wounds
• Mechanisms:
  • Direct disruption
  • Cavitation-induced traction or avulsion

Clinical spectrum:

• Neuropraxia → complete vascular transection

Lead Toxicity

• Occurs with retained fragments in:
  • Joints
  • Cerebrospinal fluid

Effects:

• Chronic synovitis
• Systemic lead poisoning

→ Indication for surgical removal

Key Clinical Pearls

• Velocity is the dominant determinant of injury severity
• Temporary cavitation explains damage beyond the bullet track
• All gunshot wounds should be considered contaminated
• Surgical decision-making depends on energy transfer, tissue damage, and anatomical involvement
• Early debridement and appropriate antibiotics significantly reduce complications

References & More

• Baum GR, Baum JT, Hayward D, MacKay BJ. Gunshot Wounds: Ballistics, Pathology, and Treatment Recommendations, with a Focus on Retained Bullets. Orthop Res Rev. 2022 Sep 5;14:293-317. doi: 10.2147/ORR.S378278. PMID: 36090309; PMCID: PMC9462949. Pubmed
• Shrestha R, Kanchan T, Krishan K. Gunshot Wounds Forensic Pathology. [Updated 2023 Apr 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: Pubmed
• Egol KA. Handbook of fractures. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2019.