Stab wound (overview)

Stab wounds are a form of penetrating trauma that may be self-inflicted or inflicted by another person either accidentally or intentionally. They may be caused from a variety of objects and may occur anywhere in the body.

Terminology

Although commonly caused by a knife as well, slash injuries differ from stab injuries in that usually only the skin is injured and the mechanism is due to more of a slicing or dragging mechanism rather than a thrusting mechanism seen in stab wounds.

Epidemiology

In one South African study stab wounds constituted over 70% of all penetrating injury and 6% of all trauma cases . Patients are usually young and are more likely to be male. Self-inflicted stab wounds are rarer than those inflicted by others.

Clinical presentation

The clinical presentation depends on the location of the stab wound, depth of injury, the structures injured and the size of the object used.

Pathology

Stab wounds usually result from a thrusting mechanism with an object (e.g. knife or scissors) that penetrates the skin and underlying tissue and may extend deeper to breach anatomical cavities (e.g. peritoneal or pleural). The location of the injury, trajectory of the object, size of the object and depth of injury all affect the potential damage that can be inflicted.

Depending on the location vascular injury (e.g. aortic, carotid) and injury to highly vascular organs (e.g. spleen) may be acutely concerning. Injuries that may compromise breathing mechanics (e.g. pneumothorax) and airway patency (e.g. trachea) are also concerning. Visceral injury (e.g. intestinal perforation) is also significant.

A short (and non-exhaustive) list of locations and their potential injuries is given :

• limbs
  • neurovascular injury
  • tendon injury
• head and neck
  • nerve injury
  • arterial injury (e.g. carotid artery transection/dissection)
  • bony injury (e.g. facial fracture)
  • direct brain injury
  • globe rupture
  • tracheal injury
  • esophageal injury​
• chest
  • nerve injury
  • arterial injury (e.g. aortic injury)
  • cardiac injury (e.g. ventricular laceration, traumatic shunt formation)
  • diaphragmatic injury
  • pneumothorax
  • hemothorax
  • hemopneumothorax
• abdomen and pelvis
  • arterial injury
  • venous injury
  • bladder injury
  • liver injury
  • spleen injury
  • kidney injury
  • viscus perforation
• spine
  • cord injury (e.g. complete cord transection, spinal cord herniation)
  • meningeal injury (e.g. dural tear)
  • arterial injury (e.g. epidural hematoma)
  • muscle injury

Radiographic features

Plain radiograph

Plain film may be useful in chest and abdominal stab wounds to show the presence of pneumothorax, subcutaneous emphysema, pleural effusion and sub-diaphragmatic gas .

Echocardiography

Stab injuries are capable of producing direct cardiac injury which can be evaluated using echocardiography .

CT

CT is the main imaging modality used in the evaluation of penetrating stab wounds. CT may show the presence of any metallic foreign bodies, the path of the stab wound, the presence of any resulting injury (e.g. laceration) and any complications .

CT angiogram

CT angiography can be used in various parts of the body to define any vascular injury, active internal bleeding and the presence of any complications such as pseudoaneurysm formation and arteriovenous fistula formation .

MRI

After metallic foreign bodies have been excluded, stabs wounds involving the spine may be imaged with MRI to evaluate the integrity of the cord .

Treatment and prognosis

Cardiac penetrating injury is fatal in 10-60% of cases .

See also

• penetrating neck trauma
• penetrating thoracic trauma