Depressed Skull Fracture

A depressed skull fracture occurs when a fragment of cranial vault is displaced inward relative to the surrounding skull.

It can be:

Closed

Skin and scalp remain intact.

Open or compound

The fracture communicates with an overlying wound.

Open depressed fractures can additionally involve:

• Dural laceration
• Brain laceration
• Contamination
• CSF leakage
• Intracranial foreign material

Common locations include:

• Frontal bone
• Parietal bone
• Temporal bone

Open frontal sinus involvement requires separate attention because violation of the posterior table can communicate the sinonasal tract with the intracranial compartment.

Assess:

• Scalp wound
• Palpable depression
• CSF leak
• Visible brain tissue
• Focal neurological deficit
• Seizure
• Underlying intracranial haematoma
• Frontal sinus injury

Do not repeatedly probe the wound.

Document whether the fracture lies over a major venous sinus because uncontrolled surgical elevation over the superior sagittal or transverse sinus can cause major haemorrhage.

CT head with bone windows: define:

• Depth of depression
• Comminution
• Pneumocephalus
• Intracranial haematoma
• Dural penetration
• Frontal sinus involvement
• Foreign bodies

CT venography is useful when the fracture crosses a major venous sinus and operative elevation is being considered.

Operative indications

An open depressed fracture depressed by more than the thickness of the adjacent skull should generally undergo operative elevation and debridement.

Operate particularly when there is:

• Depression greater than approximately 1 cm
• Dural penetration
• Gross contamination
• Intracranial haematoma requiring evacuation
• CSF leak
• Frontal sinus posterior table injury
• Gross cosmetic deformity
• Wound infection
• Significant pneumocephalus
• Neurological compression.

A closed uncomplicated depressed fracture can often be observed when there is no neurological compression or unacceptable deformity.

Operation

Perform early surgery for an open compound injury.

Steps include:

• Debride contaminated scalp and devitalised tissue
• Remove obvious foreign material
• Elevate depressed bone fragments
• Control intracranial bleeding
• Repair dura watertight where possible
• Irrigate thoroughly
• Replace viable bone fragments when contamination and infection risk permit

Primary replacement of bone is acceptable in a clean adequately debrided injury without established infection.

Avoid uncontrolled elevation of fragments embedded in a major venous sinus without a vascular control strategy.

Antibiotics

Open depressed skull fracture requires antimicrobial prophylaxis.

A practical regimen for uncomplicated open cranial fracture is:

Cefazolin 2 g IV every 8 hours

with broader therapy when there is:

• Gross contamination
• Sinus violation
• Penetrating intracranial debris

For significant sinus or soil contamination, a practical broader regimen is:

Ceftriaxone 2 g IV every 12 hours plus metronidazole 500 mg IV every 8 hours

with duration individualised according to wound contamination and operative findings.

Seizure prophylaxis

Use a 7 day early seizure prophylaxis course when significant cortical injury, open depression or intracranial haematoma is present.