Skull fracture

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Skull fracture
A piece of a skull with a depressed skull fracture
SpecialtyEmergency medicine Edit this on Wikidata

A skull fracture is a break in one or more of the eight bones that form the cranial portion of the

blunt force trauma. If the force of the impact is excessive, the bone may fracture at or near the site of the impact and cause damage to the underlying structures within the skull such as the membranes, blood vessels, and brain
.

While an uncomplicated skull fracture can occur without associated physical or

neurological damage and is in itself usually not clinically significant, a fracture in healthy bone indicates that a substantial amount of force has been applied and increases the possibility of associated injury. Any significant blow to the head results in a concussion, with or without loss of consciousness
.

A fracture in conjunction with an overlying

epidermis and the meninges, or runs through the paranasal sinuses and the middle ear
structures, bringing the outside environment into contact with the cranial cavity is called a compound fracture. Compound fractures can either be clean or contaminated.

There are four major types of skull fractures: linear, depressed, diastatic, and basilar. Linear fractures are the most common, and usually require no intervention for the fracture itself. Depressed fractures are usually comminuted, with broken portions of bone displaced inward—and may require surgical intervention to repair underlying tissue damage. Diastatic fractures widen the sutures of the skull and usually affect children under three. Basilar fractures are in the bones at the base of the skull.

Types

Linear fracture

Linear skull fractures are breaks in the bone that transverse the full thickness of the skull from the outer to inner table. They are usually fairly straight with no bone displacement. The common cause of injury is blunt force trauma where the impact energy transferred over a wide area of the skull.[citation needed]

Linear skull fractures are usually of little clinical significance unless they parallel in close proximity or transverse a

venous sinus thrombosis, and epidural hematoma. In young children, although rare, the possibility exists of developing a growing skull fracture especially if the fracture occurs in the parietal bone.[1]

Depressed fracture

Depressed skull fracture

A depressed skull fracture is a type of fracture usually resulting from blunt force trauma, such as getting struck with a hammer, rock or getting kicked in the head. These types of fractures—which occur in 11% of severe head injuries—are comminuted fractures in which broken bones displace inward. Depressed skull fractures present a high risk of increased pressure on the brain, or a hemorrhage to the brain that crushes the delicate tissue.[citation needed]

Compound depressed skull fractures occur when there is a laceration over the fracture, putting the internal cranial cavity in contact with the outside environment, increasing the risk of contamination and infection. In complex depressed fractures, the dura mater is torn. Depressed skull fractures may require surgery to lift the bones off the brain if they are pressing on it by making burr holes on the adjacent normal skull.[2]

Diastatic fracture

Cranial abnormalities in cleidocranial dysplasia including diastatic sutures

Diastatic fractures occur when the fracture line transverses one or more sutures of the skull causing a widening of the suture. While this type of fracture is usually seen in infants and young children as the sutures are not yet fused it can also occur in adults. When a diastatic fracture occurs in adults it usually affects the

lambdoidal suture as this suture does not fully fuse in adults until about the age of 60. Most adult diastatic fractures are caused by severe head injuries. Due to the trauma, diastatic fracture occurs with the collapse of the surrounding head bones. It crushes the delicate tissue, similarly to a depressed skull fracture.[citation needed
]

Diastatic fractures can occur with different types of fractures and it is also possible for diastasis of the cranial sutures to occur without a concomitant fracture. Sutural diastasis may also occur in various congenital disorders such as

cleidocranial dysplasia and osteogenesis imperfecta.[3][4][5][6]

Basilar fracture

Main article: Basilar skull fracture
Superior view of the skull base

Basilar skull fractures are linear fractures that occur in the floor of the cranial vault (skull base), which require more force to cause than other areas of the neurocranium. Thus they are rare, occurring as the only fracture in only 4% of severe head injury patients.

Basilar fractures have characteristic signs: blood in the

ecchymosis often called 'raccoon eyes'[7] (bruising of the orbits of the eyes that result from blood collecting there as it leaks from the fracture site); and retroauricular ecchymosis known as "Battle's sign" (bruising over the mastoid process).[8]

Growing fracture

A growing skull fracture (GSF) also known as a craniocerebral erosion or leptomeningeal cyst[9] due to the usual development of a cystic mass filled with cerebrospinal fluid is a rare complication of head injury usually associated with linear skull fractures of the parietal bone in children under 3. It has been reported in older children in atypical regions of the skull such as the basioccipital and the base of the skull base and in association with other types of skull fractures. It is characterized by a diastatic enlargement of the fracture.[citation needed]

Various factors are associated with the development of a GSF. The primary causative factor is a tear in the

leptomeningeal cystic mass.[10][11][12][13][14][15][16]

Cranial burst fracture

A cranial burst skull fracture, usually occurring with severe injuries in infants less than 1 year of age, is a closed, diastatic skull fracture with cerebral extrusion beyond the outer table of the skull under the intact scalp.[citation needed]

Acute scalp swelling is associated with this type of fracture. In equivocal cases without immediate scalp swelling the diagnosis may be made via the use of magnetic resonance imaging thus insuring more prompt treatment and avoiding the development of a "growing skull fracture".[17]

Compound fracture

epidermis to the meninges
allowing outside environmental contact with the skull cavity.

A fracture in conjunction with an overlying

laceration that tears the epidermis and the meninges—or runs through the paranasal sinuses and the middle ear structures, putting the outside environment in contact with the cranial cavity—is a compound fracture.[citation needed
]

Compound fractures may either be clean or contaminated. Intracranial air (pneumocephalus) may occur in compound skull fractures.[18]

The most serious complication of compound skull fractures is infection. Increased risk factors for infection include visible contamination, meningeal tear, loose bone fragments and presenting for treatment more than eight hours after initial injury.[19]

Compound elevated fracture

A compound elevated skull fracture is a rare type of skull fracture where the fractured bone is elevated above the intact outer table of the skull. This type of skull fracture is always compound in nature. It can be caused during an assault with a weapon where the initial blow penetrates the skull and the underlying meninges and, on withdrawal, the weapon lifts the fractured portion of the skull outward. It can also be caused by the skull rotating while being struck in a case of blunt force trauma, the skull rotating while striking an object as in a fall, or it may occur during transfer of a patient after an initial compound head injury.[20][21]

Anatomy

Lateral view of the human skull with the neurocranium highlighted
The three bone layers of the skull

The human skull is anatomically divided into two parts: the

facial fractures, or if the jaw is fractured, a mandibular fracture.[23]

The eight cranial bones are separated by

sutures : one frontal bone, two parietal bones, two temporal bones, one occipital bone, one sphenoid bone, and one ethmoid bone.[24]

The bones of the skull are in three layers: the hard compact layer of the external table (

red bone marrow in the middle, and the compact layer of the inner table (Lamina interna).[25]

Skull thickness is variable, depending on location. Thus the traumatic impact required to cause a fracture depends on the impact site. The skull is thick at the

mastoid processes, and the external angular process of the frontal bone. Areas of the skull that are covered with muscle have no underlying diploë formation between the internal and external lamina, which results in thin bone more susceptible to fractures.[citation needed
]

Skull fractures occur more easily at the thin squamous

dural sinuses in the posterior cranial fossa.[26]

Prognosis

Children with a simple skull fracture without other concerns are at low risk of a bad outcome and rarely require aggressive treatment.[27]

The presence of a concussion or skull fracture in people after trauma without intracranial

hemorrhage or focal neurologic deficits was indicated in long term cognitive impairments and emotional lability at nearly double the rate as those patients without either complication.[28]

Those with a skull fracture were shown to have "neuropsychological dysfunction, even in the absence of intracranial pathology or more severe disturbance of consciousness on the GCS".[29]

See also

References

  1. PMID 1190143
    .
  2. ^ Singh J and Stock A. 2006. "Head Trauma." Emedicine.com. Retrieved on January 26, 2007.
  3. PMID 8456801.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  4. PMID 9430147.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  5. PMID 17122029
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  6. S2CID 7154559
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  7. PMID 11754879.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  8. PMID 19392601.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  9. PMID 20496339
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  10. S2CID 24991254.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  11. S2CID 22659384.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  12. PMID 7792708.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  13. S2CID 5665654.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  14. S2CID 18879100.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  15. S2CID 44468528.{{cite journal}}: CS1 maint: multiple names: authors list (link
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  16. PMID 4093801.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  17. S2CID 26744592.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  18. ^ Fundamentals of diagnostic radiology by William E. Brant, Clyde A. Helms p.56
  19. PMID 17374298.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  20. ^ Elevated skull fracture[www.ijntonline.com/Dec07/abstracts/abs12.PDF]
  21. PMID 16630918.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  22. ISBN 1-60406-151-0
  23. PMID 6950035.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  24. ISBN 0-8018-5652-3
  25. ISBN 3-7945-1947-7
  26. ^ Medscape: Ali Nawaz Khan: Imaging in Skull Fractures [1]
  27. S2CID 205548333
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  28. PMID 17215737.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  29. PMID 9058000.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )

Bibliography

External links
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