Interpreting Skull Fractures and Their Causes

In an earlier blog post I addressed concussion and the specifics of brain injury. This blog post focuses on a related topic: skull fractures. This broad term represents an extensive list of 20 specific types of fracture, each with its own etiology (cause) and description. Most fractures can indicate a fall, motor vehicle collision, or other impact to the skull, but some connote assault. Determining the potential cause of a skull fracture can be an important factor in your case. Use the following list to help sort the complexities of skull fracture.

Type of FractureFracture DescriptionFracture Etiology/Causes
BasilarLinear fractures on the skull floor (base)Multiple etiology
BlowoutFracture of the floor of medial wall of the orbit (eye bone) into the sinuses; orbital rim is intactSudden blow to the eye pushes the intact globe (eyeball) back into the orbit
ComminutedMultiple fragmentation due to crushing injuriesLow velocity/high impact
CoupAt the site of impactDirect force
Contrecoup/RemoteAway from the impact siteCrushing injuries; indirect force transmitted through the moving brain
Closed/SimpleSkin is not broken or cut; no exposure to external environmentMultiple etiology
DentoalveolarSeparation of mandibular fragment that may contain teethDirect force applied anteriorly or laterally
DepressedInward displacement of bony fragmentsAffects children under three years
DiastaticOccurs along the suture line of the skullHigh velocity; caused by forces with low mass
Hairline/FissureStraight discontinuity of boneMultiple etiology
HingeLongitudinal or transverse crushing injuriesMultiple etiology
Le Fort ISeparation of all or a portion of the midface from the skull baseImpact to face
Le Fort IIMaxilla may be separated from the face; fracture extends into the orbits through the interorbital regionImpact to face
Le Fort IIIHigh horizontal maxillary fracture through the nasofrontal suture, through the medial orbital wall and frontozygomatic suture, across the arch and through the sphenoidImpact to face
LinearFracture in a straight line with no bone displacementLow velocity caused by forces with large mass
Open/CompoundThe skin is broken, and the bone is in contact and visible with external environmentMultiple etiology
PondShallow depressed fracturesContinuation of linear fractures or compression
PlugOuter table of the bone is intact; the inner table is broken outLow velocity impact with a small surface
RingCircular fracture around the foramen magnum (base/floor of the skull)Compression of lumbar spine after fall landing on feet or buttocks
StellateStar-shaped injuriesMultiple etiology