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5  Epidemiological Aspects of Craniofacial/Skull Base Fractures

The trabecular skeletal framework of the midface ab­­

5.4  Cranio-Fronto-Ethmoidal Fractures

sorbs a great deal of the kinetic energy delivered by an

accidental impact. This absorbing function of the strong

Isolated frontal sinus fractures afflict the anterior wall

bony framework surrounding the facial cavities avoids

in 29%, the posterior wall in 10% and both anterior and

direct energy transfer towards the skull base, the endoc-

posterior wall i0n 61% (Wallis and Donald 1988). In

ranium or the eyeball. Impacts hitting the lower mid-

about 9% of the anterior wall fractures and 8% of the

face are rarely combined with skull base fractures or

isolated posterior wall fractures, dural injuries occur;

dura lacerations (Vajda et al. 1987).

whereas in about 45% of the combined anterior and

In conclusion, dural injuries are more common in

posterior wall fractures, dural lacerations are diagnosed

craniofacial fractures than in subcranial fractures. In

(Wallis and Donald 1988).

general, one has to bear in mind that in about 50% of

Combined fractures of the posterior frontal sinus wall

the patients with serious midface fractures the skull

and the ethmoid (type III) occur in about 32% of cranio-

base and the dura may be involved (O Brian and Reade

facial traumas. The combination of fractures of the eth-

1984; Gruss 1986; Probst and Tomaschett 1990; Hardt

moid and sphenoid, respectively the ethmoid, cribriform

et al. 1990; Kessler and Hardt 1998).

plate and sphenoid (type II), is seen in 30.5%. In 25% of

the cases there is a combination of anterior sinus wall,

5.3.2.2  Localization

respectively anterior sinus wall, orbital roof and sphe-

noid fractures (type I) (Schroeder 1993).

Forty-seven percent of our patients showed dural inju-

Frequency of fractures/combined fractures in the region of the

ries in the region of the ethmoid roof and the cribri-

frontal sinus and skull base (Schroeder 1993)

form plate. The orbital roof was involved in 24% of the

Type I: Anterior sinus wall or anterior sinus

25%

cases and the posterior wall of the sinus in 27% (Hardt

wall roof of the orbit sphenoid fracture

et al. 1990; Neidhardt 2002).

Type II: Ethmoid sphenoid or ethmoid

30.5%