Fig. 190.—Pond Fracture of Left Frontal Bone, produced during delivery.
(From a photograph lent by Mr. J. H. Nicoll.)
As a rule the whole thickness of the skull is broken, and, as usual, the inner table suffers most. In infants the bones may be merely indented, the fracture being of the greenstick variety. All degrees of severity are met with, from a simple, localised indentation of the bone, to complete smashing of the skull into fragments.
Diagnosis.—When compound, the nature of these fractures is readily recognised on exploring the wound, but their extent is not always easy to determine, and it is not uncommon for extensive fissures to pass into the base.
A hæmatoma of the scalp may readily be mistaken for a depressed fracture. The condensation of the tissues round the seat of impact and the soft coagulum in the centre, closely simulate a depression in the bone; but if firm pressure is made with the finger, the irregular edge of the bone can be recognised, and the depressed portion is felt to be on a lower level. On the other hand, a depression in the bone is sometimes obscured by an overlying hæmatoma, and unless great care is taken the fracture may be overlooked.
Treatment.—All are agreed that compound depressed and comminuted fractures—whether associated with cerebral symptoms or not—should be operated on to enable the wound to be purified, and the normal outline of the skull to be restored by elevating or removing depressed or separated fragments. Except in young children, in whom considerable degrees of depression are frequently righted by nature, most surgeons recommend operative interference even in simple fractures with the object of elevating the depressed bone, and to anticipate subsequent complications such as persistent headache, attacks of giddiness, traumatic epilepsy, or insanity. Others, including von Bergmann and Tilmanns, consider that the risk of such sequelæ ensuing is not sufficient to justify a prophylactic operation of such severity as trephining.
The operation is described in Operative Surgery, p. 93.
Fractures of the Base
The base of the skull may be fractured by a pointed object, such as a fencing foil, a knitting pin, or the end of an umbrella, being forced through the orbit, the nasal cavities, or the pharynx. These injuries will be referred to in describing fractures of the anterior fossa.
The majority of basal fractures result from such accidents as a fall from a height, the patient landing on the vertex or on the side of the head, or from a heavy object falling on the head. The violence is therefore indirect in so far as the bone breaks at a point other than the seat of impact.