Previous to any attempt at enlargement of the trephine hole, the dura mater must be separated from the bone with the aid of Horsley’s dural separator or other suitable instrument. Of the many patterns of craniectomy forceps, the following will be found to suit all requirements:—
Keen-Hoffmann.
The visceral blade is introduced between the dura and the bone and ‘morcellement’ carried out. It is essential that the surgeon should not be too greedy, resting content with the removal of small fragments at a time.
Lane’s fulcrum forceps.
They possess great mechanical advantage and are mainly suited for the rapid removal of large portions of bone.
Horsley’s nibbling or rongeur forceps.
This instrument is mainly utilized in the smoothing and refreshing of sharp edges of bone, and in the ‘morcellement’ of the thinner portions of the skull—temporal and cerebellar regions.
De Vilbiss’s forceps.
A clever contrivance whereby the operator is enabled to cut a narrow channel in the bone. Mainly utilized in the formation of the osteoplastic flap.