From Big Medical Encyclopedia

TREPANATION (fr. trepanation, from Greek trypanon a drill, is frayed) — the surgery consisting in creation of an opening in a bone for the purpose of opening of the subject cavity. Originally this term designated only operations on bones of a calvaria where T. make most often (see the Craniotrypesis). Then trepanation began to call similar other bone operations (e.g., T. a mastoid, long tubular bones, a breast, tooth) and even on a sclera (see Trepanation of a sclera). Kind of T. the puncture of a bone (e.g., breasts, a wing of an ileal bone) for the purpose of receiving material for a lab is. researches (see Trepanobiopsiya).

The section of soft tissues at a craniotrypesis shall correspond to a projection of edges of the deleted bone plate, and at T. for the purpose of opening of a suppurative focus (see the Mastoiditis, Osteomyelitis) — localizations of purulent process. After a section of soft tissues cut a periosteum and the raspatory shift its edges in the parties on width sufficient for imposing of a trepanation opening.

At T. flat bones use the drilling tools more often (electric and manual) and a chain saw of Gigli (or Dalgren and Lyuer's nippers). On long tubular bones a trepanation opening is usually made electrotrepan or a hollowed chisel, and in an epimetafizarny zone at children — an acute spoon.