Trephine

A trephine (/trɪˈfaɪn/; from Greek τρύπανον, trypanon 'instrument for boring')[2] is a surgical instrument with a cylindrical blade.

It can be of one of several dimensions and designs depending on what it is meant to be used for.

They may be specially designed for obtaining a cylindrically shaped core of bone that can be used for tests and bone studies, cutting holes in bones (e.g., the skull) or for cutting out a round piece of the cornea for eye surgery.

A cylindrically shaped core of bone (or bone biopsy) obtained with a bone marrow trephine is usually examined in the histopathology department of a hospital under a microscope.

This article related to medical equipment is a stub.

A trephine with a center pin can be seen on the left.
Dr. John Clarke trepanning a skull, ca. 1664, in one of the earliest American portraits. Clarke has a trephine in his right hand. The painting is in Harvard Medical School . [ 1 ]