| 摘要 |
The skull of a patient is immobilized utilizing a generally ring-shaped member (crown) that can be used in place of a conventional halo or tongs, and is affixed to the patient's skull utilizing particularly advantageous skull pins. The crown has a first major portion which is in a first plane, and has a second portion extending at an angle out of the first plane. Preferably it has a generally horseshoe shape in plan view, with first and second ends spaced from each other, those ends being part of the second portion of the crown. Skull pins pass through threaded openings in the crown, including threaded openings in the second portion to attach the crown below a capital distal plane extending between the top of the ears and the top of the eyes of the patient's head. The rigid crown is preferably of a boron fiber or graphite fiber reinforced plastic. The skull pins, which do not artifact any more than bone does, comprise an exteriorly threaded cylinder of plastic (e.g. boron or carbon fiber reinforced plastic), and a skull engaging portion rigidly connected to the cylinder and extending outwardly from a first end of the cylinder and terminating in a pointed tip. The skull engaging portion is of a ceramic material, preferably a single crystal alumina ceramic material. |
