PEDICLE SCREW

• Main Author: UEDA TOMOKAZU
• Format: Patent
• Language: English; Japanese
• Published: 07.03.2024
• Subjects: DIAGNOSIS; HUMAN NECESSITIES; HYGIENE; IDENTIFICATION; MEDICAL OR VETERINARY SCIENCE; SURGERY

To surely fix a pedicle screw to a bone in the spinal fusion.SOLUTION: A pedicle screw 1 used in the spinal fusion comprises: a rod-shaped shaft part 12 which is formed with a thread; and a head part 11 which is connected to a base end 12a of the shaft part 12. The shaft part 12 includes: a first screw part 14A which is provided on the base end 12a side and in which a pitch of a thread 13 is in a prescribed size; and a second screw part 14B which is provided on the tip 12b side and in which a pitch of the thread is greater than that of the first screw part 14A. The surface of the shaft part 12 includes: a low friction surface 16 which is not subjected to a surface roughening treatment; and a high friction surface 15 which is subjected to the surface roughening treatment and has a large friction coefficient. A surface of at least a portion of the first screw part 14A is the low friction surface 16, and a surface of at least a portion of the second screw part 14B is the high friction surface 15.SELECTED DRAWING: Figure 2 【課題】脊椎固定術において、椎弓根スクリューを骨に確実に固定することができる。【解決手段】脊椎固定術に用いられる椎弓根スクリュー１であって、ねじ山が形成された棒状の軸部１２と、軸部１２の基端１２ａに接続された頭部１１を有し、軸部１２は、基端１２ａ側に設けられねじ山１３のピッチが所定の大きさである第１ねじ部１４Ａと、先端１２ｂ側に設けられ第１ねじ部１４Ａよりもねじ山のピッチが大きい第２ねじ部１４Ｂを有し、軸部１２の表面は、粗面化処理されていない低摩擦面１６と、粗面化処理されて摩擦係数が大きい高摩擦面１５とを有しており、第１ねじ部１４Ａの少なくとも一部の表面が低摩擦面１６であり、第２ねじ部１４Ｂの少なくとも一部の表面が高摩擦面１５である。【選択図】図２