A screw element for use in spinal, orthopedic or trauma surgery, the screw element including a screw axis (S) and a screw thread (3)； a drive portion (6) for engagement with a screw driver (20), wherein the drive portion (6) comprises a first recess (7) with a wall and substantially longitudinally extending drive grrooves (8) formed in the wall, a second recess (9) between a free end (5) of the screw element (1, 1') and the first recess (7), wherein the second recess (9) has a wall and a gradually increasing inner diameter towards the free end (5)； and wherein in the wall of the second recess (9) guide grooves (10) are formed at positions corresponding to the position of the drive grooves (8) that allow an engagement portion (30) of a screw driver to be guided to enter the drive grooves (8). Further, a system is provided that includes the screw element and a screw driver adapted thereto.一種脊柱、整型或創傷手術用之螺絲元件，含螺絲軸線(S)和螺絲螺紋(3)；可供與螺絲起子(20)結合之驅動部(6)，其中驅動部(6)包括第一凹部(7)有壁，和壁上所形成實質上縱向延伸之驅動凹溝(8)，第二凹部(9)介於螺絲元件(1,1')自由端(5)和第一凹部(7)間，其中第二凹部(9)有壁，朝自由端(5)逐漸加大內徑；且其中在第二凹部(9)壁，相當於驅動凹溝(8)之位置形成導引凹溝(10)，使螺絲起子的結合部(30)可被導引進入驅動凹溝(8)內。又提供系統，包含螺絲元件及其適用之螺絲起子。
