A bone anchor (100) for attaching a rod (108) to a bone has an anchor member (106) for attachment to the bone and an anchor head (104) having a U-shaped opening for receiving the rod. The bone anchor also includes a locking cap (102) that has a main body (900) and a set screw (1000). Advantageously, in one embodiment the locking cap preferably is designed such that a single tool can be used to lock the locking cap in place on the anchor body preferably with a 90° turn and preferably then drive the set screw to clamp the rod. The locking cap also preferably non-threadingly engages the anchor body. The anchor body preferably has an inclined surface on its top surface which elastically deflects extending tabs on the main body to secure the locking cap to the anchor body. A method of implantation and assembly of the bone anchor are also described.本發明提供一種用於將一桿附著至一骨之骨錨,該骨錨具有一用於附著至該骨之錨構件與一具有一用於容納該桿之U形開口之錨頭。該骨錨亦包含一具有一主體及一固定螺釘之鎖帽。有利地,在一實施例中,該鎖帽較佳地經設計使得可使用單一工具較佳地經由一90°轉動且然後較佳地驅動該固定螺釘以夾緊該桿來鎖定該鎖帽在該錨本體之適當位置處。該鎖帽亦較佳地非螺紋地嚙合該錨本體。該錨本體較佳地在其頂部表面上具有一傾斜表面,該傾斜表面彈性地偏轉在該主體上之延伸突出部以將該鎖帽緊固至該錨本體。
