A spinal-surgery system having a rod receiver and/or a cap. The cap has a cylindrical body, opposing splay-resisting flanges, and an opposing rotation-preventing/rotation-resisting wings, each wing having a lateral rotation-preventing surface and a lateral rotation-resisting surface. A receiver proximal end forms a wing-receiving cavity having a lateral rotation-preventing side and a lateral rotation-resisting side. Each flange has a proximal-facing cap splay-resist surface, and a distal-facing cap pop-on surface. Each receiver proximal protrusion has a proximal-facing sloped receiver pop-on surface, and a distal-facing sloped receiver splay-resist surface. Each rotation-preventing surface contacts a corresponding rotation-preventing side and each rotation-resisting surface contacts a corresponding rotation-resisting sides when the cap is popped on. The rotation-preventing surfaces contacting the rotation-preventing sides prevents cap rotation in a first direction. The rotation-resisting surfaces contacting the rotation-resisting sides resists cap rotation in a second direction, but allows cap rotation in the second direction to force receiver arm splay.

A compression nut for treating a bone includes a head and a body extending longitudinally from the head to a free end. The body includes an exterior threading along an exterior surface of a threaded portion of the body separated from the head via an unthreaded portion. The nut also includes a channel extending longitudinally through the body. The channel includes an interior threaded extending along an interior surface of the channel configured to threadedly engage an end of a locking screw received therein.

A locking mechanism assembly to allow locking of a fastener in an orthopedic implant having its axis at a variable angle relative to the axis of threaded through opening in the implant. The assembly includes a locking insert, having threads which mates with the threads of the through opening and which includes a smooth opening that forms a torque driving recess and an annular flange. A fixator has a head portion with external threads of a harder material than that which forms the through opening so that the threads of the fixator will deform the insert to lock the fixator in a desired position relative to the plate.

A spinal-surgery system having a rod receiver and/or a cap. The cap has a cylindrical body, opposing splay-resisting flanges, and an opposing rotation-preventing/rotation-resisting wings, each wing having a lateral rotation-preventing surface and a lateral rotation-resisting surface. A receiver proximal end forms a wing-receiving cavity having a lateral rotation-preventing side and a lateral rotation-resisting side. Each flange has a proximal-facing cap splay-resist surface, and a distal-facing cap pop-on surface. Each receiver proximal protrusion has a proximal-facing sloped receiver pop-on surface, and a distal-facing sloped receiver splay-resist surface. Each rotation-preventing surface contacts a corresponding rotation-preventing side and each rotation-resisting surface contacts a corresponding rotation-resisting sides when the cap is popped on. The rotation-preventing surfaces contacting the rotation-preventing sides prevents cap rotation in a first direction. The rotation-resisting surfaces contacting the rotation-resisting sides resists cap rotation in a second direction, but allows cap rotation in the second direction to force receiver arm splay.

A spinal-surgery system having a rod receiver and/or a cap. The cap has a cylindrical body, opposing splay-resisting flanges, and an opposing rotation-preventing/rotation-resisting wings, each wing having a lateral rotation-preventing surface and a lateral rotation-resisting surface. A receiver proximal end forms a wing-receiving cavity having a lateral rotation-preventing side and a lateral rotation-resisting side. Each flange has a proximal-facing cap splay-resist surface, and a distal-facing cap pop-on surface. Each receiver proximal protrusion has a proximal-facing sloped receiver pop-on surface, and a distal-facing sloped receiver splay-resist surface. Each rotation-preventing surface contacts a corresponding rotation-preventing side and each rotation-resisting surface contacts a corresponding rotation-resisting sides when the cap is popped on. The rotation-preventing surfaces contacting the rotation-preventing sides prevents cap rotation in a first direction. The rotation-resisting surfaces contacting the rotation-resisting sides resists cap rotation in a second direction, but allows cap rotation in the second direction to force receiver arm splay.

A compression nut for treating a bone includes a head and a body extending longitudinally from the head to a free end. The body includes an exterior threading along an exterior surface of a threaded portion of the body separated from the head via an unthreaded portion. The nut also includes a channel extending longitudinally through the body. The channel includes an interior threaded extending along an interior surface of the channel configured to threadedly engage an end of a locking screw received therein.

An implant having a receiver that is adapted to receive a polyaxial screw in the bore and either an internal or external cap. The cap can be an external or internal cap and the implant further has at least one locking aid in the form of at least one of a tactile feedback, a visual feedback or an enhanced fixation between the cap and a rod that is received in the receiver.

A fixation device is used to fix an elongate element, in particular a wire, in an opening of a retaining structure, in particular of an implant plate. The fixation device has a main body. The main body is provided with a bore for receiving the elongate element. The main body is radially deformable in a clamp area, such that the diameter of the bore can be reduced. The main body has an outer contour which is designed in such a way that, when the fixation device is inserted into the opening of the retaining structure, the clamp area is deformed such that the elongate element is clamped securely in the bore.

An implant having a receiver that is adapted to receive a polyaxial screw in the bore and either an internal or external cap. The cap can be an external or internal cap and the implant further has at least one locking aid in the form of at least one of a tactile feedback, a visual feedback or an enhanced fixation between the cap and a rod that is received in the receiver.

A spinal-surgery system having a rod receiver and/or a cap. The cap has a cylindrical body, opposing splay-resisting flanges, and an opposing rotation-preventing/rotation-resisting wings, each wing having a lateral rotation-preventing surface and a lateral rotation-resisting surface. A receiver proximal end forms a wing-receiving cavity having a lateral rotation-preventing side and a lateral rotation-resisting side. Each flange has a proximal-facing cap splay-resist surface, and a distal-facing cap pop-on surface. Each receiver proximal protrusion has a proximal-facing sloped receiver pop-on surface, and a distal-facing sloped receiver splay-resist surface. Each rotation-preventing surface contacts a corresponding rotation-preventing side and each rotation-resisting surface contacts a corresponding rotation-resisting sides when the cap is popped on. The rotation-preventing surfaces contacting the rotation-preventing sides prevents cap rotation in a first direction. The rotation-resisting surfaces contacting the rotation-resisting sides resists cap rotation in a second direction, but allows cap rotation in the second direction to force receiver arm splay.