Abstract: A bone anchoring device includes a shank to be anchored in a bone or vertebra, a head, and a receiving part receiving the head for connecting the shank to a rod. The shank and the head are separate parts. The head has a bore with a cylindrical inner surface, a ring-shaped groove provided on the inner surface, and at least one slit extending from the inner surface to the outer surface of the head. The shank has a first portion for anchoring in the bone or vertebra and a second portion with a cylindrical outer surface adjoining a free end. A projection is provided on the cylindrical outer surface which engages with the ring-shaped groove of the head, when the cylindrical second portion of the shank is inserted in the bore of the head.

Abstract: A bone screw is provided including a tubular body and a head as separate parts. The tubular body has a first end, a second end, a tubular wall defining a cavity and a plurality of openings extending through the tubular wall into the cavity. The tubular body also includes a continuous exterior bone thread on an exterior tubular surface of the tubular wall. The continuous exterior bone thread extends for at least one full revolution about the tubular surface. The head defines an inner bore and includes an engagement structure to engage with a driver to advance the bone screw in the bone when a rotating force from the driver is applied to the engagement structure in a first direction, and a connection structure to connect to the tubular body at the first end.

Abstract: A polyaxial bone anchoring device includes: an anchoring element having a shaft and a head; a receiving part having a top end, a bottom end, and an accommodation space for accommodating the head, the accommodation space having a lower opening at the bottom end, a sleeve-like insert piece configured to be positioned around a portion of the head, wherein a lower edge of the insert piece extends past the lower opening when the insert piece is seated in the receiving part; a pressure member configured to contact the head to exert pressure onto the head; wherein when the head, the insert piece, and the pressure member are arranged in the receiving part, the insert piece is tiltable with respect to the receiving part and with respect to the anchoring element, and wherein the anchoring element and the insert piece can be locked at respective angles relative to the receiving part.

Abstract: An anchoring member for a polyaxial bone anchoring device includes a bone anchoring section having a first end, a second end, a core having a first portion with a constant cross-sectional area, and a bone engagement structure on at least a portion of the core, a head, wherein a central axis extends through respective centers of the head and the first and second ends of the bone anchoring section, and a neck, the neck having an outer surface that is asymmetric with respect to the central axis, wherein a first cross-section of the neck perpendicular to the central axis includes a portion of the neck where the outer surface of the neck is at a minimum distance from the central axis, wherein a cross-sectional area of the first cross-section of the neck is at least the cross-sectional area of the first portion of the core of the bone anchoring section.

Abstract: A bone anchor includes a shank having a free end, a longitudinal axis, a channel extending axially through the shank to the free end, the channel having a first width, and at least one opening extending through a wall of the shank, and a narrowing member including an elastically deformable portion configured to extend into the channel at or near the free end. The narrowing member is adjustable from a first configuration where the deformable portion defines an opening with a width smaller than the first width to restrict a substance from exiting through the free end, to a second configuration where the deformable portion is deformed radially outwardly to define an opening with a width that is at least the first width, while at least a portion of the shank positioned at a same axial height as the deformable portion maintains a constant outer width.

Abstract: A spacer for insertion between two vertebrae includes a variable axial length and comprises a first member having a hollow interior and a tubular wall and a second member having a hollow interior and a tubular wall the second member being slidable within the first member in an axial direction for adjusting an overall length. At least the first member or the second member comprises an access opening in its wall, the opening having a size which is adapted for inserting bone grafts through the opening into the interior. The spacer further comprises a length adjustment structure being engageable with an expansion tool for telescoping the second member relative to the first member and a locking structure for fixing the axial length. The access opening, the length adjustment structure and the locking structure are arranged so as to be accessible from the same side of the spacer. The spacer allows in situ filling of bone grafts into its interior and an improved handling.

Abstract: An anchoring member is provided suitable for use in a polyaxial bone anchoring device, the anchoring member (1) comprising a bone anchoring section (2) with a bone engagement structure in at least a portion of an outer surface thereof; a head (3); a central axis (C) extending through a center of the head (3) and the bone anchoring section (2), and a neck portion (24; 24?; 24?; 24??) between the bone anchoring section and the head, wherein the neck portion is asymmetric with respect to the central axis (C); and wherein the bone anchoring section (2) has a contour in a circumferential direction adjacent to the neck portion and wherein the neck portion is at least partially recessed with respect to the contour of the bone anchoring section at one side and extends beyond the contour of the bone anchoring section at an opposite side from the central axis.

Abstract: A bone anchor includes a shaft having a first end and a second end, a bore extending from the first end to the second end, and a plug member which is insertable into the bore and guidable through the bore for closing the bore at the second end. The bone anchor is suitable for minimally invasive surgery in such a way a guide wire can be guided through the bone anchor and after the bone anchor has been anchored in the bone the plug member is inserted to close the open end of the bone anchor. A bone cement or a pharmaceutical substance can be introduced into the bone anchor.

Abstract: A polyaxial bone anchoring device includes a bone anchoring element having a head and a shaft, a receiving part having a head receiving portion, a rod receiving portion, and a bore having a bore axis, and a pressure member movable in the bore and having a first surface for engaging the head, wherein the pressure member is movable to a first position where friction between the first surface and the head generates a preload on the head to maintain the shaft at a temporary angular position relative to the receiving part, and wherein the pressure member is configured to engage the receiving part to generate a holding force for holding the pressure member at the first position without a positive lock, and wherein the pressure member is movable in and out of the first position by applying an axial force on the pressure member greater than the holding force.

Abstract: A bone anchoring device includes a receiving part including a rod receiving portion with a first end, a second end, and a U-shaped recess for receiving a rod, the recess defining two free legs, and a head receiving portion at the second end for introducing and clamping the head, and a locking ring configured to be arranged around the head receiving portion, the locking ring including an engagement structure for engagement with a tool, the engagement structure defining a width of the locking ring that is greater than a greatest width of the rod receiving portion, wherein the locking ring can assume a locking position exerting a greatest compressive force on the head receiving portion of the receiving part to lock an inserted head, and wherein the locking ring is movable out of the locking position towards the first end of the rod receiving portion.

Abstract: An expandable intervertebral implant includes a front wall, a back wall spaced apart from the front wall, and two side walls connecting the front wall and the back wall at their respective ends. The walls define a space. The implant further includes a bottom face, a top face, at least one engagement member with an engagement surface for engagement with the end plate of a vertebral body, a first adjusting element and a second adjusting element which are supported by a first support member and a second support member, respectively, and which cooperate with the respective support member such that the engagement member is reciprocally movable between a first end position and a second end position. In the first end position, the engagement surface does not project beyond the bottom face or the top face and in the second end position, the engagement surface at least partially projects outwardly beyond the bottom face or the top face. The first and the second support members are coupled by a coupling mechanism.

Abstract: A bone anchoring device includes an anchoring element having a shank to be anchored in a bone or a vertebra and a receiving part connected to the shank, and a rod for connecting at least two anchoring elements, the rod having at least a tubular portion. The receiving part comprises a recess for receiving said rod. The bone anchoring element also includes a locking element cooperating with the receiving part to secure the rod in the recess, a filling piece being arranged between the locking element and the rod for exerting pressure onto the rod to lock the rod in the recess. The filling piece includes a rod contacting surface which contacts a portion of said rod. The shape of the rod contacting surface is adapted to the shape of the portion of the rod.

Abstract: A coupling device for coupling a bone anchor to a rod includes a receiving part having a longitudinal axis, a channel for receiving a rod, and an accommodation space for holding a head of a bone anchor, a pressure member having a first portion for holding and clamping the head and a deformable portion with a free end, and a locking member. The pressure member is expandable for inserting the head and adjustable to lock the head. When the deformable portion is at a first configuration, the free end of the deformable portion is supported by the receiving part, and at least part of the locking member is movable to exert a force on the deformable portion for adjusting the deformable portion to a second configuration where at least part of the deformable portion is farther away from the longitudinal axis compared to the first configuration.

Abstract: A bone anchoring device includes a bone anchoring element having a head and a shaft, a receiving part for coupling the bone anchoring element to a stabilization element, the receiving part having a bore having a bore axis, a seat member configured to be arranged in the bore and to be rotatable around the bore axis, the seat member forming a seat for polyaxially holding the head, the seat member being configured to allow a greater pivot angle of the bone anchoring element in a first direction compared to other directions when the bone anchoring element and the seat member are in the receiving part, and a pressure member configured to contact the head to exert pressure onto the head, and to be connected to the seat member, such that the pressure member is rotatable together with the seat member around the bore axis.

Abstract: A polyaxial bone anchoring device includes a bone anchoring element having a head and a shaft, a receiving part having a head receiving portion, a rod receiving portion, and a bore having a bore axis, and a pressure member movable in the bore and having a first surface for engaging the head, wherein the pressure member is movable to a first position where friction between the first surface and the head generates a preload on the head to maintain the shaft at a temporary angular position relative to the receiving part, and wherein the pressure member is configured to engage the receiving part to generate a holding force for holding the pressure member at the first position without a positive lock, and wherein the pressure member is movable in and out of the first position by applying an axial force on the pressure member greater than the holding force.

Abstract: A targeting device for guiding a drill arrangement for forming an arc-shaped bore in an assembly of adjacent bones or bone fragments, comprises a support frame, a pivoting device mounted to the support frame and arranged to receive the drill arrangement and to allow a pivoting movement of the drill arrangement along an arc-shaped path having a predetermined radius of curvature rc around a pivot axis. The support frame is provided with at least three fixation devices each configured to fix a bone or bone fragment of the bone assembly to define a fixed position in space of the bone assembly with respect to the pivoting device when the bone assembly is installed on the support frame.

Abstract: A receiving part for connecting a shank of a bone anchoring element to a rod. The receiving part has a first end, a second end and a recess having a substantially U-shaped cross section. The recess extends from the first end in a direction of the second end forming two legs open at the first end. The recess defines a channel to receive the rod. The channel has a longitudinal axis. The legs have an inner thread to receive a securing element having an outer thread cooperating with the inner thread. The legs are provided with stiffening structures. In one embodiment, the stiffening structures are formed by the wall thickness of the outer edges of the legs being larger than the wall thickness of the legs at a location closest to the central axis of the receiving part.

Abstract: A polyaxial bone anchoring device includes an anchoring element having a shaft and a head; a receiving part having a channel for receiving a rod therein, a coaxial bore and a seat portion for receiving the head; a pressure element having a head contacting surface portion; wherein the head is pivotable with respect to the receiving part and can be fixed at an angle by exerting pressure via the pressure element onto the head, and wherein the head has an oversize with respect to the head contacting surface portion such that an interference fit is achieved that clamps the head by the friction between the head and the head contacting surface portion. The curved outer surface portion has a largest diameter and the head contacting surface contacts the head at least in a region including the largest diameter.

Abstract: A polyaxial bone anchoring device includes an anchoring element having a shank and a head having an outer surface portion shaped as a segment of a sphere, a receiving part having a seat portion for receiving the head, and a pressure element having a head contacting surface portion having at least two circumferentially distinct projections and defining a recess for holding the head, the recess having a first region configured to receive the head and a second region defined by at least part of one of the projections and having an undersize compared to the shape of the head, such that when the head is held in the recess, the projections extend over a portion of the head with the largest outer diameter, and the head contacting surface portion corresponding to the second region is expanded from a neutral position to clamp the head by friction.

Abstract: A method for assembling a bone anchoring device includes inserting a bone anchoring element in a first holder of a tool and inserting a receiving part in a second holder of the tool, actuating the tool from a first configuration towards a second configuration to insert a head of the bone anchoring element into the receiving part; continuing actuation of the tool towards the second configuration to move a locking ring and a receiving part body of the receiving part relative to each other until the locking ring assumes a second position with respect to the receiving part body in which the locking ring is latched to the receiving part body in a position where the locking ring compresses a portion of the receiving part body to compress the head, such that the head is held in and cannot be removed from the receiving part body and the bone anchoring element is held adjustably at a first angular position relative to the receiving part, and removing the attached bone anchoring element and receiving part from the tool