Abstract: A polyaxial bone anchoring device includes a receiving part with a rod receiving portion defining a recess for receiving a rod, and a head receiving portion with a wall that defines an accommodation space for accommodating a head of an anchoring element, and a locking member positionable at least partially around the head receiving portion and movable from a first position where the head can pivot in the accommodation space to a second position where an angular position of the head is locked. The wall of the head receiving portion further defines at least one cavity in communication with the accommodation space that reduces a radial thickness of at least part of the wall located between the accommodation space and the locking member, and at least part of the cavity is separated radially from the accommodation space by a portion of the wall.

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: A bone anchoring device includes an anchoring element having a shank for anchoring in a bone and a head, a receiving part configured to pivotably receive the head, and a pressure member for exerting pressure on the head to clamp the head in the receiving part, the pressure member defining a head receiving recess for pivotably holding at least a portion of the head therein and comprising a first surface configured to restrict removal of the head from the head receiving recess. The head includes a first position indication structure configured to engage a second position indication structure of the bone anchoring device when the shank assumes a first angular position relative to the receiving part. The first and second position indication structures disengage from one another when the shank is moved out of the first angular position to a different angular position.

Abstract: A polyaxial bone anchoring device includes a receiving part with a rod receiving portion defining a recess for receiving a rod, and a head receiving portion with a wall that defines an accommodation space for accommodating a head of an anchoring element, and a locking member positionable at least partially around the head receiving portion and movable from a first position where the head can pivot in the accommodation space to a second position where an angular position of the head is locked. The wall of the head receiving portion further defines at least one cavity in communication with the accommodation space that reduces a radial thickness of at least part of the wall located between the accommodation space and the locking member, and at least part of the cavity is separated radially from the accommodation space by a portion of the wall.

Abstract: An anchoring element includes a shank for anchoring to bone and a separate head that is connectable to the shank. The head has an exterior surface with a spherically-shaped section and an unthreaded tool engagement surface that is engageable with a drive tool when the head and the shank are connected to one another.

Abstract: A bone anchoring device includes a receiving part with a rod receiving portion having a first end, a second end, a recess for the rod, an outer surface, and a first engagement structure on the outer surface that extends farther radially outwardly than other parts of the rod receiving portion, and a flexible head receiving portion for inserting and clamping the head. The bone anchoring device also includes a locking ring configured to be arranged around the head receiving portion for locking the head, the locking ring having an outer surface and a second engagement structure on the outer surface that extends farther radially outwardly than the outer surface of the rod receiving portion. The engagement structures are configured to be engaged by an instrument to move the locking ring from a locking position to a position where the inserted head is pivotable.

Abstract: A bone screw includes a shank having a longitudinal axis, a tip configured to be inserted first into bone, a core, and a thread with a plurality of turns winding in a helix around at least part of the core to engage bone. The thread has a lower flank and an upper flank, wherein for a first section of the thread, the upper and lower flanks form a first angle for at least one full turn, and wherein for a second section of the thread, the upper and lower flanks form a second angle for at least one full turn that is greater than the first angle. An outer diameter of the second section adjacent to the first section is at least as wide as an outer diameter of the first section adjacent to the second section.

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: A polyaxial bone anchoring device includes a receiving part with a rod receiving portion defining a recess for receiving a rod, and a head receiving portion with a wall that defines an accommodation space for accommodating a head of an anchoring element, and a locking member positionable at least partially around the head receiving portion and movable from a first position where the head can pivot in the accommodation space to a second position where an angular position of the head is locked. The wall of the head receiving portion further defines at least one cavity in communication with the accommodation space that reduces a radial thickness of at least part of the wall located between the accommodation space and the locking member, and at least part of the cavity is separated radially from the accommodation space by a portion of the wall.

Abstract: A bone anchoring device includes an anchoring element having a shank for anchoring in a bone and a head, a receiving part configured to pivotably receive the head, and a pressure member for exerting pressure on the head to clamp the head in the receiving part, the pressure member defining a head receiving recess for pivotably holding at least a portion of the head therein and comprising a first surface configured to restrict removal of the head from the head receiving recess. The head includes a first position indication structure configured to engage a second position indication structure of the bone anchoring device when the shank assumes a first angular position relative to the receiving part. The first and second position indication structures disengage from one another when the shank is moved out of the first angular position to a different angular position.

Abstract: An anchoring element includes a shank for anchoring to bone and a separate head that is connectable to the shank. The head has an exterior surface with a spherically-shaped section and an unthreaded tool engagement surface that is engageable with a drive tool when the head and the shank are connected to one another.

Abstract: A bone anchoring device includes a receiving part with a rod receiving portion having a first end, a second end, a recess for the rod, an outer surface, and a first engagement structure on the outer surface that extends farther radially outwardly than other parts of the rod receiving portion, and a flexible head receiving portion for inserting and clamping the head. The bone anchoring device also includes a locking ring configured to be arranged around the head receiving portion for locking the head, the locking ring having an outer surface and a second engagement structure on the outer surface that extends farther radially outwardly than the outer surface of the rod receiving portion. The engagement structures are configured to be engaged by an instrument to move the locking ring from a locking position to a position where the inserted head is pivotable.

Abstract: A coupling device for coupling a rod to a bone anchor includes a receiving part having a central axis, a coaxial passage, and an engagement recess extending laterally into the passage, and a pressure member having an expandable portion to clamp the head, a radially outwardly facing surface, and an engagement surface extending from the radially outwardly facing surface. The engagement surface of the pressure member is recessed from an outer surface of the receiving part. The pressure member is movable axially from a first position towards a second position where the receiving part directly engages the pressure member to increase a compression force on the expandable portion for clamping an inserted head. The engagement surface of the pressure member is engageable through the engagement recess of the receiving part by the instrument to move the pressure member axially from the second position back towards the first position.

Abstract: A coupling device for coupling a rod to a bone anchor includes a receiving part having first and second ends, a central axis, and two legs defining a recess at the first end for receiving the rod, a pressure member configured to exert pressure on an inserted head, and an actuating member with an engagement surface configured to engage the pressure member. When a first portion of the actuating member moves axially in a first direction, the engagement surface is configured to move from a first axial position to a second axial position to adjust the pressure member from a non-locking position where the head is pivotable to a locking position where the head is locked. When a second portion of the actuating member moves in the first direction, the pressure member is adjusted from the locking position back to the non-locking position.

Abstract: A bone anchoring device includes an anchoring element having a shank and a head, a receiving part configured to pivotably receive the head, and a pressure member defining a head receiving recess for pivotably holding the head and having a portion configured to extend to a side opposite a free end of the head and to exert pressure on the side opposite the free end to clamp the head in the receiving part. The head has a first position indication structure configured to engage a second position indication structure of the pressure member when the shank assumes a first angular position, and to disengage from the second position indication structure when the shank is at an angular position different from the first angular position. The second position indication structure is engageable with the first position indication structure without protruding into a profile defined by the head receiving recess.

Abstract: A closure assembly for securing an elongate stabilization element in a receiving part of a bone anchoring device includes a first closure member and a second closure member. The first closure member is receivable between legs of the receiving part, has an axis of rotation, and includes an outer surface with an engagement portion configured to engage the legs of the receiving part, and an inner surface having at least a portion that is threaded and that defines a central passage that passes axially through the first closure member. The second closure member has an axis of rotation and an outer surface having a threaded portion configured to cooperate with the threaded portion of the inner surface of the first closure member. The threaded portion of the outer surface of the second closure member includes a multi-start thread with at least two starts.

Abstract: A coupling device for coupling a rod to a bone anchor includes a receiving part having a central axis, a coaxial passage, and an engagement recess extending laterally into the passage, and a pressure member having an expandable portion to clamp the head, a radially outwardly facing surface, and an engagement surface extending from the radially outwardly facing surface. The engagement surface of the pressure member is recessed from an outer surface of the receiving part. The pressure member is movable axially from a first position towards a second position where the receiving part directly engages the pressure member to increase a compression force on the expandable portion for clamping an inserted head. The engagement surface of the pressure member is engageable through the engagement recess of the receiving part by the instrument to move the pressure member axially from the second position back towards the first position.

Abstract: An anchoring element includes a shank for anchoring to bone and a separate head that is connectable to the shank. The head has an exterior surface with a spherically-shaped section and an unthreaded tool engagement surface that is engageable with a drive tool when the head and the shank are connected to one another.

Abstract: A bone anchoring device includes a receiving part with a rod receiving portion having a first end, a second end, a recess for the rod, an outer surface, and a first engagement structure on the outer surface that extends farther radially outwardly than other parts of the rod receiving portion, and a flexible head receiving portion for inserting and clamping the head. The bone anchoring device also includes a locking ring configured to be arranged around the head receiving portion for locking the head, the locking ring having an outer surface and a second engagement structure on the outer surface that extends farther radially outwardly than the outer surface of the rod receiving portion. The engagement structures are configured to be engaged by an instrument to move the locking ring from a locking position to a position where the inserted head is pivotable.

Abstract: A bone anchoring device includes an anchoring element having a shank and a head, a receiving part configured to pivotably receive the head, and a pressure member defining a head receiving recess for pivotably holding the head and having a portion configured to extend to a side opposite a free end of the head and to exert pressure on the side opposite the free end to clamp the head in the receiving part. The head has a first position indication structure configured to engage a second position indication structure of the pressure member when the shank assumes a first angular position, and to disengage from the second position indication structure when the shank is at an angular position different from the first angular position. The second position indication structure is engageable with the first position indication structure without protruding into a profile defined by the head receiving recess.