Abstract: A closure for an open headed medical implant, such as a bone screw. The closure having a cylindrical body having an axis of rotation and also having a radially outer surface with a thread or other guide and advancement structure thereon. The body having a plurality of apertures that open onto a top surface of the body and that are parallel to but spaced from the axis of rotation. The closure also has a break-off head centrally attached by a neck to the top surface of the body.

Abstract: A bone anchoring device for a spinal column fixation system includes an anchoring part, a bearing part for mounting at least one connection element thereon and a fixing element. The connection element is adapted for fixing to at least two bone anchoring devices. The anchoring part and the bearing part are mounted on each other, movable relative to each other in an assembly position and fixable relative to each other by the fixing element in an implantation position. The fixing element is of integral construction and has a proximal fixing element section, a distal fixing element section and a predetermined break-off area formed between the proximal and distal fixing element sections. The distal fixing element section has a receptacle for engagement with a tool for transferring the bone anchoring device from the assembly position to the implantation position. The device may be part of an improved spinal column fixation system.

Abstract: A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in a receiver and retained within the receiver by a retaining structure in the form of an open ring. The receiver has a U-shaped channel for receiving a spinal fixation rod. The shank upper portion is designed to directly frictionally engage the spinal fixation rod when a closure structure operably urges the rod toward the upper portion, fixing the bone screw shank body in a selected angular orientation with respect to the receiver.

Abstract: Polyaxial bone anchor assemblies include a shank having an upper portion and a retainer for holding the shank upper portion in a receiver. The shank upper portion retainer interface is one of conical, cylindrical or curvate and may further include a radial ridge or undercut. The assemblies may include compression inserts.

Abstract: A medical implant assembly includes a polyaxial bone anchor having a shank with an upper portion, a receiver, a retainer for holding the shank upper portion in the receiver, a lower compression insert with surfaces for closely receiving an elongate connecting member and a closure structure that may independently engage the lower compression insert to lock the shank with respect to the receiver while selectively not locking the elongate member. Projections or splines of the shank upper portion mate with holding pockets on the retainer. The bone anchor includes a shank upper surface exclusively engaging the lower compression insert that is spaced from the retainer, the retainer and shank being configured for polyaxial motion with respect to the receiver prior to locking.

Abstract: Polyaxial bone anchor assemblies include a shank having an upper portion and a retainer for holding the shank upper portion in a receiver. The shank upper portion retainer interface is one of conical, cylindrical or curvate and may further include a radial ridge or undercut. The assemblies may include compression inserts.

Abstract: Polyaxial bone anchor assemblies include a shank having an upper portion and a retainer for holding the shank upper portion in a receiver. The shank upper portion retainer interface is one of conical, cylindrical or curvate and may further include a radial ridge or undercut. The assemblies may include compression inserts.

Abstract: The present teachings provide one or more surgical implements for repairing damaged tissue, such as in the case of a spinal fixation procedure. A multiplanar bone anchor system for a fixation procedure is provided. The system can include a bone fastener. The bone fastener can include a head and a second end adapted to engage an anatomy. The bone fastener can extend along a longitudinal axis. The system can also include a coupling arrangement coupled to the head of the bone fastener so that the bone fastener is rotatable about the longitudinal axis to define a first plane of motion. The system can further include a saddle, which can be coupled to the coupling arrangement. The saddle can be movable relative to at least one of the bone fastener and the coupling arrangement to define a second plane of motion.

Abstract: A pedicle screw assembly having an axial load element engaging the structure joining the screw and the rod retainer. The axial load element generally holds the rod retainer in place with respect to the screw, while allowing manual movement when desired. In one embodiment, the pedicle screw assembly includes a ball-and-socket joint joining the screw head to the rod retainer. The assembly may include a saddle configured to secure a ball at the head of the screw within a socket in the rod retainer. The saddle may provide resilient compression in the axial direction. For example, the saddle may include a pair of axially-offset slots that extend partially across the saddle from opposite sides to define a bridge section. The resiliency of the saddle may be controlled by varying the characteristics of the slots and consequently the bridge section.

Abstract: A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in an integral receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down-loadable compression insert with tool receiving arm extensions, a down-loadable friction fit split retaining ring and an up-loadable shank upper portion cooperate to provide for pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. The shank and receiver once assembled cannot be disassembled.

Abstract: A mechanism to connect the supporting portions of orthopaedic implants such as in the head, spine, upper limb and lower limb and thereby prevent loosening and fretting at the implant interface of an orthopaedic implant construct has been developed based on shape memory effect and super-elasticity of shape memory materials such as nickel-titanium (nitinol or NiTi) shape-memory-alloy, without the use of typical threaded fastening technique. Advantages are conferred by making the entire device, not just connecting pieces, out of shape memory alloy and having shape memory effect and super-elasticity. Heating the memory head of the device will compress the connection portion without the use of an auxiliary device (e.g. coupling member) so that the connection portion can be completely clamped down by the memory head.

Abstract: A multiaxial pedicle screw for vertebral osteosynthesis, including: a pedicle screw comprising a spherical head having a recess for the rotation of said pedicle screw; a socket that is hinged onto the spherical head of the pedicle screw and is provided with two diametrically opposed side grooves for receiving a connection rod; a tightening means for maintaining the position of the connection rod that is engaged into said socket; and a locking means that is positioned between said spherical head of the pedicle screw and the socket. The locking means is formed of a ring, at least the base or distal portion of which consists of a cold-compactible material having a resilient deformation capacity. Said locking means enables the locking of the socket in a desirable direction relative to the spherical head of the pedicle screw according to the position of the pedicle screw after the anchoring thereof.

Abstract: A polyaxial bone anchoring device includes a bone anchoring element having a shank and a head, a head receiving part having a first end, an open second end, and a hollow interior portion for receiving the head therein, a locking ring configured to be mounted around the head receiving part and having a rod receiving portion, a cap configured to be connected to the head receiving part, the cap having a central axis and two opposite legs extending in a direction of the central axis, and a locking element configured to extend from the cap to lock relative positions of the bone anchoring element and an inserted rod relative to the head receiving part, wherein the cap is rotatable relative to the head receiving part between a first position in which the cap is movable and a second position in which the legs engage the head receiving part.

Abstract: An implant includes a body sized and shaped for insertion into a facet joint, the implant including a first bone fixation element receiving opening extending through a portion thereof along a first axis oriented so that, when the implant is received within a facet joint in a desired configuration, a bone fixation element inserted into the first bone fixation element receiving opening will extend into a first one of the vertebra forming the facet joint.

Abstract: A polyaxial bone anchoring device includes a bone anchoring element having a shank and a head, a head receiving part having a first end, an open second end, and a hollow interior portion in communication with the open second end for receiving the head therein, the head receiving part being flexible for clamping the head, a locking ring configured to be mounted around the head receiving part and having a rod receiving portion, a cap configured to be connected to the head receiving part, and a locking element configured to extend from the cap to engage an inserted rod, wherein the head is pivotable in and the cap and the locking ring are rotatable relative to the head receiving part, and wherein when the locking element is tightened, an inserted rod and an angular position of the bone anchoring element are locked relative to the head receiving part.

Abstract: An orthopedic fixation system, including a tissue anchor including a first instrument engagement feature and a second instrument engagement feature; a first tool engageable with the first instrument engagement feature, and a second tool engageable with the second instrument engagement feature, where the first and second tools are engageable simultaneously with the tissue anchor.

Abstract: A polyaxial bone screw assembly includes a threaded shank body having an upper capture structure, a head, a retaining ring and a nut. The external capture structure surface includes a threaded portion and a smooth portion; the smooth portion for slidably mating with the retaining ring and the threaded portion for rotatable attachment to the nut within a cavity of the head. The nut fixes the retaining ring to the shank and also provides a tool engagement formation for driving the shank body into bone.

Abstract: A polyaxial bone anchoring device includes a bone anchoring element having a shank and a head, a receiving part having a first end and a second end, a central axis, a first bore, a second bore, and a first support surface between the first bore and the second bore that is substantially perpendicular to the central axis, and an insert piece having a seat for pivotably holding the head, a bounding edge, and a second support surface configured to engage the first support surface to support the insert piece when mounted to the receiving part, the second support surface formed by a projection at an end of the insert piece opposite the bounding edge, wherein the insert piece projects out of the second bore and is rotatable, and is configured to permit the bone anchoring element to pivot at a larger angle at a first location of the bounding edge.

Abstract: The fastening system consists of the polyaxial ball and socket joint used in conjunction with a bone screw having threads on one end for use in anchoring to the spine and a spherical connector on the other end operating as a pivot point about which a connecting assembly moves in a polyaxial fashion. A substantially U-shaped connecting assembly has a lower receptacle that operates as a socket for housing a retainer ring within a retaining ring groove.

Abstract: An implant assembly and a method of assembling the same are provided, the implant assembly including a receiver extending along a central longitudinal axis between a proximal end and an opposite distal end, the receiver including a distal portion defining a receptacle opening at the distal end and a pair of arms extending from the distal portion along the central longitudinal axis on opposite sides of a passage with the passage opening at opposite sides of the receiver, a bone anchor including a distal bone engaging portion and a head at a proximal end of the distal bone engaging portion, the head being positioned in the receptacle with the bone engaging portion in a selected orientation relative to the central longitudinal axis of the receiver and a connector member configured to form a rigid interface between the receiver and the head of the bone anchor thereby providing torque transfer throughout the implant assembly.

Abstract: Provided is a spinal fixation system including a taper lock screw including an inner housing and an outer housing that are translatable relative to one another to transition the taper lock screw between a locked position and an unlocked position. A locking device releasably connects to and operationally interacts with a flange of the taper lock screw. An unlocking device releasably connects to and operationally interacts with inner housing unlocking tool receptors of the taper lock screw to unlock the taper lock screw.

Abstract: A bone anchor assembly is provided, which may be used in cervical, thoracic, lumbar or sacral areas of the spine or other orthopedic locations. The anchor assembly includes a bone anchor, a receiver mounted to the bone anchor, a saddle within the receiver, and an engaging member. The receiver extends along a central longitudinal axis proximally away from the bone anchor. A rod or other elongated connecting element is received in a passage of the receiver in contact with the saddle, and the engaging member engages the connecting element against the saddle, which engages the saddle against the proximal head of the bone anchor in the receiver. The orientation of the saddle in the receiver is adjustable to correspond to the orientation of the connecting element relative to the central longitudinal axis of the receiver.

Abstract: A bone fastener includes a receiver defining a longitudinal axis and extending between a proximal end and a distal end, the proximal end including a first wall and a second wall that define an implant cavity, each wall having a proximal face. At least one of the first wall and the second wall include an extension extending proximally from the proximal face along the longitudinal axis, the extension having a distal end integral with the proximal face and a proximal end including a first locking part configured for fixation with a second locking part of an instrument. A bone penetrating member has a proximal end and a distal end, the proximal end of the bone penetrating member being connected with the distal end of the receiver.

Abstract: A device for attaching an elongated member to a vertebral member and provide for dampened movement of the elongated member. The device may include a receiver that receives an elongated member. The receiver may be movably attached to an anchor that may be attached to a vertebral member. A dampener may be positioned within the receiver. Further, one or more slots may be positioned in the receiver. The dampener and/or slots dampen the translational movement of the receiver and attached elongated member relative to the anchor in first and second directions, and may also buffer forces applied into the spine.

Abstract: A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in a one piece receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down-loadable compression insert and a friction fit split retainer are located in the receiver providing pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. Laterally located, spaced crimping apertures in the receiver press receiver walls into engagement with the insert to prohibit rotation of the insert with respect to the receiver.

Abstract: The present invention generally provides a polyaxial fixation device having a shank with a spherical head formed on a proximal end thereof, and a receiver member having an axial passage formed therein that is adapted to polyaxially seat the spherical head of the shank. The polyaxial bone screw further includes an engagement member that is adapted to provide sufficient friction between the spherical head and the receiver member to enable the shank to be maintained in a desired angular orientation before locking the spherical head within the receiver member.

Abstract: Screws for anchoring in cancellous or other low-quality bone are described. One type of screw addresses the problem of extravasation of bone cement when filling an area of low-quality bone. The screw includes an expandable container for retaining bone cement and anchoring the screw in low-quality bone. The screw also includes an anchoring device for holding the screw in place in the bone while it is supplied with bone cement or other appropriate filler. The screw further includes a head for connecting to a rod or other apparatus. A second type of screw uses an expandable container to deform two or more fins to compress cancellous bone and/or anchor in cancellous bone.

Abstract: A collar for extenders and an extender assembly including a collar is disclosed. The collar is configured to receive extenders and maintain the extenders in a parallel orientation so as to prevent splaying and premature beak-off of the extenders from the spine. Methods of use are disclosed.

Abstract: A polyaxial bone anchoring device includes an anchoring element having a shank and a head, a receiving part having a first end and a second end, a central axis, and an accommodation space for accommodating the head, the accommodation space having an opening at the second end, a sleeve-like insert piece configured to be arranged around a portion of the head and to be arranged in and to pivot in the accommodation space, and a pressure member including a portion configured to exert pressure onto the head, wherein the anchoring element and insert piece are pivotable with respect to the receiving part such that respective angles formed by a central axis of the insert piece with the central axis of the receiving part and a central axis of the anchoring element are adjustable, and can be locked by exerting pressure with the pressure member onto the head.

Abstract: A spinal alignment system is disclosed that includes a rod and a plurality of uniplanar screw assemblies that include a screw, a cap, and a housing. The screw and cap are configured such that the relative angular displacement between the screw and the cap is limited to a first limit angle in a first plane and to a second limit angle in a second plane that is perpendicular to the first plane, the second limit angle being larger than the first limit angle. The housing is coupled to the cap and configured to maintain the cap in proximity with the head of the screw. The housing has two elongated elements forming a U-shaped saddle. The alignment system also includes a plurality of locking cap assemblies that capture the rod within the U-shaped saddle and are tightened to fixedly couple the rod to the respective uniplanar screw assemblies.

Abstract: A polyaxial bone anchoring device includes an anchoring element having a shaft and a head, a receiving part having a first end and a second end, a bore extending from the first end towards the second end, a seat for receiving the head, and at least one threaded through hole transverse to the bore, a pressure element to exert pressure onto the head, such that the head is pivotable and can be locked at an angle relative to the receiving part, the pressure element having at least one hole configured to at least partially align with the through hole, and at least one set screw threadable into the through hole to engage the pressure element at the hole such that a force is exerted by the pressure element onto the head that maintains the head at an adjustable angular position relative to the receiving part by friction.

Abstract: A polyaxial bone anchoring system includes a receiving part having an accommodation space, a first anchoring element having a first head, a sleeve-like insert piece configured to be arranged around a portion of the first head and to be arranged in the accommodation space, a second anchoring element having a second head, and a pressure member configured to exert pressure onto the first head or the second head, wherein when one of the first anchoring element or the second anchoring element is connected to the receiving part, the connected anchoring element is pivotable relative to the receiving part and can be locked at an angle relative to the receiving part by exerting pressure with the pressure member onto the respective head of the connected anchoring element, and wherein the first bone anchoring element and the second bone anchoring element are configured to be interchangeably connectable to the receiving part.

Abstract: An anti-splay member is configured for engagement with a bone fastener and includes a body defining a longitudinal axis and a threaded cavity extending along the longitudinal axis. The cavity is configured for engagement with a screw. Opposing retainer members extend transversely from the body and are configured to engage a proximal end of the bone fastener to prevent radial expansion of the proximal end. At least one locking member extends from the body and is configured for engagement with the proximal end of the bone fastener. Methods of use are disclosed.

Abstract: The present teachings provide one or more surgical implements for repairing damaged tissue, such as in the case of a spinal fixation procedure. A uniplanar bone anchor system for a fixation procedure is provided. The system can include a bone fastener including a head with a bearing surface and a shaft adapted to engage an anatomy. The system can also include a saddle, which can include a first bore formed about a longitudinal axis that receives the bone fastener and a coupling bore defined transverse to the longitudinal axis. The system can also include a coupling system, which can have a second bearing surface. The coupling system can be received through the coupling bore such that the second bearing surface of the coupling system can contact the bearing surface to permit the bone fastener to move in only one plane.

Abstract: Embodiments are generally directed to an apparatus for reducing a rod into an orthopedic fixation device. An embodiment provides a rod-reducing apparatus. The rod-reducing apparatus may comprise a housing comprising a threaded through bore. The rod-reducing apparatus further may comprise a reduction shaft comprising a shaft portion and a through bore in the shaft portion, wherein the shaft portion may be configured to be received within the threaded through bore of the housing. The locking cap driver may comprise a locking cap driver comprising a shaft portion that may be configured to be received within the through bore of the reduction shaft, wherein a distal end of the shaft portion may be configured for attachment to a locking cap assembly.

Abstract: A resorbable screw fastener and a method of firing with an applicator capable of applying a surgical fastener to tissue in order to form tissue connection to secure objects to tissue, the fastener including a body portion having a helical thread, a head portion disposed at the proximal end of the body portion. The resorbable screw fastener is 100% resorbed in vivo during a period of time ranging from about 14 days to about one year after implantation.

Abstract: A retraction device comprises at least one retracting blade and a pedicle screw. The retracting blade has a distal end having at least one projection with a passage for engaging a retention pin. The pedicle screw has a threaded body and a movable head. The movable head has at least one recess with a channel that can be aligned with the passage of the projection.

Abstract: A bone screw having a screw member possessing a threaded section and a head and a receiving part at the head end for receiving a rod to be connected to the bone screw is provided. The receiving part has on open first bore and a substantially U-shaped cross-section having two free legs provided with a thread. Furthermore, the receiving part has a second bore on the end opposite to the first bore whose diameter is greater than that of the threaded section and smaller than that of the head. On the bottom of the first bore a seat for the head is provided. In order that the screw member can be pivoted to at least one side by an enlarged angle, the edge bounding the free end of the second bore viewed relative to the axis of the first bore is of asymmetric construction.

Abstract: A fracture fixation device is described for fixing a bone having a near cortex and a far cortex, comprising a shaft portion configured to span a distance between the near cortex and the far cortex of the bone; a head portion adjoining the shaft portion and providing for engagement of the device with a bone plate, wherein the head portion is integral with the shaft portion; and a threaded front section for engagement of the device with the far cortex of the bone, wherein the device permits motion of the shaft portion relative to the near cortex.

Abstract: Disclosed are spinal fusion assemblies for use in skeletal systems. The assembly includes a coupling element that can be coupled to a fixation element, such as, for example, a screw with a head that removably mates with the coupling element. The coupling element and fixation element are configured to be coupled to an elongate stabilizer, such as a rod, that is positioned between a top and a bottom saddle. A compression member, such as a compression nut, is configured to mate with the coupling element and provides a compressive force to the top and bottom saddles to secure the elongate stabilizer therebetween. The top and bottom saddles are movably positioned within the coupling element such that they can gradually reposition and self-align into a secure engagement with the stabilizer as the compression member provides the compressive force.

Abstract: A crimping tool for producing a polyaxial bone anchoring device (1, 1?) is provided. The crimping tool includes at least one tip holder having a crimping tip and an inclined passage and an actuating member having at least an inclined leg, wherein the inclination of the inclined passage corresponds to the inclination of the inclined leg.

Abstract: A polyaxial screw assembly includes a pedicle screw, a coupling, an insert, and a housing. The pedicle screw includes a shank having a helical thread formed thereon and a head at one end. The coupling is positioned on top the pedicle screw and releasably engages portions of the head. The coupling and pedicle screw are positioned within a distal portion of the housing. The pedicle screw is slid through an opening in the insert and the insert is thread into the distal portion of the housing to retain the coupling and the pedicle screw within the housing. The pedicle screw is rotatable and pivotable relative to the housing. Compressing the coupling within the housing locks the pedicle screw in a desired orientation.

Abstract: Implementations of the present disclosure provide a snap fit rod and fastener system including one or more fasteners for securing one or more rods to secure a spine or other anatomical structure. The fasteners include a fixation shaft, a clamp and a connector. The fixation shaft (for example a pedicle screw) is configured to frictionally engage a bone (vertebra) or other workpiece. The clamp has a pressure responsive portion that defines an opening configured to receive a rod. The connector is configured to connect the clamp to the fixation shaft and exert pressure on the clamp to modify the opening and secure the rod. A bias mechanism, such as a washer spring may be included to urge against the pressure responsive portion and which can be overcome by pressure on the rod for the “snap fit” effect. For additional adjustability, the clamp may be pivotally mounted on the fixation shaft.

Abstract: Systems, methods, and apparatuses for bone fixation are presented. In one aspect, presented herein is a screw for bone fixation, an insertion tool, and a method for stabilization across a bone joint of the spine. The bone screw has an elongate shank defining an internal longitudinal passage. The screw has an external threaded surface and a tapered distal end. The insertion tool engages the head of the screw and is used to drive the screw into the desired bone joint.

Abstract: A polyaxial bone screw assembly includes a threaded shank body having an integral upper portion receivable in an integral receiver, the receiver having an upper channel for receiving a longitudinal connecting member and a lower cavity cooperating with a lower opening. A down-loadable compression insert, a down-loadable friction fit split retaining ring having inner and outer tangs and an up-loadable shank upper portion cooperate to provide for pop- or snap-on assembly of the shank with the receiver either prior to or after implantation of the shank into a vertebra. The shank and receiver once assembled cannot be disassembled.

Abstract: In order to improve a bone screw with a shaft defining a longitudinal axis and with a head which can be brought into engagement with a bone screw receiving means of a bone plate for the releasable connection of the bone screw to the bone plate, wherein a securing element for securing a connection between the bone screw and the bone plate is provided, wherein the bone screw can be brought from a position of engagement, in which the bone screw is held on the bone plate, into a release position, in which the bone screw can be released from the bone plate, wherein the securing element can be brought from a non-securing position, in which the bone screw can be brought into the release position, into a securing position for securing the connection between the bone screw and the bone plate, in which the bone screw takes up the position of engagement, such that a bone plate can be fixed to bone parts more easily and more securely it is suggested that the securing element be supported on the bone screw so as to be mov

Abstract: A two step locking screw assembly includes a receiving member for receiving a fixation member and an anchor having an enlarged portion and a shank. The enlarged portion of the anchor may be seated in the receiving member. An insert may also extend inside the receiving member. An outer fastener may be positioned in the receiving member. The outer fastener may include a central opening and a pair of ramped flanges. An inner fastener may be disposed inside the central opening of the outer fastener.

Abstract: A fixation device for bones includes a member which has at least one bore for receiving a bone screw, wherein the at least one bore comprises a first internal thread portion. The bone screw has a first shaft section provided with a first external thread portion arranged to cooperate with the internal thread portion of the at least one bore, and a head section having a diameter larger than that of the shaft section to provide a catch arranged to engage with a stop formed in the bore. The bone screw further has a second shaft section which includes a clearance groove extending between the catch of the head section and the external thread of the first shaft section. The clearance groove allows disengagement of the two thread portions, such that the bone screw is prevented from being unscrewed off the bore when it is loosened within the adjacent bone.

Abstract: A dynamic fixation medical implant includes a longitudinal connecting member assembly having an elongate coil-like outer member and an inner cylindrical core attached to the outer member at only one end thereof. Some assemblies include a second longitudinal connecting member in the form of a rod that is fixed to the inner core and extends outwardly from the assembly. Certain assemblies include a threaded core or threaded inserts that cooperate with a helical slit of the coil-like outer member. Two or more cooperating bone screw assemblies attach to the connecting member assembly. The bone screw assemblies may include upper and lower compression members for affixing to and cradling the coil-like outer member only, allowing relative movement between the outer member and the inner cylindrical core. Press fit or snap-on features attach one end of the coil-like outer member to one end of the inner cylindrical core.

Abstract: A cannulated compression screw is used as an orthopedic implant and has a threaded distal end with an insertion tip that includes at least one and preferably two, three or four flutes to allow the screw to be self-tapping. Optionally, the screw also includes one or more reverse cutting flutes proximal to the insertion tip. The distal threads are cancellous threads having a generally constant minor diameter and a generally constant major diameter and a generally constant thread pitch. An intermediate portion of the screw is non-threaded and the proximal end includes a compression wedge or taper that has at least one, and preferably two to five flutes that terminate before the top of the screw. The proximal end further includes a radiused bevel to the terminal surface that includes a hexagonal torque driving recess. The diameter of the non-threaded shaft section is constant distal from the compression wedge to the distal tip where it defines the minor diameter of the threaded portion.