Patent ID: 12201328

DETAILED DESCRIPTION

Various non-limiting embodiments of the present disclosure will now be described to provide an overall understanding of the principles of the structure, function, and use of the apparatuses, systems, methods, and processes disclosed herein. One or more examples of these non-limiting embodiments are illustrated in the accompanying drawings. Those of ordinary skill in the art will understand that systems and methods specifically described herein and illustrated in the accompanying drawings are non-limiting embodiments. The features illustrated or described in connection with one non-limiting embodiment may be combined with the features of other non-limiting embodiments. Such modifications and variations are intended to be included within the scope of the present disclosure.

Reference throughout the specification to “various embodiments,” “some embodiments,” “one embodiment,” “some example embodiments,” “one example embodiment,” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with any embodiment is included in at least one embodiment. Thus, appearances of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” “some example embodiments,” “one example embodiment, or “in an embodiment” in places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

The examples discussed herein are examples only and are provided to assist in the explanation of the apparatuses, devices, systems and methods described herein. None of the features or components shown in the drawings or discussed below should be taken as mandatory for any specific implementation of any of these the apparatuses, devices, systems or methods unless specifically designated as mandatory. For ease of reading and clarity, certain components, modules, or methods may be described solely in connection with a specific figure. Any failure to specifically describe a combination or sub-combination of components should not be understood as an indication that any combination or sub-combination is not possible. Also, for any methods described, regardless of whether the method is described in conjunction with a flow diagram, it should be understood that unless otherwise specified or required by context, any explicit or implicit ordering of steps performed in the execution of a method does not imply that those steps must be performed in the order presented but instead may be performed in a different order or in parallel.

Described herein are example embodiments of bone anchors (e.g., hooks, screws, etc.) useful for orthopedic procedures such as, for example, spinal fixation. In the illustrated embodiments a pedicle screw is disclosed to teach the features of a bone anchor and how the one or more embodiments of tulip head extenders engage and/or work with such illustrative pedicle screws, but the disclosure is not to be limited only to pedicle screws, nor are the tulip head extenders limited to engaging and/or working with only pedicle screws.

Referring toFIG.1, a representative pedicle screw100is shown. Pedicle screw100can be any of known pedicle screws with any of known beneficial features for installation and use in processes and systems such as, for example, of spinal fixation. For the purposes of the present disclosure, the pedicle screw is described as including a screw shank102, a neck104, a head106, which is often referred to as a tulip head106. The tulip head106can include first and second tulip arms112opposed from each other. First and second tulip arms form a channel107. First and second tulip arms112can extend from a curved lower surface (e.g., rod seat108) defining the substantially U-shaped interior channel107. The channel107can be constructed to receive a spinal fixation rod (e.g.,122) and can include a channel axis. The channel axis can correspond to, and be coincident with, a longitudinal axis of a spinal fixation rod when it is reduced into the channel107.

The shank can have an inner diameter and an outer diameter, the inner diameter and outer diameter each being determined by the size of the screw and the depth of threads110on shank102. The thread depth, pitch, and other dimensional features can be predetermined based on the requirements of the pedicle screw, as is known in the art. That is, the proportions of the pedicle screw depicted are for illustrative purposes only and variations in the length, shape, and/or configuration of such pedicle screw may vary such as, for example, the shape and size of the head, the length of the shank, diameter of the screw, thread pitch, thread length, number of thread leads, shank induced compression and the like may be varied without departing from the scope of the disclosure.

Other components and features of a pedicle screw may be included that aid in its insertion into a bone and its use. For example, as depicted in the partial cross-sectional view of tulip head106inFIG.2, tulip head106may include features for compatible operation with driving tool (not shown) and a rod reduction device (not shown). As a specific example, a rod reduction device, as is known in the art, may be used to engage with tulip head106to urge, or reduce, a spinal fixation rod into the channel107and toward the rod seat108, manipulate one or more vertebrae, and/or insert a set screw for temporary or stationary fixation of the spinal rod into the pedicle screw tulip head106. For this reason, tulip head106can have various features, such as grasping tabs112and/or pockets114, for connectivity and operation of the driving tool, rod reducing tool, and/or other instruments, and internal threads116for receiving a set screw or other implants and/or instruments.

Referring now toFIG.3, there is shown a pedicle screw100screwed into a bone118, the surface of which is representatively depicted by the dashed line120. Bone118can be a pedicle, and pedicle screw100can be driven into the pedicle until the neck104is adjacent the bone118. In an embodiment, the pedicle can be undertapped for the appropriate screw size. After the pedicle is undertapped a flexible feeler probe may be used to verify presence of threads in the tapped hole. To measure the length of the hole, a feeler probe is advanced to the floor of the hole and a hemostat is clamped to the feeler probe at the point where it exits the pedicle. The appropriate screw diameter and length may subsequently be selected based on both preoperative measurement and intraoperative observation. The same technique can be repeated for any remaining pedicles that need to be inserted and/or instrumented.

A rod reduction tool can be applied over the tulip head106of the screw. In an embodiment, fingers of the rod reduction device can engage the pockets114of the pedicle screw tulip head106. The rod122can then be reduced by the rod reduction device to set in rod seat108. A set screw driver can then be used to introduce a set screw124. The set screw can be passed through the rod reduction device and rotated until it bottoms out, securing rod122into the tulip head106.

As depicted inFIG.3, once rod122is reduced into tulip head106and set screw124is set, the distance D1from bone surface120and the axial center126of rod122is immovably fixed. As illustrated, the distance D1is shown as extending to the axial center of the rod122, but for description purposes the dimensions D1, as well as D2and D3described below, can be measured to the top or bottom of the rod without departing from the scope of the disclosure.

Referring toFIG.4there is shown an embodiment of a tulip head extender10that, when engaged to and/or installed into tulip head106, can facilitate the repositioning of rod122with respect to bone surface120from a distance D1an additional distance D2, for a total distance D3. As can be understood, extender10permits the vertical repositioning of rod122from an original position shown as122′ without disturbing pedicle screw100. The distance D2can be predetermined by varying the geometry of extender10, as will be more fully understood in light of the description below.

An embodiment of tulip head extender10as shown inFIG.4is depicted in more detail inFIG.5. In the illustrated embodiments, terms such as “vertical,” “upper,” “lower” “upwardly,” and “downwardly” are used in relation to the extender10in the orientation shown in the FIGS, and corresponding to the orientation generally experienced in use of pedicle screws and related instrumentation. Extender10can have an upper body portion12joined to a lower body portion14. The upper body portion12can be integrally formed with lower body portion14, such as by machining from a blank, injection molding, etc., or the two parts can be manufactured separately and joined by adhesive, welding, press fit, or the like. Upper body portion12can have a first extender arm16and a second extender arm18opposed to the first extender arm. First extender arm16and second extender arm18can extend from a curved lower surface defining a substantially U-shaped interior channel22that can have a first channel axis24. The first channel axis24can correspond to, and be coincident with, a longitudinal axis of a rod122when reduced into extender10. The first interior threads20of first and second extender arms can be complementary to receive an appropriately sized set screw (not shown). As can be understood from the description above, first and second extender arms16and18, first interior threads20, and interior channel22correspond to the same or similar functional features of a tulip head, such as tulip head106of pedicle screw100. As can be further understood, the features of the upper portion12of extender10can include any features51desired or required on illustrative bone anchors such as, for example, pockets, tabs, indentations, and openings, to engage with a variety of instruments such as, for example, a particular rod reducing tool, and, as such, facilitate rod reduction by known techniques, albeit reducing the rod a shorter distance than what would have been required to reduce it to the original rod seat108(e.g.,FIGS.2and3).

Lower portion14can extend downwardly from the upper portion12, and can have a portion sized to fit into the channel107and seat on the rod surface108of tulip head106of pedicle screw100. That is, lower portion14can be a substantially U-shaped protrusion, joined to upper portion12by generally parallel spaced apart first and second U-shaped sides,26and28(side28on the side not seen inFIG.5). First and second U-shaped sides can be substantially identical in size and shape and have a protrusion width PW having a dimension sized according to the channel width of the tulip head106of the pedicle screw100. First and second U-shaped sides can be spaced apart a distance defining a protrusion depth PD, the protrusion depth PD being a dimension suitable for stable securement to the tulip head106of pedicle screw100, and can be predetermined based on the sizing and requirements of related instrumentation. First and second sides26and28need not be U-shaped, but can have any shape constrained only in that the lower portion14be able to be insertable into and seat with the tulip head106of a pedicle screw100(e.g., channel107and seat108). Thus, first and second sides26and28can have rectangular shape, for example, and remain functionally capable of being seated into the tulip head106of pedicle screw100.

The extender10can have first and second surfaces30and32, which can be generally horizontally oriented portions of the lower surface of upper portion12, and which can abut the top surface of tulip head106of pedicle screw100when the extender10is set into place. Although in some embodiments, the extender10may not have first and second surfaces30and32or such surface may not be generally horizontally oriented. In some embodiments, first and second sides26and28can extend a distance L1below and generally perpendicular to first and second surfaces30and32to the bottom of the U-shaped sides. Distance L1can be substantially equal to the depth of the channel having the rod seat108of tulip head106. Curved lower surface22of upper portion12of extender10can be a distance L2measured from the bottom of the U-shaped first and second sides26and28. Distance L2can be greater than distance L1, and can be predetermined by design of extender10based on the desired distance D3, as shown inFIG.4.

Lower portion14can have an open interior portion34defined between first and second U-shaped sides26and28, and in which can be disposed an extender set screw36. Open interior portion34can have open access through a pair of opposing windows38,40(window40on the side not seen inFIG.5) through which the extender set screw36may be inserted into and then in its position therein, threads of extender set screw36can extend radially outwardly from windows38,40. That is, the outside thread diameter of set screw36can be greater than the protrusion width PW. This allows the threads of the extender set screw36to threadingly engage the inner threads116of the first and second tulip arms112when the lower portion14is inserted into the tulip channel107, engaging and/or connecting the extender10to the tulip head100. As can be understood from the description herein, extender set screw36serves functionally similar to the set screw124shown inFIG.3to set, however, the extender10into the tulip head106of pedicle screw100as shown inFIG.4rather than to set the rod122into the tulip head as shown inFIG.3.

An access opening42in upper portion12can extend downwardly through the upper portion12in a direction generally perpendicular to first channel axis24. Access opening42provides access to the top of extender set screw36. Extender set screw36can have on its top surface a driving portion which can engage with a driver to permit rotation of extender set screw36such that its external threads engage the internal threads116of tulip head106, driving the extender set screw down into the tulip channel107and connecting the extender10to the pedicle screw100.

Thus, according to the description above with reference toFIGS.4and5, it can be understood that extender10can be attached to the tulip head106of a pedicle screw100to increase the distance from bone surface120from a distance having a dimension D1to a distance having a dimension D3, which is greater than D1. As described, the lower portion14of extender10can be positioned between the tulip arms112and the threads of extender set screw36can engage the interior threads116of tulip head106. Extender set screw36can be rotated by a driver extending through access opening42of extender10to connect and/or secure extender10to tulip head106. Once extender is secured to tulip head106by tightening extender set screw36, first and second extender arms16and18, first interior threads20, and interior channel22effectively define a second tulip head into which a spinal fixation rod122can be reduced. The distance having a dimension D2above which a rod would be reduced into tulip head106of pedicle screw100can be predetermined by adjusting by design the various described components and dimensions. Thus, in operation, a doctor or other operator can choose an extender10having dimensions, including dimensions L1and L2for the particular pedicle screw100being utilized, and the distance D3that the rod is suspended or positioned over the bone and/or the distance the rod is suspended and/or positioned over the installed pedicle screw. As can be understood, therefore, extender10provides great flexibility to increase the rod reduction height relative to bone surface120for a fixed position of a tulip head106of a fixed pedicle screw100.

An embodiment of tulip head extender10similar to that shown inFIG.4is depicted in more detail inFIG.6-12.FIG.6illustrates in a perspective view that extender10can comprise a one-piece molded body, forged and/or machined body, and, as shown inFIG.7, a set screw can be disposed internally to the extender10body. As an example, extender10can be molded of any polymer material, and can be injection molded. As described above, extender10can have an upper body portion12joined to a lower body portion14. Upper body portion12can have two opposing extender arms16,18, each including a portion of interior threads20. First arm16and second arm18can extend from a curved lower surface defining a substantially U-shaped interior channel22that can have a first channel axis24. The first channel axis24can correspond to, and be coincident with, a longitudinal axis of a rod122when reduced into extender10(not shown). The first interior threads20of first and second arms can be complementary to receive an appropriately sized set screw36, as shown inFIGS.7-12. An access opening42in upper portion12can extend downwardly through the upper portion12in a direction generally perpendicular to first channel axis24. Access opening42provides access to the top of extender set screw36. Extender set screw36can have on its top surface a driving portion44which can be a male or female socket that can engage with a driver to drive rotation of extender set screw36. InFIG.8, a representative female socket driving portion44having a generally star-shaped geometry is illustrated.

As can be understood from the description above, first and second extender arms16and18, first interior threads20, and interior channel22correspond to the same or similar functional features of a tulip head, such as tulip head106of pedicle screw100. As can be further understood, the features of the upper portion12of extender10can include any features51desired or required on illustrative bone anchors such as, for example, pockets, tabs, indentations, and openings, to engage with a variety of instruments such as, for example, a particular rod reducing tool, and, as such, facilitate rod reduction by known techniques, albeit reducing the rod a shorter distance than what would have been required to reduce it to the original rod seat108.

As shown in the side elevation views ofFIGS.9and10, lower portion14can extend downwardly from the upper portion12, and can have a portion sized to fit into the channel107and seat on the rod surface108of tulip head106of pedicle screw100. First and second U-shaped sides can be substantially identical in size and shape and have a protrusion width PW having a dimension sized according to the channel width of the tulip head106of the pedicle screw100. First and second U-shaped sides can be spaced apart a distance defining a protrusion depth PD, the protrusion depth PD being a dimension suitable for stable securement to the tulip head106of pedicle screw100, and can be predetermined based on the sizing and requirements of related instrumentation. First and second sides26and28need not be U-shaped, but can have any shape constrained only in that the lower portion14be able to be insertable into and seat with the tulip head106of a pedicle screw100. Thus, first and second sides26and28can have rectangular shape, for example, and remain functionally capable of being seated into the tulip head106of pedicle screw100.

The extender10can have first and second surfaces30and32, which can be generally horizontally oriented portions of the lower surface of upper portion12, and which can abut the top surface of tulip head106of pedicle screw100when the extender10is set into place. First and second sides26and28can extend a distance L1below and generally perpendicular to first and second surfaces30and32to the bottom of the U-shaped sides. As discussed above with respect toFIG.5, but for conciseness not shown inFIGS.9-12, a distance L1can be substantially equal to the depth of the channel having the rod seat108of tulip head106. Curved lower surface22of upper portion12of extender10can be a distance L2measured from the bottom of the U-shaped first and second sides26and28. Distance L2can be greater than distance L1, and can be predetermined by design of extender10based on the desired distance D3, as shown inFIG.4.

Lower portion14can have an open interior portion34defined between first and second U-shaped sides26and28, and in which can be disposed an extender set screw36. Open interior portion34can have open access through a pair of opposing windows38,40(window40on the side not seen inFIG.5) through which the extender set screw36may be inserted into and then, when in its position therein, threads of extender set screw36can extend radially outwardly from the windows38,40. That is, the outside thread diameter of set screw36can be greater than the protrusion width PW. This allows the threads of the extender set screw36to threadingly engage the inner threads116of the first and second tulip arms112when the lower portion14is inserted into the tulip channel107, engaging and/or connecting the extender10to the tulip head100. As can be understood from the description herein, extender set screw36serves functionally as the set screw124shown inFIG.3to set, however, the extender10into the tulip head106of pedicle screw100as shown inFIG.4rather than to set the rod122into the tulip head as shown inFIG.3.

FIGS.11and12are partial cross-sectional views ofFIGS.9and10respectively and are provided for descriptive detail with respect to the various structure and features described above. For conciseness all the descriptive detail is not repeated, but the FIGS. can be understood by the description above and the various numbered call-outs ofFIGS.11and12.

Referring now toFIG.13there is shown another example embodiment of a tulip head extender10that, when installed onto tulip head106, can facilitate the repositioning of rod122with respect to bone surface120from a distance having a dimension D1to an additional distance having a dimension D2, for a total distance having a dimension D3. As can be understood, extender10permits the vertical repositioning of rod122from an original position shown as122without disturbing the original position of pedicle screw100. The dimension D2can be predetermined by varying the geometry of extender10, as will be more fully understood in light of the description below.

The example embodiment of extender10shown inFIG.13can have a rod securing body portion50having two opposing arms16,18, each including a portion of first interior threads20. First and second opposing arms can extend upwardly from a curved lower surface defining a substantially U-shaped interior channel22that can have a first channel axis24. First arm16and second arm18can be described as being opposed across a first imaginary plane P1parallel to first channel axis24and bisecting the securing body portion50, and, when in use also bisecting tulip head106in a like manner.

Extender10can have generally parallel spaced apart first and second U-shaped sides,26and28. First and second U-shaped sides can be substantially identical in size and shape and have a separation width SW having a dimension sized according to the size of the tulip head106of the pedicle screw100over which extender10can be lowered and set, somewhat in saddle fashion. First and second sides26and28(opposite side of side26) can each have an externally facing surface that is generally planar and perpendicular to the imaginary plane P1. First and second sides26and28need not be U-shaped, but can have any shape constrained only by general design and function considerations. Thus, first and second sides26and28can have rectangular shape, for example, and remain functionally capable of being saddled over the tulip head106of pedicle screw100.

The first interior threads20of first and second arms can be complementary to receive an appropriately sized set screw (not shown). As can be understood from the description above, first and second arms16and18, first interior threads20, and interior channel22correspond to the same or similar functional features of a tulip head, such as tulip head106of pedicle screw100. As can be further understood, the features of the rod securing body50of extender10can include any features51desired or required on illustrative bone anchors such as, for example, pockets, tabs, indentations, and openings, to engage with a variety of instruments such as, for example, a particular rod reducing tool, and, as such, facilitate rod reduction as known, albeit reducing the rod a shorter distance than what would have been required to reduce it to the original rod seat as shown inFIG.13.

Rod securing body50can be secured to tulip head106in any suitable manner, for example, by securing to mating engagement portions. For example, rod securing body50can have tabs that can engage pockets114of tulip head106. In an embodiment, tabs of rod securing body can be flexibly resilient, and can be separated apart while rod securing body is pressed down onto tulip head106and snapped inwardly when tabs engage pockets114. In another embodiment, a first set screw can be, optionally, threadingly engaged to the internal extender threads20and threaded through the extender until it threadingly engages the internal threads116of tulip head106. The first set screw can be threaded into the tulip head to the desired position to secure and/or hold a spinal fixation rod122in position within the extender channel between the curved surface of the channel22and the first set screw, and at the same time, to hold and/or secure the extender50to tulip head106. Optionally, a second extender set screw (e.g., extender set screw36) can be threadingly engaged to the internal threads20of the extender50to provided additional hold and/or securement of the spinal fixation rod122to the extender. Rod securing body50can have generally flat, inwardly extending surfaces52that can abut the top surface of tulip head106when rod securing body is positioned for receiving a rod. Interior channel22can have a lower surface a distance having a dimension L3above the lower surface of the extender10. Inwardly extending surfaces52can be disposed at a forth distance having a dimension L4above the lower surface of extender10.

Once extender10, as described with reference toFIG.13, is secured to tulip head106by placing over the tulip head106in a saddle-like fashion, first and second arms16and18, first interior threads20, and interior channel22effectively define a second tulip head into which a rod122can be reduced. The dimension D2above which a rod would be reduced into tulip head106of pedicle screw100can be predetermined by adjusting by design the various described components and dimensions. Thus, in operation, a doctor or other operator can choose an extender10having dimensions, including dimensions L3and L4for the particular pedicle screw100being utilized, and the desired dimension D3for elevated rod reduction. As can be understood, therefore, extender10provides great flexibility to increase the rod reduction height relative to bone surface120for a fixed position of a tulip head106of a fixed pedicle screw100.

Thus, according to the description above with reference toFIG.13, it can be understood that in an embodiment extender10can be attached to the tulip head106of a pedicle screw100to increase the distance from bone surface120from a first distance having a dimension D1to a third distance having a dimension D3, which is greater than D1. Once extender10is secured to tulip head106, first and second arms16and18, first interior threads20, and interior channel22effectively define a second tulip head into which a rod122can be reduced. The second dimension D2above which a rod would be reduced into tulip head106of pedicle screw100can be predetermined by adjusting by design the various described components and dimensions. Thus, in operation, a doctor or other operator, can choose an extender10having dimensions, including dimensions L3and L4for the particular pedicle screw100being utilized, and the desired dimension D3for rod reduction. As can be understood, therefore, extender10provides great flexibility to increase the rod reduction height relative to bone surface120for a fixed position of a tulip head106of a fixed pedicle screw100.

Referring now toFIGS.14-21, there is shown another example embodiment of a tulip head extender10that, when installed onto tulip head106, can facilitate the repositioning of rod122with respect to bone surface120from a distance having a dimension D1to an additional distance having a dimension D2, for a total distance having a dimension D3(as depicted inFIG.18). As can be understood by the description herein, extender10permits the vertical repositioning of rod122without disturbing the original position of a pedicle screw100. The dimension D2can be predetermined by varying the geometry of extender10, as will be more fully understood in light of the description below.

As shown in the embodiment ofFIGS.14-21, extender10can comprise three discrete parts that together serve to fix a spinal fixation rod122on a pedicle screw head106at an elevated distance from the bone in which pedicle screw is affixed.FIG.14shows a perspective view of an extender10comprising three discrete parts, namely a saddle70, a cap72, and a set screw74, which can be in all respects identical to the set screw36described above. All three parts can be made of any suitable material, including injection molded polymer materials.

Referring toFIG.15, saddle70can be disposed within the tulip head106of a pedicle screw (i.e., within channel107). Saddle70can be slid into the tulip head106and can rest on the rod seat108. Saddle70can have on the upper, rod-facing side a surface that defines an elevated rod seat108. Saddle70is described in more detail with respect toFIG.19.

Referring toFIG.16, a cap72can be snapped onto tulip head106, for example, by utilizing tabs74that can clip onto pockets114of tulip head106. One tab74can be hooked into one pocket114, and the cap72can be rotated and pressed such that the other tab74can be hooked, or snapped, into the opposite pocket114. In other words, the tabs74can be fabricated from a material and/or by design such that one or more of the tabs74can flex outward to go over and/or about the outer circumference of the tulip head and then snap back into its normal position into one or more of the pockets114. Once snapped onto tulip head106, cap72is secured onto tulip head106as shown inFIG.17. A spinal fixation rod122may be positioned into the saddle prior to the cap73being positioned upon and secured to the tulip head, thus positioning the rod122between the saddle and the cap. Once positioned, the set screw36may be threadingly engaged to the tulip head106and/or the cap72. Alternatively, once the saddle70and cap72are positioned onto the tulip head106, a spinal fixation rod122can be positioned between them, and secured to the tulip head106by inserting and securing a set screw36, as shown inFIG.14(i.e., threadingly engaged to the tulip head106and/or the cap72).

A schematic perspective view of the extender10shown inFIGS.14-17is depicted inFIG.18. Once extender10, as described with reference toFIGS.14-16, is secured to a pedicle screw head106having a rod seat108at an elevation D1above the bone surface, the elevated rod seat108′ can be elevated above the rod seat108by a distance having a dimension D2which can be predetermined by adjusting by design the various described components and dimensions. Thus, in operation, a doctor or other operator can choose an saddle70having dimensions, specifically a saddle height dimension as discussed below, for the particular pedicle screw100being utilized, and the desired dimension D3for elevated rod reduction. As can be understood, therefore, extender10provides great flexibility to increase the rod reduction height relative to bone surface120for a fixed position of a tulip head106of a fixed pedicle screw100.

FIG.19shows a perspective view of a representative saddle70used in the extender10shown inFIGS.14-17. In particular, saddle70can be generally H-shaped having a longitudinally extending curved surface80that serves as the elevated rod seat108. A pair of opposing guide tabs82can be disposed at each longitudinal end of the curved surface80. The size and spacing of tabs82can be predetermined according to the dimensions of the tulip head106onto which saddle70is placed. Saddle70can have a thickness from a bottom surface to a top surface of the elevated rod seat108′ SH, as shown inFIG.19. The saddle height SH can be predetermined for the desired dimension D3for elevated rod reduction.

Referring toFIG.20, there is shown a perspective view of cap72. Cap72can have two opposed tabs74that can have a general hook-shape such that a first tab74′ with a hook feature84′ that can engage with a pocket114of tulip head106, as illustrated above with respect toFIG.16. A second tab74″ with a second hook feature84″ can be pressed down and snapped into a pocket114on the opposite side of a tulip head106. A stress relief feature86, which can include a slot88and/or a slit90on the upper portion of cap72, from which tabs74extend downwardly, can be included on cap72. Cap72can also have indented features, such as a pocket114′ on opposite side surfaces of cap72. Pockets114′ provide a connection for connectivity and operation of known instruments such as, for example, a driving tool and/or rod reducing tool.

Referring toFIG.21there is illustrated in perspective a set screw36having external threads that engage with the internal threads of the tulip head of a pedicle screw, or other internal threads of extenders10as described herein. Set screw36can be turned by a tool that can be inserted into a driving portion44that can be a socket into which a driving tool can be inserted and securely rotated to rotate set screw36.

Referring toFIGS.22-25there is illustrated further example embodiments of extenders10that facilitate positioning of a spinal fixation rod122both laterally and upwardly with respect to a fixed pedicle screw100tulip head106.FIGS.22and23illustrate an extender10that facilitates laterally elevated in-line positioning of rod22.FIGS.24and25illustrate an extender10that facilitates laterally elevated cross positioning of rod22.

As shown inFIG.22, an extender10is illustrated that permits a rod122to be reduced to an elevation greater than the elevation dictated by a pedicle screw100fixed in a bone118. As shown inFIGS.22and23, extender10can be a unitary construction, and can have a mounting bar60that can be cylindrical, and can be sized to fit and be secured into tulip head106of fixed pedicle screw100. Securement of mounting bar60into tulip head106can be, for example, by a set screw (not shown) tightened into internal threads116of tulip head106. Mounting bar can have any cross section, but can be a cylindrical shape having a central axis62.

Extender10as illustrated inFIGS.22and23can have disposed on an upturned end of mounting bar60an extender tulip head64that can be in size, shape, and function, substantially identical to tulip head106of pedicle screw100. In general, extender tulip head64can have two opposing arms16,18, each including a portion of interior threads20. First arm16and second arm18can extend from a curved lower surface defining a substantially U-shaped interior channel22that can have a first channel axis24can be coincident with the central axis of rod122and can be generally parallel to and in the same plane as central axis62. The first interior threads20of first and second arms can be complementary to receive an appropriately sized set screw (not shown). As can be understood from the description herein, first and second arms16and18, first interior threads20, and interior channel22correspond to the functional features of a tulip head, such as tulip head106of pedicle screw100. As can be further understood, the features of the extender tulip head64can include any features required (but not shown) to engage with a particular rod reducing tool, and, as such, facilitate rod reduction as known, albeit reducing the rod to distance having a dimension D3rather than distance a lesser dimension D1, as shown inFIG.22.

In the embodiment illustrated inFIGS.22and23, the first channel axis24and the central rod axis62of mounting bar60are parallel and in the same plane, and thus a fixation rod122reduced into extender tulip head64is “in line” with the mounting bar60, and thus in line directionally with where the fixation rod122would have been mounted in the tulip head106of pedicle screw100.

As can be understood with respect toFIGS.24and25, an example of another extender10that facilitates fixation of a rod122both laterally and upwardly with respect to a fixed pedicle screw100tulip head106is shown. The extender ofFIGS.24and25is identical in most respects to that shown inFIGS.22and23, with the material difference being that extender tulip head64has a different orientation, such that a rod122reduced into it would not be “in line” with mounting bar, but be at some angle to it, albeit remaining elevated by distance having a dimension D2with respect to the mounting bar. In an embodiment, first arm16and second arm18can extend from a curved lower surface defining a substantially U-shaped interior channel22that can have a first channel axis24that is generally parallel to but in different plane than central axis62. In an embodiment, first channel axis24can be in a plane that is substantially perpendicular to a plane in which central axis62resides. However, in general, as described above, the first interior threads20of first and second arms can be complementary to receive an appropriately sized set screw (not shown). As can be understood from the description herein, first and second arms16and18, first interior threads20, and interior channel22correspond to the functional features of a tulip head, such as tulip head106of pedicle screw100. As can be further understood, the features of the extender tulip head64can include any features required (but not shown) to engage with a particular rod reducing tool, and, as such, facilitate rod reduction as known, albeit reducing the rod to distance to a dimension D3rather than to a distance having a dimension D1which is less than D3, as shown inFIG.24.

As depicted inFIG.25dimension D3can be varied depending on the dimensions of extender10, specifically the distance which can be measured from mounting bar axis62and a lower surface66of head64, which distance can be the dimension L5. More particularly, dimension D3can be varied depending on the distance which can be measured from mounting bar axis62and a rod seating surface22of head64, which distance can be the dimension L6.

The extenders10disclosed herein can provide a benefit in the installation and use of spinal fixation rods. In general, a method of use of extender10includes affixing an extender10to an installed tulip head of a pedicle screw, thereby extending, with respect to the pedicle bone, the distance from the pedicle bone that a spinal fixation rod will seat. In general, an extender10can safely span a gap between the distance from the pedicle bone of the rod seat108of a tulip head106of an installed pedicle screw and the distance that is determined as safely seating a spinal fixation rod.

For extenders10of the type illustrated and disclosed, for example, with respect toFIGS.4-12, the extender10can have a set screw, e.g., set screw36ofFIGS.8and10, threaded through the extender10and threaded onto the internal threads116of the tulip head106, thereby securing the extender10to the tulip head106. After the extender10is secured to the tulip head106, a spinal fixation rod122can be seated in the extender and secured, e.g., with another set screw threaded into first interior threads20as depicted inFIG.5.

For extenders10of the type illustrated and disclosed, for example, with respect toFIGS.14-21, the saddle70provides for the extended distance with respect to the pedicle bone, i.e., the distance from the pedicle bone that a spinal fixation rod will seat. The cap72can then be snapped over the top of the tulip head into the slots on the side thereof. A set screw can then be tightened down, thereby pulling the cap72upward on the slots locking it in place.

The apparatuses and methods disclosed herein may be used and/or applied in any regions of the spine such as for example, cervical, thoracic, lumbar, sacral, or coccygeal regions. In some examples, the apparatuses and methods disclosed herein may be used and/or applied in severely curved regions of the spine, for example, the lumbar region of the spine, i.e., for a spinal fixation rod secured to any or all of L1-L5vertebrae. The lumbar region can often exhibit extreme lumbar curves where a spinal fixation rod would necessarily need to be significantly deformed, thus creating large stresses in the rod and/or the pedicle screw and/or the bone, as well as possible fracture of either the rod, screw, or bone. Extenders10can also be used in other vertebrae, including, for example, in the upper thoracic region for severe kyphosis, i.e., for a spinal fixation rod secured to any or all of T1-T12vertebrae, where there can also be significantly rod stresses present. Extenders10can also be used in vertebrae of the cervical region, i.e., for a spinal fixation rod secured to any or all of C1-C7.

Representative embodiments of the present disclosure described above can be described as follows.

In an embodiment a method of use can include the following steps: inserting a pedicle screw having a tulip head in a vertebral bone to a predetermined distance; placing a spinal fixation rod in close proximity to, e.g., hovering over, the tulip head of the inserted pedicle screw; determining that the distance the spinal fixation rod must be reduced into the tulip head is too great to allow for safe reduction of the spinal fixation rod into the tulip head, e.g., because of the likelihood of excessive stress on the pedicle bone; securing an extender10to the tulip head of the pedicle screw; seating the spinal fixation rod into the extender10; and securing the spinal fixation rod into the extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: providing a tulip head of a pedicle screw; providing a spinal fixation rod; securing an extender10to the tulip head of the pedicle screw; seating the spinal fixation rod into the extender10; and securing the spinal fixation rod into the extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: providing a tulip head of a pedicle screw screwed into a pedicle bone; providing a spinal fixation rod; securing an extender10to the tulip head of the pedicle screw; seating the spinal fixation rod into the extender10; and securing the spinal fixation rod into the extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone; securing at least one extender10to the tulip head of at least one of the tulip heads of at least one of the pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone; recognizing that the required shape of an attached spinal fixation rod will exert excessive stress on the pedicle bone; securing at least one extender10to the tulip head of at least one of the tulip heads of at least one of the plurality of pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone of the spine; recognizing that the required shape of an attached spinal fixation rod exerts excessive stress on the pedicle bone; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the lumbar region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of L1-L5; recognizing that the required shape of an attached spinal fixation rod exerts excessive stress on the pedicle bone or the pedicle screw; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10in the lumbar region of the spine.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the cervical region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of C1-C7; recognizing that the required shape of an attached spinal fixation rod exerts excessive stress on the pedicle bone or the pedicle screw; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10in the cervical region of the spine.

A method of use for extenders as described above can be described as a method for securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the thoracic region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws each comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of T1-T12; recognizing that the required shape of an attached spinal fixation rod exerts excessive stress on the pedicle bone or the pedicle screw; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; bending a spinal fixation rod to an approximate shape; seating the bent spinal fixation rod into the at least one extender10; and securing the spinal fixation rod into the at least one extender10in the thoracic region of the spine.

A method of use for extenders as described above can be described as a method for repositioning and securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the lumbar region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws, each of the pedicle screws comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of L1-L5; seating a spinal fixation rod into a portion of the tulip heads; recognizing that the required shape of the spinal fixation rod exerts, or will exert, excessive stress on the pedicle bone or the pedicle screw; removing the spinal fixation rod from the portion of the tulip heads; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; re-seating the spinal fixation rod to into the portion of tulip heads, including the at least one extender10; and securing the spinal fixation rod into the tulip heads, including the at least one extender10, in the lumbar region of the spine. For each of the methods of use described above involving bending a spinal fixation rod prior to it being secured to an extender10, the shape of the relevant portion of the spinal fixation rod122, i.e., at and near the extender10, can be characterized as wherein the radius of curvature of the bend in the spinal fixation rod is greater when used with an extender10relative to the radius of curvature necessary without the use of an extender10.

A method of use for extenders as described above can be described as a method for repositioning and securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the cervical region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws, each of the pedicle screws comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of C1-C7; seating a spinal fixation rod into a portion of the tulip heads; recognizing that the required shape of the spinal fixation rod exerts, or will exert, excessive stress on the pedicle bone or the pedicle screw; removing the spinal fixation rod from the portion of the tulip heads; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; re-seating the spinal fixation rod to into the portion of tulip heads, including the at least one extender10; and securing the spinal fixation rod into the tulip heads, including the at least one extender10, in the cervical region of the spine. For each of the methods of use described above involving bending a spinal fixation rod prior to it being secured to an extender10, the shape of the relevant portion of the spinal fixation rod122, i.e., at and near the extender10, can be characterized as wherein the radius of curvature of the bend in the spinal fixation rod is greater when used with an extender10relative to the radius of curvature necessary without the use of an extender10.

A method of use for extenders as described above can be described as a method for repositioning and securing a spinal fixation rod to a pedicle bone, the method including the following steps: on the thoracic region of a spine of a patient in need of orthopedic surgery, providing a plurality of pedicle screws, each of the pedicle screws comprising a tulip head, and each screwed into a respective pedicle bone of the spine selected from the group consisting of T1-T12; seating a spinal fixation rod into a portion of the tulip heads; recognizing that the required shape of the spinal fixation rod exerts, or will exert, excessive stress on the pedicle bone or the pedicle screw; removing the spinal fixation rod from the portion of the tulip heads; securing at least one extender10to at least one of the tulip heads of at least one of the plurality of pedicle screws; re-seating the spinal fixation rod to into the portion of tulip heads, including the at least one extender10; and securing the spinal fixation rod into the tulip heads, including the at least one extender10, in the thoracic region of the spine. For each of the methods of use described above involving bending a spinal fixation rod prior to it being secured to an extender10, the shape of the relevant portion of the spinal fixation rod122, i.e., the at and near the extender10, can be characterized as wherein the radius of curvature of the bend in the spinal fixation rod is greater when used with an extender10relative to the radius of curvature necessary without the use of an extender10.

A method for securing a spinal fixation rod to a pedicle bone in the lumbar region of a spine of a patient in need of orthopedic surgery to modify the curvature of the lumbar region, the method including the following steps: providing a plurality of pedicle screws, at least one of the pedicle screws comprising a tulip head, and each screwed into a respective pedicle of a vertebrae of the spine selected from the group consisting of L1-L5; providing a pedicle screw extender; reducing a spinal fixation rod at least partially into the tulip head; recognizing that upon full reduction and securing of the spinal fixation rod into the tulip head the spinal fixation rod will exert excessive stress on the respective vertebra; removing the spinal fixation rod from the tulip head; securing the pedicle screw extender to the tulip head; re-reducing the spinal fixation rod into the pedicle screw extender; and securing the spinal fixation rod into the pedicle screw extender.

A method for securing a spinal fixation rod to a pedicle bone of a spine of a patient in need of orthopedic surgery to modify the curvature of the spine, the method including the following steps: providing a tulip head of a pedicle screw; providing a pedicle screw extender; providing a spinal fixation rod; securing the pedicle screw extender to the tulip head of the pedicle screw; seating the spinal fixation rod into the pedicle screw extender; and securing the spinal fixation rod into the pedicle screw extender.

A method for securing a spinal fixation rod to a pedicle bone on the lumbar region of a spine of a patient in need of orthopedic surgery to modify the curvature of the lumbar region, the method including the following steps: providing a pedicle screw comprising a tulip head, the pedicle screw being screwed into a pedicle bone of a vertebrae of the spine selected from the group consisting of L1-L5; providing a pedicle screw extender; recognizing that the required shape of an attached spinal fixation rod exerts excessive stress on the pedicle bone; securing the pedicle screw extender to the tulip head of the pedicle screw; bending a spinal fixation rod to an approximate desired curvature of the lumbar region; seating the spinal fixation rod into the pedicle screw extender; and securing the spinal fixation rod into the pedicle screw extender.

The method of paragraph C wherein the pedicle screw extender comprises: an upper body portion joined to a lower body portion, the upper body portion having two opposing arms extending upwardly from a curved lower surface to define a substantially U-shaped interior channel having a first channel axis, the curved lower surface defining an access opening extending through the upper body portion in a direction generally perpendicular to the first channel axis, the lower body portion extending downwardly as a protrusion from the upper body portion and joined to the upper body portion and having first and second sides, the first and second sides being substantially planar and parallel and separated by an interior portion, the first and second sides defining a protrusion height and a protrusion width, and a screw disposed in the interior portion and having external threads defining a thread diameter greater than the protrusion width.

The foregoing description of embodiments and examples has been presented for purposes of illustration and description. It is not intended to be exhaustive or limiting to the forms described. Numerous modifications are possible in light of the above teachings. Some of those modifications have been discussed, and others will be understood by those skilled in the art. The embodiments were chosen and described in order to best illustrate principles of various embodiments as are suited to particular uses contemplated. The scope is, of course, not limited to the examples set forth herein, but can be employed in any number of applications and equivalent devices by those of ordinary skill in the art. Rather it is hereby intended the scope of the invention to be defined by the claims appended hereto.