Rod coupling assembly for bone stabilization structure

Abstract

To provide a bone implant and a stabilization rod coupling assembly for fixing a stabilization rod to the bone implant.SOLUTION: A bone implant 1110 includes a radially recessed collet reception region 1112. The recessed collet reception region includes a surface extending in a radial direction arranged so as to form an angle of less than 90 degrees with respect to a longitudinal axis of the bone implant. The recessed collet reception region includes a proximal end with an undercut ledge configuration that is sized and configured to interface with and couple to a collet 1134 of a tulip assembly 1130.SELECTED DRAWING: Figure 11A

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority based on U.S. Provisional Patent Application No. 62 / 938,546, filed on November 21, 2019, the entire disclosure of which is incorporated herein by reference for all purposes.

[0002] (Incorporation by Reference) All publications and patent applications mentioned in this specification are incorporated herein by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

Background Art

[0003] Bone implants can be used, but are not limited to, assisting in the fixation of bone in spinal surgery such as spinal fusion. The proximal region of the bone implant can be configured to couple to a tulip. The tulip is generally rotatable relative to the implant in a first movable state, and the tulip is further configured to receive a rod for fixation.

Summary of the Invention

Problems to be Solved by the Invention

[0004] Implants, tulips, and assemblies generally need to securely couple the implant, tulip, and rod.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a rod coupling system. The rod coupling system can include a bone implant and a tulip assembly.

[0006] In this aspect, the bone implant has a proximal region spaced from the distal region, and the proximal region is sized and configured to interface with a tulip assembly. The tulip assembly can include a tulip and a collet sized and configured to be at least partially disposed within the tulip. The proximal region of the bone implant includes a radially recessed collet receiving region sized and configured to receive an implant interface region that projects radially inwardly of the collet therein. The recessed collet receiving region includes a radially extending surface disposed at an angle of less than 90 degrees with respect to the longitudinal axis of the bone implant, the angle being measured distally with respect to the radially extending surface. The tulip assembly has an opening sized and configured to receive a stabilization rod therethrough. The implant interface region of the collet can include a radially extending surface disposed at an angle with respect to the longitudinal axis of the collet, and when the implant interface region interfaces with the recessed collet receiving region, the radially extending surface of the implant interface region is disposed to face the radially extending surface of the recessed collet receiving region.

[0007] In this aspect, the radially extending surface of the implant interface region of the collet can be orthogonal to the longitudinal axis of the collet.

[0008] In this aspect, the radially extending surface of the recessed collet receiving region can be disposed at an angle of less than 85 degrees with respect to the longitudinal axis of the implant.

[0009] In this aspect, the radially extending surface of the recessed collet receiving region can be disposed at an angle greater than 45 degrees with respect to the longitudinal axis of the implant.

[0010] In this aspect, the surface extending in the radial direction of the recessed collet receiving region can be arranged at an angle exceeding 75 degrees with respect to the longitudinal axis of the implant.

[0011] In this aspect, the surface extending in the radial direction of the recessed collet receiving region can be arranged at an angle of 70 degrees to 89 degrees with respect to the longitudinal axis of the implant.

[0012] In this aspect, the tulip assembly can optionally be modular and can be adapted to be delivered separately from the bone implant and can be movably fixed to the bone implant after the bone implant is at least partially implanted into the bone. The proximal end of the implant includes an internal thread sized and configured to receive a tapered guide rod on the inside, and the tulip assembly is adapted to advance along the tapered guide rod and advance over the proximal end of the implant to couple the tulip assembly and the bone implant.

[0013] In this aspect, the proximal region of the bone implant includes a chamfered proximal end that facilitates the expansion of the distal end of the collet when the collet advances over the chamfered proximal end, and when the collet advances distally over the proximal region of the bone implant, the implant interface region protruding radially inward of the collet moves radially inward and into the recessed collet receiving region by the recessed collet receiving region. The coupling of the collet and the implant can be performed before the implant is implanted into the bone.

[0014] In this aspect, the proximal region of the bone implant can be configured to facilitate the opening of the distal end of the collet when the collet advances over the proximal end. When the collet further advances over the bone implant, the implant interface region protruding radially inward of the collet returns into the recessed collet receiving region toward a stationary state by the recessed collet receiving region.

[0015] In this aspect, the recessed collet receiving region can have a depth ranging from 0.1 mm to 2.0 mm.

[0016] In this aspect, the proximal region of the bone implant may not be provided with an outer thread.

[0017] In this aspect, the proximal region of the bone implant can have the outermost sleeve surface, and the outermost sleeve surface is sized and configured to extend over at least a portion of the distal end of the tulip. The outermost sleeve surface may be the surface of the outer implant sleeve, and the outer implant sleeve may be disposed around the inner shank of the implant.

[0018] In this aspect, the recessed collet receiving region can have an annular configuration around the bone implant.

[0019] One aspect of the present disclosure is a bone implant having a recessed collet receiving region, the recessed collet receiving region including a radially extending surface disposed at an angle of less than 90 degrees with respect to the longitudinal axis of the bone implant, the angle being measured distally with respect to the radially extending surface. Although similar in every way, compared to a system having a radially extending surface orthogonal to the longitudinal axis of the bone implant, the radially extending surface is angled to reduce the possibility that the collet expands and loosens in response to an axial force.

[0020] This aspect can include any other suitable features of the bone implant, system, or assembly described herein.

[0021] One aspect of the present disclosure is a tulip assembly for fixing to a bone implant and to a stabilization rod. The tulip assembly may or may not be modular.

[0022] In this aspect, the tulip can include one or more side openings sized and configured to receive an elongate stabilization rod therethrough.

[0023] This aspect can include a collet having a partially spherical configuration, the collet being sized to be disposed at least partially within the tulip, the tulip having an inner surface and the collet having an outer surface being sized and configured together to interface with each other when the collet is disposed within the tulip, both the inner surface of the tulip and the outer surface of the collet being configured relative to each other such that the tulip is movable relative to the collet in a movable arrangement.

[0024] In this aspect, the collet can include an implant interface region that projects radially inwardly, the projecting implant interface region including a radially extending surface disposed at an angle to the longitudinal axis of the collet and an axially extending surface that intersects the radially extending surface. The radially inward projection facilitates the distal end of the collet sinking towards a recessed region in the proximal region of the bone implant as the collet advances over the proximal region of the bone implant.

[0025] In this aspect, the tulip assembly can include a saddle sized and configured to be disposed at least partially proximal to the collet within the tulip. The saddle has a distal region having an inner curved inner surface formed to engage a curved proximal region of the collet. The saddle has a proximal end with a rod recessed region having a configuration shaped to interface with an elongate rod.

[0026] In this aspect, the radially inward projection of the collet can have a height from 0.1 mm to 2.0 mm.

[0027] In this aspect, the radially extending surface can be orthogonal to the longitudinal axis of the collet.

[0028] In this aspect, the axially extending surface may be parallel to the longitudinal axis of the collet.

[0029] In this aspect, the axially extending surface may be tapered and may be arranged at an angle of 0 to 20 degrees with respect to the longitudinal axis of the collet.

[0030] One aspect of the present disclosure is a bone implant adapted to couple to a tulip assembly. The bone implant has an elongated body having a long axis and a proximal region, and the proximal region is sized and configured to be coupled within a collet of the tulip assembly. In this aspect, the proximal region includes a radially recessed collet receiving region, and the collet receiving region includes a radially extending surface arranged at an angle of less than 90 degrees with respect to the long axis, a distal axially extending surface, and a proximal axially extending surface. The distal axially extending surface and the proximal axially extending surface are on both sides of the radially extending surface, and the proximal axially extending surface is arranged further radially outward from the long axis than the distal axially extending surface.

[0031] In this aspect, the proximal end of the proximal region may have a chamfered configuration.

[0032] In this aspect, the distal axially extending surface may be parallel to the long axis.

[0033] In this aspect, the distal axially extending surface may form an angle of 0 to 25 degrees with respect to the long axis.

[0034] In this aspect, the proximal axially extending surface may be parallel to the long axis.

[0035] In this aspect, the proximal region of the elongated body may not be provided with an external thread.

[0036] In this aspect, the radially concave collet receiving region may have an annular configuration around the proximal region of the elongated body.

[0037] In this aspect, the radially concave collet receiving region may have a depth of from 0.1 mm to 2.0 mm relative to the outer dimensions of the implant that is axially adjacent to the concave collet receiving region.

[0038] One aspect of the present disclosure is a bone implant adapted to be coupled to a tulip assembly. The bone implant can have a long axis and a proximal region, and the proximal region is sized and configured to be coupled to a collet of the tulip assembly. The proximal region can include a radially concave collet receiving region having a proximal end with an undercut ledge.

[0039] In this aspect, it can include any other suitable features of any implant, system, or assembly herein.

Brief Description of the Drawings

[0040]

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[0041] The disclosure herein relates to a rod coupling system or assembly. The rod coupling assembly herein includes a tulip and is adapted and configured to be coupled to a stabilization rod that is part of a bone stabilization structure. The rod coupling assembly in this context is also considered to include an implant or have an implantable portion that is fixed to tissue (e.g., bone), and the implant is coupled to the tulip. The rod may be part of a larger structure that can be used to stabilize one or more regions of the patient's body, such as the spine or pelvis. In some embodiments, the rod coupling assembly herein can be disposed in a lower region of the spine, such as in the region of the sacroiliac joint.

[0042] The disclosure of the present specification related to rod coupling assemblies is related to several aspects disclosed by published application WO2020 / 168269, which are hereby incorporated by reference in their entirety for all purposes. For example, but not limited to, FIGS. 25A through 26B of published WO2020 / 168269 show an exemplary rod coupling assembly that includes a head portion 2506 having a coupler 2524, a body 2526, and a nut (not shown). The nut has an outer thread that engages an inner thread disposed within a proximal recess of the body 2526 to tighten a spinal rod (not shown) against the bottom of the channel 2528 of the body 2526. As shown in FIG. 25B, the proximal end of the shank portion 2502 can include a circumferential rib or barb 2530 for snap-fitting the head portion 2506 to the shank portion 2502. The head portion can be considered as part of the rod coupling assembly. The head portion does not directly contact the tissue, but can be considered as part of the implant.

[0043] Figures 1A through 1E of the present specification show an exemplary rod coupling assembly 110, which is shaped and sized to be fixed to the implant portion 100 and the rod 130 (only a portion of which is shown). The assembly 110 includes a body 111, which is also referred to herein as a tulip. The implant 100 has a rounded (optionally at least partially spherical) proximal end 101, which is shaped and sized to stably but movably interface with the curved inner surface 112 of the body 111 (shown in FIG. 1B) and the curved inner surface of the implant stabilization member 120 (e.g., a saddle) (shown in FIG. 1D). In the position of FIG. 1D (and the fully assembled views of FIGS. 1A and 1E), due to the spherical surfaces of the three components (implant 100, body 111, and implant stabilization member 120), the body 111 is rotatable to some extent with respect to the proximal end 101 of the implant 100. The position of the curved surfaces is such that the implant axis "IA" (FIG. 1D) is not in line with the body axis "MB". Preferably, the angle (as shown) is at least 15 degrees, and in some embodiments, it is between 35 degrees and 55 degrees, optionally about 45 degrees (e.g., between 42 degrees and 48 degrees). Thus, the spherical orientation provides a desired or preferred angle between the body (e.g., the tulip) and the implant, enabling the desired or preferred angle while allowing some degree of rotational freedom between the body and the implant.

[0044] In the positions shown in FIGS. 1A and 1C through 1E, the channel 113 of the tulip 111 communicates with and is aligned with the internal channel of the implant, which includes a distal port 102. Thereby, a drug can be delivered from the tulip through the implant to the subject as needed. The channel or port 113 of the tulip also allows access to a rotary drive mechanism such as a hex drive or a torx drive (registered trademark).

[0045] When the implant stabilization member 120 (e.g., a saddle) is advanced to the position shown in FIG. 1D, the rod 130 can be positioned relative to the rod channel of the tulip such that the rod extends through the rod channel. FIGS. 1A and 1E show a portion of the rod disposed within the tulip. The rod and the tulip are well known in the art. To fix the rod in place, a rod stabilization member 140 (e.g., a threaded set cap) can be advanced into the body by rotation of the threads, as shown in FIGS. 1A and 1E, until it engages the rod 130 and helps to fix the rod in place. The implant stabilization member 120 also has a proximal curved surface (shown in FIG. 1B) configured to stably interface with a portion of the rod, as shown in the cross-sectional view of FIG. 1E. In an exemplary use, the rod 130 can extend in a direction generally considered from top to bottom and can be part of a spinal stabilization system that includes additional bone anchors (“implants”). Once the rod is fixed, the entire assembly, including the implant, is basically a safe and stable structure.

[0046] Figures 2A through 2J show a portion of an exemplary rod coupling assembly 200, but for clarity, do not show the rod and set cap (e.g., set cap 140 of FIGS. 1A through 1E). Figures 2A through 2J show a portion of the rod coupling assembly and show how the body or tulip 220 is secured to the implant portion 210. In any of the embodiments herein, the rod can be secured to the tulip 220 using any of the rod stabilizing members 140 shown in the disclosure herein, for example, the embodiment of FIG. 1A. FIG. 2A shows an exploded view of the rod coupling assembly 200, which may be considered to include the proximal region of the implant portion 210. The rod coupling assembly 200 includes a body or tulip 220, a distal collet portion 230, a proximal collet portion 240, and a saddle 250. The implant 210 may be at least partially threaded as shown and sized and shaped to be secured within bone.

[0047] The tulip 220 is configured to receive both the spherical collet portion and the saddle within its internal channel as shown in FIG. 2D. The proximal collet portion 240 includes a slit formed therein as shown. In FIGS. 2B, 2C, and 2D, the split collet is separated from the mating tapered inner surface 231. As the proximal portion of the implant portion 210 advances within the collet, the implant proximal end deflects or splits the collet fingers outwardly. As shown in FIGS. 2E through 2G, with continued advancement of the implant portion, the collet fingers backspin and deflect inwardly around the implant groove 211.

[0048] The saddle 250 can include one or more slots (shown in FIG. 2A) sized and configured to interface with swaged bosses to limit the amount of movement relative to the tulip.

[0049] And a rod (not shown for clarity) can be advanced through the tulip 220, and a threaded set cap (not shown for clarity) can be advanced distally. In this way, as shown in FIGS. 2H - 2J, the rod presses against the saddle 250, compressing the collet. This fixes the proximal portion of the implant to the rod coupling assembly and stably couples the rod to the rod coupling assembly.

[0050] In the embodiments of FIGS. 2 - 7 and 11 of the present specification, when a desired angle is created between the tulip and the implant, the set screw advances, thereby advancing the set screw and the rod relative to the saddle against the collet. Then, the slotted collet is compressed against the tulip, and the tulip compresses and fixes the collet against the proximal portion of the implant. This is a general method of fixing the assembly to the implant and the rod.

[0051] Figures 3A and 3B show a variation of the embodiment of FIGS. 2A - 2H (like parts are designated with like reference numerals), and the rod coupling assembly includes a threaded saddle and a proximal collet that interface with a threaded tool 260. As shown in FIG. 3A, when the threaded tool 260 is threaded into the saddle and collet, if the tool is pulled in the proximal direction relative to the tulip 220’, the saddle and collet are pulled in the proximal direction and disengaged from the distal spherical collet. Thereby, the saddle can be retracted proximally, providing the option to remove the tulip if necessary (e.g., if the implant portion has loosened). Also, the tulip can have side channels (as shown in FIGS. 1A - 1E). The side channels can provide access to the proximal end of the implant as needed, for example, when the tulip rotates and the physician cannot access the main channel of the tulip. The distal collet portion 230 (or 230’) allows the tulip 220 to rotate relative to the implant portion 210 at a preferred angle.

[0052] Figures 4A - 4H are exemplary embodiments of a rod coupling assembly 400 that includes a body or tulip 420, a spherical collet 430 (shown with a slit in FIG. 4A), a saddle 450, a set cap 460, and a split annular member 440. An implant portion 410 is also shown, and its proximal region includes a groove 411 or other similar type of indentation or recessed area formed therein. The implant 410 can be assembled with the split annular member 440 (e.g., split ring) as in the configuration of FIGS. 4A and 4B. The body or tulip 420 houses the spherical member 430 and the saddle 450. For clarity, the rod passing through the tulip is not shown, but the threaded set cap 460 can be advanced within the body and advanced until the rod is fixed in a predetermined position. This will be described in detail in other paragraphs of this specification.

[0053] The split annular member 440 has a tapered proximal surface 441 as shown in FIGS. 4B and 4C. As shown in FIGS. 4D, 4E, and 4F, when the implant portion 410 and the annular member 440 advance into the tulip 420 and the spherical collet 430, the split annular member 440 is pushed distally into the deepest part of the tapered implant groove 411. When torque is applied to the set cap 460, the split annular member 440 is pushed into the shallow part of the tapered implant groove 411 and into the groove in the spherical collet 430 as shown in FIGS. 4G and 4H.

[0054] FIGS. 5A through 5D show an exemplary rod coupling assembly similar to the embodiment of FIGS. 4A through 4H, with like or similar parts being given like reference numerals. All disclosures according to the description of FIGS. 4A through 4H can be clearly incorporated into the embodiment of FIGS. 5A through 5D unless shown to the contrary. In FIGS. 5A through 5D, the split annular member 540 is relatively larger than in FIGS. 4A through 4H and can be pre-assembled into the groove in the spherical member 530 as shown in FIGS. 5B through 5D. In this embodiment, the movement of the annular member is opposite to the movement of the annular member in FIGS. 4A through 4H. When the proximal region of the implant 510 advances into the spherical member 530, the annular member 540 is pushed proximally into the deepest part of the groove of the spherical member as shown in FIG. 5C. When the proximal region of the implant 510 advances further, the annular member 540 snaps into the groove 511 of the implant. When torque is applied to the set cap, the split annular member 540 is pushed into the shallow part of the groove of the spherical member as shown in FIG. 5D.

[0055] Figures 6A through 6E show an embodiment of a rod coupling assembly 600 including a body or tulip 620, a saddle 650, a spherical collet 630, and a set cap (not shown). The threads 611 (FIG. 1B) in the proximal region of the implant 610 interface with the internal threads of the spherical collet shown in FIG. 6C. As shown in FIG. 6E, the body or tulip 620 and the collet assembly 630 are threaded onto the implant, and the tulip 620 driver engages the hexagon or Torx® of the spherical collet. The threads can be serrated threads. The spherical collet has a slit formed therein such that the spherical collet is slightly compressed radially when it rotates. Then, the rod can be placed through the tulip and the set cap can be torqued to secure the rod in place.

[0056] When the rod is fixed to the rod coupling assembly of a fixed implant (such as any of those described herein), bending loads may be applied to the tulip and the implant. It may be beneficial for the rod coupling assembly and / or the implant to be configured and / or sized to function to resist bending loads. Figures 7A through 7E show merely exemplary rod coupling assemblies where a part of the implant or an implant portion interfaces with the body or the tulip and, in particular, provides support to the tulip so as to provide more resistance to bending loads. In Figure 7C, the shank 710 of the implant 700 is an example of an elongate member of an implantable portion, such as any of the elongate inner members (such as the shank) in PCT Application Publication WO2020 / 168269, the disclosure of which is incorporated herein by reference. The outer sleeve 712 generally refers to an outer member disposed at least partially around the inner member or shank 710. Figure 7D shows a non-limiting example of an implant 700 that includes an outer sleeve 712 and an inner elongate body 710 (such as a shank portion). The sleeve includes a proximal region 713 that has a configuration that extends radially outward such that its proximal end is disposed radially outside and around at least a part of the tulip 720 and provides support to the tulip. The tulip also functions as a locking mechanism for the outer sleeve.

[0057] The sleeve 710 in this exemplary embodiment may be any of the outer elongate members herein, including, for example, the body 2504 of Figure 25B of PCT Application Publication WO2020 / 168269. Further, any of the outer elongate members (such as the body 2504 of Figure 25B of PCT Application Publication WO2020 / 168269) may include a proximal region that extends radially outward, as the sleeve 710 of Figures 7A through 7E does. The implant in this embodiment may adopt a wide variety of shapes and configurations and may include a proximally extending region 713 that is sized and configured to interface with the outer surface of the tulip.

[0058] Figures 8A through 8G show embodiments of a rod coupling assembly that are similar in some respects to the embodiments shown in Figures 7A through 7E, and any suitable disclosure can be incorporated into the embodiments by reference. In this embodiment, the sleeve portion 812 of the implant extends more substantially around the tulip 820 than in Figures 7A through 7E, providing more support and more resistance to bending loads. The spherical component in this embodiment is part of the implant as the spherical element 830 of the implant, shown in Figure 8C. Figures 8D and 8E show the clearance 870 between the tulip 820 and the implant sleeve 812 under normal or unloaded conditions. Figures 8F and 8G show an extreme loading scenario and show how the outer sleeve 812 functions as a brace to prevent excessive distortion of the neck region of the inner shank 810. For clarity, the rod and set screw are not shown.

[0059] As discussed herein, some rod coupling assemblies may be subject to bending loads when implanted. FIGS. 9A through 9F illustrate an exemplary tulip including an inner tulip member and an outer tulip member. The tulip 920 shown in FIGS. 9A through 9F can be used with implants other than those shown or described herein. The tulip 920 includes an outer tulip 923 and an inner tulip 921. The tulips of FIGS. 9A through 9F can be incorporated into any suitable embodiment of this specification unless otherwise indicated. FIGS. 9A through 9C show the tulip members 921 and 923 without the other parts of the rod coupling assembly. FIG. 9D shows an exemplary implant portion 910 with a spherical member 911 disposed within the inner tulip 921. As shown, the clearance 925 between the outer tulip 923 and the inner tulip 921 in the unlocked position allows the spherical member 911 to snap into the interface of the inner tulip. And in FIG. 9E, after the rod 980 is disposed and the set cap 970 is tightened, as shown, the inner tulip 921 is pulled and moves proximally relative to the outer tulip 923. As shown in FIG. 9F, the tapered interface between the outer tulip 923 and the inner tulip 921 allows the tulip assembly to lock onto the spherical member 911. In this final configuration, the outer tulip serves to prevent the inner tulip from spreading. Subject to a bending load, the inner tulip may be prone to spreading. As shown, the rod coupling assembly can also include a saddle that can advance onto the spherical member, such as any of the saddles of this specification. An example of the inner tulip member of this embodiment is configured to move axially relative to the outer tulip member during use.

[0060] Figures 10A through 10I show exemplary embodiments of a rod coupling assembly similar to the embodiments shown in Figures 9A through 9F and including an inner tulip member and an outer tulip member. Any suitable disclosure according to the embodiments of Figures 9A through 9F, for example, the disclosure of the inner tulip being pulled proximally and into the outer tulip by a set cap, can be incorporated into the disclosure of 10A - 10I unless shown to the contrary. As shown, and as in the case of the embodiments of Figures 9A through 9F, the inner tulip 1021 has a distal end with at least one slit 1025 therein and is capable of some spreading and collapsing during axial movement. In this embodiment, one difference is the configuration of the outer tulip 1023 and the way it can be rotated (simply by way of example, for example, a quarter or 1 / 4 turn) before finally tightening the set cap 1080. Rotating the outer tulip 1023 causes a portion 1025 of the outer tulip 1023 to extend over an area of the inner tulip, as shown in the figure, thereby providing more radial support to the tulip arms and reducing the likelihood of the inner tulip spreading. In other embodiments, the outer tulip and / or the inner tulip can have different configurations and can be rotated by more than a quarter turn (90 degrees) or less than a quarter turn, for example, at an angle between 0 degrees and 180 degrees, for example, between 5 degrees and 135 degrees, for example, between 45 degrees and 135 degrees, for example, at an angle of 90 degrees.

[0061] Figures 11A through 11J illustrate additional exemplary embodiments of a rod coupling system or rod coupling assembly 1100 that includes an exemplary bone implant 1110 and a tulip assembly 1130. It should be understood that alternative systems can include the bone implant 1110 and other types of tulip assemblies (including those not described herein). It should be understood that alternative systems can include the tulip subassembly 1130 and other types of bone implants (including those not described herein). Further, it should be understood that alternative systems can include one or more features of the bone implant 1110, as well as other types and features of the tulip subassembly (including those not described herein). It should be understood that alternative systems can include one or more features of the tulip subassembly 1130, as well as other types and features of the bone implant (including those not described herein).

[0062] Systems 1100 and other similar systems described herein that include a tulip assembly and a bone implant can also be referred to as a rod coupling assembly or rod coupling system because the system can be used to couple or secure a stabilization rod to the tulip assembly and the bone implant.

[0063] System 1100, bone implant 1110, and tulip assembly 1130 can be understood to include other features described herein, even if their textual description does not explicitly disclose those features.

[0064] In an exemplary aspect of this embodiment, the interface between the collet and the proximal region of the bone implant is sized and configured to reduce the possibility that the distal end of the collet expands and loosens in response to an axial force (e.g., a proximal force) applied to the tulip. For example, the proximal force applied to the tulip by the movement of the rod may be transmitted to the collet, which may cause the undesirable loosening or expansion of the distal end of the collet over time.

[0065] Furthermore, the interface between the collet and the implant in the exemplary embodiments of FIGS. 11A through 11J is configured to resist or minimize the tendency to loosen due to the axial force caused by the retraction of the rod. Retraction of the rod generally occurs when the physician positions the rod protruding from the tulip and then retracts the rod (i.e., pulls the rod into the implant tulip) to obtain an anatomical correction. This step is performed before the collet is fixed in place. These retractions apply a large force to the implant, and since the collet is not yet fixed, the collet may come apart. The interface between the collet and the implant in FIGS. 11A through 11J is an example of an interface that is sized and configured to ensure that the collet remains closed or to increase the likelihood that the collet remains closed during these retractions.

[0066] To reduce the possibility that the collet loosens or expands in response to these forces, in these scenarios, the implant undercut forms or creates a gap 1102 (FIG. 11E) between surfaces 1114 that are not parallel to each other and the collet surface facing the surface 1114. The collet surface may be orthogonal to the longitudinal axis. When an axial force is applied to the tulip, the gap 1102 provides space so that the distal force applied to the vertical surface of the collet is reduced, reducing the possibility of collet expansion and loosening. Reducing the possibility of collet expansion and loosening is mentioned in comparison to a system having a radially extending surface 1114 that is similar in all respects and orthogonal to the longitudinal axis LA of the bone implant, or a system without a gap.

[0067] The undercut at the proximal end of the bone implant recess 1112 can be described in various ways. The undercut can be described as a collet receiving region 1112 of a recess in the proximal region of the implant that includes a radially extending surface (e.g., 1114) disposed at an angle of less than 90 degrees with respect to the longitudinal axis of the bone implant, and the angle is measured distally with respect to the radially extending surface as shown as angle α in FIG. 11D. In FIG. 11D, the angle is also shown with respect to the axially extending surface 1118, but the axially extending surface 1118 need not be flat as shown and may be a curved surface. Note that in any embodiment of the present specification, the surface 1114 or its extension may form an angle with the longitudinal axis of the implant or an axis parallel to the longitudinal axis, and the angle may be the same angle α in both cases.

[0068] The undercuts of the present specification can also be described and claimed functionally herein. For example, compared to a system having a radially extending surface that is similar in all respects but orthogonal to the longitudinal axis of the bone implant, the radially extending surface is angled so that the distal end of the collet can be reduced in its ability to expand and loosen in response to axial forces.

[0069] The undercut of this specification can be described as including a proximal region having a radially concave collet receiving region, or a region including a radially extending surface disposed at an angle of less than 90 degrees with respect to the major axis. The undercut of this specification can be described as including a proximal region having a radially concave collet receiving region having distal axially extending surfaces (e.g., surface 1118) and proximal axially extending surfaces (e.g., 1116) on both sides of a radially extending surface (e.g., 1114). The proximal axially extending surface is disposed further radially outward from the major axis than the distal axially extending surface, examples of which are shown in FIGS. 11D and 11E.

[0070] The undercut can be considered to include a radially extending surface 1114 and one or more surfaces extending therefrom, such as axially extending surface 1118 and axially extending surface 1116. In this example, the undercut includes the distal end of the axially extending surface 1116 that extends further distally than the proximal end of the radially extending surface 1114, as shown in FIGS. 11D and 11E.

[0071] As described herein, the axially extending surface need not necessarily be parallel to the major axis of the implant, but rather can be considered to be at an angle thereto and still axially extend, or be a curved surface and still be considered to axially extend.

[0072] The collet 1134 or any collet of this specification can include a linear slit or slot formed therethrough to allow for expansion and crushing of the distal end of the collet, such as general collet features. Thereby, as the collet advances over the proximal end of the implant, the collet can expand. In some embodiments, the proximal end of the implant can facilitate expansion of the collet, for example, by having a chamfered surface 1120 (FIG. 11C), which can help expand the distal end of the collet as the collet slides distally over the proximal end of the implant. When the collet implant interface region 1135 (FIG. 11B) advances distally relative to the recessed region 1112, due to the crushability of the distal end of the collet by the slit / slot, the collet implant interface region 1135 sinks into the recess 1112. As shown in FIGS. 11A, 11B, and 11E, by snapping or sinking into a predetermined position in the recessed region 1112, the collet is fixed in a predetermined position relative to the proximal region 1111 of the implant. The tulip 1132 can move relative to the collet 1134 until a fixing screw is screwed into the tulip (internal thread shown in FIG. 11A) and the rod is fixed in a predetermined position (not shown in FIGS. 11A - 11I), but any rod of this specification can be arranged through an opening on the side surface of the tulip.

[0073] The collet implant interface region 1135 shown in FIG. 11B is an example of an implant interface region protruding radially inward of the collet and is shown to be disposed in and interface with the recessed region 1112 of the collet 1134. The radially extending surface of the collet 1134 shown in FIG. 11E, facing the implant surface 1114, can be orthogonal to the central axis of the collet. In other embodiments, the radially extending surface of the collet 1134 can be arranged at an angle to the long axis.

[0074] In some embodiments, the radially extending surface of the implant interface region of the collet (e.g., as shown in FIG. 11E) is orthogonal to the longitudinal axis of the collet.

[0075] In some embodiments, the radially extending surface of the collet receiving region of the implant recess is disposed at an angle of less than 85 degrees (e.g., angle α in FIG. 11D) with respect to the longitudinal axis of the implant. In some embodiments, the angle α may be greater than 45 degrees with respect to the longitudinal axis of the implant. In some embodiments, the angle α is greater than 75 degrees with respect to the longitudinal axis of the implant. In some embodiments, the angle is between 70 degrees and 89 degrees with respect to the longitudinal axis of the implant.

[0076] In some embodiments, the recessed collet receiving region (e.g., region 1112) has a depth of 0.1 mm to 2.0 mm with respect to the outer dimensions of the implant that are axially adjacent to the recessed region 1112.

[0077] In any of the embodiments herein, the proximal region of the bone implant may not be provided with an external thread as shown in the examples of FIGS. 11A to 11J.

[0078] In some embodiments, the recessed collet receiving region of the implant has an annular configuration around the bone implant, as shown in FIG. 11C.

[0079] Even if not shown herein, the collet of any system herein can have a partial spherical configuration and the tulip can have a corresponding inner surface. The surfaces of the collet and the tulip are sized and configured together to interface with each other when the collet is disposed within the tulip. Both the inner surface of the tulip and the outer surface of the collet can be sized and configured to enable the tulip to move relative to the collet in a movable state, as in the embodiments of FIGS. 11A to 11J.

[0080] Either the tulip assembly or the rod coupling assembly of this specification may further include a saddle sized and configured to be disposed within the tulip and at least partially proximal to the collet. The saddle of this specification can have a distal region with a curved inner surface shaped to engage the curved proximal region of the collet. The saddle of this specification can have a proximal end with a recessed region having a configuration shaped to interface with the outer surface of an elongate rod (e.g., as shown in the embodiments of FIGS. 11A - 11J).

[0081] Any of the collets of this specification can have one or more openings formed therein. When a set screw is threaded onto the outer surface of the rod within the tulip of FIG. 11A, a force is applied to the rod (not shown), thereby applying a force to the saddle. This, together with the collet / tulip interface, causes compression of the collet around the proximal end of the implant. Once the tulip is at the desired angle, the set screw can be advanced as described herein to essentially stabilize the tulip with respect to the rod and the implant.

[0082] Exemplary bone implants are shown herein, but the bone implants that can be part of the rod coupling assembly of this specification can be configured and sized as a wide variety of bone implants. For example, the bone implants of this specification may or may not have threads provided along at least a portion of their length. The bone implants of this specification can be configured to proceed into one or more iliac bones, or the sacrum, or other vertebrae.

[0083] One aspect of the present disclosure is a bone implant with or without an associated tulip assembly. The bone implant can have an elongated body with a long axis and a proximal region, the proximal region being sized and configured to be coupled within a collet of the tulip assembly. The proximal region of the implant can include a radially recessed collet receiving region (e.g., region 1112), the recessed collet receiving region including a radially extending surface (e.g., surface 1114) disposed at an angle of less than 90 degrees relative to the long axis (or center) of the implant. The collet receiving region of the implant also includes a distally axially extending surface and a proximally axially extending surface, the distally axially extending surface and the proximally axially extending surface being on opposite sides of the radially extending surface, and the proximally axially extending surface being disposed further radially outward from the long axis or central axis than the distally axially extending surface.

[0084] The proximal end of any bone implant herein can have a chamfered configuration as labeled 1120 in the example shown in FIG. 11C.

[0085] The distally axially extending surface (e.g., surface 1118) can be disposed at an angle of 0 degrees to 25 degrees relative to the long axis of the implant.

[0086] Any of the bone implants herein can include a proximal region having a lumen with internal threads, as shown in FIG. 11A. In some embodiments that couple as a modular tulip assembly, the internal threads are sized and configured to interface with external threads on a guide rod, and the guide rod can facilitate advancement over the proximal region of the elongated body of the modular tulip assembly that includes the collet.

[0087] Any of the undercut ledge configurations herein can be described as similar to a cliff having an upper surface, at least a portion of which extends distally relative to a radially extending wall portion of the cliff.

[0088] The tulip assembly of the present specification can be coupled to the implant before insertion or can be modularly coupled to the implant after the implant is at least partially implanted into the bone. Whether or not the tulip assembly is modularly coupled to the implant before the bone implant is implanted, the tulip assembly can include any of the features of any tulip assembly of the present specification.

[0089] The tulips of the present specification can include any suitable features common to existing tulips. Figures 11A through 11J show an exemplary tulip having a first side opening and a second side opening sized and configured to receive an elongate rod therethrough. Figures 11A through 11J show an exemplary tulip assembly comprising a collet including an implant interface region (e.g., region 1135) projecting radially inwardly, and as shown, the projecting implant interface region includes a radially extending surface disposed at an angle to the longitudinal axis of the collet and an axially extending surface intersecting the radially extending surface. The radially inward projection facilitates the distal end of the collet to sink towards a recessed region in the proximal region of the bone implant as the collet advances over the proximal region of the bone implant (or the implant moves axially within the collet). Also, any of the tulip assemblies of the present specification can include a saddle disposed within the tulip and sized to be disposed at least partially proximal to the collet. Any of the saddles can have a distal region with a curved inner surface shaped to engage the curved proximal region of the collet. Any saddle of the present specification can have a proximal end with a recessed region having a configuration shaped to interface with an elongate rod.

[0090] Any of the tulip assemblies of this specification can include a collet having one or more openings or slits, such that the collet is enabled to apply a radially inward clamping force in response to forces applied to the collet from the tulip and the saddle.

[0091] Any of the tulip assemblies of this specification can include a radially inward protrusion (e.g., implant interface region 1135) having a height from 0.1 mm to 2.0 mm, the dimensions of which can be considered to be substantially the same depth as any of the recessed implant regions of this specification.

[0092] Any of the collets of this specification can include a protrusion including a surface extending radially orthogonal to the long axis of the collet, as illustratively shown in FIG. 11E.

[0093] Further disclosure of the system components and features disclosed in U.S. Patent Nos. 8,845,693 and 9,655,656 can be relevant to the disclosure of this specification, the entire disclosure of which is hereby incorporated by reference for all purposes.

[0094] FIGS. 11F through 11J show steps and delivery tools of merely exemplary methods for coupling a modular tulip assembly to an implant.

[0095] Figures 11F and 11G show implant 1110 being implanted using implant delivery tool 1190. After implant delivery tool 1190 is removed, guide rod 1192 is coupled to the proximal region of the bone implant such that the guide rod extends proximally from the bone implant, as shown in Figure 11H. After the guide rod is removed, tulip delivery tool 1194, which is coupled to tulip assembly 1130, is used to advance the tulip assembly over the guide rod, as shown in Figures 11I and 11J. This method can further include advancing the collet relative to the proximal end of the proximal region of the bone implant and expanding the distal end of the collet as the collet advances over the proximal region of the bone implant. This method further includes continuing to advance the collet over the proximal region of the bone implant until the radially inner protrusion of the collet moves radially inward and into the recessed region of the bone implant, the recessed region of the bone implant having a proximal end with an undercut ledge configuration.

[0096] In some embodiments, the bone implant is implanted with the tulip assembly already coupled thereto.

Claims

1. 1. A rod coupling system comprising a bone implant and a tulip assembly for securing a rod to the bone implant, the bone implant has a proximal region spaced from a distal region, the proximal region sized and configured to interface with a tulip assembly, the tulip assembly including a tulip and a collet sized and configured to be disposed at least partially within the tulip; the tulip assembly having an opening sized and configured to receive a stabilization rod therethrough; a proximal region of the bone implant including a radially recessed collet receiving area sized and configured to receive therein a radially inwardly projecting implant interface region of the collet, the recessed collet receiving area including a radially extending surface disposed at an angle of less than 90 degrees relative to a longitudinal axis of the bone implant, the angle being measured distally to the radially extending surface; the implant interface region of the collet includes a radially extending surface disposed at an angle relative to a longitudinal axis of the collet, the radially extending surface of the implant interface region being disposed to face the radially extending surface of the collet receiving region of the recess when the implant interface region is interfaced with the collet receiving region of the recess. system.

2. the radially extending surface of the implant interface region of the collet is perpendicular to a longitudinal axis of the collet; The system of claim 1 .

3. the radially extending surface of the collet receiving area of ​​the recess is disposed at an angle of less than 85 degrees relative to a longitudinal axis of the bone implant; The system of claim 1 .

4. the radially extending surface of the collet receiving area of ​​the recess is disposed at an angle of greater than 45 degrees relative to a longitudinal axis of the bone implant; The system of claim 1 .

5. the radially extending surface of the collet receiving area of ​​the recess is disposed at an angle of greater than 75 degrees relative to a longitudinal axis of the bone implant; The system of claim 1 .

6. the radially extending surface of the collet receiving area of ​​the recess is disposed at an angle of between 70 degrees and 89 degrees relative to the longitudinal axis of the bone implant; The system of claim 1 .

7. the tulip assembly is modular and adapted to be delivered separately from the bone implant and movably secured to the bone implant after the bone implant is at least partially implanted within the bone; The system of claim 1 .

8. a proximal end of the bone implant including internal threads sized and configured to receive an internally threaded guide rod; the tulip assembly is adapted to be advanced over the threaded guide rod and over the proximal end of the bone implant to movably secure the tulip assembly and the bone implant. The system of claim 7.

9. the proximal region of the bone implant includes a chamfered proximal end to facilitate expansion of the distal end of the collet as the collet is advanced over the chamfered proximal end; a collet receiving area of ​​the recess such that as the collet is advanced distally over the proximal region of the bone implant, the radially inwardly projecting implant interface region of the collet moves radially inwardly into the collet receiving area of ​​the recess. The system of claim 1 .

10. the proximal region of the bone implant is configured to facilitate opening of the distal end of the collet as the collet is advanced over the proximal end; a collet receiving area of ​​the recess such that as the collet is further advanced over the bone implant, a radially inwardly protruding implant interface area of ​​the collet moves back into the collet receiving area of ​​the recess toward a resting state. The system of claim 1 .

11. The collet receiving area of ​​the recess has a depth of 0.1 mm to 2.0 mm. The system of claim 1 .

12. the proximal region of the bone implant is free of external threads; The system of claim 1 .

13. the proximal region of the bone implant having an outermost sleeve surface sized and configured to extend over at least a portion of the distal end of the tulip; The system of claim 1 .

14. the outermost sleeve surface being a surface of an outer implant sleeve, the outer implant sleeve being disposed about an inner shank of the implant; The system of claim 13.

15. a collet receiving area of ​​the recess having an annular configuration around the bone implant; The system of claim 1 .

16. 1. A rod coupling system comprising a bone implant and a tulip assembly for securing a rod to the bone implant, the bone implant has a proximal region spaced from a distal region, the proximal region configured to interface with a tulip assembly, the tulip assembly including a tulip and a collet sized and configured to be at least partially disposed within the tulip; the tulip assembly having an opening configured to receive a stabilization rod therethrough; the proximal region of the bone implant includes a recessed collet receiving region sized and configured to receive therein a radially inwardly projecting implant interface region of a collet; the collet receiving area of ​​said recess includes a radially extending surface disposed at an angle of less than 90 degrees relative to a longitudinal axis of the bone implant, said angle being measured distal to said radially extending surface, said radially extending surface being angled to reduce the likelihood of the collet expanding and coming loose in response to axial forces, as compared to a system having a radially extending surface that is similar in all respects but perpendicular to the longitudinal axis of the bone implant; the implant interface region of the collet includes a radially extending surface disposed at an angle relative to a longitudinal axis of the collet, the radially extending surface of the implant interface region being disposed to face the radially extending surface of the collet receiving region of the recess when the implant interface region is interfaced with the collet receiving region of the recess. Rod coupling system.

17. 17. A rod coupling system according to claim 16, further comprising the features of any system according to any one of claims 1 to 15.

18. 1. A rod coupling system comprising a bone implant and a tulip assembly for securing a rod to the bone implant, the bone implant has a proximal region spaced from a distal region, the proximal region configured to interface with a tulip assembly including a collet; the tulip assembly having an opening configured to receive a rod therethrough, the tulip assembly including a collet and a saddle sized to be disposed at least partially within the tulip; the proximal region of the bone implant includes a recessed collet receiving region configured and sized to receive an implant interface region of a collet therein, the collet receiving region including an axially extending surface of the recess and a radially extending surface disposed at an angle of less than 90 degrees relative to a longitudinal axis of the bone implant, the axially extending surface of the recess and the radially extending surface intersecting one another; the collet has a partial spherical configuration, the tulip has an inner surface and the collet has an outer surface, the outer surfaces being sized and configured to interface with one another when the collet is disposed within the tulip, and both the inner surface of the tulip and the outer surface of the collet are configured to movably permit movement of the tulip relative to the collet; the collet includes an implant interface region including a radially extending surface disposed at an angle relative to a longitudinal axis of the collet, the radially extending surface of the implant interface region disposed to face the radially extending surface of the collet receiving region of the recess when the implant interface region is interfaced with the collet receiving region of the recess; the saddle is sized to be disposed within the tulip and at least partially proximal to the collet, the saddle having a proximal end with a recessed area having a configuration shaped to interface with an elongate rod; the collet has one or more openings therein such that the collet exerts a radially inward clamping force in response to forces exerted on the collet by the tulip and the saddle; a set screw sized and configured to thread into the tulip and apply a force to the elongate rod to fix the position of the tulip relative to the bone implant; Rod coupling system.

19. 19. A rod coupling system according to claim 18, further comprising the features of any system according to any one of claims 1 to 15.

20. A tulip assembly (optionally a modular tulip assembly) for fastening to a bone implant and a stabilization rod, a tulip having a first side opening and a second side opening sized and configured to receive an elongated stabilization rod therethrough; a collet having a partial spherical configuration, the collet sized to be disposed at least partially within the tulip, the tulip having an inner surface and the collet having outer surfaces that are together sized and configured to interface with each other when the collet is disposed within the tulip, both the inner surface of the tulip and the outer surface of the collet being mutually configured to allow the tulip to move relative to the collet in a movable arrangement; a saddle disposed within the tulip and sized and configured to be disposed at least partially proximal to the collet, the saddle having a distal region with a curved inner surface shaped to mate with the curved proximal region of the collet, the saddle having a proximal end with a rod recessed region having a configuration shaped to interface with the elongate rod; a setscrew sized and configured to thread into the tulip and apply a force to the elongated rod to secure the elongated rod in position relative to the tulip; Equipped with the collet includes a radially inwardly protruding implant interface region, the protruding implant interface region including a radially extending surface disposed at an angle with respect to a longitudinal axis of the collet and an axially extending surface intersecting the radially extending surface, the radially inward protrusion facilitating a distal end of the collet to collapse towards the recessed area of ​​the proximal region of the bone implant as the collet is advanced over the proximal region of the bone implant; the collet has one or more openings or slits formed therein to allow the collet to apply a radially inward clamping force in response to forces applied to the collet by the tulip and the saddle; Modular tulip assembly.

21. The radially inward protrusion of the collet has a height of 0.1 mm to 2.0 mm.

21. The modular tulip assembly of claim 20.

22. the radially extending surface is perpendicular to a longitudinal axis of the collet; 21. The modular tulip assembly of claim 20.

23. the axially extending surface is parallel to a longitudinal axis of the collet; 21. The modular tulip assembly of claim 20.

24. the axially extending surface is tapered and disposed at an angle of 0 to 20 degrees relative to a longitudinal axis of the collet; 21. The modular tulip assembly of claim 20.

25. 1. A bone implant adapted to couple to a tulip assembly, comprising: an elongate body having a longitudinal axis and a proximal region, the proximal region sized and configured to be coupled within a collet of a tulip assembly; the proximal region includes a radially recessed collet receiving region including a radially extending surface disposed at an angle of less than 90 degrees relative to the longitudinal axis, a distal axially extending surface, and a proximal axially extending surface, the distal axially extending surface and the proximal axially extending surface being on opposite sides of the radially extending surface, the proximal axially extending surface being disposed further radially outward from the longitudinal axis than the distal axially extending surface. Bone implants.

26. a proximal end of the proximal region having a chamfered configuration; 26. A bone implant according to claim 25.

27. the distal axially extending surface is parallel to the longitudinal axis; 26. A bone implant according to claim 25.

28. the distal axially extending surface is at an angle of 0 to 25 degrees relative to the longitudinal axis; 26. A bone implant according to claim 25.

29. the proximal axially extending surface is parallel to the longitudinal axis; 26. A bone implant according to claim 25.

30. the proximal region having a bore with internal threads; the internal threads are sized and configured to interface with external threads of a guide rod that can facilitate advancement of a modular tulip assembly including a collet over the proximal region of the elongate body.

26. A bone implant according to claim 25.

31. the proximal region of the elongate body is free of external threads; 26. A bone implant according to claim 25.

32. the radially recessed collet receiving region has an annular configuration about the proximal region of the elongate body.

26. A bone implant according to claim 25.

33. the radially recessed collet receiving area has a depth of 0.1 mm to 2.0 mm relative to an outer dimension of the bone implant axially adjacent the recessed collet receiving area; 26. A bone implant according to claim 25.

34. 1. A bone implant adapted to couple to a tulip assembly, comprising: an elongate body having a longitudinal axis and a proximal region; the proximal region is sized and configured to couple to a collet of a tulip assembly; the proximal region includes a radially recessed collet receiving region having a proximal end with an undercut ledge; Bone implants.

35. 35. The bone implant of claim 34, further comprising any suitable feature of any bone implant of any one of claims 26 to 33.

36. 1. A kit for implanting a bone implant and a modular tulip assembly, comprising: a bone implant delivery tool secured to a proximal end of the bone implant and adapted to deliver said bone implant into a bone; a guide rod having a distal end with an outer profile configuration that is secured to an inner surface configuration of a proximal end of the bone implant; a tulip assembly delivery tool adapted to couple to a tulip assembly, the tulip assembly delivery tool having an internal lumen communicating with a distal opening, the internal lumen and the distal opening sized and configured to receive the guide rod to facilitate delivery of the tulip assembly over the guide rod; Equipped with kit.

37. 1. A method for fastening a bone implant to a rod, comprising: advancing the bone implant into the bone with a bone implant delivery tool coupled to a proximal region of the bone implant; detaching the bone implant delivery tool from the bone implant and removing the bone implant delivery tool; coupling a guide rod to a proximal region of the bone implant such that the guide rod extends proximally from the bone implant; coupling a tulip assembly delivery tool to a tulip assembly, the tulip assembly including a tulip, a collet disposed at least partially within the tulip, and a saddle within the tulip and at least partially proximal to the collet; advancing the tulip assembly over the guide rod using a tulip assembly delivery tool; advancing the collet against a proximal end of a proximal region of the bone implant and expanding a distal end of the collet as the collet advances over the proximal region of the bone implant; continuing to advance the collet over a proximal region of the bone implant until a radially inward protrusion of the collet moves radially inward and into an area of ​​a recess in the bone implant, the area of ​​the recess having a proximal end with an undercut ledge configuration; Including, method.

38. further comprising the steps of placing a rod through a side opening in the tulip and threading a set screw into the tulip until the set screw applies a stabilizing force to the rod and the tulip is fixed in position relative to the bone implant.

38. The method of claim 37.

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