Vertebral fastener assembly

Abstract

A spinal fastener assembly (1) engaged in a posterior spinal fastener system comprises a bone fastener (10), a rod receiving head (30) configured to receive a spinal rod (2), fastening means (60, 70) configured to exert a retaining and / or clamping force between the spinal rod and the rod receiving head, and a tether (80) connecting or coupling the rod receiving head (30) to the bone fastener (10). When the bone fastener (10) is introduced into the spine, the spinal rod (2) is positioned within the central pocket (41) of the rod receiving head (30) and the rod fastening means (60; 70) clamps the spinal rod (2) within the central pocket (41) and blocks the position of the tether (80) within the tether retaining means (36) of the rod receiving head (30) at a predetermined distance (X2).

Description

[Technical field]

[0001] The present invention relates to a spinal fastener assembly and a surgical method for engaging the spinal fastener assembly to a posterior spinal fastener system. [Background technology]

[0002] In orthopedic surgery around the spine, posterior spinal stabilization systems are often placed at target sites to realign, correct, and / or stabilize the spine to compensate for malalignments caused by, for example, spinal degeneration, excessive lordosis, kyphosis, and scoliosis, as well as malalignments caused by trauma, for example, fractures.

[0003] A typical posterior spinal stabilization system consists of multiple pedicle screws connected by rods. In a first step, the pedicle screws are screwed through the pedicle bone into the vertebral bodies at different levels of the spine. In a second step, the pedicle screws are connected by a rod with the desired shape or curvature. Using a spinal guiding instrument, the vertebral body containing the pedicle screw is pushed towards the rod (or vice versa). When the rod reaches its final position within the rod-receiving head of the pedicle screw, it is firmly fixed by tightening a set screw against the rod. This fixation will initiate the fusion of the involved levels of the spine.

[0004] The spinal column includes several vertebral levels separated by intervertebral discs. The intervertebral discs provide a cushioning effect and, due to their flexibility, allow a person to bend the spine. When several vertebral bodies are connected by a posterior spinal system, the involved level is unable to perform this function. As a result, the adjacent or neighboring levels must partially compensate for this function.

[0005] As a result, the sudden transition of mobile spinal levels to a rigid long multilevel screw-rod construct will result in higher stresses that may lead to complications such as new pathological kyphosis starting at adjacent levels.

[0006] As a result, for example, proximal and distal junctional kyphosis (PJK) and dislodgment (DJK) are major complications and challenges in adult multilevel spinal fusion surgery. Often, complications result in the need for revision surgery.

[0007] To reduce the risk of PJK and DJK, the use of more dynamic transitional implants such as tethers (non-fusion spinal devices intended to treat idiopathic scoliosis) or hooks instead of rigid pedicle screws has been shown to reduce the risk of implant-related failure such as unscrewing. However, both of these approaches have technique-related drawbacks. In particular, the tether needs to be passed under the lamina or around the spinal process, tensioned, and then tied. This requires visualization of the site, involves damage to the surrounding soft tissue, and has the risk of damage to the dura or spinal cord when the tether is passed under the lamina. Furthermore, these steps increase the complexity and duration of the surgery.

[0008] Another common cause of complications is the fixation of the rod to the most proximal screw. This fixation step usually requires a large force because the rod is rarely fully bent and stresses can occur at the screw-bone interface. These stresses can cause screw-bone loosening. Also, in osteoporosis surgery and spinal deformity surgery, full rod bending to match position is often difficult due to the limited range of correction, especially in rigid spinal deformities. Osteoporosis and high stresses affecting the screw-bone interface can cause screw loosening, especially at the apex of the deformity and at any level where there is a larger offset between the locking position of the screw head and the rod. Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above, therefore, there is a need for an improved vertebral fastener assembly that reduces stress on the pedicle screw-bone interface, particularly when transitioning from a mobile spine to a rigid screw-rod construct, and thus provides a smoother transition from an instrumented level to adjacent levels above and / or below. Such a vertebral fastener assembly should be compatible with the screw-rod constructs used to treat spinal pathologies, should be capable of being applied in a manner that minimizes damage to soft tissue, should allow variable adjustment of stiffness and distance between the spine and the connecting rod to accommodate individual differences in patient anatomy, and should not require manipulations involving hand tying or tensioning tethers that result in non-reproducible results. [Means for solving the problem]

[0010] The present invention provides, inter alia, a spinal fastener assembly for engagement with a posterior spinal fastener system, the spinal fastener assembly comprising: a bone fastener having a bone fastener head portion, a bone engaging elongated shaft, and a first drive portion for introducing the bone fastener into a target bone; a rod receiving head configured to receive and at least partially surround a spinal rod in a first rod receiving opening having a central pocket with a clamping seat; fastening means configured to exert a holding and / or clamping force between the spinal rod and the rod receiving head; and at least one flexible elongated member connecting or coupling the rod receiving head to the bone fastener. The fastening means preferably comprises a body having a fastening means top side and a fastening means bottom side. The bone fastener further comprises at least one first flexible elongated member retaining means. The rod receiving head preferably comprises a head top end and a head bottom end. The first rod receiving opening in the rod receiving head preferably extends from an anterior side to a posterior side. The rod receiving head further comprises at least one second flexible elongate member retaining means and a first rod setting or clamping mechanism. The clamping means comprises a second drive for engaging the clamping means within the rod receiving head. The spinal fastener assembly has a second clamping mechanism sized and shaped to engage with the first rod setting or clamping mechanism. The second clamping mechanism may be embodied within the at least one clamping means. The flexible elongate member comprises an elongate flexible body sized and shaped to engage with the first and second flexible elongate member retaining means, at least a portion of the elongate flexible body spanning between the bone fastener head portion and the rod receiving head bottom end, the bone fastener head portion being spaced a distance from the rod receiving head bottom end. The engagement comprises clamping a section of the elongate flexible body within the rod receiving head.

[0011] The spinal fastener assembly has a locked configuration and an unlocked configuration, in which in the locked configuration the elongated flexible member is biased against the clamp seat and movement of the flexible elongated member through at least one of the first and second flexible elongated member retaining means is prevented, and in the unlocked configuration the elongated flexible member can be displaced, in particular the span between the bone fastener head portion and the rod receiving head bottom end can be adjusted to space the bone fastener head portion at different predetermined distances from the rod receiving head bottom end.

[0012] In other words, a spinal fastener assembly engaged to a posterior spinal fastener system includes a bone fastener, a rod receiving head configured to receive a spinal rod, fastening means configured to exert a retaining and / or clamping force between the spinal rod and the rod receiving head, and a tether connecting or coupling the rod receiving head to the bone fastener. When the bone fastener is introduced into the spine, the spinal rod is positioned within a central pocket of the rod receiving head and the rod fastening means fastens the spinal rod within the central pocket and blocks the position of the tether within the tether retaining means of the rod receiving head at a predetermined distance.

[0013] The first and second fastening mechanisms may be configured as female and / or male threads.

[0014] At least one of the first or second flexible elongate member retaining means may be sized large compared to the cross-section of the flexible elongate member.

[0015] At least one of the first or second flexible elongate member retaining means preferably completely surrounds the flexible elongate members to prevent separation of the flexible elongate members. The flexible elongate member retaining means may comprise one or more passages in the bone fastener head portion and in the rod receiving head bottom end. Preferably, two parallel passages are provided in the bone fastener head portion, and the rod receiving head bottom end preferably has two essentially parallel series of passages from one side from the exterior of the rod receiving head into a central pocket of the rod receiving head and from the central pocket towards the exterior of the rod receiving head, within the central pocket the fastening means being configured to engage two parallel oriented corresponding portions of the flexible elongate members.

[0016] At least one of the first flexible elongate member retaining means may be oriented top to bottom, and at least one of the first flexible elongate member retaining means may also be defined as distal to proximal or oriented side to side.

[0017] The fastening means may be configured as a primary fastening means sized and shaped to receive the inner fastening means, where the inner and primary rod fastening means may be threadably engaged by an inner thread and an outer thread.

[0018] In the locked configuration, the primary fastening means may abut the spinal rod with the flexible elongate member or tether abutting the spinal rod and the clamp seat.

[0019] The rod receiving head may include an end seat that forms an insertion depth stop for the main rod clamping means, allowing the spinal rod to be unblocked in its longitudinal movement when the main rod clamping means is fully clamped.

[0020] An intermediate inlay can be disposed between the clamp seat and at least one of the primary or inner fastening means to separate the action of the primary and inner fastening means, thereby allowing the blocked configuration of the flexible elongate member to be reached independently of adjustments to the position of the spinal rod. In particular, in the locked configuration, the inner fastening means can abut the spinal rod and the flexible elongate member or tether abuts the intermediate inlay and the clamp seat. In another configuration of the intermediate inlay, in the locked configuration, the inner fastening means can abut the intermediate inlay and the flexible elongate member abuts the intermediate inlay and the clamp seat.

[0021] In the locked configuration, the spinal rod may abut the first rod receiving opening end and the bottom side of the primary fastening means.

[0022] The outer periphery of the bone fastener head portion may be primarily non-circular or non-rotationally symmetric, such as a rectangular prism. Further, the first flexible elongate member retaining means may be one central or two parallel passages or through-bores perpendicular to the longitudinal direction of the bone fastener, or the first flexible elongate member retaining means may be four parallel passages or through-bores parallel to the longitudinal direction of the bone fastener, for example at the corners of a rectangular prism.

[0023] The first drive portion may include internal threads for attachment of a bone cement insertion cannula.

[0024] With regard to the material of the flexible elongate member, the flexible elongate member may be made of UHMWPE fibers, nylon fibers, polyester fibers, PET fibers, or stainless steel, cobalt chrome, or titanium (alloy) cables, as well as woven or braided strands of biocompatible surgical suture material, such as polyaramid, carbon fiber, or silk.

[0025] The flexible elongate member may be a circular cable or band. The flexible elongate member may be attached in a symmetrical manner or to one side of the rod-receiving head.

[0026] The bone fastener may include an insertion depth stop disposed distally adjacent the bone fastener head portion, the insertion depth stop configured to prevent too deep insertion into the bone.

[0027] The rod-receiving head may include a rod fastening means receiving extension protruding from a head apex of the rod-receiving head. Two such extensions on the head apex preferably each have a breakaway groove at the corresponding head apex so that the extension may be removed when the rod fastening means is positioned over the spinal rod.

[0028] The rod-receiving head can include a first driver-shaped aperture extending through a bottom end of the head that allows a screwdriver to be introduced through the rod-receiving head to secure the bone fastener within the bone while the rod-receiving head is already connected to the bone fastener head via the connecting flexible elongate member.

[0029] The flexible elongate member preferably has a distal coupling end for attachment to an insertion device and, in particular, allows for adjustment of the span distance between the bottom of the rod-receiving head and the head of the bone fastener in the unlocked configuration.

[0030] If an intermediate inlay is provided, it may include a second rod receiving opening having a first depth "D1" less than the diameter of the spinal rod or a second depth "D2" greater than the diameter of the spinal rod, thereby either blocking any longitudinal movement of the spinal rod or, conversely, allowing longitudinal movement of the spinal rod.

[0031] The flexible elongate member may enter or exit the rod-receiving head from a bottom end of the head, and / or the flexible elongate member may enter or exit the rod-receiving head from an outer wall of the head.

[0032] The present invention further includes a kit comprising the aforementioned spinal fastener assembly and an insertion device including a tensioning mechanism for tensioning the flexible elongate member, the tensioning mechanism comprising a tether holding element, e.g., a hook running along the insertion device in the longitudinal direction of the bone fastener, that adjusts the distance between the bone fastener head and the rod receiving head.

[0033] Such a kit may include a tension measuring device so that the adjustment of the distance may be controlled to a particular tension.

[0034] The above-described spinal fastener assemblies may be used in a surgical method for engaging a spinal fastener assembly with a posterior spinal fastener system, the method including providing such a spinal fastener assembly, inserting a bone fastener into a spine while a rod-receiving head is positioned a predetermined distance from a bone fastener head portion, introducing a spinal rod into a central pocket of the rod-receiving head, and tightening the rod clamping means against the spinal rod in the central pocket to block the position of the tether in the tether retaining means of the rod-receiving head. In a preferred variation of the inner clamping means, the inner clamping means only clamps the intermediate inlay to the tether and does not contact the rod.

[0035] If the spinal fastener assembly includes a spinal tensioning mechanism configured to move the tether hold hooks longitudinally of the bone fastener, during a clamping step of the clamping means against the spinal rod in the central pocket, the rod receiving head bottom end is moved relative to the spinal rod, the clamping step being stopped prior to blocking the position of the tether in the tether retaining means of the rod receiving head, and the further step of activating the spinal tensioning mechanism to tension the tether positioned about the tether hold hooks and positioning the bone fastener head portion a predetermined distance from the rod receiving head bottom end, followed by terminating the clamping step by the inner and / or primary clamping means to block the position of the flexible elongated member in the tether retaining means of the rod receiving head.

[0036] The spinal fastener assembly may be used in dedicated spinal implants to reduce stress after spinal correction and to prevent proximal and distal adjacent intervertebral kyphosis deformity. The present invention also relates to a method for adapting the distance between the rod-receiving head and the bone fastener of the spinal fastener assembly, thus allowing the rod to be locked at different distances from the spinal column and / or allowing the spinal fastener assembly to be used for correction purposes.

[0037] Further embodiments of the invention are defined in the dependent claims.

[0038] Preferred embodiments of the present invention are described below with reference to the drawings, which are intended to illustrate, but not to limit, preferred embodiments of the present invention. [Brief description of the drawings]

[0039] [Figure 1A] FIG. 13 shows a perspective view of a vertebral fastener assembly in a pre-assembled state without a spinal rod. [Figure 1B] 1B shows an exploded view of the elements of FIG. 1A. [Figure 2A] FIG. 1B shows a perspective view of the bone fastener of FIG. [Figure 2B] FIG. 2B shows a perspective view on the head of the bone fastener of FIG. 2A. [Figure 2C] FIG. 2B shows a side view of the bone fastener of FIG. 2A. [Figure 2D] 2C shows a cross-sectional view of the bone fastener of FIG. 2C taken along line 2C-2C. [Figure 3A] FIG. 1B shows a perspective view of the rod-receiving head of FIG. [Figure 3B] 3B shows a different perspective view of the rod-receiving head of FIG. 3A. [Figure 3C] FIG. 1B shows a perspective view of the rod-receiving head of FIG. [Figure 4A] FIG. [Figure 4B] 1 shows a further perspective view of the main fastening means; [Figure 5A]FIG. [Figure 5B] 1 shows a further perspective view of the inner fastening means; [Figure 6A] 4A and 5A in an exploded view. [Figure 6B] 4A and 5A, in which the inner fastening means is not yet fully screwed in. FIG. [Figure 6C] FIG. 5B shows a partial cross-sectional view of the main fastening means of FIGS. 4A and 5A with the inner fastening means screwed over the underside. [Figure 7A] FIG. 1 shows a perspective view of a flexible elongate member or tether arrangement without showing other elements of the spinal fastener assembly. [Figure 7B] 1 shows different perspective views of a tether. [Figure 8A] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8B] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8C] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8D] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8E] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8F] 13 illustrates one step in the sequence for loading a rod into a spinal fastener assembly. [Figure 8G] 8B shows a perspective view of a spinal fastener assembly similar to FIG. 8A, but with an internal second fastening means. [Figure 8H] FIG. 13 shows a perspective view of a vertebral fastener assembly with a side wall removed. [Figure 8I] 8B shows a perspective view of a spinal fastener assembly similar to FIG. 8A, but with an internal second fastening means that allows longitudinal movement of the spinal rod. [Figure 8J] 8I shows a perspective view of FIG. 8I with the internal fastening means blocking the spinal rod. [Figure 9A] 1B shows an exploded view of a variant of a vertebral fastener assembly similar to the assembly according to FIG. 1A, but with an additional intermediate inlay for growth guidance applications. [Figure 9B] 9B shows a perspective view of FIG. 9A with the intermediate inlay installed within the rod-receiving head. [Figure 10A] 9B shows a perspective view of the intermediate inlay of FIG. 9A. [Figure 10B] 9B shows a perspective view of the intermediate inlay of FIG. 9A. [Figure 10C] 9B shows a perspective view of the intermediate inlay of FIG. 9A. [Figure 10D] FIG. 2 shows two side views of two different heights of intermediate inlays for a standard tethered spinal fastener application and a growth guidance application. [Figure 11A] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11B] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11C] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11D] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11E] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11F] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11G]13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 11H] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a modified spinal fastener assembly having an intermediate insert; [Figure 12A] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a variation of a spinal fastener assembly having two different intermediate inserts. [Figure 12B] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a variation of a spinal fastener assembly having two different intermediate inserts. [Figure 12C] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a variation of a spinal fastener assembly having two different intermediate inserts. [Figure 12D] 13A-13C show several perspective views of the introduction and fixation of a spinal rod in a variation of a spinal fastener assembly having two different intermediate inserts. [Figure 13A] 13 illustrates the assembly of an insertion device to a spinal fastener assembly. [Figure 13B] 13 illustrates the assembly of an insertion device to a spinal fastener assembly. [Figure 13C] 13 illustrates the assembly of an insertion device to a spinal fastener assembly. [Figure 13D] 13 illustrates the assembly of an insertion device to a spinal fastener assembly. [Figure 14A] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14B] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14C] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14D] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14E] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14F] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14G] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14H] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14I] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14J] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14K] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14L] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14M] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14N] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14O] 1A-1D illustrate implantation of a spinal fastener assembly into a patient's spine. [Figure 14P] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14Q] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14R] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14S] 1A-1D illustrate implantation of a spinal fastener assembly into a patient's spine. [Figure 14T] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14U] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14V] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14W] 1A-1D illustrate implantation of a spinal fastener assembly into a patient's spine. [Fig. 14X]1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 14Y] 1 illustrates the implantation of a spinal fastener assembly into a patient's spine. [Figure 15A] 1 illustrates a perspective view of an alternative bone fastener; [Figure 15B] 1 illustrates a perspective view of an alternative bone fastener; [Figure 16A] FIG. 1 illustrates a perspective view of a front loading rod-accepting head. [Figure 16B] FIG. 1 shows a perspective view of a side-loading rod-receiving head. [Figure 17A] 13 shows a variation having a dual rod receiving head for receiving two spinal rods. [Figure 17B] 13 shows a variation having a dual rod receiving head for receiving two spinal rods. [Figure 18A] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18B] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18C] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18D] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18E] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18F] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 18G] 13 shows variations in tether placement within the rod-receiving head and variations in clamping mechanisms. [Figure 19A] 4 shows a tether clamping step with a modified fastening means. [Figure 19B] 4 shows a tether clamping step with a modified fastening means. [Figure 19C]4 shows a tether clamping step with a modified fastening means. [Figure 20A] 18 and 19 show growth-inducing variations of the variations in FIG. [Figure 20B] 18 and 19 show growth-inducing variations of the variations in FIG. [Figure 20C] 18 and 19 show growth-inducing variations of the variations in FIG. [Figure 20D] 18 and 19 show growth-inducing variations of the variations in FIG. [Figure 21A] Shown is a dual tether band and intermediate inlay providing bilateral tensioning. [Figure 21B] Shown is a dual tether band and intermediate inlay providing bilateral tensioning. [Figure 21C] Shown is a dual tether band and intermediate inlay providing bilateral tensioning. [Figure 22A] Shown is a dual tether band at the fastener and intermediate inlay providing one-sided tensioning. [Figure 22B] Shown is a dual tether band at the fastener and intermediate inlay providing one-sided tensioning. [Figure 22C] Shown is a dual tether band at the fastener and intermediate inlay providing one-sided tensioning. [Figure 23A] A single tether band for the fastener and intermediate inlay is shown providing single sided tensioning. [Figure 23B] A single tether band for the fastener and intermediate inlay is shown providing single sided tensioning. [Figure 24C] A single tether band for the fastener and intermediate inlay is shown providing single sided tensioning. [Figure 24A] 1 shows a single tether band for a fastener that provides one-sided tensioning without an intermediate inlay. [Figure 24B] 1 shows a single tether band for a fastener that provides one-sided tensioning without an intermediate inlay. [Figure 24C]1 shows a single tether band for a fastener that provides one-sided tensioning without an intermediate inlay. [Figure 25A] Shown are two single tether bands for fasteners with intermediate inlays providing bilateral tensioning. [Figure 25B] Shown are two single tether bands for fasteners with intermediate inlays providing bilateral tensioning. [Figure 25C] Shown are two single tether bands for fasteners with intermediate inlays providing bilateral tensioning. [Figure 26A] 1 shows a bilateral insertion device with two tether hold hooks. [Figure 26B] 1 shows a bilateral insertion device with two tether hold hooks. [Figure 27] 13A-13C show variations of spinal fastener assemblies that include a spacer between the bone fastener and the rod receiving head. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Figure 1A shows a perspective view of a spinal fastener assembly 1 in a pre-assembled state without a spinal rod 2. Figure 1B shows an exploded view of the elements of Figure 1A.

[0041] The spinal fastener assembly comprises: a bone fastener 10, more specifically a spinal pedicle screw for engagement within a target vertebral body; a rod-receiving head 30 configured to receive and at least partially surround the spinal rod 2; at least one flexible elongate member 80, referred to herein as a tether, that flexibly connects or couples the rod receiving head 30 to the bone fastener 10; at least one main fastening means 60 for setting or fastening the rods and / or tethers; at least one inner fastening means 70 for fastening the rods and / or tethers; Equipped with.

[0042] As will be explained in more detail below, the spinal fastener assemblies are intended to be combined with longer posterior spinal stabilization constructs consisting of state of the art pedicle screws and posterior rods.

[0043] With reference to Figures 2A-2D, bone fastener 10 is shown in greater detail. Figure 2A shows a perspective view of bone fastener 10 of Figure 1A, while Figure 2B shows a perspective view of the head of bone fastener 10 of Figure 2A, while Figure 2C shows a side view of bone fastener 10 of Figure 2A and provides section line 2D-2D used in Figure 2D, which is for a cross-sectional view of the bone fastener of Figure 2C taken along line 2D-2D.

[0044] Bone fastener 10 includes a bone fastener head portion 11 and a bone engaging elongated shaft 12. The end of the shaft forms the distal end 22 or tip of the bone fastener, and the apex of head portion 11 forms the proximal end 23 of the bone fastener. Elongated shaft 12 includes external threads 15 for anchoring within a target bone. Bone fastener head portion 11 includes an internal first drive 14 for engaging an insertion aid, such as a screwdriver.

[0045] The bone fastener head portion 11 further comprises at least one first flexible elongate member retaining means 13. In this example, the first flexible elongate member retaining means 13 is configured as two horizontal bores or channels extending through the head portion 11 and is disposed adjacent to the side of the first drive portion 14. The term horizontal means substantially perpendicular to the longitudinal axis of the screw. The first flexible elongate member retaining means 13 is configured to surround at least a portion of the tether 80. For wear and friction reduction purposes, the edges of the first flexible elongate member retaining means 13 are blended or chamfered. As shown, the head portion 11 has a larger perimeter than the elongate shaft 12, thus forming a mechanical depth stop 24 to prevent the bone fastener from being inserted too deeply into the target bone. In contrast to standard pedicle screws, bone fastener head portion 11 is primarily non-circular or non-rotationally symmetrical to provide sufficient space for first flexible elongate member retaining means 13 .

[0046] The spinal fastener 10 is intended to be connected to the rod receiving head 30 by a flexible elongate member 80. The flexible connection transfers primarily tensile forces to the spinal fastener 10 and the bone interface. To this end, the male thread may have an asymmetrical thread shape that is specifically configured to withstand tensile forces, for example by having a flat proximal angle and a steeper distal angle.

[0047] In this example, the drives are shaped as hex lobe or "Torx" drives. The first drive 14, as shown in Figure 2B, is shaped as a bore having circumferentially arranged recesses.

[0048] Typically, when implanting a bone fastener in osteoporotic bone, bone cement is injected through the bone fastener to harden around distal end 22 of the bone fastener to enhance the primary stability of the osteoporotic bone. To this end, bone fastener 10 includes a central cannula 16 having intersecting bores 17 along distal section 25 of elongated shaft 12. To prevent leakage of bone cement, first drive portion 14 may include internal threads 18 for rigid attachment of a bone cement injection device.

[0049] In many cases, central cannula 16 also forms a guide channel that allows bone fastener 10 to be inserted over a previously placed guidewire or Kirschner wire into the target bone. The upper surface of head 11 may be a flat surface.

[0050] The bone fastener 10 may include one central single horizontal channel in the center that traverses the recess in the first drive portion 14. The tether retaining means need not be a round bore but may be, for example, a slotted hole or other formed channel for receiving a band as the tether means.

[0051] 3A, 3B, and 3C show three different perspective views of the rod-receiving head 30 of FIG. 1A. The rod-receiving head 30 includes a head apex end 31 and a head bottom end 32. The rod-receiving head 30 has a first rod-receiving opening 33 beginning at the apex end 31 and extending from an anterior side 34 to a posterior side 35. The first rod-receiving opening extends toward and terminates adjacent the head bottom end, thus defining a first rod-receiving opening end 100. As shown, the rod-receiving opening end is semicircular in shape, but may alternatively be flat, flat with rounded corners, V-shaped, and the like. The preferred semicircular shape provides the most material and therefore enhances the stability of the rod-receiving head. The head bottom end 32 is positioned to face the proximal end 23 of the bone fastener 10. In this example, the bone fastener proximal end 23 and the head bottom end 32 are shaped as flat surfaces.

[0052] In other words, the rod-receiving head 30 has a U-shape extending away from the bottom head end 32 .

[0053] The rod-receiving head further comprises a blind central pocket 41 intersecting the first rod-receiving opening 33 and extending from the head top end 31 towards the head bottom end 32. Adjacent to the head bottom end 32, the central pocket 41 has an underside surface defining a clamping seat 42. Alternatively, the clamping seat may be formed by a sidewall 43 of the central pocket 41, as described below with respect to Figures 18 and 19. At least a portion of the central pocket sidewall 43 is configured as a first rod setting or fastening mechanism portion 37, for example, as internal threads 40a, 40b sized and shaped to receive a primary fastening means 60. The central pocket 41 may be sized and shaped as a stepped central pocket 41 with a stepped section 50 defining an end seat 38. The end seat 38 may limit the insertion depth of the primary fastening means 60, as described in more detail below. The rod receiving head 30 further comprises at least one second flexible elongate member retaining means 36 configured as a passageway extending into and across the clamp seat area from the lower outer or head bottom end 31. The second flexible elongate member retaining means 13 is configured to at least partially surround a portion of the tether 80.

[0054] Two extensions 39a and 39b are provided at and protrude proximally from the free end 31 of the generally U-shaped rod receiving head. In the region of the connection or protrusion start, the rod receiving head 30 and / or the extension 39 include an internal and / or external breakaway groove 55. In one embodiment, a first rod setting or tightening mechanism portion 37 extends within the extension towards the extension end 51. The extensions facilitate the insertion of the posterior rod during surgery and are removed by breaking or cutting as described in the surgical step of FIG.

[0055] The central pocket 41 may also have a clamp seat 42 at the bottom of the U-shaped head. The extension may also have bilateral intermediate extensions 39c as shown in the embodiment of Figure 17A.

[0056] The rod receiving head 30 and / or primary fastening means receiving extensions 39a, 39b are sized and shaped to mate with the inner wall 145 of the insertion device 140, thus providing an anti-rotational element 47, such as a flat surface 48, which provides a rotationally stable connection between the spinal fastener assembly 1 and the insertion device 140. As described in Figures 13A-13G, the rotationally stable coupled insertion device allows the surgeon to counter or resist torque applied to the entire spinal structure during the final fastening step of the inner fastening means 70 and / or primary fastening means 60.

[0057] Figures 4A and 4B show perspective views of the main fastening means 60. Figures 5A and 5B show perspective views of the inner fastening means 70. Figure 6A shows an exploded view of the fastening means 60 and 70 of Figures 4A and 5A. Figures 6B and 6C show partial cross-sectional views of the fastening means 60, 70 of Figures 4A and 5A, where the inner fastening means 70 is screwed into the main rod fastening means 60 at different depths.

[0058] The primary fastening means 60 comprises a first body 61 having a primary fastening means top side 65 and a primary fastening means bottom side 62. The internal recess forms a second drive 63, e.g., a hex lobe drive, for engaging the primary fastening means 60 within the rod receiving head 30. The primary fastening means 60 comprises a primary second fastening mechanism portion 64 sized and shaped to engage with the first rod setting or fastening mechanism portion 37. The second rod fastening mechanism portion 64 is shaped as an external thread, and thus the primary rod fastening means 60 is configured as a first grub screw. The combined first and second fastening mechanism portions 37, 64 form a fastening mechanism, or a coupling between the primary fastening means and the rod receiving head. As described, in this example the fastening mechanism is threaded. The coupling may also be achieved, for example, by a bayonet coupling, a friction coupling, a press fit coupling, a snap fit coupling, or a Morse taper coupling, or the like.

[0059] In this example, the primary fastening means 60 further comprises a through bore 67 at least partially provided with an internal thread 66 sized and shaped to receive an internal fastening means 70 .

[0060] The inner fastening means 70 comprises a second body 71 having an inner fastening means top side 75 and an inner fastening means bottom side 72. The inner recess forms a third drive 73 configured to engage with an insertion tool, such as a screwdriver. In this example, the third drive is configured as a hex lobe drive. More specifically, the third drive is sized and shaped similarly to the first drive 14 and therefore can be operated with the same screwdriver. The inner fastening means further comprises an outer second fastening mechanism 74 sized and shaped to engage within the internal threads of the primary fastening means 60. The inner fastening means 70 is configured as a second grub screw.

[0061] As shown in the two cross-sectional views of Figures 6B and 6C, the inner and primary fastening means 60, 70 are threadedly engaged by inner and outer threads 66 and 74, respectively. As the inner fastening means rotates, the inner fastening means can advance through the primary fastening means such that the primary fastening means bottom side 62 or the inner fastening means bottom side 72, respectively, are the downwardly or distally projecting portions of the fastening means assembly 60 / 70.

[0062] As will be explained in more detail with respect to Figures 8, 9, 11 and 18-25, the primary and inner fastening means 60, 70 may perform different fastening functions. The primary fastening means 60 may, for example, securely fasten the spinal rod in a final position, or may hold the rod adjacent to a final position, or may simultaneously fasten the rod and tether in a final position. The inner fastening means may simultaneously fasten the rod and tether, or may specifically fasten only the tether. Thus, the primary fastening means may function as a spinal rod setting means, a spinal rod fixing means, and a combined spinal rod and tether fixing means. Respectively, the inner fastening means may function as a combined rod and tether fixing means, or as an isolated tether fixing means.

[0063] 7A and 7B show two different perspective views of the flexible elongated member 80 or tether or tether band arrangement without other elements of the spinal fastener assembly 1. The flexible elongated member or tether 80 comprises a thin, elongated flexible body 81 sized and shaped to engage within the first and second flexible elongated member retaining means 13 and 36. At least one distance determining portion 82 spans between the proximal end 23 of the bone fastener head portion 11 and the rod receiving head bottom end 32. Reference numeral 83 refers to the tether portion to be blocked that is disposed above the clamp seat 42, and reference numeral 84 (also noted as "C") refers to the bone fastener guided portion that is disposed within the flexible elongated member retaining means 13. Reference numeral 87 refers to the loop portion of the flexible elongated member 80. In other embodiments, the loop portion 87 may be replaced with a longer elongated flexible body 81 toward the symmetrically disposed distal coupling ends 86 .

[0064] The flexible elongate member 80 is typically made of woven or braided strands of surgical suture material, such as biocompatible UHMWPE, nylon, polyester, PET fibers, etc. Alternatively, biocompatible metallic materials, such as stainless steel, cobalt-chromium, or titanium (alloy) cables, may be used. Polyaramid, carbon fiber, and silk are further alternatives. Additionally, the flexible elongate member 80 has at least one distal coupling end 86 for attachment to an insertion device 140.

[0065] 8A-8J show a sequence of different steps for mounting a spinal rod 2 to a spinal fastener assembly 1. For purposes of illustration, adjacent pedicle screws and vertebral bodies to which the bone fasteners 10 are secured are not shown.

[0066] 8A-8C show a sequence of introducing the spinal rod 2 into the central pocket 41 of the rod receiving head 30, followed by blocking the spinal rod 2 by the primary fastening means 60. In FIG. 8A-8C, the primary fastening means 60 is threaded into the female threaded mechanism 40 of the rod receiving head 30 until the primary fastening means 60 abuts the end seat 38 adjacent the end of the internal thread. In this example, the distance from the lower surface of the primary fastening means 60 to the bottom of the groove in the rod receiving head 30 is greater than the diameter of the spinal rod 2. Thus, the tether 80 remains free or unclamped and can still travel through the flexible elongate member retaining means 13 and 36. In other words, the spinal rod 2 is not blocking the movement of the tether. FIG. 8D-8F show a sequence of decreasing the distance X1 between the surface of the head bottom end 31 and the proximal end of the bone fastener head portion 11 toward the distance X2. FIG. 8D illustrates a first condition of the spinal fastener assembly 1 with the bone fastener head portion 11 spaced a first distance X1 from the rod receiving head bottom end 32.

[0067] By tensioning the tether 80 (proximally or in the direction of arrow 85), the distance X1 is reduced to a distance X2. In a next step, the inner fastening means 70 is assembled and screwed into the primary fastening means 60. The inner fastening means passes through the primary fastening means 60 and abuts the spinal rod 2 with its bottom side 72, thus urging the spinal rod towards the clamp seat 42 while the tether is disposed between the spinal rod and the clamp seat. Upon final tightening of the inner fastening means, the spinal rod, tether and clamp seat are blocked from each other, preventing any movement of the tether and spinal rod. In other words, the spinal rod 2 blocks the portion 83 of the tether 80. To modify the spinal fastener assembly 1 to yet a different distance X2 between the bone fastener head portion 11 and the rod receiving head bottom end 32, the spinal rod 2 and tether can be loosened by unscrewing the inner fastening means 70, thereby allowing the blocked tether portion 83 to move freely again within the flexible elongated retaining means 13, 36.

[0068] 8D and 8E show a condition that maintains a particular spinal rod 2 position while still allowing the spinal rod to move along its length and allows the string of tether 80 to move, while FIG. 8F shows a locked configuration, in which the flexible elongate member or tether 80 is biased against the clamp seat 42 by the spinal rod preventing movement of the flexible elongate member 80 through at least one of the first and second flexible elongate member retaining means 13 or 36.

[0069] 8G and 8H show the final removal of rod fastening means receiving extensions 39a, 39b and cutting away the remaining tether strands.

[0070] Figure 8I shows a detailed partial cross-sectional view of the spinal fastener assembly 1 of Figure 8A with the internal second rod fastening means 70 positioned to allow longitudinal movement of the spinal rod 2 as described with reference to Figure 8E, and Figure 8J shows the internal second fastening means 70 blocking the spinal rod 2 and tether 80 as described with reference to Figure 8F.

[0071] FIG. 9A shows an exploded view of a variant vertebral fastener assembly 1′ similar to the assembly 1 according to FIG. 1A. This variant includes an intermediate inlay 130 configured to hold the spinal rod 2 and clamp the tether 80 in the clamp seat 42. FIG. 9B shows a perspective view of FIG. 9A with the inlay assembled in the rod-receiving head 30. FIGS. 10A-10C show perspective views of the intermediate inlay 130 of FIG. 9A, while FIG. 10D shows two side views of two different heights of the inlay for a standard spinal fastener assembly application and a growth-inducing application. In the growth-inducing application, the spinal rod 2 remains freely movable along the longitudinal axis, while the tether 80 is clamped and blocked.

[0072] The modified vertebral fastener assembly 1' has a rod receiving head 30 with a U-shaped groove that creates a central pocket 41 that allows the spinal rod 2 to be positioned laterally. The difference between the vertebral fastener assemblies 1 and 1' is the space and recess provided on the inside and interior of the rod receiving head 30 to accommodate the intermediate insert 130. The intermediate insert 130 comprises a second rod receiving opening 131 and a clamping surface 132 on a bottom side 137. Furthermore, the intermediate insert 130 comprises a central driver channel 133 that allows a driver to be engaged through the rod receiving head into the first drive part 14 of the bone fastener 10. The central driver channel 133 also provides the possibility of introducing a bone cement injection device into the bone fastener head 11. Furthermore, the intermediate insert 130 has two leg portions 138a, 138b that are U-shaped and have a top surface 136. The proximally facing leg portions 138a, 138b are formed by a second rod receiving opening 131 that defines the inner side walls 139a, 139b of the leg portions 138a, 138b. The leg portions are configured to at least partially surround the spinal rod. In this example, one of the leg portions has two vertically (top to bottom) oriented side slits 135 that form a central locking element 134. The central locking element 134 is configured as a matching snap mechanism sized and shaped to engage within a corresponding recess in the rod receiving head. This engagement prevents inadvertent release of the intermediate insert during implantation or handling of the spinal fastener assembly. The intermediate insert 130 or the clamp seat 42 may include a rough structure, such as a groove or another macro / micro roughness, for engaging with the flexible elongated member 80, thereby providing increased friction.

[0073] The intermediate inlay 130A for tether screw application and the intermediate inlay 130B for growth guidance application have an internal groove or rod receiving opening 131 with a lateral diameter or width sufficient to accommodate the diameter of the spinal rod 2. The difference between the two inlays 130A, 130B is the height difference D1 and D2 between the top surface 136 of the respective inlay 130A, 130B and the bottom surface of the groove / second rod receiving opening 131.

[0074] In the insert 130A, the distance D1 is smaller than the diameter of the spinal rod 2. Thus, when the inner fastening means 70 is screwed into the primary fastening means, the inner fastening means 70 abuts against the top of the spinal rod and blocks the spinal rod.

[0075] In the insert 130B, the distance D2 is greater than the diameter of the spinal rod 2. Thus, when the inner fastening means 70 is screwed into the primary fastening means, the inner fastening means 70 will abut against the top surface 136, leaving a small gap between the top of the spinal rod and the inner fastening means bottom side surface 72, so that the spinal rod can still move along the length of the spinal rod.

[0076] 11A-11H show several perspective views of the introduction and fixation of a spinal rod 2 in a modified vertebral fastener assembly 1' with an intermediate insert 130. FIG. 11A shows the insertion of the rod. FIG. 11B shows the rod 2 in a starting position. FIG. 11C shows the insertion of the primary fastening means 60. As the rod 2 is already positioned near the vertebra and fixed in the adjacent pedicle, when the primary fastening means engages the spinal rod, the rod receiving head 30 is forced to advance towards the spinal rod 2. Thus, on the other side, the distance determining portion 82 is longer because the bone fastener 10 has already been screwed into the associated pedicle.

[0077] Here, the primary fastening means 60 is screwed into the internal threads of the head 30 which terminate above the surface 136. In other words, the primary fastening means 60 abuts the head 30 before contacting the spinal rod 2.

[0078] The distance determined by the portion 82 of the tether in Fig. 11C can be adapted by tensioning the tether 80. As shown in Fig. 11D, the distance 82 is shortened / reduced. Fig. 11E shows the insertion of the inner fastening means 70 and Fig. 11F shows the final fastening of the inner fastening means 70 on the rod 2, pressing the intermediate insert 130 and thus blocking the tether 80.

[0079] 11G shows the clamping mechanism unclamped and FIG. 11H shows the clamping mechanism clamped with fastener assembly 1' having intermediate insert 130. Inner fastening means 70 is advanced forwardly through primary fastening means 60 and clamps tether 80 by engagement against spinal rod 2.

[0080] 11G, the spinal rod 2 can still move between the primary fastening means bottom side 62 and the intermediate inlay 130. The primary fastening means 60 abuts against the end seat 38 in the rod receiving head 30, and the intermediate inlay 130 is spaced from the clamp seat 42 such that the tether 80 and spinal rod 2 are in an unclamped state.

[0081] 11H shows the inner fastening means bottom side 72 engaging the spinal rod captured within the intermediate insert 130. As the inner fastening means 70 advances towards a final position as indicated by the rotating arrow, the clamping force of the screw mechanism generated is transferred to the spinal rod 2 as indicated by the arrow in the spinal rod 2, to the intermediate insert 130, and finally to the tether 80 disposed between the inner fastening means bottom side 72 and the clamp seat 42 which opposes the clamping force.

[0082] In this example, the primary fastening means 60 functions as a rod setting means and the inner fastening means 70 functions as a rod and tether fixing means, in other words, when the inner fastening means is fastened in the final position, the tether and the spinal rod are blocked at the same time.

[0083] 12A-12D show multiple perspective views of the introduction and fixation of the spinal rod 2 in a variant of the vertebral fastener assembly 1' having two different intermediate inlays 130A, 130B. FIGs. 12A and 12C show a variant of inlay 130A in which the tether 80 and the spinal rod 2 are blocked when the inner fastening means 70 is tightened. FIGs. 12B and 12D show a variant of inlay 130B in which only the tether 80 is blocked when the inner fastening means 70 is tightened. The spinal rod 2 remains mobile in the variant of the growth-inducing vertebral fastener assembly.

[0084] The difference between the two inlays 130A, 130B is based on a distance D1 or D2 that is smaller or larger than the diameter φ of the spinal rod 2, respectively.

[0085] 13A-13D show the assembly of the insertion device 140 to the spinal fastener assembly 1. The combination of the assembly of the insertion device 140 with the spinal fastener assembly 1 (or 1′) creates a kit 300.

[0086] Posterior spinal surgery is often performed percutaneously and / or transmuscularly. The surgical site is close to delicate soft tissue structures, such as nerves and vascular structures, which demands high safety when instruments are used for certain surgical steps. Thus, spinal instrumentation systems typically include outer cannulated instruments that guide other instruments within their central cannula, thus reducing the risk of inadvertent damage to other structures.

[0087] Thus, an insertion device 10 as shown in FIGS. 13A-13G can hold a spinal fastener assembly 1 and serve several purposes, namely: Providing an extension of the spinal fastener assembly for manipulation of the spinal fastener assembly by the operating surgeon - Safely guide supporting instruments such as first and second screwdrivers; · Safely directing the assembly / disassembly keys for installation and removal of the spinal fastener assemblies; Controlled tensioning of the tether It is an elongated device that facilitates

[0088] 13E-13G illustrate the assembly of a first driver 160 into the insertion device 140 and into the spinal fastener assembly 1, passing through the rod receiving head 30, through the first driver shaped aperture 49, and into the complementarily sized and shaped first driver 14 of the bone fastener 10. The driver 160 has a hex-lobe (Torx) first working head 162 and further a first handle 161. In this example, the first working head couples the first driver shaped aperture 49 of the rod receiving head 30 to the first driver 14 of the bone fastener 10. As a result, when the first driver 160 is rotated to embed the bone fastener 10 into the target bone, the entire spinal fastener assembly 1, including the assembled insertion device, is rotated.

[0089] 14A-14Y illustrate the surgical steps for implanting a spinal fastener assembly 1 into a patient's spine 8. FIG.

[0090] FIG. 14A shows five vertebral segments 7 of an exemplary section of the spine, i.e., spine or vertebral column 8. Four standard pedicle screws 5 are installed at the lower level of the spine 8. FIG. 14B shows a vertebral fastener assembly 1 being loaded into an insertion device 140 and introduced through the pedicle into the fifth, here most upper shown vertebral body. For illustrative purposes, only a small section of the spine, more specifically a thoracic segment, is shown. Additional vertebral bodies continue to the upper and lower vertebral bodies. Note that in the example shown, a proximal adjacent intervertebral kyphosis deformity prevention scenario is shown. Similar steps may be applied to a distal adjacent intervertebral kyphosis deformity scenario. Additionally, the pedicle screw and spinal rod constructs may be longer and include more vertebral bodies or segments. Note that for illustrative purposes, the surgical steps are only shown on one side of the spine.

[0091] FIG. 14B shows the insertion device 140 pre-mounted on the spinal fastener assembly 1, with the first screwdriver 160 rotated to screw the bone fastener 10 into the pedicle bone. FIG. 14C shows the final position of the bone fastener 10, i.e., the bone fastener head portion 11 is positioned adjacent to the outer surface of the target pedicle bone, and the threaded elongated shaft 12 is recessed into the pedicle bone and vertebral body. The oversized bone fastener head portion forms a mechanical stop to prevent too deep insertion and undesired blocking of the tether 80 disposed thereon. Note that the tether 80 is disposed along the insertion device 140. The insertion device 140 has a tensioning knob 142 connected to a tensioning mechanism 148 configured as an internal spindle structure 143 on which a tether hold hook 144 is disposed. As the tensioning knob is rotated, the hold hook is actuated to move along the longitudinal axis of the insertion device 140, thus tensioning the tether 80. In this example, a clockwise rotation will tension the tether. If there are two tethers 80 symmetrically mounted on either side of the head 30 (as described below), then the hold hooks 144 can be mounted on either side of the device 140. The tethers 80 do not have to be symmetrically mounted.

[0092] FIG 14D shows the driver 160 being removed by withdrawing it. FIG 14E shows the insertion of the spinal rod 2 into the head of the pedicle screw 5, through the first rod receiving opening 33 of the spinal fastener assembly 1 and through the parallel slits of the insertion device 140. As shown, the first rod receiving opening 33 and the parallel slits at least partially overlap. The next step involves the fixation of the spinal rod 2 into the standard pedicle screw 5 with a set screw 4, referred to as standard FIG 14A and FIG 14G.

[0093] Figures 14F and 14G show the placement of a standard pedicle screw set screw 4. The vertebrae 8' straighten as shown in dashed lines when the set screw is tightened as shown in Figure 14H. Figure 14I shows the release of the tether 80, which provides mobility to the rod-receiving head 30. The tensioning knob 142 of the insertion device 140 is rotated counterclockwise to release the tether 80.

[0094] FIG 14J illustrates the insertion of a second driver 260 with a second working head 261 and a second handle 262. The working head 261 is advanced forward within the insertion device 140 and engaged within the primary fastening means 60, as shown in FIG 14K. By rotating the second driver 260 clockwise, as shown in FIG 14L, the primary fastening means 60 is tightened and engaged against the spinal rod 2. Upon engagement and further tightening, the rod receiving head 30 is forced to move towards the spinal rod 2 while the vertebral segment 7' in question remains in place and the distance determining portion 82 of the tether 80 lengthens as shown in FIG 14M.

[0095] Figure 14N shows the second screwdriver 260 removed. The following steps are illustrated in relation to Figure 14O: Pretensioning tether 80 by rotating spindle structure 143 within device 140 in the opposite direction to that shown in Figure 14I causes hook 144 to advance toward knob 142 and straighten tether 80.

[0096] FIG 14P illustrates the positioning of a force measuring device 150 on the insertion device 140. The force measuring device 150 is coupled to the tensioning knob 142 of the insertion device 140 as shown in FIG 14Q. As the rotation knob 151 of the force measuring device 150 rotates, an applied torque is transmitted to the spindle structure, generating tension on the tether. In this example, the force measuring device provides feedback regarding the actual tension in the tether.

[0097] Knowledge of the tension applied is important as not only is too much tension important, but too little tension can prevent the spinal fastener assembly from providing the desired graduated stress transfer from the fused vertebrae to the mobile vertebrae.

[0098] Figure 14R illustrates the process of tightening tether 80 to the proper tension using force measuring device 150. Spindle structure 143 of insertion device 140 translates the applied torque into longitudinal movement of tether hold hook 144 and thus tension on tether 80. Figure 14S simply illustrates removal of the force measuring device after the correct predetermined tension has been reached.

[0099] The next step is shown in Fig. 14T. Preferably, the same first screwdriver 160 is inserted into the insertion device 140 to avoid too many instruments, but different ones can be inserted. As mentioned above, the insertion device 140 and all its elements include a central passage that is oversized for the first and second screwdrivers 160, 260, as well as other instruments such as the inner fastening means 70. Thus, the inner fastening means can be engaged into the main fastening means using the first screwdriver 160.

[0100] Figure 14U shows the rotation of the driver head 161 in a clockwise rotation of the driver 160, which allows the inner fastening means 70 to be tightened into the main fastening means 60, blocking the whole system. This step is also shown in Figures 11G and 11H.

[0101] After removal of the first screwdriver 160, Fig. 14V shows the introduction of an assembly / disassembly key 170. The assembly / disassembly key 170 is inserted into the insertion device 140. The insertion device 140 is disengaged from the rod-receiving head 30 by rotating the rotation knob of the assembly / disassembly key 170 counterclockwise, as shown in Fig. 14W.

[0102] The shaft of the assembly / disassembly key 170 is advanced through the insertion device 140 and engaged into the locking bolt 146 rotatably coupled to the insertion device. As the assembly / disassembly key 170 rotates the locking bolt 146, the locking bolt 146 is threaded into the rod-receiving head 30, and more specifically, engaged into the female threads of the rod fastening means receiving extensions 39a, 39b.

[0103] FIG. 14X shows the pedicle screw and posterior rod construct after removal of the insertion device 140, including the remaining loop of tether 80 and the two side extensions 39a, 39b.

[0104] FIG. 14Y shows the spinal fastener assembly 1 after the next operational step, i.e., the extensions 39a, 39b have been cut or broken at the break grooves at the free ends of the rod receiving head 30, and the remaining tether of the tether loop 80 strand has been severed.

[0105] 14A-14Y show four standard pedicle screws 5 installed at the lower level of the vertebra 8 and one bone fastener assembly 1 introduced through the pedicle into the fifth, here the uppermost, vertebral body. Alternatively, two or more bone fastener assemblies 1 may be installed at the end of the spinal rod construct. In this case, it is important that the tethers 80 are tensioned so that both tethers are tightened. Removal of one of the bone fastener assemblies by over-tightening one tether compared to the other should be prevented. In a preferred method, the vertebral fastener assemblies placed at the end of the spinal rod are tensioned less than the vertebral fastener assemblies placed closer to the middle of the spinal rod.

[0106] In one other embodiment, the vertebral fasteners placed at the ends of the rods are tensioned with a force between 0 and 40 Newtons, and the vertebral fasteners placed near the middle of the spinal rods are tensioned with a force between 40 and 100 Newtons.

[0107] 15A and 15B show perspective views of a bone fastener variation 10' having proximal-distal flexible elongate member retaining means 13 oriented in the longitudinal direction of the bone fastener 10. The flexible elongate member retaining means 13 are substantially regularly or symmetrically arranged about the elongate shaft 12 to provide a uniform stress distribution within the target bone.

[0108] All of the above-described embodiments of the spinal fastener assembly 1 have been described in the context of a U-shaped rod receiving head 30 extending away from the head bottom end 32 and opening towards the insertion device 140. Other variations are possible without departing from the above-described surgical method of implantation of the spinal fastener assembly 1 shown in Figures 14A-14X.

[0109] FIG. 16A shows a perspective view of a front-loading rod-receiving head 30'. The variation using a front-loading head 30' is most practical to use at the end of the construct due to the rod-receiving opening having a closed configuration. The rod-receiving opening 33' is sized and shaped as a through-bore for the spinal rod 2. When used in the middle of the construct, the spinal rod must travel through the rod-receiving head before engaging the spinal rod in an otherwise standard pedicle screw.

[0110] FIG. 16B shows a perspective view of a side-loading rod-receiving head 30″. Because the head is not closed and the U-shaped opening is oriented substantially perpendicular to the longitudinal direction of the rod-receiving head 30″, the variation using the side-loading rod-receiving head 30″ can be used anywhere in the structure. As shown in the detail view section of FIG. 16B, the side-loading rod-receiving head may be provided with a corresponding side-loading intermediate insert 130′.

[0111] However, it is not possible to use the inlays 130A or 130B as described above. However, it is possible to use a similar inlay having an L-shaped configuration, in which case the inner screw 70 presses on only one side. In Fig. 16B, an inlay is shown that is u-shaped, with the second rod-receiving opening 131 facing to the side.

[0112] 17A and 17B show a variant with a dual rod-receiving head 30D for receiving two spinal rods 2. The rod-receiving head thus comprises a first rod-receiving opening 33 and an adjacent rod-receiving opening 53. FIG. 17A shows a variant with extensions 39a, 39b, 39c in place. The intermediate extension 39c has two faces facing towards the rod-receiving openings 33, 53, while the internal thread functions as a rod setting or tightening mechanism. FIG. 17B shows the embodiment of FIG. 17A with extensions 39a, 39b, 39c broken away. Note that the first rod receiving opening 33 has a main fastening means 60 and an inner fastening means 70 which secures the dual head 30D onto the spinal rod 2 and blocks the (not yet cut) tether 80 in place, while the adjacent rod receiving opening 53 is provided with a single tertiary fastening means or standard set screw 60''.

[0113] Spinal fastener assemblies with dual rod receiving heads are used, for example, to extend existing or in situ systems, and / or to provide a transition to different size rods, and / or to provide higher stiffness. A dual rod receiving head may include two parallel rods and thus provide, for example, twice as much stiffness.

[0114] 18A-18E show yet another variation of the spinal fastener assembly 1″. The spinal rod locking principle and the tether locking principle of this variation allow for blocking the tether 80 and the spinal rod in separate ways 2. In other words, the clamping force generated by the main fastening means only holds the rod 2 in place, and the clamping force generated by the inner fastening means only blocks the tether 80, respectively. As will be explained in more detail later, the variation of FIG. 18 further includes an alternative looping sequence or installation of the tether through and into the second flexible elongate member retaining means of the rod raving head 30.

[0115] FIG. 18A shows an orthogonal side view of the spinal fastener assembly 1″ including a cut plane line at the level of one placement of the second flexible elongate member retaining means of the rod raving head. FIG. 18B shows a corresponding cross-sectional view in which only the rod receiving head is in section.

[0116] Perspective views 18C-18H show a spinal fastener assembly 1'' including the cross-section of the rod-receiving head depicted in FIG. 18B. The detailed views of FIGS. 18D and 18E show the rod-receiving head in non-cross-section.

[0117] In this example, a similar arrangement of second flexible elongate member retaining means is located on the opposite side of the central plane of the spinal fastener assembly.

[0118] FIG. 18C shows the first surgical step where the spinal rod is introduced into the rod receiving head 30. In the next step shown in FIG. 18D, the primary fastening means 60 is assembled and screwed towards the spinal rod 2 for engagement therewith. In the next step shown in FIG. 18E, the primary fastening means 60 is further advanced by screwing, forcing the rod receiving head 30 to advance towards the spinal rod 2. During this process, the tether portion disposed between the rod receiving head bottom end 32 and the proximal end of the bone fastener 10 stretches. The tether 80 advances through the first and second flexible elongate member retaining means 13, 36. As shown in more detail in FIG. 19, the rod will move until it seats against the rod receiving opening end 100, and is thus clamped directly by the rod receiving head and the primary fastening means bottom side 62.

[0119] 18F, tightening of the tether is shown. When the tether is tensioned, the distance between rod receiving head bottom end 32 and the proximal end of bone fastener 10 decreases.

[0120] Figure 18G shows the engagement of the inner fastening means 70 into the primary fastening means 60. The inner fastening means is screwed into its final position as shown in Figure 18H. The inner fastening means engages against the intermediate insert 130, clamping the tether 80.

[0121] 19A and 19B show the details of the tether clamping step, and FIG. 19C shows the primary fastening means in more detail. For visualization purposes, the rod receiving head 30 and the primary fastening means 70 are shown in cross section. FIG. 19A shows the spinal rod already clamped by the rod receiving opening end 100 of the rod receiving head 30 and the primary fastening means bottom side 62. The intermediate inlay top surface 136 projects into the threaded throughbore 67 and terminates above the top surface of the spinal rod 2. The inner fastening means is engaged within the primary fastening means and advanced to contact the intermediate inlay top surface 136. In this case, the bottom side 137 is spaced from the clamp seat 42, and therefore the tether 80 is not clamped. The loop portion 87 is shown on the left, and furthermore, the return spanning portion 82 passes through the passage or flexible elongate member retaining means 36. The blocked tether portion 83 of the alternative embodiment is realized here with blocked tether portion 183, where the intermediate insert 130 is pressed downwards according to the black arrow, blocking the tether 80 at this position of the clamp seat.

[0122] 19B shows the next step where advancement of the inner fastening means urges the intermediate insert towards the clamp seat 42 to clamp the tether 80. Note that in the final position as shown in FIG 19B, there is a space between the spinal rod 2 and the inner fastening means bottom side 72.

[0123] In this example, the primary fastening means 60 functions as the stand-alone rod fastening means and the inner fastening means 70 functions as the stand-alone tether fastening means.

[0124] The advantage of the variants of Figures 18 and 19 is that the tether 80 made of a softer material such as synthetic fibers is not an intermediate force transmission element for the spinal rod clamping process. The spinal rod 2 is clamped directly by a hard material, thus realizing a reduced risk of the rod slipping. One further advantage is explained in Figure 20.

[0125] 19C shows a modified primary fastening means 60' in more detail. The first body of the primary fastening means 60' comprises a stepped section dividing the first body 61 into a nominal diameter portion 68 and a reduced diameter portion 69 located adjacent the bottom side 62. The reduced diameter portion has an outer periphery or edge that is smaller than the inner periphery or edge of the end seat 38. As shown in FIG. 19A, the primary fastening means bottom side 62 biases the rod 2 against the rod receiving opening end 100 before the threaded outer diameter portion biases against the end seat 38.

[0126] Figures 20A-20D show another variation of the spinal fastener assembly from that described in Figures 18 and 19. This variation involves a growth-guiding locking principle in which only the tether 80 is clamped and blocked. For visualization purposes, the rod receiving head (Figures 20A-20C) and the primary fastening means (Figures 20A-20B) are shown in cross-section.

[0127] 20A and 20B show the spinal rod 2 engaged within the rod receiving opening 33. The primary fastening means 60 is biased against the end seat 38 and is securely locked in this position. As shown, the distance X3 between the primary fastening means bottom side 62 and the rod receiving opening end 100 is just slightly greater than the diameter of the spinal rod, so that the primary fastening means 60 functions as a rod setting means and the spinal rod 2 remains movable along the longitudinal axis of the spinal rod 2 relative to the rod receiving head 30.

[0128] Note that in this state, the intermediate insert 130 is spaced from the clamp seat 42 and therefore the tether 80 is not clamped.

[0129] 20C shows the clamping step. The inner fastening means 70 is further screwed into the main fastening means 60, forcing the intermediate insert 130 towards the clamp seat 42, so that the tether portion disposed therebetween is clamped. The inner fastening means 70 functions as a tether fixing means.

[0130] It should be noted that the configuration of the tethers through the first and second flexible elongate member retaining means is different than that described for Figure 7. The rod receiving head comprises six second elongate member retaining means 36, four of which are substantially regularly divided about the center of the elongate head 30 and extend from the head bottom end 32 into the clamp seat 42 to define a bottom passage 110. The other two second elongate member retaining means 36 extend from the central pocket 41 to the outside of the rod receiving head 30 and are positioned adjacent the clamp seat 42 to define a side passage 111. The six second elongate member retaining means 36 are divided into two substantially symmetrically arranged sets of passages.

[0131] Focusing on one set of passageways, tether 80 is disposed through first and second elongate member retaining means in the following sequence: starting inside central pocket 41, tether 80 passes through first bottom passageway 110a toward bone fastener head portion 11, then through first elongate member retaining means 13, then through second bottom passageway 110b from rod receiving head bottom end 32 into central pocket 42, then through adjacently disposed side passageway 111a, and exiting this side passageway outside rod receiving head 30.

[0132] Referring to the intermediate insert 130, as shown, this variation includes a stepped clamping surface 132. The stepped shape is formed by a notch and defines a clearance 139 that cannot transmit high clamping forces. As a result, a larger portion of the clamping force is concentrated on the portion of the tether located at the transition region 190 from the bottom passage 110 to the side passage 111.

[0133] The intended use of the aforementioned spinal fastener assembly 1'' can be adapted from a fully locked configuration to a growth-guiding configuration by the choice of the variant of the primary fastening means 60, 60'. The advantage of this principle is that this decision can be made intraoperatively after implantation of the bone fastener 10 in the target bone. A further advantage is that of logistics or stock keeping units. The pre-assembled components of the spinal fastener assembly 1'' for both purposes are the same, i.e. bone fastener 10, rod receiving head 30, intermediate inlay 130 and tether 80.

[0134] 21A-21C show another variation of the spinal fastener assembly 1'''. This variation includes a flexible elongate member 80 configured as a flat tether band 180 having a width that is substantially greater than its thickness. To retain the tether band 180, corresponding first and second flexible member retaining means 13 and 36 have an elongate or slot shape.

[0135] The example of Figures 21A-21C shows the tether band 180 as a flexible elongate member having two free strands 181a, 181b disposed along the rod receiving head. At the end, the tether band includes a distal bond end 86 configured as an eye 186 for attachment to an insertion device 140 for the tensioning step. As shown, the second tether retaining means 36 of the rod receiving head 30 is configured as two bottom passages 110 and two oppositely disposed side passages 111.

[0136] The tether band 180 is placed through the first and second elongate member retaining means 13, 36 in the following sequence: the tether band 180 starts along the rod receiving head, passes through the first side passage 111a, then through the most adjacent first bottom passage 110a, then toward the bone fastener head portion 11, then through the first elongate member retaining means 13, then through the second bottom passage 110b from the rod receiving head bottom end 32 into the central pocket 42, then through the most adjacent disposed side passage 111b, and exits this side passage outside the rod receiving head 30.

[0137] 21C, there is shown the clamping of the tether band 180 by the intermediate inlay 130. The intermediate inlay 130 is urged towards the clamp seat 42 by the tightening of the inner fastening means 70, clamping the tether band 180 at the transition regions 190a, 190b from the bottom passage 110 to the side passage 111.

[0138] 22A-22C show another variation of a spinal fastener assembly 1'''' from that described in FIG. 21. The example in FIG. 22 shows that the tether band 180 has one free strand 181 disposed along the rod receiving head, and that the tether band 180 has an enlarged stop portion 187 opposite the rod receiving head 30. The free strand 181 includes an eye 186 for attachment to an insertion device 140 to facilitate the tensioning step.

[0139] The tether band 180 is placed through the first and second elongate member retaining means 13, 36 in the following sequence: the tether band 180 starts along the rod receiving head, passes through the first side passage 111a, then through the most adjacent first bottom passage 110a, then toward the bone fastener head portion 11, then through the first elongate member retaining means 13, then through the second bottom passage 110b from the rod receiving head bottom end 32 into the central pocket 42, then through the most adjacently disposed side passage 111b, and exits this side passage on the exterior of the rod receiving head 30. The enlarged stop portion 183 engages the exterior of the rod receiving head 30 at the first side passage 111a, thus preventing disengagement or unraveling of the tether band 180 from the first and second elongate member retaining means 13, 36.

[0140] 22C, there is shown the clamping of the tether band 180 by the intermediate inlay 130. The intermediate inlay 130 is urged towards the clamp seat 42 by the tightening of the inner fastening means 70, clamping the tether band 180 at the transition region 190 from the bottom passage 110b to the side passage 111b.

[0141] 23A-23C show another variation of a spinal fastener assembly 1'''''' from that described in FIG. 22. The example of FIG. 23 shows that the tether band 180 has one free band end portion or strand 181 disposed along the rod receiving head, and that the tether band 180 has an enlarged stop portion 287 opposite the bone fastener head portion 11.

[0142] The tether band 180 is placed through the first and second elongate member retaining means 13, 36 in the following sequence: the tether band 180 starts along the bone fastener head portion 11, passes through the first elongate member retaining means 13, then passes through the second bottom passage 110a from the rod receiving head bottom end 32 into the central pocket 42, then passes through the adjacently disposed side passage 111, and exits the side passage outside of the rod receiving head 30. An enlarged stop portion 287 engages the outside of the bone fastener head portion 11 at the beginning of the first flexible elongate member retaining means 13, thus preventing disengagement or unraveling of the tether band 180 from the first and second elongate member retaining means 13, 36.

[0143] 23C, there is shown the clamping of the tether band 180 by the intermediate inlay 130. The intermediate inlay 130 is urged towards the clamp seat 42 by tightening of the inner fastening means 70, clamping the tether band 180 at the transition region 190 from the bottom passage 110 to the side passage 111. This variation includes the basic variation of the spinal fastener assembly 1, although it has the disadvantage of asymmetric loading.

[0144] 24A-24C show another variation of spinal fastener assembly 1'''''' from that described in FIG. 23. The example in FIG. 24 shows that tether band 180 has one free strand 181 disposed along the rod receiving head, and tether band 180 has an enlarged stop portion 287 opposite the bone fastener head portion 11.

[0145] The tether band 180 is placed through the first and second elongate member retaining means 13, 36 in the following sequence: the tether band 180 starts along the bone fastener head portion 11, passes through the first elongate member retaining means 13, then passes through the second bottom passage 110a from the rod receiving head bottom end 32 into the central pocket 42, then passes through the oppositely disposed side passage 111, and exits the side passage outside of the rod receiving head 30. The tether band 180 spans the majority of the clamp seat 42, traverses the first rod receiving opening 33, and intersects with the first rod receiving opening 33.

[0146] 24C, clamping of the tether band 180 by the spinal rod 2 is shown. The spinal rod is urged towards the clamp seat 42 by tightening of the primary tightening means, clamping the tether band 180 and spinal rod 2 within the clamp seat. This variation includes the basic variation of the spinal fastener assembly 1, although it has the disadvantage of asymmetric loading. Note that this variation does not include the inner tightening means 70.

[0147] 25A-25C show a spinal fastener assembly 1'''''''' that is yet another variation from that shown in FIG. 21. This variation includes two separate tether bands 180a, 180b. The example of FIG. 23 shows that tether bands 180a, 180b each have one free strand 181 disposed along the rod receiving head, and that tether bands 180a, 180b each have an enlarged stop portion 387 below the bone fastener head portion 11.

[0148] The tether bands 180a, 180b are disposed through the first and second elongate member retaining means 13, 36, respectively, in the following sequence: the tether band 180a starts at the underside of the bone fastener head portion 11, passes through the first elongate member retaining means 13a, then through the second bottom passage 110a from the rod receiving head bottom end 32 into the central pocket 42, then through the adjacently disposed side passage 111a, and exits the side passage outside the rod receiving head 30. The enlarged stop portion 387 engages the underside of the bone fastener head portion 11 at the beginning of the first flexible elongate member retaining means 13a, thus preventing disengagement or unraveling of the tether band 180a from the first and second elongate member retaining means 13, 36. The tether band 180b is similarly disposed through the first and second elongate member retaining means 13b, 36b.

[0149] 25C, there is shown the clamping of the tether bands 180 by the intermediate inlay 130. The intermediate inlay 130 is urged towards the clamp seat 42 by the tightening of the inner fastening means 70, clamping the tether bands 180a, 180b at the transition regions 190a, 190b from the bottom passages 110a, 110b to the side passages 111a, 111b.

[0150] 26A and 26B show an exemplary insertion device 140' having bilateral tether hold hooks 144 for tensioning an exemplary spinal fastener assembly as shown in FIGS. 21 and 25, where the hooks 144 engage with the eyes 186.

[0151] FIG. 27 shows a variation of the spinal fastener assembly with a spacer 90 between the bone fastener 10 and the rod receiving head 30, provided as an essentially flat disk. The spacer 90 prevents any collision between the bone fastener 10 and the rod receiving head 30 that could cause debris. In this example, the flexible elongated member 80 or a portion thereof is surrounded by the spacer. The spacer 90 may be made of a permanently remaining biocompatible plastic material such as PEEK, polyethylene, or the like. Alternatively, the spacer 90 may be made of a bioabsorbable material such as polylactide. The spacer 90 of FIG. 27 has a central hole that allows access to the bone fastener head portion 11 by the rod fastening means 60, 70. The essentially rectangular spacer 90 with rounded edges further comprises several holes, one hole at each corner to accommodate the flexible elongated member 80 passing therethrough. Such a spacer 90 can be combined with any of the embodiments of the invention in Figures 1A-26B, for example the spacer 90 in the embodiment of Figures 23A-23C includes one slit as a "hole" along one side of the spacer 90 to accommodate the tether band 180. The slit can also be partially open towards the outer edge of the spacer to allow the tether band 180 to be guided at one or both of its side edges.

[0152] While the present invention has been illustrated and described in detail in the drawings and the foregoing description, such illustration and description should be considered as illustrative or exemplary and not restrictive, and the invention is not limited to the disclosed designs. Other embodiments and variations can be understood and effected by those skilled in the art when practicing the claimed invention, based on a study of the drawings, the disclosure, and the appended claims. New embodiments or variations can be obtained by combining any of the above teachings.

[0153] For example, while the working head of the screwdriver has been described and illustrated as a hex-lobe working head, alternatively the working head may be shaped as an in-bus (hexagonal) working head, a Phillips working head, etc., with a corresponding complementary shaped drive portion. The drive portion may be configured as an external drive portion, for example, a first drive portion 14 protruding from a proximal end 23.

[0154] In the claims, the words "comprise" and "include" do not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude a plurality. The mere fact that different features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope of the invention. [Explanation of symbols]

[0155] 1. Vertebral Fastener Assembly 1' Vertebral Fastener Assembly 1'' Vertebral Fastener Assembly 1'' Vertebral Fastener Assembly 1'' Vertebral Fastener Assembly 1''''' Vertebral Fastener Assembly 2 Spinal Rod 4 Setscrew 5 Standard Spinal Screws 7 Segments of the Spine 7' Specific vertebral segment 8 spine 8' curved spine 8'' straight spine 10 Bone fasteners 10' Bone Fastener 11 Bone fastener head 12 Bone Engaging Shaft 13 Flexible elongated member holding means 14 First Drive Unit 15 Male thread 16 Central Cannula 17 Perforation 18 Female thread 20 Insertion depth stopper 21 Removal tool drive unit 22 Distal end 23 Proximal end 30 Rod receiving head 30' Front Loading Head 30'' Side Loading Head 30D double head 30O Rod Receiving Head for External Threads 31 Head tip 32 Head bottom end 33 Rod receiving opening 34 Front side 35 Posterior side 36 Flexible elongated member holding means 37 Rod setting or tightening mechanism 38 End seat 39a Extension 39b Extension 39C Extension 40 Female thread 40' Male Thread 40a female thread 40b female thread 41 Center Pocket 42 Clamp seat 43 Side wall 45 Seat 47 Anti-rotation element 48 Flat surface 49 First drive shape aperture 50 stepped section (shoulder) 51 Extension end 52 Base 53 Adjacent rod receiving openings 54 Rod setting or tightening mechanism 55 Internal or External Break Relief 60 (outer) rod fastening means / thread 60' Encircling Outer Thread 60'' Standard Set Screw 61 Main unit 62 Rod fastening means bottom side 63 Second Drive Unit 64 Rod tightening mechanism / thread 65 Top side 66 Internal Thread 70 (inner) rod fastening means 71 Main unit 72 Bottom side 73 Third Drive 74 External Thread 75 Top side 80 Flexible elongated member 80dd double tether band and double tensioning 80ds Double tether band and single sided tension 81 Long, slender, flexible body 82 Distance determination part 83 Blocked tether section 84 Bone fastener guided part 85 Arrow = tensile direction 86 Distal junction 87 Loop section 90 Spacer 100 first rod receiving opening end 110 Bottom passage 111 Side Passage 111a First side passage 111b Adjacent side passage 120 Bone cement insertion cannula 130 Intermediate insert 130A Insert for Tethered Pedicle Screw Applications 130B Inlays for growth related applications 131 second rod receiving opening 132 Clamp Surface 133 Screwdriver Passage 134 Central locking element 135 Side Slit 136 Top surface 137 Bottom 138a Proximally Facing Leg 138b proximally facing leg 140 Insertion Device 140' Double tensioned insertion device 141 Indicator 142 Tensioning knob 143 Warm 144 Tether Hold Hook 145 Interior wall 146 Side wall 147 Slit for spinal rod 148 Tensioning mechanism 150 Force measuring device 151 Rotatable Knob 160 The First Screwdriver 161 Screwdriver Head 162 Screwdriver Inbus / Torx Head 170 Assembly / disassembly key 171 Rotatable Knob 180 Tether Band 181 Free Strand 181a Freestrand 181b Free Strand 182 Distance determination part 183 Blocked tether section 186 eyes 187 Enlarged stopper section 190 Transition Zone 190a Transition Area 190b Transition Area 260 The Second Screwdriver 261 Screwdriver Head 262 Screwdriver Inbus / Torx Head 287 Enlarged stopper section 300 Kits 387 Enlarged stopper section D1 Height difference TPS D2 Height difference growth OP Outer edge X1 First Distance X2 Second distance

Claims

1. A vertebral fastener assembly (1-1'''''') engaged with a posterior vertebral fastener system, comprising: The vertebral fastener assembly (1) a bone fastener (10) having a bone fastener head portion (11), a bone-engaging elongated shaft (12), and a first drive portion (14) for introducing the bone fastener (10) into a target bone; a rod-receiving head (30) configured to receive and at least partially surround a spinal rod (2) within a first rod-receiving opening having a central pocket with a clamping seat; a fastening means (60) configured to exert a holding and / or clamping force between the spinal rod (2) and the rod-receiving head (30); At least one flexible elongate member (80, 180) connecting or coupling the rod-receiving head (30) to the bone fastener (10). Equipped with - said bone fastener (10) further comprises at least one first flexible elongate member retaining means (13); - said rod-receiving head (30, 30', 30'') comprises at least one second flexible elongate member holding means (36) and a first rod-setting or clamping mechanism part (37); - said clamping means (60, 70) comprises a second drive (63, 73) for engaging said clamping means (60, 70) in said rod receiving head (30, 30', 30''); - the vertebral fastener assembly (1-1''''''') has a second clamping mechanism portion (64) sized and shaped to engage with the first rod setting or clamping mechanism portion (37); the flexible elongated member (80, 180) comprises an elongated flexible body (81) sized and shaped to engage with the first and second flexible elongated member retaining means (13, 36), at least a portion (82) of said elongated flexible body (81) spanning between said bone fastener head portion (11) and said rod-receiving head bottom end (32), said bone fastener head portion (11) being spaced a distance (X1, X2) from said rod-receiving head bottom end (32); Vertebral fastener assembly.

2. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the vertebral fastener assembly includes a locked configuration and an unlocked configuration; In the locked configuration, the flexible elongate member (80, 180) is biased against the clamp seat (42) and movement of the flexible elongate member (80, 180) through at least one of the first and second flexible elongate member retaining means (13, 36) is prevented. Vertebral fastener assembly.

3. A vertebral fastener assembly (1-1'''''') according to claim 1 or 2, comprising: the first and second fastening mechanism portions (37, 64) being configured as internal and external threads to form a fastening mechanism or connection; Vertebral fastener assembly.

4. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: at least one of the first or second flexible elongate member retaining means (13, 36) being oversized compared to the cross section (C) of the flexible elongate member (80); Vertebral fastener assembly.

5. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: at least one of the first or second flexible elongate member retaining means (13, 36) completely surrounds the flexible elongate member (80) to prevent separation of the flexible elongate member (80); Vertebral fastener assembly.

6. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: At least one of the first flexible elongate member retaining means (13) is oriented top to bottom or side to side; Vertebral fastener assembly.

7. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the fastening means is configured as a primary fastening means (60) sized and shaped to receive an inner fastening means (70); Vertebral fastener assembly.

8. 8. A vertebral fastener assembly (1-1''''''') according to claim 7, comprising: The inner and main rod fastening means (70, 60) are threadedly engaged by an inner thread (66) and an outer thread (75); Vertebral fastener assembly.

9. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: In the locked configuration, the primary clamping means (60) abuts the spinal rod (2) and the flexible elongated members (80, 180) abut the spinal rod (2) and the clamp seat (42). Vertebral fastener assembly.

10. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the rod-receiving head (30, 30') is provided with an end seat (38) forming an insertion depth stop for the main rod clamping means (60); Vertebral fastener assembly.

11. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: an intermediate insert (130) is disposed between the clamp seat (42) and at least one of the main or inner clamping means (60, 70); Vertebral fastener assembly.

12. 12. A vertebral fastener assembly (1-1'''''') according to claim 11, comprising: In the locked configuration, the inner clamping means (70) abuts the spinal rod (2) and the flexible elongated member (80) abuts the intermediate insert (130) and the clamp seat (42). Vertebral fastener assembly.

13. 12. A vertebral fastener assembly (1-1'''''') according to claim 11, comprising: In the locked configuration, the inner clamping means (70) abuts the intermediate insert (130) and the flexible elongate member (80) abuts the intermediate insert (130) and the clamp seat (42). Vertebral fastener assembly.

14. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: In the locked configuration, the spinal rod (2) abuts the first rod-receiving opening end (100) and the primary fastening means bottom side (62). Vertebral fastener assembly.

15. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the outer peripheral edge (OP) of the bone fastener head portion (11) is primarily non-circular or non-rotationally symmetric; Vertebral fastener assembly.

16. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the first drive part (14) comprises an internal thread (18) for attaching a bone cement insertion cannula (120); Vertebral fastener assembly.

17. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the flexible elongate member (80) is made of woven or braided strands of biocompatible surgical suture material, such as UHMWPE fibers, nylon fibers, polyester fibers, PET fibers, or stainless steel, cobalt chromium, or titanium (alloy) cables, and polyaramid, carbon fiber, or silk; Vertebral fastener assembly.

18. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the bone fastener (10) includes an insertion depth stop (20) disposed adjacent to the distal side of the bone fastener head portion (11), the insertion depth stop (20) preventing over-deep insertion; Vertebral fastener assembly.

19. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the rod-receiving head (30, 30', 30'') comprises rod-clamping means (60) receiving extensions (39a, 39b) projecting from the head top end (31); Vertebral fastener assembly.

20. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the rod-receiving head (30) includes a first driver-shaped aperture (49) extending through the head bottom end (32); Vertebral fastener assembly.

21. 2. A vertebral fastener assembly (1.1') according to claim 1, comprising: the flexible elongate member (80, 180) having a distal coupling end (86) for attachment to an insertion device (140); Vertebral fastener assembly.

22. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the intermediate insert (130) comprises a second rod-receiving opening (131) having a first depth (D1) less than the diameter of the spinal rod or a second depth (D2) greater than the diameter of the spinal rod; Vertebral fastener assembly.

23. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: the flexible elongated member (80) enters or exits the rod-receiving head from the head bottom end (32), and / or the flexible elongated member (80) enters or exits the rod-receiving head from the head outer wall (50); Vertebral fastener assembly.

24. 2. A vertebral fastener assembly (1-1''''''') according to claim 1, comprising: The spinal fastener assembly (1) includes a spacer (90) disposed between the bone fastener (10) and the rod-receiving head (30). Vertebral fastener assembly.

25. 10. A kit comprising: a vertebral fastener assembly (1-1''''''') according to claim 1; and an insertion device (140) including a tensioning mechanism (148) for tensioning the flexible elongated member (80, 180).

26. 26. The kit of claim 25, further comprising a tension measuring device (150).

Images