Multi-point angled fixation implant for multiple screws

Abstract

Disclosed herein are bone anchor assemblies and related methods that can provide improved fixation of a primary bone anchor. The bone anchor assembly can include a wing having a distal portion that can define a plurality of auxiliary bone anchor openings. Each auxiliary bone anchor opening can receive an auxiliary bone anchor that can enhance fixation of the primary bone anchor of the bone anchor assembly. The plurality of auxiliary bone anchor openings can be oriented such that when the wing is coupled to the primary bone anchor assembly of a vertebral segment in a first configuration, at least one auxiliary bone anchor can be driven to extend across a facet plane of the vertebral segment, and when coupled in a second configuration, each auxiliary bone anchor received within the wing can be driven to conform to the vertebral segment.

Description

Technical Field

[0001] Orthopedic implants and related methods are disclosed herein. For example, a bone anchor assembly having multiple bone engagement points is disclosed. Background Art

[0002] Bone anchor assemblies can be used in orthopedic surgery to fix bones during healing, fusion or other processes. For example, in spinal surgery, bone anchor assemblies can be used to fix spinal fixation elements to one or more vertebrae to rigidly or dynamically stabilize the spine. Bone anchor assemblies can also be used as joints for manipulating bones (e.g., distracting, compressing or rotating one vertebra relative to another vertebra, reducing long bone fractures, etc.).

[0003] The integrity of the engagement of the bone anchor assembly with the bone can affect the transmission of corrective biomechanical forces. Although a great deal of care is taken when placing the bone anchor assembly, the bone anchor assembly is often inserted in a compromised state. For example, the bone opening in which the assembly is disposed may be stripped (e.g., by driving the bone anchor assembly beyond its optimal retention position), the bone anchor assembly may be improperly placed (e.g., using incorrect instrumentation, such as an overly large locating hole), the bone anchor assembly may be placed outside of its intended track (e.g., within a facet joint capsule or through a pedicle wall), or the bone anchor assembly may be inserted into a compromised bone (e.g., a bone that is fractured, osteoporotic, diseased, or lacks structural integrity).

[0004] When the bone anchor assembly is in a damaged state, there may be a suboptimal grip between the bone anchor assembly and the bone. The surgeon may feel that the bone anchor assembly is unsafe, and the bone anchor assembly may withdraw or become loose over time. When faced with these types of situations, the surgeon's options are limited. For example, in spinal surgery, the surgeon can remove the bone anchor assembly and skip the vertebral segment, but this may not be desirable to expand the surgical site to other vertebral segments. The surgeon can remove and reinsert larger anchors, but this may not be an option when the anchoring space in the bone is limited. The surgeon can leave the damaged bone anchor assembly in place, which may be the safest alternative if the bone anchor assembly is in a safe position and the attachment to the plate, rod or other implant structure is determined, because additional damaged fixation may be better than removal.

[0005] Even when the bone anchor assembly is in an undamaged state, the geometry of conventional bone anchor assemblies limits the flexibility of positioning the bone attachment point relative to a plate, rod, or other implant construct coupled to the bone anchor assembly.

[0006] There is a continuing need for improved bone anchor assemblies and related methods. Summary of the invention

[0007] A bone anchor assembly is disclosed that can provide improved fixation compared to conventional bone anchor assemblies. One embodiment of the assembly can include a bracket or wing extending downwardly from the receiving body member and accommodating a plurality of auxiliary bone anchors that enhance the fixation of the primary bone anchor of the assembly. Surgical methods using the bone anchor assemblies described herein are also disclosed.

[0008] In one aspect, a bone anchor assembly may include: a bone anchor; a receiving body member coupled to a proximal end of the bone anchor and defining a recess configured to receive a rod; a closing mechanism cooperating with the receiving body member; a wing having a proximal portion disposed proximal to the receiving body member, a distal portion defining a plurality of auxiliary screw openings, and a spanning portion connecting the proximal portion and the distal portion, each of the plurality of auxiliary screw openings being configured to receive an auxiliary bone anchor screw. The plurality of auxiliary screw openings extend at an angled trajectory relative to a proximal-distal axis of the spanning portion, such that in a first configuration, each of the auxiliary screws received in each of the plurality of screw openings can conform to a vertebral segment into which the bone anchor is inserted, and in a second configuration, at least one of the plurality of auxiliary bone anchor screws received in at least one of the screw openings can extend across a facet plane of the vertebral segment into which the bone anchor is inserted. The bone anchor assembly also includes a nut configured to engage the closing mechanism to secure the proximal portion of the wing to the proximal end of the receiving body member.

[0009] The devices and methods described herein may have a variety of additional features and / or variations, all of which are within the scope of the present invention. In some embodiments, for example, the distal portion of the wing may extend generally perpendicular to the proximal-distal axis of the spanning portion. The distal portion of the wing may be configured such that an air gap exists between the distal portion of the wing and the proximal-facing surface of the bone into which the bone anchor is inserted when the bone anchor is secured to the receiving member.

[0010] In some embodiments, the central axis of each of the plurality of screw openings extends in one of a caudal direction or a cephalad direction. In some such embodiments, the central axis of each of the plurality of screw openings may extend in a medial direction. The central axis of each of the plurality of screw openings may extend at an angle between about 0 degrees and about 60 degrees relative to the proximal-distal axis of the spanning portion.

[0011] Each screw opening in a plurality of screw openings may include at least one threaded portion so that a screw can be received at a variable angle. In some such embodiments, at least one threaded portion may be a conical threaded portion. In some embodiments, each screw opening in a plurality of screw openings may define an interlocking interface.

[0012] In another aspect, a method of securing a primary bone anchor assembly to a bone is provided, the method may include: driving a primary bone anchor having a receiver member coupled to a proximal end of the bone anchor into a vertebral segment in a patient's spine; positioning a rod in the receiver member; attaching a closure mechanism to the receiver member to retain the rod in the receiver member, coupling a proximal portion of a wing to at least one of the closure mechanism and the receiver member. The wing may have a distal portion defining a first auxiliary bone anchor opening and a second auxiliary bone anchor opening and a spanning portion connecting the proximal portion and the distal portion, wherein each of the first auxiliary bone anchor opening and the second auxiliary bone anchor opening extends at an oblique angle relative to a proximal-distal axis of the spanning portion. The method may include: positioning the wing in one of a first position and a second position, in which the first position the first and second auxiliary bone anchors received in the wing are conformal to the vertebral segment into which the bone anchor is driven, and in the second position at least one of the first and second auxiliary bone anchors received in the wing extends across a facet plane of the vertebral segment into which the bone anchor is driven; inserting the first auxiliary bone anchor through the first auxiliary bone anchor opening at a first trajectory; inserting the second auxiliary bone anchor through the second bone anchor opening at a second trajectory; and driving the first auxiliary bone anchor into the vertebral segment at the first trajectory and driving the second auxiliary bone anchor into the bone at the second trajectory, such that the first and second auxiliary bone anchors enhance fixation of the primary bone anchor.

[0013] The method may also include: positioning the wing relative to the receiver member so that the first auxiliary bone anchor opening and the second bone anchor opening are offset in a cephalad direction; driving the first auxiliary bone anchor at the first trajectory so that the first auxiliary bone anchor extends completely within the vertebral segment into which the primary bone anchor is driven; and driving the second auxiliary bone anchor at the second trajectory so that the second auxiliary bone anchor extends completely within the vertebral segment into which the primary bone anchor is driven. In some such embodiments, the vertebral segment into which the primary bone anchor is driven may be a vertebral segment of a cervical spine.

[0014] The method may further include positioning the wing relative to the receiver member such that the first auxiliary bone anchor opening and the second bone anchor opening are offset in a caudal direction, and driving at least one of the first auxiliary bone anchor and the second auxiliary bone anchor to intrude upon a facet plane of the vertebral segment into which the primary bone anchor is driven. In some embodiments, positioning the wing may further include positioning the wing such that an air gap exists between the distal portion of the wing and a proximally facing surface of the vertebral segment into which the primary bone anchor is driven.

[0015] Coupling the proximal portion of the wing to at least one of the closure mechanism and the proximal surface of the receiver member may include attaching the wing via an extended set screw and locking the wing in place with a nut. In some such embodiments, the method may also include rotating the wing relative to the receiver member about the axis of the extended screw to achieve a desired first auxiliary bone anchor opening trajectory and a desired second auxiliary bone anchor opening trajectory.

[0016] In some embodiments, driving the primary bone anchor into a vertebral segment in the spine may include: driving the primary bone anchor into a fused vertebral segment of the spine. In some embodiments, driving the first auxiliary bone anchor at the first trajectory and driving the second auxiliary bone anchor at the second trajectory may cause at least one of the first auxiliary bone anchor and the second auxiliary bone anchor to move away from the primary bone anchor.

[0017] In some embodiments, the central axis of the first auxiliary bone anchor opening and the central axis of the second auxiliary bone anchor opening can each be offset from the proximal-distal axis of the spanning portion by an angle between about 0 degrees and about 60 degrees. In some embodiments, the first trajectory can extend at an oblique angle relative to the central axis of the first auxiliary bone anchor opening.

[0018] Inserting the first auxiliary bone anchor and inserting the second auxiliary bone anchor may also include engaging a threaded surface of the first auxiliary bone anchor with an interlocking interface of the first auxiliary bone anchor opening and engaging a threaded surface of the second auxiliary bone anchor with an interlocking interface of the second auxiliary bone anchor opening.

[0019] In any of the foregoing embodiment methods, the closure mechanism may include a threaded post having a radially extending shoulder portion. Coupling the proximal portion of the wing to at least one of the closure mechanism and the proximal terminal end of the receiver member may include: disposing at least a portion of the threaded post through an opening formed in the proximal portion of the wing; and receiving the radially extending shoulder portion extending at least partially over the proximal terminal end of the receiver member in a counterbore formed around the opening in the distally facing surface of the proximal portion of the wing.

[0020] Any of the above features or variations can be applied to any specific aspect or embodiment of the present disclosure in a variety of different combinations. No specific combination is explicitly described only to avoid redundancy in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A is an exploded perspective view of a prior art bone anchor assembly;

[0022] Figure 1B for Figure 1A A cross-sectional view of a bone anchor assembly;

[0023] Figure 1C for Figure 1A A perspective view of a bone anchor assembly showing an extended tab;

[0024] Figure 2A is a perspective view of a bone anchor assembly and a spinal rod;

[0025] Figure 2B for Figure 2A An exploded perspective view of a bone anchor assembly and a spinal rod;

[0026] Figure 2C for Figure 2A A perspective view of a bone anchor assembly and a spinal rod;

[0027] Figure 2D for Figure 2A A top view of a bone anchor assembly and a spinal rod;

[0028] Figure 2E for Figure 2A A perspective view of a wing portion of a bone anchor assembly;

[0029] Figure 2F for Figure 2A Another perspective view of the wing portion of the bone anchor assembly;

[0030] Figure 2G for Figure 2A Another perspective view of the wing portion of the bone anchor assembly;

[0031] Figure 2H for Figure 2A Another perspective view of the wing portion of the bone anchor assembly;

[0032] Fig.2I for Figure 2A A perspective view of a bone anchor assembly and spinal rod showing the height-adjustable wings;

[0033] Figure 2J for Fig.2I A perspective view of a wing portion of a bone anchor assembly;

[0034] Figure 2K for Fig.2I Another perspective view of the wing portion of the bone anchor assembly;

[0035] Figure 2L for Fig.2I Another perspective view of the wing portion of the bone anchor assembly;

[0036] Figure 2M for Fig.2I Another perspective view of the wing portion of the bone anchor assembly;

[0037] Figure 3A is a perspective view of a bone anchor assembly and a spinal rod attached to a spine;

[0038] Figure 3B for Figure 3A A perspective view of a wing portion of a bone anchor assembly;

[0039] Figure 3C for Figure 3A Another perspective view of the wing portion of the bone anchor assembly;

[0040] Figure 3D for Figure 3A Another perspective view of the wing portion of the bone anchor assembly;

[0041] Figure 3E for Figure 3A A side view of a wing portion of a bone anchor assembly;

[0042] Figure 3F for Figure 3A Another perspective view of the wing portion of the bone anchor assembly;

[0043] Figure 3G for Figure 3A Another perspective view of the wing portion of the bone anchor assembly;

[0044] Figure 3H for Figure 3A a top view of a wing of a bone anchor assembly of wherein the angled distal portion faces in a caudal direction;

[0045] Fig. 3I for Figure 3A a top view of a wing of a bone anchor assembly of wherein the angled distal portion faces in a cephalad direction;

[0046] Figure 4A for Figure 3A A cross-sectional view of a wing portion of a bone anchor assembly prior to being secured to a closure mechanism;

[0047] Figure 4B for Figure 4A A cross-sectional view of a wing secured to a closure mechanism;

[0048] Figure 4C for Figure 4A Another cross-sectional view of the wing secured to the closure mechanism;

[0049] Figure 5A is a perspective view of a bone anchor assembly and a spinal rod attached to a spine;

[0050] Figure 5B for Figure 5A A perspective view of a wing portion of a bone anchor assembly;

[0051] Figure 5C for Figure 5A Another perspective view of the wing portion of the bone anchor assembly;

[0052] Figure 5Dfor Figure 5A A side view of a wing portion of a bone anchor assembly;

[0053] Figure 5E for Figure 5A a top view of a wing of a bone anchor assembly of wherein the angled distal portion faces in a cephalad direction;

[0054] Fig. 5F for Figure 5A a top view of a wing of a bone anchor assembly of wherein the angled distal portion faces in a caudal direction;

[0055] Fig. 6A is a perspective view of a wing portion of a bone anchor assembly;

[0056] Figure 6B for Fig. 6A Side view of the appendage;

[0057] Figure 6C for Fig. 6A Another side view of the wing;

[0058] Fig.6D for Fig. 6A A side cross-sectional view of a wing portion;

[0059] Fig. 6E for Fig. 6A Another side cross-sectional view of the wing portion;

[0060] Figure 7 is a perspective view of a bone anchor assembly and a spinal rod attached to a spine;

[0061] Figure 8 for Figure 7 A perspective view of one embodiment of a wing portion of a bone anchor assembly;

[0062] Fig. 9 for Figure 7 a side cross-sectional view of a wing portion of a bone anchor assembly;

[0063] Fig.10 for Fig. 9 A detailed cross-sectional view of a wing;

[0064] Fig.11 As an example Figure 7 A perspective view of a wing portion of a bone anchor assembly;

[0065] Fig.12 As an example Figure 7 Another perspective view of the wing portion of the bone anchor assembly;

[0066] Fig.13 for Figure 7 A side view of a wing portion of a bone anchor assembly;

[0067] Fig.14For along Fig.11 The line AA in Figure 7 a cross-sectional view of a wing portion of a bone anchor assembly;

[0068] Fig.15 For along Fig.11 The line BB in Figure 7 a cross-sectional view of a wing portion of a bone anchor assembly;

[0069] Fig.16 for Figure 7 a top view of a wing portion of a bone anchor assembly of the embodiment of the present invention, wherein the auxiliary bone anchor assembly opening extends in a cephalad direction;

[0070] Fig.17 for Figure 7 a top view of a wing portion of a bone anchor assembly, wherein the auxiliary bone anchor assembly opening extends in a caudal direction;

[0071] Fig.18 is a perspective view of a bone anchor assembly and a spinal rod attached to a spine;

[0072] Fig.19 for Fig.18 A perspective view of a wing portion of a bone anchor assembly;

[0073] Fig. 20 for Fig.18 A perspective view of a wing portion of a bone anchor assembly;

[0074] Fig.21 For along Fig. 20 The line CC in Fig.18 a cross-sectional view of a wing portion of a bone anchor assembly;

[0075] Fig. 22 for Fig.18 a top view of a wing portion of a bone anchor assembly, wherein the auxiliary bone anchor assembly opening extends in a caudal direction;

[0076] Fig.23 for Fig.18 A top view of a wing portion of a bone anchor assembly of the embodiment of the present invention, wherein the auxiliary bone anchor assembly opening extends in a cephalad direction; and

[0077] Fig.24 Embodiment methods of using the supplemental fixation members of the present disclosure to enhance fixation of a bone anchor assembly are illustrated. DETAILED DESCRIPTION

[0078] A bone anchor assembly is disclosed that can provide improved fixation compared to conventional bone anchor assemblies. An exemplary assembly can include a bracket or wing extending downwardly from the receiving body member and accommodating one or more auxiliary bone anchors that enhance the fixation of the primary bone anchor of the assembly. Another exemplary assembly can include a plate disposed between the receiving body member and the rod and accommodating one or more auxiliary bone anchors that enhance the fixation of the primary bone anchor of the assembly. Another exemplary assembly can include a hook extending outwardly from the receiving body member to hook onto an anatomical structure or another implant to enhance the fixation of the primary bone anchor of the assembly. Surgical methods using the bone anchor assemblies described herein are also disclosed.

[0079] Certain exemplary embodiments will now be described to obtain a comprehensive understanding of the principles of structure, function, manufacture and use of the systems and methods disclosed herein. One or more examples of these embodiments are shown in the accompanying drawings. It should be understood by those skilled in the art that the devices and methods specifically described herein and shown in the accompanying drawings are non-limiting exemplary embodiments. The features shown or described in conjunction with an exemplary embodiment may be combined with the features of other embodiments.

[0080] Prior art bone anchor assembly

[0081] Figures 1A to 1C A prior art bone anchor assembly 100 is shown having various features that may be included in the bone anchor assemblies described below. It should be understood that the bone anchor assembly 100 shown is exemplary and that the bone anchor assemblies described herein may include additional or alternative features.

[0082] The illustrated bone anchor assembly 100 includes a bone anchor 102, a receiver member 104 for receiving a spinal fixation element (such as a spinal rod 106) to be coupled to the bone anchor 102, and a closure mechanism 108 for capturing the spinal fixation element within the receiver member and fixing the spinal fixation element relative to the receiver member. The bone anchor 102 includes a proximal head 110 and a distal shaft 112 configured to engage a bone. The receiver member 104 has a proximal end and a distal end, the proximal end having a pair of spaced arms 114A, 114B defining a recess 116 therebetween, and a distal end having a distal end surface defining an opening through which at least a portion of the bone anchor 102 extends. The closure mechanism 108 can be positioned between the arms 114A and 114B and can be engaged therewith to capture the spinal fixation element (e.g., the spinal rod 106) within the receiver member 104 and fix the spinal fixation element relative to the receiver member.

[0083] The proximal head 110 of the bone anchor 102 is generally in the shape of a truncated sphere having a flat proximal surface and a distal surface that is approximately spherical. The illustrated bone anchor assembly 100 is a polyaxial bone screw designed for later implantation into a pedicle or lateral block of a vertebra. The proximal head 110 of the bone anchor 102 engages the distal end of the receiver member 104 in a ball-and-socket arrangement, wherein the proximal head and distal shaft 112 can pivot relative to the receiver member. The distal surface of the proximal head 110 of the bone anchor 102 and the mating surfaces within the distal end of the receiver member 104 can have any shape that facilitates this arrangement, including, for example, spherical (as shown), annular, conical, truncated conical, and any combination of these shapes.

[0084] The distal shaft 112 of bone anchor 102 can be configured to engage bone, and in the illustrated embodiment, comprises an outer bone engagement thread. The thread form for distal shaft 112 can be selected, including the number of threads, pitch, major and minor diameters and thread shape, to promote connection with bone. Exemplary thread forms are disclosed in the U.S. Patent Application Publication 2011 / 0288599 filed on May 18, 2011 and the U.S. Patent Application Publication 2013 / 0053901 filed on August 22, 2012, which are incorporated herein by reference. The distal shaft 112 can also include other structures for engaging bone, including hooks. The distal shaft 112 of bone anchor 102 can be hollow, with a central channel or cannula extending the length of the bone anchor, so that the bone anchor is delivered by a guide wire in a minimally invasive procedure, for example. Other components of the bone anchor assembly 100, including, for example, the closure mechanism 108, the receiving body member 104, and the compression member or cap 118 (described below), may be hollow or otherwise have openings to allow delivery through a guidewire. The distal shaft 112 may also include one or more sidewall openings or perforations that communicate with the cannula to allow bone ingrowth or to allow bone cement or other materials to be dispensed through the bone anchor 102. The sidewall openings may extend radially from the cannula through the sidewall of the distal shaft 112. An exemplary system for delivering bone cement to the bone anchor assembly 100 and an alternative bone anchor configuration that facilitates cement delivery are described in U.S. Patent Application Publication No. 2010 / 0114174, filed on October 29, 2009, which is hereby incorporated by reference herein. The distal shaft 112 of the bone anchor 102 may also be coated with a material that allows bone growth (eg, hydroxyapatite), and the bone anchor assembly 100 may be partially or fully coated with an anti-infective material (eg, triclosan).

[0085] The proximal end of the receiving body member 104 includes a pair of spaced arms 114A, 114B defining a U-shaped recess 116 therebetween for receiving a spinal fixation element, such as a spinal rod 106. Each of the arms 114A, 114B may extend from the distal end of the receiving body member 104 to a free end. The outer surface of each of the arms 114A, 114B may include features such as a recess, a pit, a notch, a protrusion, etc. to facilitate connection of the receiving body member 104 to an instrument. For example, the outer surface of each arm 114A, 114B may include an arcuate groove at the corresponding free end of the arm. Such grooves are described in more detail in U.S. Patent 7,179,261, issued on February 20, 2007, which is incorporated herein by reference.

[0086] The distal end of the receiver member 104 includes a distal end surface that is generally annular in shape defining a circular opening through which extends at least a portion of the bone anchor 102. For example, the distal shaft 112 of the bone anchor 102 can extend through the opening.

[0087] The bone anchor 102 is selectively fixable relative to the receiver member 104. Prior to fixation, the bone anchor 102 is movable relative to the receiver member 104 within an angled pyramid generally defined by the geometry of the distal end of the receiver member and the proximal head 110 of the bone anchor 102. The bone anchor assembly 100 can be an advantageous angle screw, such as disclosed in U.S. Pat. No. 6,974,460, issued Dec. 13, 2005, and U.S. Pat. No. 6,736,820, issued May 18, 2004, both of which are incorporated herein by reference. Alternatively, the bone anchor assembly 100 can be a conventional (non-biased) multi-axial screw, in which the bone anchor 102 pivots the same amount in each direction.

[0088] The spinal fixation element (e.g., spinal rod 106) may directly contact the proximal head 110 of the bone anchor 102 or may contact an intermediate element, such as a compression member 118. The compression member 118 may be located within the receiving body member 104 and interposed between the spinal rod 106 and the proximal head 110 of the bone anchor 102 to compress the distal exterior surface of the proximal head into direct fixed engagement with the distal interior surface of the receiving body member 104. The compression member 118 may include a pair of spaced-apart arms 120A and 120B defining a U-shaped seat 122 for receiving the spinal rod 106 and a distal surface of the proximal head 110 for engaging the bone anchor 102.

[0089] The proximal end of the receiving body member 104 can be configured to receive a closure mechanism 108 that can be positioned between and engage the arms 114A and 114B of the receiving body member. The closure mechanism 108 can be configured to capture a spinal fixation element (e.g., a spinal rod 106) within the receiving body member 104 to fix the spinal rod relative to the receiving body member and to fix the bone anchor 102 relative to the receiving body member. The closure mechanism 108 can be a single set screw having external threads for engaging internal threads disposed on the arms 114A, 114B of the receiving body member 104. However, in the illustrated embodiment, the closure mechanism 108 includes an external set screw 124 operable to act on the compression member 118 and an internal set screw 126 operable to act on the rod 106. The receiving body member 104 can include one or more extension tabs 128 ( Figure 1C 114A, 114B. The extension tabs 128 may be integrally formed with or may be coupled to one or more extension tabs that extend proximally from the receiving body member 104 to functionally extend the length of the arms 114A, 114B. The extension tabs 128 may facilitate installation and assembly of a fixed or stable configuration and may be removed prior to completion of the surgical procedure.

[0090] The bone anchor assembly 100 may be used with a spinal fixation element, such as a rigid spinal rod 106. Alternatively, the spinal fixation element may be a dynamic stabilization member that allows for controlled motion between instrumented vertebrae.

[0091] In use, the bone anchor assembly 100 can be assembled so that the distal shaft 112 extends through the opening in the distal end of the receiving body member 104 and the proximal head 110 of the bone anchor 102 is received in the distal end of the receiving body member 104. A driving instrument can be adapted to the bone anchor 102 to drive the bone anchor into the bone. The compression member 118 can be located within the receiving body member 104, whereby the arms 120A, 120B of the compression member are aligned with the arms 114A, 114B of the receiving body member 104, and the lower surface of the compression member 118 is in contact with the proximal head 110 of the bone anchor 102. A spinal fixation element (e.g., a spinal rod 106) can be positioned in the recess 116 of the receiving body member 104. The closing mechanism 108 can engage the internal threads provided on the arms 114A, 114B of the receiving body member 104. A torque may be applied to the external set screw 124 to move it within the recess 116 so as to force the compression member 118 onto the proximal head 110 of the bone anchor 102, thereby locking the angular position of the bone anchor 102 relative to the receiving body member 104. A torque may be applied to the internal set screw 126 to force the spinal rod 106 into engagement with the compression member 118, thereby fixing the spinal rod 106 relative to the receiving body member 104.

[0092] The bone anchor assemblies described below may be configured to operate in conjunction with or may include any of the features of the above-described types (i.e., bone anchor assembly 100) or other types of bone anchor assemblies known in the art. Exemplary bone anchor assemblies include uniaxial screws, polyaxial screws, uniplanar screws, favorable angle screws, and / or any of a variety of other bone anchor types known in the art. More information about favorable angle screws can be found in U.S. Patent Application Publication No. 2013 / 0096618, filed on October 9, 2012, which is incorporated herein by reference.

[0093] Multi-point fixation implant

[0094] Figures 2A to 2M An exemplary embodiment of a bone anchor assembly 200 is shown, showing a spinal rod 206. As described above, bone anchors can sometimes be inserted in a damaged state. This may be undesirable, especially in the cervical region of the spine where there is limited bone area in which additional bone anchors may be installed. The bone anchor assembly 200 shown can allow for supplemental fixation of a primary bone anchor in a compact footprint without necessarily requiring removal or reinsertion of the primary bone anchor. As shown, the bone anchor assembly 200 may include a bone anchor 202, a receiving body member 204, a closure mechanism 208, a bracket or wing 230, a nut 232, and one or more auxiliary bone anchors 234. When used, the wing 230 may be fixed to the receiving body member 204 (e.g., using the closure mechanism 208 and the nut 232), thereby providing the ability to enhance the fixation of the bone anchor 202 with the one or more auxiliary bone anchors 234.

[0095] Except as described below or as will be readily understood by one of ordinary skill in the art, the bone anchor 202 and the receiving body member 204 are substantially similar to the bone anchor 102 and the receiving body member 104 described above. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted herein. The bone anchor assembly 200 may include any one or more of the features of the bone anchor assembly 100 described above.

[0096] The closure mechanism 208 can be selectively fixed to the receiving body member 204 to capture the spinal fixation element (e.g., spinal rod 206) in the receiving body member. Tightening or locking the closure mechanism 208 can effectively fix the spinal rod 206 relative to the receiving body member 204, and fix the angular position of the bone anchor 202 relative to the receiving body member 204. The closure mechanism 208 shown is in the form of a threaded column, with a distal portion 208d with an increased diameter and a proximal portion 208p with a reduced diameter. In other embodiments, the proximal portion 208p and the distal portion 208d can have the same diameter, or the diameter of the proximal portion can be greater than the diameter of the distal portion. The distal portion 208d of the closure mechanism 208 can be threaded into the receiving body member 204 to engage the spinal rod 206 disposed in the receiving body member. The proximal portion 208p of the closure mechanism 208 can protrude above the receiver member 204 (eg, above a proximally facing terminal surface of the receiver member) and pass through an opening 236 formed in the wing 230, as described further below.

[0097] In the illustrated embodiment, the closing mechanism 208 abuts directly against the spinal rod 206, which in turn abuts directly against the head of the bone anchor 202. However, it should be understood that one or more intermediate elements may also be included in the bone anchor assembly 200. For example, the bone anchor assembly 200 may include a compression member of the type described above disposed between the spinal rod 206 and the head of the bone anchor 202. The closing mechanism 208 may be a single set screw as shown, or may include an external set screw operable to act on the compression member and an internal set screw operable to act on the rod 206. The closing mechanism 208 may include a drive interface (e.g., star-shaped, flat head, cross head, square or other) to facilitate advancement or retraction of the closing mechanism using a drive instrument relative to rotation of the receiving body member 204.

[0098] The nut 232 may include a central opening 238 sized to receive at least a portion of the proximal end 208p of the closure mechanism 208 therethrough. The central opening 238 may include internal threads corresponding to the external threads of the closure mechanism 208, so that the nut 232 may be threaded onto the closure mechanism and tightened to secure the wing 230 to the closure mechanism and the receiving body member 204 on which the closure mechanism is disposed. The outer surface of the nut 232 may be faceted or otherwise configured to facilitate application of torque to the nut. In some embodiments, the nut 232 may have a hexagonal or square cross-section.

[0099] like Figures 2E to 2H As shown, the bracket or wing 230 can include a proximal portion 230p that can contact the receiver member 204, a distal portion 230d that can contact or be disposed near a bone surface, and a spanning portion 230s that contacts the proximal and distal portions.

[0100] The proximal portion 230p of the wing 230 may include a central opening 236 that is sized to receive at least a portion of the closure mechanism 208 therethrough. For example, the central opening 236 is sized to receive the proximal portion 208p of the closure mechanism 208 therethrough. The central opening 236 may include a smooth non-threaded interior surface to allow the wing 230 and the closure mechanism 208 to rotate freely relative to each other. The proximal-facing surface 240 of the proximal portion 230p of the wing 230 may be domed or rounded to provide an atraumatic surface and reduce the risk of tissue inflammation after implantation. The distal-facing surface 242 of the proximal portion 230p of the wing 230 may be configured to engage the proximal-facing surface of the receiver member 204. The distal-facing surface 242 may form a negative or substantially negative surface of the proximal-facing surface of the receiver member 204. For example, the proximal-facing surfaces of the arms 214A, 214B of the receiving body member 204 can be radially convex, and the distal-facing surface 242 of the wing 230 can define a radially concave channel that receives the convex ends of the arms. In some embodiments, the central opening 236 or another feature of the wing 230 can be sized and configured to snap fit to or capture a portion of the closure mechanism 208 or the proximal surface of the receiving body member 204.

[0101] The distal portion 230d of the wing 230 can include one or more openings 244 configured to receive the bone anchor 234 therethrough. Although two bone anchor openings 244 are shown in the illustrated embodiment, it should be understood that the wing 230 can include any number of bone anchor openings (e.g., one, two, three, four, five, etc.). The bone anchor openings 244 can include any of a number of features for receiving the bone anchor 234 at different angles and / or increasing the security and stability with which the bone anchor can be secured to the wing 230. Exemplary features that may be included are disclosed in U.S. Pat. Nos. 7,637,928, issued Dec. 29, 2009; 8,343,196, issued Jan. 1, 2013; 8,574,268, issued Nov. 5, 2013; 8,845,697, issued Sept. 30, 2014; and 8,758,346, issued Jun. 24, 2014, each of which is hereby incorporated by reference herein. For example, the bone anchor opening 244 may be at least partially threaded to receive a variable angle locking screw having a threaded proximal head. As shown, the opening 244 may have a plurality of threaded posts spaced apart to define a plurality of non-threaded recesses. In the illustrated embodiment, each opening 244 has four threaded posts. The threaded column can be arranged around the inner surface of each opening 244 for engaging the threads on the head of the locking auxiliary bone anchor and / or the variable angle locking auxiliary bone anchor. Thus, the auxiliary bone anchor 234 can be locked coaxially with the central axis of the opening 244 together with the wing 230, or locked at a selected angle within a selectable angle range relative to the central axis of the opening. The auxiliary bone anchor 234 may include a feature that facilitates such variable angle locking, such as a proximal head that is at least partially spherical, the sphere having threads, and the threads having a profile that follows the arc radius of curvature of the spherical portion of the head. The variable angle capability of the screw / opening interface can allow the user to place the locking auxiliary bone anchor into the bone at any angle within the defined angle limit, thereby providing improved placement flexibility and eliminating or reducing the need to conform the distal portion of the wing to the bone surface to achieve the desired insertion angle. The auxiliary bone anchor 234 can be driven into the bone by diverging or converging longitudinal axes (relative to each other and / or relative to the main bone anchor 202), which can provide improved resistance to pull-out. In some embodiments, the interior surface of the opening 244 may be smooth or spherical, without threads or locking features.

[0102] The central axis of each opening 244 may be perpendicular or substantially perpendicular to the distally facing surface 246 of the wing 230. Alternatively, one or more openings may have a central axis that extends at an oblique angle relative to the distally facing surface 246. In the illustrated embodiment, the central axis of each opening 244 extends at an angle of about 7 degrees relative to the distally facing surface 246. In some embodiments, the central axis of each opening 244 may extend at an angle between about 0 degrees and about 15 degrees relative to the distally facing surface 246 (e.g., embodiments for bone attachment locations that allow direct proximal to distal screw insertion). In some embodiments, the central axis of each opening 244 may extend at an angle between about 15 degrees and about 45 degrees relative to the distally facing surface 246 (e.g., embodiments for bone attachment locations where angled trajectories can avoid or target specific anatomical structures). An angled or divergent central axis can advantageously increase the pull-out resistance of the structure.

[0103] The distal portion 230d of the wing 230 may have a distally facing surface 246 that is configured to contact the bone or to be disposed close to the bone. The distally facing surface 246 may include teeth, textures, or other surface features to enhance the grip with the adjacent bone. The distal portion 230d of the wing 230 may have a lateral surface 248 that abuts the sidewall of the receiver member 204. The lateral surface 248 may form the negative sidewall of the receiver member 204 so that the distal portion 230d of the wing 230 may be close to the receiver member with a minimum gap or zero gap therebetween. For example, the lateral surface 248 may be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer sidewall of the receiver member 204.

[0104] The spanning portion 230s of the wing 230 may extend vertically in the proximal-distal direction to connect the proximal portion 230p of the wing to the distal portion 230d of the wing. The spanning portion 230s of the wing 230 may have a lateral surface 250 that engages the side wall of the receiving body member 204. The lateral surface 250 may form the negative side of the side wall of the receiving body member 204 so that the spanning portion 230s of the wing 230 can be close to the receiving body member with minimal or zero clearance therebetween. For example, the lateral surface 250 may be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer side wall of the receiving body member 204. The lateral surface 250 may also include one or more protrusions 252 for engaging corresponding recesses 254 formed in the side wall of the receiving body member 204, or one or more recesses in which the protrusions of the receiving body member are received. The interaction between the one or more protrusions 252 and the one or more recesses 254 can be effective to limit or prevent rotation of the wing 230 relative to the receiving body member 204. The interaction can also be effective to limit or prevent movement of the wing 230 along the proximal-distal axis relative to the receiving body member 204. The spanning portion 230s can include a band or rib 256 to enhance the structural rigidity of the wing 230. The rib 256 can be formed on an outer surface of the spanning portion 230s, opposite the lateral surface 250 that engages the receiving body member 204.

[0105] The proximal portion 230p, the distal portion 230d and the spanning portion 230s may be integrally formed as an integral unit as shown, or one or more of the components may be separate and selectively attached to other components. In some embodiments, a kit of modular components may be provided to allow selection of the components most appropriate for a given use. For example, a spanning portion 230s of an appropriate height may be selected based on the distance between the proximal end of the receiver member 204 and the bone surface in a given application.

[0106] One or more portions of the wing 230 may be flexible or deformable to allow the wing to be customized for a particular situation. For example, the distal portion 230d of the wing 230 may be flexible or deformable to allow the distal portion to be contoured to a bone surface. The distal portion 230d may be contoured prior to implantation or in situ. The distal portion 230d may be contoured using a separate bending instrument, or by tightening the bone anchor 234 to deform the distal portion into close contact with the bone surface. The distal portion 230d of the wing 230 may be pre-shaped or pre-contoured (e.g., during manufacturing) to match the bone surface to be used with the bone anchor assembly 200.

[0107] By way of further example, the spanning portion 230s of the wing 230 can be flexible or deformable to allow the position of the bone anchor opening 244 to be adjusted relative to the receiving body member 204. The spanning portion 230s can be bent or flexed inwardly or outwardly (e.g., in the medial-lateral direction) to move the bone anchor opening 244 inwardly toward the receiving body member 204 or outwardly away from the receiving body member. Such bending can also increase or decrease the effective height of the wing 230 to accommodate different distances that may be encountered between the proximal end of the receiving body member 204 and the bone surface. The spanning portion 230s can be bent or flexed upwardly or downwardly (e.g., in the superior-inferior direction) to move the bone anchor opening 244 relative to the receiving body member 204. The spanning portion 230s can be contoured prior to implantation or in situ. The spanning portion 230s can be contoured using a separate bending instrument, or by tightening the bone anchor 234 to deform the spanning portion into a desired shape. For a given application, the spanning portion 230s of the wing 230 may be pre-shaped or pre-contoured, such as during manufacturing.

[0108] For another example, the proximal portion 230p of the wing 230 may be flexible or deformable, and / or the joint or location where the proximal portion 230p, the distal portion 230d, and the spanning portion 230s are connected may be flexible or deformable. The proximal portion 230p, the distal portion 230d, and the spanning portion 230s may be connected by a living hinge or other joint to allow adjustment of their relative positions.

[0109] The spanning portion 230s may have an adjustable height. Figures 2I to 2M As shown, the spanning portion 230s may include a first flexible or deformable leg and a second flexible or deformable leg 258. By bending the legs 258 inwardly toward each other, the height of the spanning portion 230s can be increased. By bending the legs 258 outwardly toward each other, the height of the spanning portion 230s can be reduced. Each leg 258 may include an upper portion and a lower portion connected by a flexible joint (e.g., a living hinge, a pivot pin, etc.). A chamfered surface or a semicircular surface may be formed at the connection between the leg 258 and the proximal and distal portions 230p, 230d of the wing 230 to reduce material stress when the leg is bent. Similarly, a chamfered or semicircular cutout may be formed, where the upper and lower portions of each leg 258 intersect. The cutout may reduce stress and provide an engagement surface for clamping the leg using a tool configured to apply a compressive force to the leg 258.

[0110] The bone anchor assembly 200 can provide the surgeon with significant flexibility. The wing 230 can be easily flipped to be positioned on either side of the rod 206 (e.g., on the inside of the rod or on the outside of the rod). Before the wing is finally locked to the receiving body member 204, the wing 230 can be freely rotated about the closure mechanism 208 to allow the auxiliary bone anchor hole 244 to be positioned relative to the spinal rod 206 to be positioned in different positions, such as Figure 2D As described in detail above, the wing 230 can be deformable or flexible, or can include a deformable portion or a flexible portion, to allow the wing to fit closely with the receiver member 204 to match the contour of the bone surface, to reposition the auxiliary bone anchor hole 244 relative to the receiver member, and / or to adjust the height of the wing to accommodate receiver members of different heights or situations (situations where the primary bone anchor 202 is over-inserted into the bone or inserted into the bone).

[0111] See again Figure 2A , the most proximal extent of each auxiliary bone anchor 234 can be located distally of the spinal rod 206. In other embodiments, the most proximal extent of each auxiliary bone anchor 234 can be located distally of the most distal extent of the receiving body member 204. These configurations can advantageously reduce the overall profile of the assembly 200. The wing 200 can be Z-shaped or substantially Z-shaped.

[0112] The wing 230 can extend radially outward from the receiving body member 204 (e.g., a distance equal to the width of the distal portion 230d of the wing). The extent to which the wing 230 extends outward from the receiving body member 204 can vary between different embodiments. In the illustrated embodiment, the ratio of the wing extension to the rod diameter (or the ratio of the wing extension to the width of the rod receiving recess in the receiving body member) is about 2:1. In some embodiments, the ratio can be less than about 10:1, less than about 5:1, less than about 3:1, less than about 2:1, less than about 1:1, and / or less than about 0.5:1. In some embodiments, the ratio can be about 10:1, about 5:1, about 3:1, about 2:1, about 1:1, or about 0.5:1.

[0113] The center of the auxiliary bone anchor hole 244 (and therefore at least a portion of the auxiliary bone anchor 234 disposed therein) can be radially spaced from the center of the opening in the receiving body member 204 in which the primary bone anchor 202 is disposed. In some embodiments, the spacing can be less than about 2.5 times the diameter of the receiving body member 204. In some embodiments, the spacing can be less than about 2 times the diameter of the receiving body member 204. In some embodiments, the spacing can be less than the diameter of the receiving body member 204. In some embodiments, the spacing can be between about 5 mm and about 10 mm. In some embodiments, the spacing can be about 7.5 mm. In some embodiments, the auxiliary bone anchor 234 can be contained within a shell that is no greater than 2.5 times the diameter of the receiving body member 204. In some embodiments, the auxiliary bone anchor 234 can be contained within a shell that is no greater than 2 times the diameter of the receiving body member 204.

[0114] The auxiliary bone anchor 234 may include any of the features of the bone anchor 202 described above, and may be replaced or additionally used with any of a variety of other bone screws or other anchors. As described above, the auxiliary bone anchor 234 may have a threaded proximal head to facilitate variable angle locking with the wing 230. In some embodiments, the auxiliary bone anchor 234 may have a length of about 6 mm to about 20 mm (e.g., in embodiments for cervical applications). In some embodiments, the auxiliary bone anchor 234 may have a length of about 6 mm to about 100 mm (e.g., in embodiments for lumbar or sacral applications). The length of the auxiliary bone anchor 234 may be selected based on various factors, including the available safe bone at any given attachment location. The length of the auxiliary bone anchor 234 may be equal to the length of the main bone anchor 202. The length of the auxiliary bone anchor 234 may be less than the length of the main bone anchor 202. The length of the auxiliary bone anchor 234 may be between about 60% and about 80% of the length of the main bone anchor 202. The length of the auxiliary bone anchor 234 may be about 70% of the length of the main bone anchor 202. The auxiliary bone anchor 234 may be about 10 mm in length. The auxiliary bone anchor 234 may be about 14 mm in length. In some embodiments, two 10 mm auxiliary bone anchors may be used with one 14 mm primary bone anchor. In some embodiments, one 14 mm auxiliary bone anchor may be used with one 14 mm primary bone anchor. The shank diameter of the auxiliary bone anchor 234 may be equal to the shank diameter of the primary bone anchor 202. The shank diameter of the auxiliary bone anchor 234 may be less than the shank diameter of the primary bone anchor 202. The shank diameter of the auxiliary bone anchor 234 may be between about 50% and about 70% of the shank diameter of the primary bone anchor 202. The shank diameter of the auxiliary bone anchor 234 may be about 60% of the shank diameter of the primary bone anchor 202.

[0115] As mentioned above Figures 2A to 2MIn the embodiments described above, supplemental fixation of the primary bone anchor in the bone anchor assembly may be achieved using a wing or bracket having one or more bone anchor openings through which one or more auxiliary bone anchors may be driven into the bone. However, in some cases, surgeons may encounter difficulties in placing certain bone anchors with angular trajectories. The variability of the bony anatomy of the spine may make it difficult to position the distal portion of the wing in close proximity to the bone to facilitate proper engagement or fastening with the anchor. The driving instrument used to drive the auxiliary anchor into the bone may require more clearance to access the bone anchor opening of the wing.

[0116] To address such potential difficulties in supplemental fixation of auxiliary bone anchors, various embodiments of bone anchor assemblies including wings or brackets having angled distal portions are disclosed herein. In some embodiments, the distal portion of the wing may be angled to the right or left of the spanning portion of the wing to facilitate placement of bone anchors having a cranial trajectory (i.e., toward the patient's head) and / or a caudal trajectory (i.e., toward the patient's feet). In some embodiments, alternatively or in addition, the distal portion of the wing or bracket may be angled inwardly or outwardly to facilitate placement of bone anchors having a medial trajectory (i.e., toward the middle of the patient) or a lateral trajectory (i.e., toward the side of the patient). Such angling may facilitate improved engagement or lifting of the auxiliary anchor with the bone and / or facilitate driving instruments into the bone anchor opening of the wing.

[0117] FIG. 3A to FIG. 3I An exemplary embodiment of a bone anchor assembly 500 is shown including a bracket or wing 530 having an angled distal portion 530d. Figure 3A The distal portion 530d is angled toward the right side of the wing 530 when viewed from a perspective of FIG. The bone anchor assembly 500 may include a bone anchor 502, a receiving body member 504, a closure mechanism 508, a bracket or wing 530, a nut 532, and an auxiliary bone anchor 534. The wing 530 may be secured to the receiving body member 504 (e.g., using the closure mechanism 508 and the nut 532), thereby providing the ability to enhance the fixation of the bone anchor 502 with the auxiliary bone anchor 534 having an angular trajectory. The closure mechanism 508 may be secured to the receiving body member 504 to capture a spinal fixation element (e.g., a spinal rod 506) within the receiving body member. Tightening or locking the closure mechanism 508 may effectively secure the spinal rod 506 relative to the receiving body member 504 and fix the angular position of the bone anchor 502 relative to the receiving body member 504.

[0118] The bone anchor 502, the receiving body member 504, the closure mechanism 508, the nut 532, and the auxiliary bone anchor 534 are substantially similar to those described above with reference to FIG. Figures 2A to 2MThe bone anchor 202, the receiving body member 204, the closing mechanism 208, the nut 232 and the auxiliary bone anchor 234 are described. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The bone anchor assembly 500 may include any one or more of the features of the bone anchor assembly 200 and / or the bone anchor assembly 100 described above.

[0119] In the illustrated embodiment, the bracket or wing 530 may include a proximal portion 530p, an angled distal portion 530d, and a spanning portion 530s connecting the proximal portion of the wing to the distal portion. The proximal portion 530p of the wing 530 may extend horizontally from the proximal end of the spanning portion 530s of the wing 530. The proximal portion 530p may include a proximal facing surface 540 and a distal facing surface 542. The proximal facing surface 540 of the proximal portion 530p of the wing 530 may be domed or rounded to provide a trauma-free surface and reduce the risk of tissue inflammation after implantation. The distal facing surface 542 of the proximal portion 530p of the wing 530 may be configured to abut against the proximal terminal or surface of the receiver member 504. The distal facing surface 542 may form a negative or substantially negative of the proximal terminal or surface of the receiver member 504. For example, the proximal-facing surface of the arms of the receiver member 504 may be radially convex, and the distal-facing surface 542 of the wings 530 may define a radially concave channel (not shown) that receives the convex end of the arm.

[0120] The proximal portion 530p of the wing 530 may define a central opening 536 extending through the proximal-facing surface 540 and the distal-facing surface 542. The central opening 536 may be oriented so that the central axis of the opening A3 is perpendicular or substantially perpendicular to the distal-facing surface 542 of the proximal portion 530p of the wing 530. The size of the central opening 536 may be set so that the closing mechanism 508 can be inserted through the opening and extend at least partially above the proximal-facing surface 540 of the proximal portion 530p of the wing 530. The central opening 536 may include a smooth non-threaded interior surface to allow the wing 530 and the closing mechanism 508 to rotate freely relative to each other. The size and configuration of the central opening 536 or another feature of the wing 530 may be set to snap fit or capture a portion of the closing mechanism 508 or the proximal surface of the receiving body member 504. In the exemplary embodiment shown, a counterbore 560 can be formed around the central opening 536 in the distally facing surface 542 of the proximal portion 530p of the wing 530 to accommodate a radially extending shoulder portion of the closure mechanism 508 that can extend over the proximal terminal end of the receiver member 504. FIG. 4A to FIG. 4C The structure and function of counterbore 560 are discussed in more detail.

[0121] The spanning portion 530s of the wing 530 can extend vertically in the near-distal direction to connect the proximal portion 530p of the wing to the distal portion 530d of the wing. The spanning portion 530s of the wing 530 can be an elongated arm that extends distally from the sidewall of the proximal portion 530p of the wing in a vertical or substantially vertical plane. The spanning portion 530s of the wing 530 can have a lateral surface 550 that engages or faces the sidewall of the receiver member 504. The lateral surface 550 can form the negative sidewall of the receiver member 504 so that the spanning portion 530s of the wing 530 can be close to the receiver member with a minimum gap or zero gap therebetween. For example, the lateral surface 550 can be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer sidewall of the receiver member 504. The proximal portion 530p, the distal portion 530d and the spanning portion 530s may be integrally formed as an integral unit as shown, or one or more of the components may be separate and selectively attached to other components. In some embodiments, a kit of modular components may be provided to allow selection of the components most appropriate for a given use. For example, a spanning portion 530s of an appropriate height may be selected based on the distance between the proximal end of the receiver member 504 and the bone surface in a given application.

[0122] In some embodiments, the wing 530 may include various features of a unilateral locking interface, including, but not limited to, one or more grooves 570a, 570b and a surface protrusion 570c. The unilateral locking interface enables a surgical instrument including a unilateral locking mechanism (not shown) to be rigidly retained on one side of the wing 530. An exemplary unilateral locking interface that may be included in the wing 530 is disclosed in U.S. Patent Application No. 15 / 843,618, entitled “Unilateral Implant Holders and Related Methods,” filed on December 15, 2017, the entire contents of which are incorporated herein by reference.

[0123] The angled distal portion 530d of the wing 530 can extend outwardly from the distal end of the spanning portion 530s away from the receiver member 504. The extent to which the wing 530 extends outwardly from the receiver member 504 can vary between different embodiments. In the illustrated embodiment, the ratio of the wing extension to the rod diameter (or the ratio of the wing extension to the width of the rod receiving recess in the receiver member) is about 2:1. In some embodiments, the ratio can be less than about 10:1, less than about 5:1, less than about 3:1, less than about 2:1, less than about 1:1, and / or less than about 0.5:1. In some embodiments, the ratio can be about 10:1, about 5:1, about 3:1, about 2:1, about 1:1, or about 0.5:1.

[0124] When from Figure 3EWhen viewed from a perspective of , the angled distal portion 530d is angled to the right of the vertically disposed spanning portion 530s of the wing 530. As shown, the angled distal portion 530d includes a distal surface 546 and a proximal surface 548. The distal surface 546 and the proximal surface 548 may be oriented parallel or substantially parallel. The surface 546 facing the distal side may include teeth, textures or other surface features to enhance the clamping with the adjacent bone. The distal portion 530d of the wing 530 may have a lateral surface 552 adjacent to or facing the side wall of the receiving body member 504. The lateral surface 552 may form the negative side wall of the receiving body member 504, so that the distal portion 530d of the wing 530 may be close to the receiving body member with a minimum gap or zero gap therebetween. For example, the lateral surface 552 may be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer side wall of the receiving body member 504.

[0125] The distal portion 530d of the wing 530 can define an opening 544 extending through the proximal surface 548 and the distal surface 546 to receive the auxiliary bone anchor 534. The size of the bone anchor opening 544 can be set to insert the distal shaft of the auxiliary bone anchor 534 through the opening and abut the proximal head of the auxiliary bone anchor when the auxiliary bone anchor is disposed therein. As shown in the illustrated embodiment, the bone anchor opening 544 can be oriented perpendicular to or substantially perpendicular to the distal surface 546 of the wing 530. In other arrangements, the nominal axis or central axis of the bone anchor opening can be obliquely angled relative to the distal surface 546 and / or the proximal surface 548. The distal surface 546 of the wing 530 and / or the proximal surface 548 of the wing can be obliquely angled relative to the vertical or proximal-distal axis of the wing. For example, as shown, the distal surface 546 is angled to face the right side of the vertically disposed spanning portion 530s. In such embodiments, the central axis A2 of the bone anchor opening 544 can extend downward and rightward at an oblique angle relative to the proximal-distal axis A1 of the spanning portion 530s of the wing. Figure 3A This arrangement may facilitate various bone anchor placements in which the distal end of the auxiliary bone anchor is located to the right of the spanning portion 530s of the wing when viewed from the perspective of FIG.

[0126] For example, Figure 3AAs shown, such bone anchor placements may include placements in which the wing 530 is disposed lateral to the spinal rod 506 and in which the auxiliary bone anchor 534 is driven through the bone anchor opening 544 utilizing a cephalad trajectory (i.e., toward the patient's head). This orientation may allow the auxiliary bone anchor 534 to remain entirely within the same vertebral segment as the primary bone anchor 502, such as within the lateral mass of the vertebra. It should be understood that the wing 530 may be flipped to be positioned on the other side of the illustrated rod 506 (e.g., on the inside of the rod), or on the outside of the contralateral spinal rod (not shown). In these cases, the positioning of the wing 530 may facilitate bone anchor placements in which the auxiliary bone anchor 534 may be driven through the bone anchor opening 544 utilizing a caudal trajectory (i.e., toward the patient's foot). In some embodiments, as described below with reference to Figure 5A As further discussed, the caudal trajectory can allow the auxiliary bone screw 534 to be secured in multiple cortical bone layers, such as at least two, at least three, or more. The angled distal portion 530d can allow for placement of the above-described bone anchor while maintaining the distal surface 546 of the wing 530 in contact with or in close proximity to the bone surface (e.g., within 0 mm to 3 mm).

[0127] In some embodiments, the distal surface 546 of the wing 530 may be obliquely angled to secure the central axis A2 of the bone anchor opening 544 to the right side of the spanning portion 530s of the wing 530 at any oblique angle, depending on the requirements of a particular application. Figure 3E As shown, the distal surface 546 of the distal portion 530d of the wing 530 can be obliquely angled so that the central axis A2 of the bone anchor opening 544 extends at an angle of 35 degrees to the right of the proximal distal axis A1 of the spanning portion 530s of the wing 530. Therefore, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 544, wherein the distal axis of the anchor has an angular trajectory that is coaxial with the central axis A2 of the bone anchor opening 544 to the right of the spanning portion 530s or within a defined angled cone relative to the central axis. In some embodiments, the distal surface 546 of the wing 530 can be obliquely angled so that the central axis A2 of the bone anchor opening 544 can extend to the right of the proximal distal axis A1 of the spanning portion 530s at an angle between 15 degrees and 45 degrees (including the end values).

[0128] In some embodiments, the distal surface 546 of the wing 530 can be further angled to face inwardly or outwardly relative to the vertically disposed spanning portion 530s of the wing 530. By angling the distal surface 546 inwardly or outwardly, the distal portion 530d can facilitate placement of an auxiliary bone anchor through a bone anchor opening 544 having a medial trajectory component or a lateral trajectory component in addition to or as an alternative to a cranial trajectory component or a caudal trajectory component. In some embodiments, angling the distal surface 546 inwardly or outwardly can facilitate bone anchor placement in which the auxiliary bone anchor 534 is secured within the lateral mass of the vertebra. In some embodiments, angling the distal surface 546 of the wing 530 inwardly or outwardly can provide clearance for a driving instrument on the proximal surface 548 side of the distal portion 530d of the wing 530 to enter the bone anchor opening 544. In some embodiments, the distal surface 546 of the wing 530 can be angled obliquely inwardly or outwardly to fix the central axis A2 of the bone anchor opening 544 at any medial or lateral angle relative to the proximal-distal axis A1 of the spanning portion 530s of the wing 530, based on the requirements of a particular application. Figure 3F As shown, the distal surface 546 of the distal portion 530d of the wing 530 can be angled to face inwardly toward the spanning portion 530s of the wing 530 so that the central axis A2 of the bone anchor opening 544 extends inwardly at a medial angle of 15 degrees relative to the proximal-distal axis A1 of the spanning portion 530s. Thus, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 544, wherein the distal axis of the anchor has a medial trajectory that is coaxial with the central axis A2 of the bone anchor opening 544 or within a defined angled cone relative to the central axis. In some embodiments, the distal surface 546 of the distal portion 530d of the wing 530 can be obliquely angled so that the central axis A2 of the bone anchor opening 544 can extend at a medial angle between 5 degrees and 20 degrees, inclusive.

[0129] Alternatively, if Figure 3G As shown, the distal surface 546 of the distal portion 530d of the wing 530 can be angled to face outwardly away from the spanning portion 530s so that the central axis A2 of the bone anchor opening 544 extends outwardly at a lateral angle of 15 degrees relative to the proximal distal axis A1 of the spanning portion 530s of the wing 530. Thus, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 544, wherein the distal axis of the anchor has a lateral trajectory that is coaxial with the central axis A2 of the bone anchor opening 544 or within a defined angled cone relative to the central axis. In some embodiments, the distal surface 546 of the distal portion 530d of the wing 530 can be obliquely angled so that the central axis A2 of the bone anchor opening 544 can extend at a lateral angle between 5 degrees and 20 degrees (including the end values). Such embodiments can be used to accommodate the bony anatomy of the lumbar spine.

[0130] Figure 3H for Figure 3A FIG. 5 is a top view of the wing 530 of the bone anchor assembly of FIG. 5 , wherein the angled distal portion 530d faces in the caudal direction. Figure 3H As shown, from a posterior perspective, the wing 530 can be positioned so that the angled distal portion 530d extends laterally to the left of the spinal midline and thus faces in a caudal direction. In this exemplary caudal configuration, the angled distal portion 530d of the wing 530 has an upper end 580, a lower end 582, a free lateral end 584 extending between the upper and lower ends, and a medial end 586 extending between the upper and lower ends. When the angled distal portion 530d faces caudally, the upper end 580 of the distal portion 530d is farther (or lower) than the lower end 582, so that the distal surface 546 faces in the caudal direction. In some embodiments, when the distal portion 530d is also angled medially (e.g., as described above in Figure 3F ), the upper end 580 of the distal portion 530d is further than the lower end 582 and the free lateral end 584 is further than the medial end, so that the distal surface 546 faces both the caudal direction and the medial direction. In some embodiments, when the distal portion 530d is also angled laterally (e.g., as described above in Figure 3G ), the upper end 580 of the distal portion 530d is further than the lower end 582 and the medial end 586 is further than the free lateral end 584, so that the distal surface 546 faces both the caudal direction and the lateral direction.

[0131] Fig. 3I for Figure 3A FIG. 5 is a top view of the wing 530 of the bone anchor assembly of FIG. 5 , wherein the angled distal portion 530d faces in the cephalad direction. Fig. 3I As shown, from a posterior perspective, the wing 530 can be positioned so that the distal portion 530d extends laterally to the right of the spinal midline and therefore faces in the cephalad direction. In this exemplary cephalad configuration, the angled distal portion 530d of the wing 530 has an upper end 590, a lower end 592, a free lateral end 594 extending between the upper and lower ends, and a medial end 596 extending between the upper and lower ends. With the distal portion 530d facing cephalad, the lower end 592 of the distal portion 530d is further (or lower) than the upper end 590, so that the distal surface 546 faces in the cephalad direction. In some embodiments, when the distal portion 530d is also angled medially (e.g., as described above in Figure 3F), the lower end 592 of the distal portion 530d is further (or lower) than the upper end 590 and the free lateral end 594 is further than the medial end 596, so that the distal surface 546 faces in both the cephalad direction and the medial direction. In some embodiments, when the distal portion 530d is also angled laterally (e.g., as described above in Figure 3G ), the lower end 592 of the distal portion 530d is further (or lower) than the upper end 590, and the medial end 596 is further than the free lateral end 594, so that the distal surface 546 faces in both the caudal and lateral directions.

[0132] In some embodiments, the bone anchor opening 544 may include any of a number of features for receiving the bone anchor 534 at different angles. Figures 2A to 2M As described, the bone anchor opening 544 may be at least partially threaded to receive a variable angle locking screw having a threaded proximal head. As shown, the opening 544 may have a plurality of threaded columns spaced apart to define a plurality of non-threaded recesses. In the illustrated embodiment, the opening 544 has four threaded columns. The threaded columns may be arranged around the inner surface of the opening 544 for engaging the threads on the head of the locking auxiliary bone anchor and / or the variable angle locking auxiliary bone anchor. Therefore, the auxiliary bone anchor 534 may be coaxially locked with the central axis A2 of the opening 544 together with the wing 530, or locked at a selected angle within a selectable angle range relative to the central axis A2 of the opening 544. The auxiliary bone anchor 534 may include a feature that facilitates such variable angle locking, such as a proximal head that is at least partially spherical, the sphere having a thread having a profile that follows the arc curvature radius of the spherical portion of the head side. The variable angle capability of the screw / opening interface may allow the user to place the locking auxiliary bone anchor into the bone at any angle within the defined angulation limit. In some embodiments, the interior surface of the opening 544 can be smooth or spherical, without threads or locking features.

[0133] In some embodiments, the most proximal extent of each auxiliary bone anchor 534 can be located distal to the spinal rod 506. In other embodiments, the most proximal extent of each auxiliary bone anchor 534 can be located distal to the most distal extent of the receiving body member 504. These configurations can advantageously reduce the overall profile of the assembly 500. The wing 500 can be Z-shaped or substantially Z-shaped. Although one bone anchor opening 544 is shown in the illustrated embodiment, it should be understood that the wing 530 can include any number of bone anchor openings (e.g., one, two, three, four, five, etc.).

[0134] FIG. 4A to FIG. 4C The wings or brackets 530 are shown fixed to 3A to 3H508p of the bone anchor assembly 500. As described above, the proximal portion 530p of the wing can include a distally facing surface 542 that is configured to abut against a proximal terminal end or surface of the receiving body member 504 when the wing 530 is secured to the receiving body member. For example, in some embodiments, the closure mechanism 508 is in the form of a threaded post having a distal portion 508d of increased diameter and a proximal portion 508p of reduced diameter. The distal portion 508d of the closure mechanism 508 can be threaded into the receiving body member 504 to engage the spinal rod 506 disposed in the receiving body member. The proximal portion 508p of the closure mechanism 508 can protrude above the receiving body member 504 (e.g., above the proximal terminal end or surface of the receiving body member) and pass through the opening 536 formed in the wing.

[0135] However, there may be circumstances where the distal portion 508d of the closure mechanism 508 may not be fully threaded into the receiver member 504, which may result in the radially extending shoulder portion 508s of the closure mechanism 508 protruding above the proximal end of the receiver member 504. In such circumstances, the shoulder portion 508s of the closure mechanism 508 may cause the proximal portion 530p of the wing 530 to abut against the distally facing surface 542 of the wing, thereby preventing the proximal portion 530p from abutting against the receiver member 504. This may result in a less reliable and / or inconsistent tightening of the wing 530 to the bone anchor assembly 500.

[0136] like Figure 4A and Figure 4B As shown in the exemplary embodiment of the embodiment of the present invention, a counterbore 560 can be formed around the opening 536 in the distally facing surface 542 of the proximal portion 530p to more consistently secure the wing 530 to the bone anchor assembly 500. The counterbore 560 can be an annular ring or channel formed around the opening 536. The counterbore 560 can be sized to accommodate the width of the shoulder portion 508s. The depth or height of the counterbore 560 can be configured to at least partially receive the shoulder portion 508s protruding above the receiving body member 504 so as to maintain contact between the proximal portion 530p of the wing 530 and the proximal facing surface of the receiving body member 504. The depth or height of the counterbore 560 can be configured to not exceed a threshold depth or height at which the closure mechanism can disengage from the spinal rod, thereby compromising the fixation of the rod 506 within the receiving body member 504. Embodiments including the counterbore can provide a more reliable and / or consistent fastening by ensuring that the wing is always fastened to the receiving body member, regardless of the vertical position of the closure mechanism.

[0137] Alternatively or additionally, if Figure 4CAs shown in the exemplary embodiment of , the size of the closing mechanism 508 can be set so that the radially extending shoulder portion 508s is configured to always extend above the receiving body member 504. In such an embodiment, the distally facing surface 542 of the proximal portion 530d of the wing 530 abuts against the radially extending shoulder portion 508s of the closing mechanism 508 instead of the receiving body member 504. For example, as Figure 4C As shown, the enlarged diameter distal portion 508d of the closure mechanism 508 can be configured with an extended height H that allows the shoulder portion 508s of the closure mechanism 508 to protrude above the receiving body member 504 when in contact with the spinal rod 506. Such an embodiment can provide a more reliable and / or consistent tightening of the wings 530 by ensuring that the wings are always tightened to the closure mechanism regardless of the vertical position of the closure mechanism.

[0138] As described above, some embodiments of the bone anchor assembly may include a wing having a distal portion that is angled to the left of the vertically disposed wing. In such embodiments, the auxiliary bone anchor may be configured to pass through the opening in the distal portion using a caudal trajectory or a cephalad trajectory similar to those trajectories facilitated by the wing 530 of the bone anchor assembly 500 when the bone anchor assembly is implanted on the opposite side of the patient's spine (i.e., the patient's left hand side).

[0139] FIG. 5A to FIG. 5F An exemplary embodiment of a bone anchor assembly 700 including a bracket or wing 730 having an angled distal portion 730d is shown. As shown, the bone anchor assembly 700 includes a bone anchor 702, a receiving body member 704, a closure mechanism 708, a bracket or wing 730, a nut 732, and an auxiliary bone anchor 734. The bone anchor 702, the receiving body member 704, the closure mechanism 708, the nut 732, and the auxiliary bone anchor 734 are substantially similar to those described above with reference to FIG. Figures 2A to 2M The bone anchor 202, receiving body member 204, closing mechanism 208, nut 232 and auxiliary bone anchor 234 are described. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The bone anchor assembly 700 may include any one or more of the features of one or more of the above-mentioned bone anchor assemblies.

[0140] like FIG. 5A to FIG. 5F As shown, the bracket or wing 730 may include a proximal portion 730p, an angled distal portion 730d, and a spanning portion 730s connecting the proximal portion of the wing to the distal portion. The proximal portion 730p and the spanning portion 730s of the wing 730 are substantially similar to those described above with reference to FIG. 3A to FIG. 3I as well as FIG. 4A to FIG. 4CThe proximal portion 530p and the spanning portion 530s of the wing 530 are described above. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The wing 730 may include any one or more of the features of the wing 500 described above.

[0141] In the illustrated embodiment, the distal portion 730d of the wing 730 is substantially similar to the distal portion 530d of the wing 500, except that the distal portion 730d is angled to the left of the vertically disposed spanning portion 730s (when viewed from the left). Figure 5D ). As shown, the angled distal portion 730d may include a distal surface 746 and a proximal surface 748 that may be oriented parallel or substantially parallel. The distal portion 730d of the wing 730 may define an opening 744 extending through the proximal surface 748 and the distal surface 746 to receive the auxiliary bone anchor 534. As shown in the illustrated embodiment, the bone anchor opening 744 may be oriented perpendicular or substantially perpendicular to the distal surface 746 of the wing 730. In other arrangements, the nominal axis or central axis of the bone anchor opening may be obliquely angled relative to the distal surface 746 and / or the proximal surface 748. The distal surface 746 of the wing 730 and / or the proximal surface 748 of the wing may be obliquely angled relative to the vertical or proximal-distal axis of the wing. For example, as shown, the distal surface 546 is angled to face the left side of the vertically disposed spanning portion 730s. In such embodiments, the central axis A2 of the bone anchor opening 744 can extend downward and leftward at an oblique angle relative to the proximal-distal axis A1 of the spanning portion 730s of the wing. Figure 5A This arrangement may facilitate various bone anchor placements in which the distal end of the auxiliary bone anchor is located to the left of the spanning portion 530s of the wing when viewed from the perspective of FIG.

[0142] For example, Figure 5A As shown, such bone anchor placement may include placement in which the wings 730 are disposed lateral to the spinal rod 506 and in which the auxiliary bone anchor 534 is driven through the bone anchor opening 744 using a caudal trajectory (i.e., toward the patient's foot). This orientation may allow the auxiliary bone anchor 534 to extend into one or more adjacent vertebral segments, such as across a facet joint. The caudal trajectory may allow the auxiliary bone screw 534 to be secured into multiple cortical bone layers, such as at least two, at least three, or more. For example, as Figure 5AAs shown, with the primary bone anchor 502 positioned in the superior vertebral segment, the bone anchor assembly 700 can achieve tricortical fixation, wherein the auxiliary bone anchor 534 spans the facet joint between the superior vertebral segment and the adjacent inferior vertebral segment. It should be understood that the wing 730 can be flipped to be positioned on the other side of the illustrated rod 506 (e.g., on the inside of the rod), or on the outside of the contralateral spinal rod (not shown). In these cases, the positioning of the wing 530 can facilitate bone anchor placement in which the auxiliary bone anchor 534 can be driven through the bone anchor opening 744 using a cephalad trajectory (i.e., toward the patient's head). As described above with reference to Figure 3A As described, the cephalad trajectory can allow the auxiliary bone anchor 534 to be completely retained within the same vertebral segment as the primary bone anchor 502, such as within the lateral mass of the vertebra. The angled distal portion 730d can allow for the above-described bone anchor placement while maintaining the distal surface 746 of the wing 730 in contact with or in close proximity to the bone surface (e.g., within 0 mm to 3 mm).

[0143] In some embodiments, the distal surface 746 of the wing 730 may be obliquely angled to secure the central axis A2 of the bone anchor opening 744 to the left side of the spanning portion 730s of the wing 730 at any oblique angle, depending on the requirements of a particular application. Figure 5D As shown, the distal surface 746 of the distal portion 730d of the wing 730 can be obliquely angled so that the central axis A2 of the bone anchor opening 744 extends at an angle of 35 degrees to the right of the proximal distal axis A1 of the spanning portion 730s of the wing 730. Therefore, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 744, wherein the distal axis of the anchor has an angular trajectory that is coaxial with the central axis A2 of the bone anchor opening 744 on the left side of the spanning portion 730s or within a defined angled cone relative to the central axis. In some embodiments, the distal surface 746 of the wing 730 can be obliquely angled so that the central axis A2 of the bone anchor opening 744 can extend to the left of the proximal distal axis A1 of the spanning portion 730s at an angle between 15 degrees and 45 degrees (including the end values).

[0144] As mentioned above Figure 3F and Figure 3GAs described, in some embodiments, the distal surface 746 of the wing 730 can be further angled to face inwardly or outwardly relative to the vertically disposed spanning portion 730s of the wing 730. In some embodiments, based on the requirements of a particular application, the distal surface 746 of the wing 730 can be angled obliquely inwardly or outwardly to fix the central axis A2 of the bone anchor opening 744 at any medial or lateral angle between 5 degrees and 20 degrees (inclusive) relative to the proximal-distal axis A1 of the spanning portion 730s of the wing 730. Thus, by angling the distal surface 746 inwardly or outwardly, the distal portion 730d can facilitate the placement of an auxiliary bone anchor 534 having a medial or lateral trajectory component in addition to or as an alternative to the cranial or caudal trajectory component passing through the bone anchor opening 744. In some embodiments, angling the distal surface 746 inwardly or outwardly can facilitate bone anchor placement in which the auxiliary bone anchor 534 is secured within the lateral mass of the vertebra. In some embodiments, angling the distal surface 746 of the wing 730 inwardly or outwardly can provide clearance for a driving instrument on the proximal surface 748 side of the distal portion 730d of the wing 730 to enter the bone anchor opening 744.

[0145] Figure 5E for Figure 5A FIG. 7 is a top view of the wing 730 of the bone anchor assembly of FIG. 7 , wherein the angled distal portion 730d faces in the cephalad direction. Figure 5E As shown, from a posterior perspective, the wing 730 can be positioned so that the distal portion 730d extends laterally to the left of the spinal midline and therefore faces in the cephalad direction. In this exemplary cephalad configuration, the angled distal portion 730d of the wing 730 has an upper end 780, a lower end 782, a free lateral end 784 extending between the upper and lower ends, and a medial end 786 extending between the upper and lower ends. When the distal portion 730d faces cephalad, the lower end 782 of the distal portion 730d is farther (or lower) than the upper end 780, so that the distal surface 746 faces in the cephalad direction. In some embodiments, when the distal portion 730d is also angled medially (e.g., as described above in Figure 3G ), the lower end 782 of the distal portion 730d is further (or lower) than the upper end 780 and the free lateral end 784 is further than the medial end 786, so that the distal surface 746 faces both the cephalad direction and the medial direction. In some embodiments, when the distal portion 730d is also angled laterally (e.g., as described above in Figure 3H ), the lower end 782 of the distal portion 730d is further (or lower) than the upper end 780, and the medial end 786 is further than the free lateral end 784, so that the distal surface 746 faces in both the head and lateral directions.

[0146] Fig. 5F for Figure 5A FIG. 7 is a top view of the wing 730 of the bone anchor assembly of FIG. 7 , wherein the angled distal portion 730d faces in the caudal direction. Fig. 5F As shown, from a posterior perspective, the wing 730 can be positioned so that the angled distal portion 730d extends laterally to the right of the spinal midline and thus faces in the caudal direction. In this exemplary caudal configuration, the angled distal portion 730d of the wing 730 has an upper end 790, a lower end 792, a free lateral end 794 extending between the upper and lower ends, and a medial end 796 extending between the upper and lower ends. When the angled distal portion 730d faces caudally, the upper end 790 of the distal portion 730d is farther (or lower) than the lower end 792, so that the distal surface 746 faces in the caudal direction. In some embodiments, when the distal portion 730d is also angled medially (e.g., as described above in Figure 3G ), the upper end 790 of the distal portion 730d is further than the lower end 792 and the free lateral end 794 is further than the medial end 796, so that the distal surface 746 faces both the caudal direction and the medial direction. In some embodiments, when the distal portion 730d is also angled laterally (e.g., as described above in Figure 3H ), the upper end 790 of the distal portion 730d is further than the lower end 792 and the medial end 796 is further than the free lateral end 794, so that the distal surface 746 faces both the caudal direction and the lateral direction.

[0147] As described above, some embodiments of the bone anchor assembly may include a wing having a distal portion that is angled inwardly or outwardly relative to a vertically disposed span portion without any right or left angulation. In such embodiments, the auxiliary bone anchor may be easily disposed through a bone anchor opening in the distal portion with either a medial or lateral trajectory.

[0148] FIG. 6A to FIG. 6E An exemplary embodiment of a bracket or wing 830 of a bone anchor assembly having an angled distal portion 830d is shown. As shown, the bracket or wing 830 may include a proximal portion 830p, an angled distal portion 830d, and a spanning portion 830s connecting the proximal portion to the distal portion. The angled distal portion 830d has a free lateral end 850 and a medial end 852. The proximal portion 830p and the spanning portion 830s of the wing 830 are substantially similar to those described above with reference to FIGS. 2A to 2B except as described below or as will be readily understood by one of ordinary skill in the art. Figure 2M , FIG. 3A to FIG. 3I as well as FIG. 5A to FIG. 5FThe proximal portion and the spanning portion of the wings 230, 530 and / or 730 are described above. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The wing 830 may include any one or more of the features of the wings 230, 530 and / or 730 described above.

[0149] In the illustrated embodiment, the distal portion 830d of the wing 830 is substantially similar to that described above with reference to FIG. 3A to FIG. 3I as well as FIG. 5A to FIG. 5F The angled distal portions 530d, 730d disclosed herein differ in that the distal portion 830d is angled inwardly toward the vertically disposed spanning portion 830s, rather than being angled relative to the right or left side of the wing 830s. The angled distal portion 830d of the wing 830 includes a distal surface 846 and a proximal surface 848. The distal surface 846 and the proximal surface 848 may be parallel or substantially parallel and slope downwardly. When the distal portion 830d is inwardly (or when it is extended from the vertically disposed spanning portion 830s), the distal portion 830d may be angled inwardly (or when it is extended from the vertically disposed spanning portion 830s). Figure 6B When angled (viewed inwardly from a perspective of the embodiment of the present invention), the free lateral end 850 is further away than the medial end 852 such that the distal surface 846 faces in an inward direction.

[0150] The distal portion 830d of the wing 830 can define one or more openings 844 extending through the proximal surface 848 and the distal surface 846 to receive the auxiliary bone anchor 534. As shown in the illustrated embodiment, the bone anchor opening 844 can be oriented perpendicular or substantially perpendicular to the distal surface 846 of the wing 830. The distal surface 846 of the wing 830 can be obliquely angled to face inwardly toward the vertically disposed spanning portion 830s of the wing 830 to fix the central axis A2 of the bone anchor opening 844 at a medial angle relative to the proximal-distal axis A1 of the spanning portion 830s. Thus, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 844, wherein the distal axis of the auxiliary bone anchor 534 has a medial trajectory that is coaxial with the central axis A2 of the bone anchor opening or within a defined angled cone relative to the central axis.

[0151] For example, in Fig.6DIn the exemplary embodiment of the embodiment of the present invention, the distal surface 846 of the distal portion 830d of the wing 830 can be angled to face inwardly toward the spanning portion 830s so that the central axis A2 of the bone anchor opening 844 extends inwardly at an angle of 15 degrees relative to the proximal-distal axis A1. Therefore, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 844, wherein the distal axis of the anchor has a medial trajectory of 15 degrees relative to the proximal-distal axis A1. In some embodiments, the distal surface 846 of the distal portion 830d of the wing 830 can be obliquely angled to fix the central axis A2 of the bone anchor opening 844 at a medial angle of between 5 degrees and 20 degrees (including the end values) relative to the proximal-distal axis A1 of the spanning portion 830s of the wing 830. In such embodiments, angling the distal surface 846 inwardly can facilitate bone anchor placement in which the auxiliary bone anchor 534 is fixed within the lateral mass of the vertebra. In some embodiments, angling the distal surface 846 of the wing 830 inwardly can provide clearance for a driving instrument on the proximal surface 848 side of the distal portion 830 d of the wing 830 to enter the bone anchor opening 544 .

[0152] exist Fig. 6E In the alternative embodiment shown, the distal portion 830d can be outward (or when Fig. 6E 830 s, and the distal surface 846 of the distal portion 830 d of the wing 830 can be angled obliquely so that the central axis A2 of the bone anchor opening 844 can extend at a lateral angle relative to the proximal distal axis A1 of the spanning portion 830 s of the wing 830 . Thus, the auxiliary bone anchor 534 can be easily disposed in the bone anchor opening 844 with the distal axis of the anchor having a lateral trajectory that is coaxial with the central axis A2 of the bone anchor opening 844 or within a defined angled cone relative to the central axis. In some embodiments, the distal surface 846 of the distal portion 830 d of the wing 830 can be obliquely angled so that the central axis A2 of the bone anchor opening 844 can extend at a lateral angle between 5 degrees and 20 degrees (including the end values, such as 15 degrees). In such embodiments, angling the distal surface 846 outwardly can facilitate bone anchor placement in which the auxiliary bone anchor 534 is secured in a lateral position.Such embodiments can be used to accommodate the bony anatomy of the lumbar spine.

[0153] As mentioned above Figures 2A to 2MAs described in the embodiments of , supplemental fixation of a primary bone anchor in a bone anchor assembly may be achieved using a wing or bracket having one or more bone anchor openings through which one or more auxiliary bone anchors may be driven into the bone. However, in some cases, surgeons may encounter difficulties in performing certain bone anchor placements having angular trajectories. The variability of the bony anatomy of the spine may make it difficult to position the distal portion of the wing proximate to the bone to facilitate proper engagement or tightening with the anchor. In addition, it may be desirable to insert the auxiliary bone anchor such that the auxiliary bone anchor extends through multiple cortical layers of the bone to obtain optimal additional fixation strength. Reference FIG. 3A to FIG. 6E In some embodiments, the angled distal portion of the wing may interfere with the bony anatomy of the spine or limit optimal placement of the auxiliary bone anchor screw in some applications. Additionally, in certain applications, it may be advantageous to use multiple auxiliary bone anchors to further secure or enhance the fixation of a primary bone anchor inserted into a vertebral block. Thus, it may be desirable to insert one or more auxiliary bone anchor screws at an angled trajectory to accommodate a specific spinal anatomy and / or surgical application while optimally enhancing the grip and fixation strength of the primary bone anchor.

[0154] In some embodiments of the present disclosure, the wing may have a distal portion defining a plurality of auxiliary bone anchor openings, wherein each of the auxiliary bone anchor openings may be offset or angled relative to the distal portion and relative to the proximal-distal axis of the wing, such that the auxiliary bone anchor can be driven into the bone block with an angular trajectory. In some embodiments, each of the auxiliary bone anchor openings may be angled such that the wing is fixed to the receiving body member and the auxiliary bone anchor can be driven into the bone block with an angular trajectory in a caudal or cephalad direction. As a non-limiting example, the auxiliary bone anchor openings may extend at an angle relative to the distal portion and the proximal-distal axis of the wing, such that an auxiliary bone anchor driven with a caudal trajectory may extend closer to the center of the bone block (e.g., a vertebra or its facet), thereby preventing undesirable interactions with the edges of the bone block. In addition, in an auxiliary bone anchor driven with a cephalad trajectory, the angular trajectory may keep the anchor within a thin lateral mass of a bone block, such as a vertebra. In some embodiments, the wing may be configured such that each of the auxiliary bone anchors may be inserted and extended completely within the vertebral segment into which the primary bone anchor is inserted. In other words, the bone anchor assembly may include a wing that may enable insertion of a plurality of auxiliary bone anchors at an angled trajectory such that the auxiliary bone anchors conform to the vertebral segment of the bone anchor assembly without intruding or crossing the facet plane. In other embodiments, the wing of the present disclosure may be configured such that at least one of the plurality of auxiliary bone anchors may be inserted at an angled trajectory to intrude upon the facet plane of the vertebral segment into which the primary bone anchor is inserted. In some embodiments, the auxiliary bone anchor may extend through multiple cortical levels and into adjacent vertebrae.

[0155] Figures 7 to 17An exemplary embodiment of a bone anchor assembly 900 is shown, which includes a bracket or wing 930 having a distal portion 930d, which defines a plurality of auxiliary bone anchor openings 944, which can extend in an offset or angled trajectory relative to both the distal portion and the proximal-distal axis of the wing. As will be discussed in more detail below, the wing of the present embodiment can facilitate the insertion of a plurality of auxiliary bone anchor screws into the vertebral segment of the bone assembly. In some embodiments, each of the auxiliary bone anchors can conform to the vertebral segment of the bone anchor assembly. Alternatively, the wing can be configured so that at least one auxiliary bone anchor screw can invade the facet plane of the vertebral segment of the bone anchor assembly and can extend into the adjacent vertebral segment. Therefore, the bone anchor assembly including the wing of the present disclosure can increase the pull-out strength of the main bone anchor by providing a plurality of auxiliary fixation points and distributing pressure in the bone. The wing can facilitate the insertion of a plurality of auxiliary bone anchors into a desired trajectory to take into account the anatomical structure of a specific spinal region and a specific surgical application. Thus, the wings of the present disclosure may provide the surgeon with more flexibility regarding placement of the auxiliary bone anchor to achieve optimal fixation strength and greater grip of the primary bone anchor.

[0156] refer to Figure 7 and Figure 8 , the bone anchor assembly 900 can be implanted in a vertebral segment 901. The vertebral segment 901 can have a first facet plane 905 and a second facet plane 907. The bone anchor assembly 900 can include a bone anchor (labeled 902 and visible in a vertebra 903 adjacent to the vertebra 901), a receiving body member 904, a closing mechanism 908, a bracket or wing 930, a nut 932, and one or more auxiliary bone anchors 934. The wing 930 can be secured to the receiving body member 904, for example, using the closing mechanism 908 and the nut 932. As described above, the wing 930 can be rotated relative to the closing mechanism 908. Prior to securing the wing 930, the wing can be placed in a desired position or configuration relative to the receiving body member. The desired position or configuration of the wing can establish a target insertion trajectory for each of the one or more auxiliary bone anchors 934 to be received with the auxiliary bone anchor opening 944. The closure mechanism 908 can be secured to the receiving body member 904 to capture a spinal fixation element (e.g., a spinal rod 906) within the receiving body member. In some embodiments, tightening or locking the closure mechanism 908 can effectively secure the spinal rod 906 relative to the receiving body member 904 and fix the angular position of the bone anchor 902 relative to the receiving body member 904.

[0157] The bone anchor 902, the receiving body member 904, the closure mechanism 908, the nut 932, and the auxiliary bone anchor 934 are substantially similar to those described above with reference to FIG. Figures 2A to 2MThe bone anchor 202, the receiving body member 204, the closing mechanism 208, the nut 232 and the auxiliary bone anchor 234 are described. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The bone anchor assembly 900 may include any one or more of the features of the bone anchor assembly 200, 500, 700 or 800 and / or the bone anchor assembly 100 described above.

[0158] As will be described in detail below, the wing 930 of this exemplary embodiment may include a plurality of auxiliary bone anchor openings when viewed from, for example, Figures 8 to 10 These auxiliary bone anchor openings are offset to the left side of the wing when viewed from the perspective of Figures 8 to 17 The operation of the drive clutch assembly 930 is described. In the illustrated embodiment, the bracket or wing 930 may include a proximal portion 930p, a distal portion 930d, and a spanning portion 930s connecting the proximal portion of the wing to the distal portion. In one embodiment, the distal portion 930d may extend perpendicularly or substantially perpendicularly to the proximal-distal axis of the spanning portion 930s. The proximal portion 930p of the wing 930 may extend horizontally from the proximal end of the spanning portion 930s. The wing 930 may be Z-shaped or substantially Z-shaped.

[0159] The proximal portion 930p may include a proximal-facing surface 940 and a distal-facing surface 942. The proximal-facing surface 940 may be domed or rounded to provide an atraumatic surface and reduce the risk of tissue inflammation after implantation. The distal-facing surface 942 of the proximal portion 930p may be configured to abut against the proximal terminal or surface of the receiver member 904. The distal-facing surface 942 may form a negative or substantially negative relationship to the proximal terminal or surface of the receiver member 904. For example, the proximal-facing surface of the arm of the receiver member 904 may be radially convex, and the distal-facing surface 942 of the wing 930 may define a radially concave channel (not shown) that receives the convex end of the arm.

[0160] The proximal portion 930p of the wing may define a central opening 936 extending through the proximal-facing surface 940 and the distal-facing surface 942. The central opening 936 may be oriented such that the central axis of the opening B1 is perpendicular or substantially perpendicular to the distal-facing surface 942 of the proximal portion 930p. In some embodiments, the size of the central opening 936 may be set so that the closing mechanism 908 can be inserted through the opening and extend at least partially above the proximal-facing surface 940 of the proximal portion 930p. The central opening 936 may include a smooth, non-threaded interior surface to allow the wing 930 and the closing mechanism 908 to rotate freely relative to each other. The size and configuration of the central opening 936 or another feature of the wing 930 may be set to snap onto or capture a portion of the closing mechanism 908 or the proximal surface of the receiving body member 904. In one embodiment, and as described above with reference to FIG. 4A to FIG. 4C As described, a counterbore can be formed around a central opening 936 in a distally facing surface 942 of the proximal portion 930p to accommodate a radially extending shoulder portion of the closure mechanism 908 that can extend over a proximal terminal end of the receiving body member 904. The proximal portion 930p of the wing portion 930 can include any of the features described herein with reference to the wing portions 230, 530, 730, and / or 830.

[0161] The spanning portion 930s of the wing 930 can extend vertically in the near-distal direction to connect the proximal portion 930p of the wing to the distal portion 930d of the wing. The spanning portion 930s of the wing 930 can be an elongated arm that extends distally from the sidewall of the proximal portion 930p in a vertical or substantially vertical plane. The spanning portion 930s can have a lateral surface 950 that engages or faces the sidewall of the receiver member 904. The lateral surface 950 can form the negative sidewall of the receiver member 904 so that the spanning portion 930s can be close to the receiver member with a minimum gap or zero gap therebetween. For example, the lateral surface 950 can be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer sidewall of the receiver member 904.

[0162] In some embodiments, wing 930 may include various features of a single-sided locking interface, including but not limited to one or more grooves and surface protrusions (not shown). As described and illustrated above with respect to wing 530, for example, Figure 3C and Figure 3D As shown, the unilateral locking interface enables a surgical instrument including a unilateral locking mechanism to be held on one side of the wing 930. An exemplary unilateral locking interface that may be included in the wing 930 is disclosed in U.S. Patent Application No. 15 / 843,618, entitled “Unilateral Implant Holders and Related Methods,” filed on December 15, 2017, the entire contents of which are incorporated herein by reference.

[0163] The proximal portion 930p, the distal portion 930d and the spanning portion 930s can be integrally formed as an integral unit as shown in the figure. Alternatively, one or more of the components can be separated and can be selectively attached to other components. In some embodiments, a kit of modular components can be provided to allow the selection of the most appropriate components for a given use. For example, a spanning portion 930s of appropriate height can be selected based on the distance between the proximal end of the receiving body member 904 and the bone surface in a given application. The length of the spanning portion can vary to accommodate auxiliary bone anchor screws of different lengths or desired auxiliary bone anchor screw entry points. In some embodiments, as described above, the length of the spanning portion can be adjustable. In other embodiments, the length of the spanning portion can be fixed.

[0164] In one embodiment, the wing 930 can be designed so that there is an air gap between the distal surface 946 of the distal portion 930d of the wing 930 and the bone surface of the vertebral segment associated with the bone anchor assembly 900. For example, the length of the span portion 930s can be selected or manufactured so that the distal surface 946 of the distal portion 930d is placed close to the bone surface without contacting the bone surface when the wing is fixed to the receiver of the bone anchor assembly. The length of the span portion to achieve this configuration can depend on various environmental factors, such as the patient's spinal anatomy, the configuration and size of the auxiliary bone anchor, and / or the constraints of a specific surgical application. The air gap between the wing 930 and the bone surface can be conducive to maintaining a tight locking connection between the wing and the receiver member. By preventing the distal portion of the wing from contacting the bone surface, the air gap eliminates upward or proximal contact forces from the bone, which may cause the connection between the wing and the receiver member to be maintained (propping up) or loose.

[0165] The distal portion 930d of the wing 930 can extend outwardly from the distal end of the spanning portion 930s away from the receiver member 904. The extent to which the wing 930 extends outwardly from the receiver member 904 can vary between different embodiments. In the illustrated embodiment, the ratio of the wing extension to the rod diameter (or the ratio of the wing extension to the width of the rod receiving recess in the receiver member) is about 2:1. In some embodiments, the ratio can be less than about 10:1, less than about 5:1, less than about 3:1, less than about 2:1, less than about 1:1, and / or less than about 0.5:1. In some embodiments, the ratio can be about 10:1, about 5:1, about 3:1, about 2:1, about 1:1, or about 0.5:1.

[0166] As can best be seen, for example, in Fig.14 and Fig.15In one embodiment, the distal portion 930d may extend outwardly perpendicularly or substantially perpendicularly to the proximal distal axis B2 of the spanning portion 930s. As shown, the distal portion 930d may have a distal surface 946 and a proximal surface 948. The distal surface 946 may be perpendicular or substantially perpendicular to the proximal distal axis B2 of the spanning portion 930s. The distal portion 930d of the wing may have a lateral surface 922 that abuts or faces the side wall of the receiving body member 904 so that the distal portion 930d of the wing 930 can accommodate components with a minimum or zero gap therebetween. For example, the lateral surface 922 may be concave, and its radius of curvature is equal to or substantially equal to the radius of curvature of the outer side wall of the receiving body member 904.

[0167] The distally facing surface 946 can be configured to contact or be positioned adjacent to a bone. In some embodiments, the distally facing surface 946 can include teeth, textures, or other surface features to enhance grip with adjacent bones. In other embodiments, the wing 930 can be configured such that an air gap exists between the distally facing surface 946 of the distal portion 930d and the proximally facing surface of the bone into which the primary bone anchor is inserted. As described above, this configuration can maintain the integrity of the connection between the wing 930 and the receiving body 904.

[0168] The distal portion 930d of the wing 930 can define a plurality of auxiliary bone anchor openings 944 that each extend through the proximal-facing surface 948 and the distal-facing surface 946 of the distal portion. Each of the plurality of auxiliary bone anchor openings 944 can be configured to receive an auxiliary bone anchor 934. As can be seen, for example, in Figures 8 to 10 , each auxiliary bone anchor opening 944 can be sized to insert the distal shaft of the auxiliary bone anchor 934 through the opening and abut the proximal head of the auxiliary bone anchor when the auxiliary bone anchor is disposed therein. Each bone anchor opening 944 can extend at an oblique angle relative to the proximal-distal axis B2 of the span portion 930s. Fig.14 , the central axis B3 of the auxiliary bone anchor opening 944 can be obliquely angled relative to the proximal-distal axis B2 of the wing, wherein the proximal-distal axis B3 extends perpendicularly or substantially perpendicularly to the distal surface 946 of the wing 930. For example, as shown, the bone anchor opening 944 can be angled to extend to the left of the vertically disposed spanning portion 930s. In such embodiments, the central axis B3 of the bone anchor opening 944 can extend downward and leftward at an oblique angle α1 relative to the proximal-distal axis B2 of the spanning portion 930s.

[0169] In some embodiments, the auxiliary bone anchor opening may extend at an oblique angle to the left of the proximal-distal axis B2 of the spanning portion 930s, depending on the requirements of a particular application. Fig.14, the central axis B3 of the auxiliary bone anchor opening 944 can extend downward and leftward at an inclined angle α1 relative to the proximal-distal axis B2 of the spanning portion 930s of the wing 930. Figures 8 to 10 This arrangement may facilitate placement of various bone anchors in which the distal end of the auxiliary bone anchor extends toward the left side of wing 930 when viewed from the perspective of FIG.

[0170] For example, the central axis B3 of each opening 944 may extend at an angle α1 of about 35 degrees to the left of the axis B2. In some embodiments, the central axis B3 of each opening 944 may extend at an angle α1 between about 0 degrees and about 60 degrees to the proximal-distal axis B2 of the spanning portion. Offsetting the central axis B3 of the auxiliary bone anchor opening by the angle α1 may establish an insertion trajectory of the auxiliary bone anchor into the bone that is angled along the cranio-caudal axis of the patient. For example, the angle α1 may be selected so that in the case of insertion of the auxiliary bone anchor in the caudal direction, the auxiliary bone anchor may be driven closer to the center of the vertebra or facet to avoid placement too close to the edge of the vertebra or facet, and in the case of insertion of the auxiliary bone anchor in the cephalad direction, the auxiliary bone anchor may remain within the thin lateral mass of the vertebra or facet. In some embodiments, the angle α1 may be between about 46 degrees and about 60 degrees to the proximal-distal axis B2 of the spanning portion. In some embodiments, angling the opening 944 to this extent can achieve the functions described above (i.e., keeping a caudally directed anchor away from the edge of the vertebra or facet or retaining a cephalad directed anchor within the thin lateral mass of the vertebra or facet). Fig.14 This arrangement may facilitate various bone anchor placements in which the distal end of the auxiliary bone anchor extends to the left side of the wing 930 when viewed from the perspective of FIG.

[0171] For example, Figure 7 As shown, such bone anchor placements may include placements in which the wing 930 is disposed lateral to the spinal rod 906 and in which the auxiliary bone anchor 934 is driven through the bone anchor opening 944 utilizing a cephalad trajectory (i.e., toward the patient's head). This orientation may allow the auxiliary bone anchor 934 to remain entirely within the same vertebral segment 901 as the primary bone anchor 902 associated with the bone anchor assembly 900, such as within the lateral mass of the vertebra. It should be understood that the wing 930 may be flipped to be positioned on the other side of the illustrated rod 906 (e.g., on the inside of the rod), or positioned lateral to the contralateral spinal rod (not shown). In these cases, the positioning of the wing 930 may facilitate bone anchor placements in which the auxiliary bone anchor 934 may be driven through the bone anchor opening 944 utilizing a caudal trajectory (i.e., toward the patient's foot). In some embodiments, as described below with reference to Fig.18As further discussed, the caudal trajectory may allow for the attachment of the auxiliary bone screw 934 to multiple cortical bone layers, such as at least two, at least three, or more. The angled auxiliary bone anchor opening 944 may allow for the above-described bone anchor placement while accommodating a particular spinal anatomy or surgical application.

[0172] In some embodiments, each of the bone anchor openings 944 may include any one of a number of features for receiving the bone anchor 934 at different angles. Figures 2A to 2M As described, each of the anchor valley openings 944 can be at least partially threaded to receive a variable angle locking screw having a threaded proximal head. As shown, the opening 944 can have a plurality of threaded columns 945 spaced apart to define a plurality of non-threaded recesses 947. In this way, the threads of the opening 944 can form an interlocking interface and cooperate with the threads of the auxiliary bone anchor to lock the auxiliary bone anchor therein. For example, Figures 8 to 10 An embodiment of the wing 930 is shown, wherein two auxiliary bone anchors 934 are engaged in the auxiliary bone anchor receiving recess 944. In one embodiment, the threads of the opening 944 can be tapered threads. The threaded column can be arranged around the inner surface of the opening 944 for engaging the threads on the head side of the locking auxiliary bone anchor and / or the variable angle locking auxiliary bone anchor. Therefore, the auxiliary bone anchor 934 can be locked coaxially with the central axis B3 of the opening 944 together with the wing 930, or locked at a selected angle within a selectable angle range relative to the central axis B3 of the opening 944. Although the illustrated embodiment has four rows of threads in the auxiliary bone anchor opening, it should be understood that the auxiliary bone anchor opening can have any number of rows of threads (e.g., two rows, three rows, four rows, five rows, etc.) to facilitate variable angle locking with the auxiliary bone anchor.

[0173] The auxiliary bone anchor 934 may include a feature that facilitates this variable angle locking, such as a proximal head that is at least partially spherical, the spherical shape having a thread that has a profile that follows the arc radius of curvature of the spherical portion of the head side. The variable angle capability of the locking interface (i.e., the screw / opening interface) may allow the user to place the locking auxiliary bone anchor into the bone at any angle limited within the angulation limit. The locking interface between the auxiliary bone anchor opening and the auxiliary bone anchor received therein may increase stability and prevent the auxiliary bone anchor from withdrawing from the opening. In addition, the interlocking interface may be biased to produce an angled trajectory for the insertion of the auxiliary bone anchor screw. In other embodiments, the interior surface of the opening 944 may be smooth or spherical, without threads or locking features.

[0174] In some embodiments, the most proximal extent of each auxiliary bone anchor 934 can be located distal to the spinal rod 906. In other embodiments, the most proximal extent of each auxiliary bone anchor 934 can be located distal to the most distal extent of the receiving body member 904. These configurations can advantageously reduce the overall profile of the assembly 900. Although two bone anchor openings 944 are shown in the illustrated embodiment, it should be understood that the wing 930 can include any number of auxiliary bone anchor openings.

[0175] In some embodiments, the central axis B3 of each of the plurality of auxiliary bone anchor openings may additionally or alternatively be offset along the medial axis. Fig.15 As best seen in , the central axis B3 of the auxiliary bone anchor opening 944 can extend inwardly or outwardly from the proximal distal axis B2 of the wing at an angle α2. The angle α2 can extend medially or inwardly toward the central axis B1 of the wing. Offsetting the trajectory of the central axis B3 of the auxiliary bone anchor opening inwardly or medially by the angle α2 can account for the lateral extension of the distal portion 930d of the wing and guide the auxiliary bone anchor 934 into the bone toward the centerline of the patient's spine. In some embodiments, α2 can be between about 0 degrees and about 30 degrees. In some embodiments, α2 can be between about 0 degrees and about 25 degrees. In still other embodiments, α2 can be between about 5 degrees and about 10 degrees.

[0176] Fig.16 yes Figures 8 to 14 The wing 930 of the bone anchor assembly is a top view of the wing including a plurality of auxiliary bone anchor openings 944 extending downward and to the left of the wing, wherein the central axis B3 of the auxiliary bone anchor opening 944 extends to the left side of the wing. Fig.16 As shown, from a posterior perspective, the wing 930 can be positioned so that the distal portion 930d extends outward from the left side of the bone anchor assembly (i.e., extends laterally from a bone anchor assembly placed on the left side of the spinal midline or extends medially from a bone anchor assembly placed on the right side of the spinal midline). With this orientation, the central axis B3 of the auxiliary bone anchor opening can extend in a cephalad direction (or toward the patient's head). In this exemplary cephalad configuration, each angled auxiliary bone anchor opening 944 has an upper surface 980 and a lower surface 982. In the case where the auxiliary bone anchor opening extends in the cephalad direction, the upper surface 980 is more proximal (or higher) than the lower surface 982, so that the opening of the auxiliary bone anchor opening 944 faces in the caudal direction, and the central axis B3 of the auxiliary bone anchor opening extends in a cephalad insertion trajectory, so that the auxiliary bone anchor received therein extends toward the patient's head. The distal portion 930 can extend substantially perpendicular to the wing, so that the distally facing surface 946 is perpendicular or substantially perpendicular relative to the proximal-distal axis B2 of the wing 930. In some embodiments, when the bone anchor opening is also angled medially (e.g., as described above in Fig.15), the surface of the bone anchor opening 944 closest to the spanning portion 930s can be closer (or higher) than the opposite surface of the bone anchor opening, i.e., the surface further away from the spanning portion. In some embodiments, where the auxiliary bone anchor opening is also laterally angled, the surface of the bone anchor opening 944 closest to the spanning portion 930s can be farther (or lower) than the opposite surface of the bone anchor opening.

[0177] Fig.17 yes Figures 8 to 14 A top view of the wing 930 of the bone anchor assembly, i.e., a wing including a plurality of auxiliary bone anchor openings extending downward and to the left of the spanning portion of the wing, wherein the central axis B3 of each of the auxiliary bone anchor openings 944 extends in the caudal direction. Fig.17 As shown, from a posterior perspective, the wing 930 can be positioned such that the distal portion 930d extends outward from the right side of the bone anchor assembly (i.e., extends medially from a bone anchor assembly placed to the left of the spinal midline or extends laterally from a bone anchor assembly placed to the right of the spinal midline). In this exemplary caudal configuration, each angled auxiliary bone anchor opening 944 has an upper end 990 and a lower end 992. Where the auxiliary bone anchor opening extends in a caudal direction, the upper end 990 is more distal (or lower) than the lower end 982 such that the opening of the auxiliary bone anchor opening 944 faces in a cephalad direction and the central axis B3 of the auxiliary bone anchor opening extends in a caudal insertion trajectory such that the auxiliary bone anchor received therein extends toward the patient's foot. The distal portion 930 can extend substantially perpendicular to the wing such that the distally facing surface 946 is perpendicular or substantially perpendicular relative to the proximal-distal axis B2 of the wing 930. In some embodiments, when the bone anchor opening is angled medially (e.g., as described above in Fig.15 ), the surface of the bone anchor opening 944 closest to the spanning portion 930s can be closer (or higher) than the opposite surface of the bone anchor opening, i.e., the surface further away from the spanning portion. In some embodiments, when the bone anchor opening is angled laterally, the surface of the bone anchor opening 944 closest to the spanning portion 930s can be farther (or lower) than the opposite surface of the bone anchor opening.

[0178] Some embodiments of the bone anchor assembly may include a wing having a distal portion defining a plurality of auxiliary bone anchor openings, wherein each of the plurality of bone anchor openings is angled to the right of a vertically disposed spanning portion of the wing. In such embodiments, the auxiliary bone anchor may be disposed to pass through the opening using a caudal trajectory or a cephalad trajectory similar to those trajectories facilitated by the wing 930 of the bone anchor assembly 900 when the bone anchor assembly is implanted on the opposite side of the patient's spine (i.e., the patient's left hand side).

[0179] Figures 18 to 23An exemplary embodiment of a bone anchor assembly 1000 is shown, which includes a bracket or wing 1030 having a distal portion 1030d that defines a plurality of auxiliary bone anchor openings 1044 that can extend in an offset or angled trajectory toward the right of a vertically disposed spanning portion 1030s of the wing 1030. As shown, the bone anchor assembly 1000 can be implanted in a vertebral segment 1001. The bone anchor assembly 1000 can include a bone anchor (labeled 1002 and visible in a vertebra 1003 that is adjacent to the vertebra 1001 associated with the bone anchor assembly 1000), a receiving body member 1004, a closure mechanism 1008, a bracket or wing 1030, a nut 1032, and one or more auxiliary bone anchors 1034 that can be, for example, Fig.18 A first layer of cortical bone 1009 inserted into the auxiliary bone anchor opening 1044 and traversing the vertebra 1001 can be seen. Fig.18 Also shown in FIG. 1 are first facet planes 1005 and second facet planes 1007 of the vertebrae. As described herein, in some embodiments, the auxiliary bone anchor 1034 can be driven on a facet plane (e.g., facet plane 1005) such that the bone anchor extends across multiple vertebrae and / or cortical bone layers of one or more vertebrae. The bone anchor 1002, receiving body member 1004, closure mechanism 1008, nut 1032, and auxiliary bone anchor 1034 are substantially similar to those described above with reference to FIG. 1 , except as described below or as will be readily appreciated by one of ordinary skill in the art. Figures 2A to 2M The bone anchor 202, receiving body member 204, closing mechanism 208, nut 232 and auxiliary bone anchor 234 are described. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The bone anchor assembly 1000 may include any one or more of the features of one or more of the above-mentioned bone anchor assemblies.

[0180] like Figures 18 to 23 As shown, the bracket or wing 1030 may include a proximal portion 1030p, a distal portion 1030d, and a spanning portion 1030s connecting the proximal portion of the wing to the distal portion. The proximal portion 1030p and the spanning portion 1030s of the wing 1030 are substantially similar to those described above with reference to Figures 7 to 17 The proximal portion 930p and the spanning portion 930s of the wing 930 are described above. Therefore, for the sake of brevity, a detailed description of their structure and function is omitted here. The wing 1030 may include any one or more of the features of the wing 930 described above.

[0181] In the illustrated embodiment, the distal portion 1030d and the auxiliary bone anchor openings 1044 of the wing 1030 are substantially similar to the distal portion 930d and the auxiliary bone anchor openings 944 of the wing 930, except that each of the auxiliary bone anchor openings 1044 is angled or oriented toward the right side of the vertically disposed spanning portion 1030s (when viewed from, e.g., Fig.21 1030s). As shown, the distal portion 1030d may extend outwardly from the distal end of the spanning portion 1030s perpendicularly or approximately perpendicularly to the proximal-distal axis B2 of the spanning portion. The distal portion 1030d may have a distally facing surface 1046 and a proximal-facing surface 1048. The distal surface 1046 may be perpendicular or substantially perpendicular to the proximal-distal axis B2 of the spanning portion 1030s. The distal portion 1030d may define a plurality of auxiliary bone anchor openings 1044 that each extend through the proximal-facing surface 1048 and the distal-facing surface 1046 and each are configured to receive an auxiliary bone anchor 1034. As shown in the illustrated embodiment, the bone anchor opening 1044 may be angled or offset to the right of the vertically extending axis B2 of the spanning portion 1030s, while the distal surface 1046 and the distal portion 1030d remain perpendicular or approximately perpendicular to the axis B2. In such embodiments, the central axis B3 of the bone anchor opening 1044 can extend downward and rightward at an oblique angle α1 relative to the proximal-distal axis B2 of the spanning portion 1030s of the wing. Fig.21 This arrangement can facilitate placement of various bone anchors in which the distal end of the auxiliary bone anchor extends toward the right side of the wing 1030 when viewed from the perspective of FIG. 1044. Although two bone anchor openings 1044 are shown in the illustrated embodiment, it should be understood that the wing 1030 can include any number of bone anchor openings (e.g., one, two, three, four, five, etc.). In some embodiments, multiple auxiliary bone anchor openings can be preferred to provide multiple additional fixation points to increase the pull-out strength of the bone anchor.

[0182] For example, Fig.18 As shown, such bone anchor placement may include placement in which the wings 1030 are disposed lateral to the spinal rod 1006 and in which the auxiliary bone anchor 1034 is driven through the bone anchor opening 1044 using a caudal trajectory (i.e., toward the patient's foot). This orientation may allow the auxiliary bone anchor 1034 to extend into one or more adjacent vertebral segments, such as across a facet joint or a facet plane of one or more adjacent vertebral segments. The caudal trajectory may allow at least one auxiliary bone anchor screw 1034 to be secured into multiple cortical bone layers, such as at least two, at least three, or more. For example, continuing with reference to Fig.18, with the primary bone anchor (not visible) of the bone anchor assembly 1000 positioned in the superior vertebral segment 1001, the bone anchor assembly can achieve tricortical fixation, wherein the auxiliary bone anchor 1034 spans the facet joint between the superior vertebral segment and the adjacent inferior vertebral segment 1003. It should be understood that the wing 1030 can be flipped to be positioned on the other side of the illustrated rod 1006 (e.g., on the inside of the rod), or on the outside of the contralateral spinal rod (not shown). In these cases, the positioning of the wing 1030 can facilitate bone anchor placement in which the auxiliary bone anchor 1034 can be driven through the bone anchor opening 1044 using a cephalad trajectory (i.e., toward the patient's head). As described above with reference to Figure 7 As described, the cephalad trajectory can allow at least one auxiliary bone anchor 1034 to remain entirely within the same vertebral segment, such as within the lateral mass of a vertebra, as the primary bone anchor 1002 of the bone anchor assembly 1000. The angled auxiliary bone anchor opening 1044 can allow for bone anchor placement as described above while accommodating specific spinal anatomy or surgical procedures.

[0183] Back to Fig.21 In some embodiments, the central axis B3 of the auxiliary bone anchor opening 1044 can be angled obliquely at any angle α1 to the right of the axis B2 of the span portion 1030s, depending on the requirements of a particular application. The axis B2 can be perpendicular or substantially perpendicular to the distally facing surface 1046 of the distal portion 1030d of the wing. For example, Fig.21As shown, the bone anchor opening 1044 can be obliquely angled such that the central axis B3 of the bone anchor opening 1044 extends at an angle α1 of 35 degrees to the right of the proximal-distal axis B2 of the spanning portion 1030s. In some embodiments, the bone anchor opening 1044 can be obliquely angled such that the central axis B3 of the bone anchor opening 1044 can extend to the right of the proximal-distal axis B2 of the spanning portion 1030s at an angle α1 between about 0 degrees and about 60 degrees. For example, the angle α1 can be selected so that if the auxiliary bone anchor is inserted in the caudal direction, the auxiliary bone anchor can be driven closer to the center of the vertebra or facet to avoid placement too close to the edge of the vertebra or facet, and if the auxiliary bone anchor is inserted in the cephalad direction, the auxiliary bone anchor can be retained within the thin lateral mass of the vertebra or facet. In some embodiments, the angle α1 can be between about 46 degrees and about 60 degrees from the proximal-distal axis B2 of the spanning portion. In some embodiments, tilting the opening 1044 to this extent can achieve the functions described above (i.e., keeping a caudally directed anchor away from the edge of a vertebra or facet or retaining a cephalad directed anchor within a thin lateral mass of a vertebra or facet). As described above, the auxiliary bone anchor 1044 can include one or more rows of threads 1045 to establish an interlocking interface with an auxiliary bone anchor received therein. In some embodiments, the interlocking interface can be a variable angle interlocking interface. Thus, the auxiliary bone anchor 1034 can be easily disposed in the bone anchor opening 1044 with the distal shaft of the anchor having an angular trajectory that is coaxial with the central axis B3 of the bone anchor opening 1044 or within a defined angled cone relative to the central axis.

[0184] As mentioned above Fig.15As described, in some embodiments, the bone anchor opening 1044 can be further angled to face inwardly or outwardly (i.e., medially or laterally) relative to the vertically disposed spanning portion 1030s. Thus, in some embodiments, the bone anchor opening 1044 can be angled obliquely inwardly or outwardly to fix the central axis B3 of the bone anchor opening 1044 at any medial or lateral angle α2 between about 0 degrees and about 30 degrees relative to the proximal-distal axis B2 of the spanning portion 1030s, based on the requirements of a particular application. In some embodiments, the bone anchor opening 1044 can be angled such that the central axis B3 extends at an angle α2 of about 5 degrees to about 10 degrees. Thus, by angling the bone anchor opening 1044 inwardly or outwardly, the distal portion 1030d can facilitate the placement of an auxiliary bone anchor 1034 having a medial or lateral trajectory component in addition to or as an alternative to a cranial or caudal trajectory component passing through the bone anchor opening 1044. In some embodiments, angling the bone anchor opening 1044 inwardly or outwardly can facilitate bone anchor placement in which the auxiliary bone anchor 1034 is fixed within the lateral mass of the vertebra. In some embodiments, angling the bone anchor opening 1044 inwardly or outwardly can provide clearance for a driver instrument to enter the bone anchor opening 1044.

[0185] Fig. 22 yes Fig.18 The wing 1030 of the bone anchor assembly is a top view of the wing including a plurality of auxiliary bone anchor openings 1044 extending downward and to the right of the wing, wherein the central axis B3 of the auxiliary bone anchor opening 944 extends to the right side of the wing. Fig. 22 As shown, from a posterior perspective, the wing 1030 can be positioned so that the distal portion 1030d extends outward from the left side of the bone anchor assembly (i.e., extends laterally from a bone anchor assembly placed on the left side of the spinal midline or extends medially from a bone anchor assembly placed on the right side of the spinal midline). With this orientation, the central axis B3 of the auxiliary bone anchor opening can extend in a caudal direction (or toward the patient's foot). In this exemplary caudal configuration, each angled auxiliary bone anchor opening has an upper end 1080 and a lower end 1082. In the case where the auxiliary bone anchor opening extends in the caudal direction, the upper end 1080 is more distal (or lower) than the lower end 1082, so that the opening of the auxiliary bone anchor opening 1044 faces in the cephalad direction, and the central axis B3 of the auxiliary bone anchor opening extends in a caudal insertion trajectory so that the auxiliary bone anchor received therein extends toward the patient's head. The distal portion 1030 can extend substantially perpendicular to the wing, so that the distally facing surface 1046 is perpendicular or substantially perpendicular relative to the proximal-distal axis B2 of the wing 1030. In some embodiments, when the bone anchor opening is also angled medially (e.g., as described above with reference to Fig.15In some embodiments, when the auxiliary bone anchor opening is laterally angled, the surface of the bone anchor opening 1044 closest to the spanning portion 1030s may be further away (or lower) than the opposite surface of the bone anchor opening.

[0186] Fig.23 yes Fig.18 The wing 1030 of the bone anchor assembly is a top view of the wing including a plurality of auxiliary bone anchor openings 1044 extending downward and to the right of the wing, wherein the central axis B3 of the auxiliary bone anchor opening 944 extends to the right side of the wing. Fig.23 As shown, from a posterior perspective, the wing 1030 can be positioned so that the distal portion 1030d extends outward from the right side of the bone anchor assembly (i.e., extends medially from a bone anchor assembly placed to the left of the spinal midline or extends laterally from a bone anchor assembly placed to the right of the spinal midline). With the distal portion 1030d extending laterally relative to the right side of the spinal midline, the central axis B3 of the auxiliary bone anchor opening can extend in a cephalad direction (or toward the patient's head). In this exemplary cephalad configuration, each angled auxiliary bone anchor opening 1044 has an upper end 1090 and a lower end 1092, wherein the upper end 1090 is more proximal (or higher) than the lower end 1092, such that the opening of the auxiliary bone anchor opening 1044 faces in a caudal direction, and the central axis B3 of the auxiliary bone anchor opening extends in a cephalad insertion trajectory such that the auxiliary bone anchor received therein extends toward the patient's head. The distal portion 1030 can extend substantially perpendicular to the spanning portion such that the distally facing surface 1046 is perpendicular or substantially perpendicular relative to the proximal-distal axis B2 of the wing 1030. In some embodiments, when the bone anchor opening is also angled medially (e.g., as described above with reference to Fig.15 In some embodiments, when the bone anchor opening is angled laterally, the surface of the bone anchor opening 1044 closest to the spanning portion 1030s may be further away (or lower) than the opposite surface of the bone anchor opening, i.e., the surface further away from the spanning portion.

[0187] Reference below Fig.24 Exemplary methods of using the bone anchor assemblies disclosed herein are described.

[0188] In step 1110, a surgical procedure may be initiated. For example, the procedure may be initiated by making an opening or percutaneous incision in the patient to access the bone in which the bone anchor assembly is implanted. The bone may be prepared to receive the bone anchor assembly as known in the art. For example, a standard awl, probe, and percussion procedure may be used to prepare the pedicle of a vertebra.

[0189] Next, the bone anchor is then advanced into the bone in step 1120. After the primary bone anchor is advanced into the bone, i.e., the patient's vertebrae, the user may evaluate the fixation of the bone anchor given the patient's anatomy and the particular circumstances of the surgical application in step 1130. If the user feels that the bone anchor has insufficient grip, or otherwise requires supplemental fixation, a supplemental fixation member selected based on the particular application may be added to the bone anchor assembly in step 1140. The selected fixation member may then be placed in a desired position relative to the bone anchor assembly (1150) and secured (1160). With the fixation member secured, at least one supplemental bone anchor screw may be driven into the bone to provide supplemental fixation for the bone anchor (1170).

[0190] For example, see Figures 2A to 2M In an embodiment of the present invention, the spinal rod 206 can be placed in the receiving body member 204, and the closing mechanism 208 can be threaded down onto the rod. The wing 230 can then be positioned over the closing mechanism 208 and secured in place with a nut 232. One or more auxiliary bone anchors 234 can be inserted through the wing 230 to attach the construct to the bone at a second location (or at more than two locations). The method can include bending or flexing the wing 230 to better fit the receiving body member 204 or the bone surface, such as by squeezing the legs 258 of the wing together to increase the height of the wing.

[0191] For example, see FIG. 3A to FIG. 3I In an embodiment of the present invention, the spinal rod 506 can be placed in the receiving body member 504, and the closing mechanism 508 can be threaded downwardly onto the rod. The wing 530 can be positioned above the closing mechanism 508 and secured in place with a nut 532. As described above, the wing 530 can include a distal portion 530d that is angled to the right side of the wing 530. Therefore, when the wing is positioned lateral to the bone anchor disposed on the left side of the spinal midline (when viewed from a rear vantage point), the auxiliary bone anchor 534 can be inserted through the bone anchor opening 544 and driven into the bone with a caudal trajectory. When the wing is positioned lateral to the bone anchor disposed on the right side of the spinal midline (when viewed from a rear vantage point), the auxiliary bone anchor 534 can be inserted through the bone anchor opening 544 and driven into the bone with a cephalad trajectory.

[0192] For example, see FIG. 5A to FIG. 5FIn an embodiment of the present invention, the spinal rod 506 can be placed in the receiving body member 504, and the closing mechanism 508 can be threaded downwardly onto the rod. The wing 730 can be positioned above the closing mechanism 508 and secured in place with a nut 532. As described above, the wing 730 can include a distal portion 730d that is angled to the left side of the wing 730. Therefore, when the wing is positioned lateral to the bone anchor disposed on the left side of the spinal midline (when viewed from a rear vantage point), the auxiliary bone anchor 534 can be inserted through the bone anchor opening 744 and driven into the bone with a cephalad trajectory. When the wing is positioned lateral to the bone anchor disposed on the right side of the spinal midline (when viewed from a rear vantage point), the auxiliary bone anchor 534 can be inserted through the bone anchor opening 744 and driven into the bone with a caudal trajectory.

[0193] For example, see FIG. 6A to FIG. 6D In some embodiments, the spinal rod 506 can be placed in the receiving body member 504, and the closing mechanism 508 can be threaded downwardly onto the rod. The wing 830 can be positioned above the closing mechanism 508 and secured in place with a nut 532. As described above, in some embodiments, the wing 830 can include a distal portion 830d that is angled inwardly toward the span portion 830s of the wing 830. Therefore, when the wing is positioned lateral to the bone anchor disposed to the left or right of the spinal midline (when viewed from a rear vantage point), the auxiliary bone anchor 534 can be inserted through the bone anchor opening 844 and driven into the bone with a medial trajectory. In some embodiments, the wing 830 can include a distal portion 830d that is angled outwardly away from the span portion 830s of the wing 830. Thus, when the wings are positioned lateral to a bone anchor disposed to the left or right of the spinal midline (when viewed from a posterior vantage point), the auxiliary bone anchor 534 may be inserted through the bone anchor opening 844 and driven into the bone at a lateral trajectory.

[0194] For example, see Figures 7 to 23In an embodiment, a spinal rod may be placed in a receiving body member of a bone anchor assembly, and a closing mechanism may be threaded downwardly onto the rod. After assessing the need to enhance the fixation of the bone anchor assembly using an auxiliary fixation member, a user may determine the optimal placement and trajectory of one or more auxiliary bone anchor screws to be received in the auxiliary fixation member. For example, a user may assess the patient's spinal anatomy, the goals of a particular surgical procedure, and the condition of the surrounding vertebrae to determine whether the desired auxiliary fixation should include one or more auxiliary bone anchor screws that invade the facet plane of the bone into which the bone anchor assembly is inserted. This may be suitable for applications that do not require preservation of movement between adjacent vertebrae. For example, in a surgical procedure in which a bone anchor assembly is inserted into a vertebral segment that is fused to an adjacent vertebral segment, the fixation strength of the bone anchor assembly may be increased by driving at least one auxiliary bone anchor screw through multiple layers of cortical bone. In other embodiments, the desired auxiliary fixation may include one or more auxiliary bone anchor screws that extend completely within the bone, i.e., the vertebral segment into which the bone anchor assembly is inserted, without any auxiliary bone anchor screws that extend beyond the bone. For example, such a method may be optimal in surgical applications in which movement between adjacent vertebrae is desired to be preserved. In some embodiments, it may be desirable to use multiple supplemental bone anchor screws to enhance fixation of the bone anchor assembly.

[0195] The user may then select an appropriate supplemental fixation member, again taking into account the patient anatomy and the requirements of the particular surgical application, to achieve the desired supplemental fixation. As a non-limiting example, when selecting an appropriate supplemental fixation member, the user may consider factors such as the position of the bone anchor assembly relative to the patient's spinal midline, spinal anatomy, and bone quality in the surgical area. For example, in a surgical procedure performed in a vacuum spine, the user may wish to angle the supplemental bone anchor screws so that each bone anchor screw conforms to the direction of the facet plane of the vertebra so as not to intrude on a non-fused level.

[0196] In some embodiments, the wing 930 can be positioned above the closure mechanism 908 of the bone anchor assembly 900 and secured in place with a nut 932. As described above, the wing 930 can include a distal portion 930d having a plurality of auxiliary bone anchor openings 944 extending in an offset trajectory toward the left side of the wing 930. Thus, when the wing is positioned lateral to a bone anchor disposed to the left of the spinal midline (when viewed from a posterior vantage point), the auxiliary bone anchor 934 can be inserted through the bone anchor openings 944 and driven into the bone in a caudal trajectory. When the wing is positioned lateral to a bone anchor disposed to the right of the spinal midline (when viewed from a posterior vantage point), the auxiliary bone anchor 934 can be inserted through the bone anchor openings 944 and driven into the bone in a cephalad trajectory.

[0197] For example, Figure 7As shown, the primary bone anchor may be implanted in a vertebra 901 using a bone anchor assembly 900. The vertebra 901 may be defined by an upper facet plane 905 and a lower facet plane 907. As described above, the wing 930 may be placed and secured in a desired position using fasteners 932 so that the bone anchor 934 may be inserted and driven in a trajectory that conforms to the vertebra 901 without intruding the facet planes 905, 907. A driving instrument 909 may be used to insert the bone anchor 934 into an auxiliary bone anchor opening 944 in the distal portion 930 of the wing. Figure 7 In the illustrated embodiment, the wing 930 is placed on the side of the left side of the receiving body 904. The central axis of the bone anchor opening 944 of the wing 930 extends in the cephalad direction so that the auxiliary bone anchor received therein extends toward the patient's head.

[0198] In other embodiments, the wing 1030 can be positioned above the closure mechanism 1008 of the bone anchor assembly 1000 and secured in place with the nut 1032. As described above, the wing 1030 can include a distal portion 1030d having a plurality of auxiliary bone anchor openings 1044 extending in an offset trajectory toward the right side of the wing 1030. Thus, when the wing is positioned lateral to a bone anchor disposed to the left of the spinal midline (when viewed from a posterior vantage point), the auxiliary bone anchor 1034 can be inserted through the bone anchor openings 1044 and driven into the bone in a cephalad trajectory. When the wing is positioned lateral to a bone anchor disposed to the right of the spinal midline (when viewed from a posterior vantage point), the auxiliary bone anchor 1034 can be inserted through the bone anchor openings 1044 and driven into the bone in a caudal trajectory.

[0199] As described above, some embodiments of the wing may include one or more auxiliary bone anchor openings having an interlocking interface that can facilitate a variable angle locking connection with an auxiliary bone anchor screw. Thus, in these embodiments, a user can insert and drive an auxiliary bone anchor through an auxiliary bone anchor opening coaxial with the central axis of the auxiliary bone anchor opening or at an oblique angle relative to the central axis of the auxiliary bone anchor opening. In this way, the wing can provide an extended range of angles or trajectories through which an auxiliary bone anchor can be inserted into the bone to enhance the fixation of the primary bone anchor.

[0200] The above steps may be repeated to install additional bone anchor assemblies with or without supplemental fixation members at the same or different vertebral levels. Final tightening or other adjustments to the construct may be made, and the procedure may be completed and the incision closed using known techniques.

[0201] In any of the above embodiments or methods, the primary bone anchor may be omitted and the user may rely solely on one or more secondary fixation features to secure the bone anchor assembly. This may advantageously allow for a position of fixation to be completely offset from the receiver member, such as if an initially placed bone anchor needs to be removed due to improper positioning or insufficient gripping or when the receiver member needs to be positioned in a position where the bone anchor cannot be inserted.

[0202] While the methods shown and described herein refer to bone anchor assemblies placed in the pedicles or lateral masses of a vertebra, it should be understood that the systems and methods herein may be used with any bone, non-bone tissue, or inanimate or non-tissue object.

[0203] The supplemental fixation members disclosed herein may be implanted in a subsequent surgical procedure in the same surgical procedure as the bone anchors, receiver members, and spinal rods or in the case of revision surgery.

[0204] It should be noted that any order of method steps expressed or implied in the above description or in the accompanying drawings should not be understood as limiting the disclosed method to perform the steps in that order. On the contrary, the various steps of each method disclosed herein can be performed in any order in a variety of orders. In addition, since the described methods are only exemplary embodiments, various other methods including additional steps or including fewer steps are also included in the scope of the present disclosure.

[0205] As will be apparent from the foregoing, in at least some embodiments, the systems and methods disclosed herein can provide enhanced fixation for a given surgical site, providing greater bone fixation strength at a given location without necessarily requiring moving fixation to additional vertebrae or skipping / adding involved vertebrae.

[0206] The bone anchor assembly disclosed herein and its various components can be made of any of a variety of known materials. Exemplary materials include materials suitable for surgical applications, including metals (such as stainless steel, titanium or alloys thereof), polymers (such as PEEK, ceramics, carbon fiber), etc. The various components of the device disclosed herein can be rigid or flexible. One or more components or portions of the device can be formed of a radiopaque material to facilitate visualization under fluoroscopy and other imaging techniques, or formed of a radiolucent material so as not to interfere with the visualization of other structures. Exemplary radiolucent materials include carbon fiber and high-strength polymers.

[0207] The systems and methods disclosed herein can be used in minimally invasive surgery and / or open surgery. Although the systems and methods disclosed herein are described in their entirety in the context of spinal surgery, it should be understood that the systems and methods disclosed herein can be used in any of a variety of surgeries performed on humans or animals and / or in fields unrelated to implants or surgery.

[0208] While specific embodiments have been described above, it should be understood that numerous changes can be made within the spirit and scope of the concepts described. Accordingly, the present disclosure is not intended to be limited to the embodiments described, but rather has the full scope defined by the language of the following claims.

[0209] The above exemplary embodiments describe spinal surgery applications. Although this is a contemplated use, the methods and devices of the present disclosure may be equally applicable to other areas of the patient's body. Thus, the devices described herein may be formed into a variety of sizes and materials suitable for various areas of the patient's body.

[0210] Based on the above embodiments, those skilled in the art will appreciate additional features and advantages. Therefore, the present disclosure is not limited by what has been specifically shown and described. All publications and references cited herein are expressly incorporated herein by reference in their entirety.

Claims

1. A bone anchor assembly, comprising: Bone anchor; a receiver member coupled to the proximal end of the bone anchor and defining a recess configured to receive a rod; a closing mechanism, the closing mechanism cooperating with the receiving body member; a wing having a proximal portion disposed proximal to the receiving body member, a distal portion defining a plurality of screw openings, and a spanning portion connecting the proximal portion and the distal portion, each of the plurality of screw openings being configured to receive an additional bone anchor screw therein; as well as a nut configured to engage the closure mechanism to secure the proximal portion of the wing to the proximal end of the receiver member, wherein the plurality of screw openings extend at an angled trajectory relative to a proximal-distal axis of the spanning portion such that in a first configuration, each auxiliary bone anchor screw received in each of the plurality of screw openings can conform to a vertebral segment into which the bone anchor is inserted, and in a second configuration, at least one auxiliary bone anchor screw of the plurality of auxiliary bone anchor screws received in at least one of the plurality of screw openings can extend across a facet plane of the vertebral segment into which the bone anchor is inserted; and The central axis of each of the plurality of screw openings extends at an oblique angle to the left or right of the proximal-distal axis of the spanning portion.

2. The assembly of claim 1, wherein the distal portion extends substantially perpendicular to the proximal-distal axis of the spanning portion. 3 . The assembly of claim 1 , wherein a central axis of each of the plurality of screw openings extends in one of a caudal direction or a cephalad direction. 4 . The assembly of claim 2 , wherein a central axis of each of the plurality of screw openings extends in a medial direction.

5. The assembly of claim 1, wherein each screw opening of the plurality of screw openings defines an interlocking interface.

6. The assembly of claim 1, wherein each of the plurality of screw openings includes at least one threaded portion to enable receipt of a screw at a variable angle.

7. The assembly of claim 5, wherein the at least one threaded portion is a tapered threaded portion.

8. The assembly of claim 1, wherein a central axis of each of the plurality of screw openings extends at an angle between 0 and 60 degrees relative to the proximal-distal axis of the spanning portion.

9. The assembly of claim 1, wherein the distal portion of the wing is decoupled from a proximally facing surface of a bone into which the bone anchor is inserted.

Images