Spinal implant system and method of use

Abstract

A bone fastener (12) includes a first member (14) including a first surface (22) defining an implant cavity (24). The first member includes a first portion (32) non-rotatable relative to the first surface and a second portion (42) including a second surface (44) defining a portion of the implant cavity and a slot (54). A second member (16) is configured to penetrate tissue and is connectable with the first member. The first member is rotatable relative to the second member in a first plane of the body and the second portion is movable relative to the first portion in a second plane of the body such that the first portion is relatively translatable in the slot. Implants, systems, instruments, and methods are disclosed.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to medical devices for treating spinal conditions, and more particularly to a spinal implant system including a bone fastener and related methods. BACKGROUND

[0002] Spinal pathologies and conditions, such as scoliosis and other curvatures abnormalities, kyphosis, degenerative disc disease, herniated discs, osteoporosis, spondylolisthesis, stenosis, tumors, and fractures can be caused by factors including trauma, disease, and degenerative conditions caused by injury and aging. Spinal conditions often result in symptoms including deformity, pain, nerve damage, and partial or complete loss of mobility.

[0003] Non-surgical therapies, such as medication, rehabilitation, and exercise, can be effective, but can fail to alleviate symptoms associated with these diseases. Surgical treatment of these spinal conditions includes correction, fusion, fixation, discectomy, laminectomy, and implantable prosthetics. As part of these surgical treatments, spinal constructs such as vertebral rods are often used to provide stability to the treatment area. As healing occurs, the rod transfers stress from the damaged or defective area to restore proper alignment and generally support the vertebral members. During the surgical treatment, one or more rods and bone fasteners can be delivered to the surgical site. The rod can be attached to the exterior of two or more vertebral members via the fasteners. The present disclosure describes improvements to these prior art techniques. SUMMARY

[0004] In one embodiment, a bone fastener is provided. The bone fastener includes a first member including a first surface defining an implant cavity. The first member includes a first portion that is non-rotatable relative to the first surface and a second portion including a second surface defining a portion of the implant cavity and a slot. A second member is configured to penetrate tissue and is connectable with the first member. The first member is rotatable relative to the second member in a first plane of the body and the second portion is movable relative to the first portion in a second plane of the body such that the first portion is relatively translatable in the slot. In some embodiments, implants, systems, instruments, and methods are disclosed.

[0005] In one embodiment, the bone fastener includes a receiver including an inner surface defining an implant cavity. The receiver includes a crown rotationally fixed with the inner surface and includes a saddle defining a wall and a slot of the implant cavity. A bone screw shaft includes a head having a mating element engageable with the crown. The receiver is rotatable relative to the shaft in a transverse plane of the body and the saddle is movable relative to the crown in a sagittal plane of the body such that the crown is translatable in the slot.

[0006] In one embodiment, a spinal implant system is provided. The spinal implant system includes a plurality of alternating implant receivers including at least one implant receiver. The at least one implant receiver includes an inner surface defining an implant cavity and includes a crown non-rotatable relative to the inner surface. A saddle defines a portion of the implant cavity and a slot. A bone screw shaft includes a head engageable with the implant receiver such that the shaft is compatible with the plurality of implant receivers. The receiver is rotatable relative to the shaft in a transverse plane of the body and the saddle is movable relative to the crown in a sagittal plane of the body such that the crown is translatable in the slot. BRIEF DESCRIPTION OF DRAWINGS

[0007] The present disclosure will become more fully understood from the detailed description given herein below, and the accompanying drawings, wherein:

[0008] Figure 1 is a perspective view of components of one embodiment of a spinal implant system according to the principles of the present disclosure, with parts separated;

[0009] Figure 2 is a perspective view of components of the system shown in Figure 1

[0010] Figure 3 is a perspective view of components of the system shown in Figure 1

[0011] Figure 4 is a perspective view of components of the system shown in Figure 1

[0012] Figure 5 is a perspective view of components of the system shown in Figure 1

[0013] Figure 6 is a perspective view of components of the system shown in Figure 1

[0014] Figure 7 is a perspective view of components of one embodiment of a spinal implant system according to the principles of the present disclosure, with parts separated;​​​​​

[0015] Figure 8 is a perspective view of components of one embodiment of a spinal implant system according to the principles of the present disclosure, with parts separated;

[0016] Figure 9 is a perspective view of components of one embodiment of a spinal implant system according to the principles of the present disclosure, with parts separated;

[0017] Figure 10 is a cross-sectional view of components of one embodiment of a spinal implant system according to the principles of the present disclosure;

[0018] Figure 11 is a perspective view of components of the system shown in Figure 10

[0019] Figure 12 is a perspective view of components of one embodiment of a spinal implant system according to the principles of the present disclosure;

[0020] Figure 13 is a perspective view of components of the system shown in Figure 12

[0021] Figure 14 is a side view of components of one embodiment of a spinal implant system according to the principles of the present disclosure;

[0022] Figure 15 is a side view of components of the system shown in Figure 14

[0023] Figure 16 is a perspective view of a patient anatomy; and

[0024] Figure 17 is a side view of components of one embodiment of a spinal implant system according to the principles of the present disclosure, disposed with a vertebra. DETAILED DESCRIPTION

[0025] Exemplary embodiments of the disclosed surgical systems and related methods of use are discussed in relation to medical devices for treating musculoskeletal conditions and more particularly in relation to spinal implant systems including bone fasteners. In one embodiment, the present spinal implant system includes an implant including a bone fastener (e.g., a bone screw). In some embodiments, the systems and methods of the present disclosure are used with spinal arthrodesis or fixation procedures, for example, with the cervical, thoracic, lumbar, and / or sacral regions of the spine.

[0026] ​​​In some embodiments, the spinal implant system includes an implant, e.g., a bone screw. In some embodiments, the bone screw includes a receiver, a crown, a saddle defining a slot, and a bone screw shaft. In some embodiments, the bone screw shaft includes a head having a mating element that is engageable with the crown. In some embodiments, the receiver is rotatable relative to the shaft in a transverse plane of the body, and the saddle is movable relative to the crown in a sagittal plane of the body, such that the crown is translatable in the slot.

[0027] In some embodiments, the spinal implant system includes a pedicle screw including a selectively coupled transverse-sagittal adjustment receiver. In some embodiments, the spinal implant system includes a receiver configured to accommodate transverse and sagittal anatomical differences. In some embodiments, the spinal implant system includes a modular system including an array of members, e.g., receivers, selectively coupled to a member, e.g., a bone screw shaft. In some embodiments, the spinal implant system facilitates sagittal correction and / or manipulation when seating a spinal rod with a receiver.

[0028] In some embodiments, the spinal implant system includes a bone screw including a screw shaft including a head. In some embodiments, the head is configured in an array of configurations. In some embodiments, the array of head configurations gives a surgeon flexibility and choice in the operating room such that an array of receivers can be connected with the head. In some embodiments, the array of head configurations reduces the amount of inventory delivered to the operating room for a procedure.

[0029] In some embodiments, the spinal implant system includes an implant, e.g., a transverse mono-axial sagittal adjustment screw. In some embodiments, the screw includes a saddle. In some embodiments, the saddle is configured for sagittal adjustment and / or motion tolerance of a spinal implant, e.g., a spinal rod. In some embodiments, the screw includes a head attachment. In some embodiments, the head attachment is a universal head attachment. In some embodiments, transverse adjustment and / or motion tolerance is achieved through the universal head attachment. In some embodiments, the universal head attachment is configured in a transverse plane to facilitate active correction, e.g., by manipulating a sagittal plane to adjust the head to a desired correction.

[0030] In some embodiments, the spinal implant system includes a bone screw including a screw shaft including a head. In some embodiments, the head includes mating elements including flats engageable with a crown. In some embodiments, the flats and crown interface in a keyed manner such that the shaft is only pivotal relative to the receiver through the transverse plane.

[0031] In some embodiments, the spinal implant system includes a crown and a saddle. In some embodiments, the crown and the saddle are configured for engagement. In some embodiments, the crown and the saddle are configured for an interference fit, e.g., a snap-fit engagement. In some embodiments, during manufacturing, the saddle is positioned with the crown via a manufacturing press. In some embodiments, the crown is configured to provide an increase in axial grip on the spinal rod and an increase in flexion and / or extension strength.

[0032] In some embodiments, the spinal implant system includes a crown, a saddle, and a retaining member and / or a protrusion. In some embodiments, the retaining member and / or the protrusion includes, e.g., a welded element. In some embodiments, the retaining member and / or the protrusion is configured to hold the saddle with the crown and limit angular rotation of the saddle when seated in a receiver. In some embodiments, the retaining member and / or the protrusion is welded to the crown. In some embodiments, the retaining member and / or the protrusion includes a press fit or threaded connection with the crown and / or the saddle.

[0033] In some embodiments, the spinal implant system includes a modular system including a bone fastener including an array of members, e.g., bone screw shafts that can be selectively coupled to members, e.g., receivers. In some embodiments, the spinal implant system includes selectively coupled bone fasteners that can be assembled at the operating table or in situ. In some embodiments, the selectively coupled bone fasteners are assembled with non-instrumented and / or manual assembly. In some embodiments, non-instrumented assembly involves manually engaging the screw shafts with the head / receiver of the bone fastener. In some embodiments, non-instrumented assembly involves manually pop-on engaging the screw shafts with the head / receiver of the bone fastener. In some embodiments, the force required to manually engage the screw shafts with the head / receiver of the bone fastener in non-instrumented assembly is in the range of 2 N to 50 N. In some embodiments, the force required to manually engage the screw shafts with the head / receiver of the bone fastener in non-instrumented assembly is in the range of 5 N to 10 N. In some embodiments, such a configuration provides manually engageable components of the bone fastener that can be assembled without the need for an instrument, and after assembly, the assembled components have a selected pullout strength and / or can be pulled apart, removed, and / or separated with minimal force required.

[0034] In some embodiments, the head assembly includes a ring that is disposed with an implant receiver that connects with the screw shaft assembly. In some embodiments, the ring is configured for snapping onto the screw shaft assembly. In some embodiments, the force required to snap the ring onto the screw shaft assembly is in the range of 2 N to 50 N. In some embodiments, the force required to snap the ring onto the screw shaft assembly is in the range of 5 N to 10 N.

[0035] In some embodiments, the present disclosure can be used to treat spinal conditions, such as degenerative disc disease, herniated discs, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumors, and fractures. In some embodiments, the present disclosure can be used for other bone and bone-related applications, including those associated with diagnosis and treatment. In some embodiments, the disclosed spinal implant system can alternatively be used for surgical treatment of patients in prone or supine positions, and / or for various surgical approaches to the spine, including anterior, posterior, posterior midline, lateral, posterolateral, and / or anterolateral approaches, as well as in other body regions. The present disclosure can also be used alternatively for procedures to treat the lumbar, cervical, thoracic, sacral, and pelvic regions of the spine. The spinal implant system of the present disclosure can also be used on animals, bone models, and other inanimate substrates, for example, in training, testing, and demonstration.

[0036] The present disclosure can be more easily understood and further advantages and benefits can be obtained, by reference to the following detailed description of embodiments in conjunction with the attached drawings, which form a part of this specification. It is to be understood that the application is not limited in its application to the specific devices, methods, conditions or parameters described and / or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting. In some embodiments, as used in the specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. References to a particular number of values includes at least that particular value unless the context clearly dictates otherwise. Ranges can be expressed herein as "about" or "approximately" one particular value and / or "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that all spatial references (for example, horizontal, vertical, top, bottom, lower, upper, side, etc.) are for illustrative purposes only and can be varied within the scope of the present disclosure. For example, references to "upper" and "lower" are relative and are used for ease of description and can be reversed without affecting the scope of the disclosure.

[0037] As used in the specification and the appended claims, "treating" or "treatment" of a disease or condition means performing an intervention that can include administering one or more drugs to a patient (human, normal or otherwise), employing surgical procedures, and / or employing instruments designed to affect the treatment of the disease or condition, such as a microdiscectomy instrument for removing part of an outpouching or herniated disc and / or bone spur, to reduce a sign or symptom of the disease or condition. The alleviation can occur prior to or following the manifestation of the sign or symptom of the disease or condition. Thus, treatment includes preventing the disease or adverse condition (e.g., preventing a patient that can be predisposed to a disease from developing the disease, but has not yet been diagnosed with the disease). Further, treatment does not require complete alleviation of signs or symptoms, does not require a cure, and specifically includes procedures that have little or no effect on the patient. Treatment can include inhibiting the disease, e.g., arresting its development, or relieving the disease, e.g., causing regression of the disease. For example, treatment can include reducing acute or chronic inflammation; alleviating pain and promoting repair of new ligaments, bone and other tissues; as an adjunct in surgery; and / or any repair procedure. Moreover, as used in the specification and the appended claims, the term "tissue" includes soft tissue, ligaments, tendons, cartilage, and / or bone, unless specifically referred to otherwise.

[0038] The following discussion includes descriptions of surgical systems including bone fasteners, related components, and methods of employing the surgical systems according to the principles of the present disclosure. Alternative embodiments are also disclosed. Reference will be made to the exemplary embodiments of the application illustrated in the drawings. Turning to the drawings, Figures 1 to 17 FIG. 1 shows components of a spinal implant system 10.

[0039] Components of the spinal implant system 10 can be fabricated from biologically acceptable materials suitable for medical applications, including metals, synthetic polymers, ceramics and bone material, and / or composites thereof. For example, components of the spinal implant system 10 can be fabricated, individually or collectively, from materials such as stainless steel alloys, commercially pure titanium, titanium alloys, Grade 5 titanium, ultra-high-molecular-weight polyethylene, Grade 5 titanium, cobalt-chrome alloys, super-elastic metallic alloys (e.g., Nitinol, super-elastic ), ceramics and composites thereof (such as calcium phosphate (e.g., SKELITE™), thermoplastics (e.g., polyaryletherketone (PAEK), including polyetheretherketone (PEEK), polyetherketoneketone (PEKK), and polyetherketone (PEK), carbon-PEEK composites, PEEK-BaS04polymeric rubbers, polyethylene terephthalate (PET)), fabric, silicone, polyurethane, silicone-polyurethane copolymer, polymeric rubber, polyolefinic rubber, hydrogel, semi-rigid and rigid materials, elastomers, rubber, thermoplastic elastomers, thermoset elastomers, elastomer composites, rigid polymers (including polyphenylene, polyamide, polyimide, polyetherimide, polyethylene, epoxy), bone material (including autograft, allograft, xenograft, or transgenic cortical and / or cortical cancellous bone and tissue growth or differentiation factors), partially absorbable materials (e.g., composites of metals with calcium-based ceramics, composites of PEEK with calcium-based ceramics, composites of PEEK with absorbable polymers), fully absorbable materials (e.g., calcium-based ceramics such as calcium phosphate, tricalcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate, or other absorbable polymers such as polyketone, polyglycolide, polylactate, polycaprolactone), and combinations thereof.

[0040] Various components of spinal implant system 10 can have material composites including the materials described above to achieve various desired properties such as strength, rigidity, elasticity, compliance, biomechanical performance, durability, and radiolucency or imaging preference. Components of spinal implant system 10 can also be made of heterogeneous materials, such as combinations of two or more of the materials described above, individually or collectively. Components of spinal implant system 10 can be integrally formed, integrally connected, or include fastening elements and / or instruments, as described herein.

[0041] Spinal implant system 10 includes a spinal implant, such as a bone fastener 12. Bone fastener 12 includes a proximal member, such as a receiver 14 that is connectable with a distal member, such as a bone screw shaft 16 that is configured to penetrate vertebral tissue, as shown in Figure 1 Receiver 14 is rotatable relative to shaft 16 in a plane (e.g., a transverse plane TP of the body), as shown in Figure 17 In some embodiments, receiver 14 is manually engageable with shaft 16 to couple receiver 14 with shaft 16. In some embodiments, receiver 14 is engageable with shaft 16 via an instrument. In some embodiments, receiver 14 is engageable with shaft 16 without an instrument and / or in a non-instrumented assembly.

[0042] Receiver 14 extends along and defines an axis XI, as shown in Figure 1The receiver 14 includes a pair of spaced apart arms 18, 20 that include an inner surface 22 that defines an implant cavity 24, as shown. Figure 2 The cavity 24 is configured for seating a component of a spinal construct (e.g., a spinal rod 26), as shown. Figures 14 to 17

[0043] The arms 18, 20 each extend parallel to an axis XI. In some embodiments, the arms 18 and / or 20 can be seated in alternating orientations relative to the axis XI, such as transverse, perpendicular, and / or other angular orientations, such as acute or obtuse, coaxial, and / or can be offset or staggered. The arms 18, 20 each include an arcuate outer surface that extends between a pair of side surfaces. At least one of the outer surface and the side surfaces of the arms 18, 20 has at least one recess or cavity therein that is configured to accommodate an insertion tool, a compression instrument, and / or an instrument for inserting and tensioning the bone fastener 12. In some embodiments, the arms 18, 20 are connected at their proximal and distal ends such that the receiver 14 defines a closed slot for the spinal rod 26. In some embodiments, the spinal rod 26 can be integrally formed with or preassembled with the receiver 14. In some embodiments, at least one of the inner surface 22 and / or the inner surface of the arms 18, 20 has at least one recess or cavity therein that is configured to accommodate an insertion tool, a compression instrument, and / or an instrument for inserting and tensioning the bone fastener 12.

[0044] The cavity 24 is substantially U-shaped. In some embodiments, all or only a portion of the cavity 24 can have an alternating cross-sectional configuration, such as closed, V-shaped, W-shaped, oval, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configurations. A portion of the surface 22 includes a thread form 28 adjacent the arm 18 and a thread form 30 adjacent the arm 20, as shown. Figure 10 The thread forms 28, 30 are each configured for engagement with a coupling member (e.g., a set screw (not shown)) to retain the spinal rod 26 within the cavity 24. In some embodiments, the surface 22 can seat the coupling member in alternative securing configurations (e.g., a friction fit, a pressure fit, a locking protrusion / recess, a locking keyway, and / or an adhesive). In some embodiments, all or only a portion of the surface 22 can have an alternative surface configuration (e.g., rough, arcuate, wavy, mesh, porous, semi-porous, dimpled, and / or textured) to enhance engagement with the spinal rod 26 and / or the set screw. In some embodiments, the receiver 14 can include alternative configurations, such as closed, open, and / or side access.

[0045] As Figure 4 and Figure 10 ​As shown, receiver 14 includes a portion, such as a crown 32 configured to be seated within cavity 24. Crown 32 is non-rotatable or rotationally fixed relative to surface 22. As shown, crown 32 includes a circumferential wall 34 having an end surface 36 and an end surface 38. In some embodiments, all or only a portion of surfaces 36, 38 can have an alternative cross-sectional configuration, such as an elliptical, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration. Figure 4

[0046] Surface 36 defines a protrusion, such as a circumferential flange 40, as shown Figure 4 and Figure 10 As shown, flange 40 is configured to engage with a surface 44 of a saddle 42, as shown Figure 3 and Figure 10 and as described herein. In some embodiments, all or only a portion of flange 40 can have an alternative cross-sectional configuration, such as an elliptical, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration.

[0047] Surface 36 defines a protrusion 41, as shown Figure 4 and Figure 10 As shown, receiver 14 includes a recessed surface defining a groove 46. Protrusion 41 is configured to be seated with groove 46. The engagement of protrusion 41 with the recessed surface defining groove 46 holds crown 32 with receiver 14. In some embodiments, all or only a portion of protrusion 41 can have an alternative surface configuration, such as rough, arcuate, wavy, webbed, porous, semi-porous, recessed, and / or textured. In some embodiments, surface 36 includes one or more protrusions 41. Figure 10

[0048] Surface 38 defines a recess 48 including a mating element, such as a flat 49 configured to engage with a mating element, such as a flat 74 of a head 50 of shaft 16, as shown Figure 1 , Figure 10 and Figure 11 and as described herein. Flat 49 is configured to interface with flat 74 to resist and / or prevent rotation of receiver 14 about axis XI in the perpendicular motion plane. In this configuration, shaft 16 is free to rotate relative to receiver 14 along a single axis and / or in a single plane. Head 50 is capable of engaging with and moving relative to surface 38 such that shaft 16 is capable of rotating in a single plane, such as a transverse plane TP relative to a body of receiver 14 and / or a vertebra, as shown Figure 17 ​​As shown. In some embodiments, all or only a portion of the recess 48 can have an alternative surface configuration, such as rough, arcuate, wavy, mesh, porous, semi-porous, dimpled, and / or textured.

[0049] In some embodiments, the crown 32 includes an opening configured for seating a guide wire when the receiver 14 is used in conjunction with a guide wire and translating over the guide wire when implemented with a cannulated screw. In some embodiments, the opening is centrally positioned through the crown 32.

[0050] The surface 44 of the saddle 42 includes a wall 52 defining a portion of the cavity 24, as shown. Figure 3 and Figure 9 As shown, the surface 44 defines a slot 54 configured for engagement with the crown 32 (e.g., the flange 40). The slot 54 includes a track 56 defining an arcuate path of the saddle 42 such that the flange 40 is translatable (e.g., rotatable) within the track 56. The track 56 defines a rotational limit of the saddle 42 relative to the crown 32. The saddle 42 is movable relative to the crown 32 in a plane (e.g., a sagittal plane SP of the body, as shown) such that the flange 40 is relatively translatable in the track 56 of the slot 54, as shown. In some embodiments, the saddle 42 is configured for sagittal adjustment and / or motion tolerance of the spinal rod 26, as shown. In some embodiments, all or only a portion of the slot 54 can have an alternative cross-sectional configuration, such as an elliptical, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration. In some embodiments, the surfaces 44 / walls 52 of the crown 32 and the saddle 42 are engaged via an interference fit. In some embodiments, the interference fit includes a press-fit assembly with a releasable friction fit. Figure 10 Figure 16 The surface 44 of the saddle 42 includes a wall 52 defining a portion of the cavity 24, as shown. Figure 10 and Figure 14 As shown, the surface 44 defines a slot 54 configured for engagement with the crown 32 (e.g., the flange 40). The slot 54 includes a track 56 defining an arcuate path of the saddle 42 such that the flange 40 is translatable (e.g., rotatable) within the track 56. The track 56 defines a rotational limit of the saddle 42 relative to the crown 32. The saddle 42 is movable relative to the crown 32 in a plane (e.g., a sagittal plane SP of the body, as shown) such that the flange 40 is relatively translatable in the track 56 of the slot 54, as shown. In some embodiments, the saddle 42 is configured for sagittal adjustment and / or motion tolerance of the spinal rod 26, as shown. In some embodiments, all or only a portion of the slot 54 can have an alternative cross-sectional configuration, such as an elliptical, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration. In some embodiments, the surfaces 44 / walls 52 of the crown 32 and the saddle 42 are engaged via an interference fit. In some embodiments, the interference fit includes a press-fit assembly with a releasable friction fit.

[0051] The saddle 42 includes a top surface 58, as shown. Figure 3 and Figure 10 As shown, the surface 44 defines a slot 54 configured for engagement with the crown 32 (e.g., the flange 40). The slot 54 includes a track 56 defining an arcuate path of the saddle 42 such that the flange 40 is translatable (e.g., rotatable) within the track 56. The track 56 defines a rotational limit of the saddle 42 relative to the crown 32. The saddle 42 is movable relative to the crown 32 in a plane (e.g., a sagittal plane SP of the body, as shown) such that the flange 40 is relatively translatable in the track 56 of the slot 54, as shown. In some embodiments, the saddle 42 is configured for sagittal adjustment and / or motion tolerance of the spinal rod 26, as shown. In some embodiments, all or only a portion of the slot 54 can have an alternative cross-sectional configuration, such as an elliptical, oblong, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration. In some embodiments, the surfaces 44 / walls 52 of the crown 32 and the saddle 42 are engaged via an interference fit. In some embodiments, the interference fit includes a press-fit assembly with a releasable friction fit.

[0052] ​The spinal implant system 10 includes a band, such as a retaining ring 62, configured for temporary capture of the head 50 of the shaft 16 (as shown in Figure 5 and Figure 10 shown) and / or secure attachment of the components of the bone fastener 12, as described herein. The spinal implant system 10 includes a band, such as a ring 60, configured for placement adjacent to the ring 62 in the contracted orientation and the expanded distracted orientation to facilitate secure attachment of the components of the bone fastener 12.

[0053] As shown in Figure 10 , the receiver 14 includes a portion 64. The portion 64 includes a surface 66. The surface 66 defines a cavity, such as a recess 68. The recess 68 is configured for placement of the ring 60. In some embodiments, the recess 68 extends around all or a portion of the surface 66. The surface 67 defines an expansion recess 69. The ring 60 includes a circumference that defines an opening, such as a gap. In some embodiments, the gap is sized such that the thickness of the gap is less than the height and the width. In some embodiments, the gap is sized to allow the ring 60 to translate through the bottom of the receiver 14 by circumferential contraction. In some embodiments, all or only a portion of the surface 66 can have an alternative surface configuration, such as rough, arcuate, wavy, mesh, porous, semi-porous, concave, and / or textured.

[0054] As shown in Figure 10 , the portion 64 includes a surface 70. The surface 70 defines a cavity, such as a recess 72. The recess 72 is configured for placement of the ring 62. The ring 62 includes a circumference that extends between ends of the ring 62. In some embodiments, the ends define an opening, such as a gap. In some embodiments, the gap is sized such that the thickness of the gap is less than the height and the width. In some embodiments, the gap is sized to allow the ring 62 to engage the surface 70 by circumferential contraction. In some embodiments, all or only a portion of the surface 70 can have an alternative surface configuration, such as rough, arcuate, wavy, mesh, porous, semi-porous, concave, and / or textured.

[0055] The receiver 14 and the shaft 16 are capable of engagement in a snap-fit assembly. In some embodiments, the receiver 14 and the shaft 16 are capable of engagement in a pop-on assembly. In some embodiments, the receiver 14 and the shaft 16 are capable of engagement in various secure configurations, such as a friction fit, a pressure fit, a locking keyway, and / or an adhesive. As described above, the shaft 16 includes a flat 74 capable of engagement with the flat 49 of the crown 32, as shown in Figure 1 and Figure 11The flat 74 is configured to interface with the flat 49 in a keyed manner such that the shaft 16 pivots relative to the receiver 14 through a transverse plane only. In some embodiments, the head 50 includes one or more ridges, flat surfaces, and / or arcuate surfaces to improve the grip of the head 50 with the crown 32.

[0056] The head 50 includes a tool engagement portion 76 configured to engage a surgical tool or instrument, such as a drill, as shown and described herein. In some embodiments, the portion 76 includes a hexagonal cross-section. In some embodiments, the portion 76 can have an alternative cross-section, such as a rectangular, polygonal, hexalobular, oval, or irregular cross-section. Figure 1

[0057] The shaft 16 includes an outer surface 78 having external threading 80, as shown. In some embodiments, the external threading can include a single thread turn or a plurality of discrete threads. In some embodiments, other engagement structures can be positioned along the surface 78 in lieu of or in addition to the threading 80 configuration described above, such as a spike configuration, barbs, expansion elements, raised elements, and / or spikes to facilitate engagement with tissue (e.g., vertebral tissue). Alternatively, in some embodiments, the surface 78 can have various surface configurations, such as, for example, rough, arcuate, wavy, porous, semi-porous, concave, polished, and / or textured surface configurations. Figure 1

[0058] In some embodiments, the receiver 14 is selected from a plurality of alternative receivers 14 and the bone screw shaft 16 is engageable with the receiver 14 via the mating surface such that the shaft 16 is interchangeable with a plurality of shafts 16.

[0059] ​​In some embodiments, the receiver 14 is capable of being manually engaged with the screw shaft 16 in a non-instrumented assembly, as described herein. In some embodiments, the manual engagement and / or non-instrumented assembly of the receiver 14 with the shaft 16 includes coupling without the use of a separate and / or independent instrument that engages with components of the shaft 16 to effect assembly. In some embodiments, the manual engagement and / or non-instrumented assembly includes a practitioner, surgeon, and / or medical personnel grasping the receiver 14 and the shaft 16 and forcibly assembling the components. In some embodiments, the manual engagement and / or non-instrumented assembly includes a practitioner, surgeon, and / or medical personnel grasping the receiver 14 and the shaft 16 and forcibly snap fitting the components together, as described herein. In some embodiments, the manual engagement and / or non-instrumented assembly includes a practitioner, surgeon, and / or medical personnel grasping the receiver 14 and the shaft 16 and forcibly click fitting the components together and / or click fitting the receiver 14 onto the shaft 16, as described herein. In some embodiments, a force in the range of 2N to 50N is required to manually engage the receiver 14 and the shaft 16 and forcibly assemble the components. For example, a force in the range of 2N to 50N is required to snap fit and / or click fit assemble the receiver 14 and the shaft 16. In some embodiments, a force in the range of 5N to 10N is required to manually engage the receiver 14 and the shaft 16 and forcibly assemble the components. For example, a force in the range of 5N to 10N is required to snap fit and / or click fit assemble the receiver 14 and the shaft 16. In some embodiments, this configuration provides manually engageable components that can be assembled without the need for an instrument, and after assembly, the assembled components have a selected pullout strength and / or can be pulled apart, removed, and / or separated with minimal required force. In some embodiments, the receiver 14 can be seated with the head 50 in alternative secure configurations, such as a friction fit, a pressure fit, a locking protrusion / recess, a locking keyway, and / or an adhesive.

[0060] In some embodiments, the spinal implant system 10 includes a spinal implant kit as described herein that includes a plurality of shafts 16 and / or receivers 14. The shafts 16 and / or receivers 14 are configured for selection such that components of the bone fastener 12 are interchangeable in configurations having a range of motion that is limited to a single plane.

[0061] In assembly, operation, and use, the spinal implant system 10, similar to the systems and methods described herein, includes a shaft 16 for connection with a receiver 14 and, as described herein, is used with a surgical procedure to treat a spinal condition affecting a spinal segment of a patient. The spinal implant system 10 is used with a surgical procedure to treat a condition or injury of a diseased segment of a spine.

[0062] In some embodiments, the shaft 16 is selected from a kit of multiple shafts 16 for interchangeably connecting with the receiver 14 to include a bone fastener, where the receiver 14 is rotatable relative to the shaft 16 in the transverse plane TP of the body, and the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body, such that the crown 32 is translatable in the slot 54. In some embodiments, the kit of shafts 16 includes multiple shafts 16 that have different movement configurations when assembled with the interchangeable receiver 14, such as polyaxial movement, sagittal angulation movement, fixed shaft movement, monoaxial movement, and / or mono-planar movement.

[0063] In some embodiments, the receiver 14 is assembled with the crown 32, the saddle 42, the ring 60, and the ring 62, as shown in Figure 1 and Figures 7 to 10 . The ring 62 is provided with the recess 72 in the contracted orientation, and the ring 60 is provided with the recess 68 in the contracted orientation, as shown in Figure 10 . As described herein, the shaft 16 is interchangeable with the receiver 14, as shown in Figure 15 . The receiver 14 is assembled with the shaft 16 by translating the receiver 14 in the direction indicated by arrow A in Figure 1 . The head 50 is engaged with the receiver 14 such that the surface of the head 50 is engaged with the ring 62, such that the ring 62 is translated in the direction indicated by arrow C in Figure 1 , thereby seating the ring 62 in the recess 69 in the expanded orientation. The head 50 is further translated through the receiver 14 in the direction indicated by arrow B in Figure 10 , and further through the ring 62 as the ring 62 is driven back into the recess 72. As shown in Figure 1 , Figure 10 and Figure 11 , the ring 62 elastically contracts around the head 50 to its natural state when the flat 74 is engaged with the recess 48 to temporarily capture the shaft 16.

[0064] For example, the crown 32 is manipulated via engagement by a surgical instrument to translate the crown 32 in the direction indicated by arrow D in Figure 8 . The surface 38 of the crown 32 engages the ring 60 to seat the ring 60 in the recess 69, such that the ring 60 elastically opens to the expanded orientation. The ring 60 is oriented to abutting and / or contact engagement with the ring 62 to resist and / or prevent the ring 62 from translating from the recess 72 into the recess 69, thereby providing a fixed connection of the components of the bone fastener 12 that includes permanently capturing the head 50 and the shaft 16 in a configuration having a range of motion limited to a single plane, such as in a monoaxial movement configuration.

[0065] For example, the crown 32 is manipulated via engagement by a surgical instrument to translate the crown 32 in the direction indicated by arrow D in Figure 9The saddle 42 is translated in the direction indicated by the middle arrow E to manipulate the saddle 42. The saddle 42 is engaged with the crown 32 in an interference fit, for example a snap-fit engagement, via the slot 54 and the flange 40, as shown. When engaged, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 32 is translatable in the slot 54, as shown. In some embodiments, the saddle 42 is positioned with the crown 32 during manufacturing via a manufacturing press and / or a press fit. In some embodiments, the crown 32 is configured to provide an increase in axial grip on the spinal rod 26 and an increase in flexion and / or extension strength. Figure 10 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 32 is translatable in the slot 54. Figure 16 As shown, when engaged, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. In some embodiments, the saddle 42 is positioned with the crown 32 during manufacturing via a manufacturing press and / or a press fit. In some embodiments, the crown 32 is configured to provide an increase in axial grip on the spinal rod 26 and an increase in flexion and / or extension strength. As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54.

[0066] In use, to treat a spinal condition, the bone fastener 12 including the shaft 16 and the receiver 16 can be threadably connected and engaged with tissue. In some embodiments, the bone fastener 12 is disposed adjacent to the vertebrae V at a surgical site and manipulated to drive, twist, insert or otherwise engage with a surgical procedure to connect the shaft 16 with the vertebrae VI and V2 as described herein. The receiver 14 is rotatable relative to the shaft 16 in the transverse plane TP of the body and the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 32 is translatable in the slot 54, as shown. Figures 14 to 17 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54.

[0067] As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figures 12 to 13 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figure 12 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54.

[0068] As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figure 13 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figures 12 to 13 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54.

[0069] As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figure 13 As shown, the saddle 42 is movable relative to the crown 32 in the sagittal plane SP of the body such that the crown 26 is translatable in the slot 54. Figure 12The retaining member 145) engages the surface 144 of the saddle 142. In some embodiments, all or only a portion of the passage 141 can have an alternative cross-sectional configuration, such as an oval, a rectangle, a triangle, a square, a polygon, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration.

[0070] The surface 144 of the saddle 142 defines a wall 152 that defines a portion of the cavity 124, as Figure 12 and Figure 13 The surface 144 defines a slot 154 configured for engagement with the retaining member 145, as Figures 12 to 13 The retaining member 145 is configured to hold the saddle 142 and the crown 132 together and limit angular rotation of the saddle 142 when seated in the receiver 114. In some embodiments, the surface 147 of the retaining member 145 is welded to the crown 132. In some embodiments, the retaining member 145 includes a press fit or threaded connection with the crown 132 and / or the saddle 142. The saddle 142 is movable relative to the crown 132 in a plane (e.g., a sagittal plane SP of the body), as Figure 16 shown. In some embodiments, all or only a portion of the retaining member 145 can have an alternative cross-sectional configuration, such as an oval, a rectangle, a triangle, a square, a polygon, irregular, uniform, non-uniform, offset, staggered, and / or tapered cross-sectional configuration.

[0071] In some embodiments, the spinal implant system 10 includes a medicament that can be seated, encapsulated, coated, or layered within, on, or around components and / or surfaces of the spinal implant system 10. In some embodiments, the medicament can include a bone growth promoting material (e.g., bone graft) to enhance fixation of the fixation element with the vertebrae. In some embodiments, the medicament can be a HA coating. In some embodiments, the agent can include one or more therapeutic and / or medicinal agents for release (including sustained release) to treat, for example, pain, inflammation, and degeneration.

[0072] In some embodiments, with the spinal implant system 10, microsurgical and image-guided techniques can be used to access, view, and repair spinal deterioration or injury. Components of the spinal implant system 10 can be made of radiolucent materials such as polymers. Radioactive markers can be included for identification under x-ray, fluoroscopy, CT, or other imaging techniques.

[0073] In some embodiments, spinal implant system 10 can include one or more bone fasteners 12 (such as the bone fasteners described herein) and / or fixation elements, which can be used at a single vertebral level or at multiple vertebral levels. In some embodiments, bone fasteners 12 can engage with the vertebrae in various orientations, such as in series, in parallel, offset, staggered, and / or alternating vertebral levels. In some embodiments, bone fasteners 12 can be configured as polyaxial screws, sagittally angulated screws, pedicle screws, monoaxial screws, mono-plane screws, fixation screws, anchors, tissue penetrating screws, conventional screws, expansion screws. In some embodiments, bone fasteners 12 can be used with wedges, anchors, buttons, clips, clasps, friction fittings, compression fittings, expanding rivets, U-pins, pegs, adhesives, posts, connectors, fixation plates, and / or columns.

[0074] It is to be understood that various modifications can be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

1. A bone fastener comprising: a first member comprising a first surface defining an implant cavity, the first member comprising a first portion and a second portion, the first portion being non-rotatable relative to the first surface, the second portion comprising a second surface defining a portion of the implant cavity and a slot, the first portion comprising a protrusion and a circumferential flange extending 360 degrees around the protrusion; and a second member configured to penetrate tissue and connectable with the first member; wherein the first member is rotatable relative to the second member in a first plane of the body and the second portion is movable relative to the first portion in a second plane of the body such that the first portion is relatively translatable in the slot; and wherein the first portion is engaged with the second portion in an interference fit.

2. The bone fastener of claim 1, wherein the interference fit comprises a press assembly having a releasable friction fit.

3. The bone fastener of claim 1, wherein the circumferential flange is engaged with the second portion in an interference fit.

4. The bone fastener of claim 1, wherein the first portion comprises a welding element having a circumferential flange engaged with the second portion in an interference fit.

5. The bone fastener of claim 1, wherein the first plane is a transverse plane of the body and the second plane is a sagittal plane of the body.

6. The bone fastener of claim 1, wherein the first member is manually engageable with the second member in a non-instrumented assembly to connect the members.

7. The bone fastener of claim 1, wherein the members are engageable in a snap-fit assembly.

8. The bone fastener of claim 1, wherein the members are engageable in a pop-on assembly.

9. The bone fastener of claim 1, wherein the slot comprises a track defining an arcuate path of the second portion.

10. The bone fastener of claim 1, wherein the second member comprises a flat engageable with the first portion, the flat interfacing in a keyed connection such that the second member is only pivotal relative to the first member through the first plane.

11. The bone fastener of claim 1, wherein the first member is selected from a plurality of alternating first members and the second member comprises a mating surface engageable with the first member such that the second member is interchangeable with the plurality of second members.

12. A bone fastener comprising: a receiver comprising an inner surface defining an implant cavity, the receiver comprising a crown and a saddle, the crown being rotationally fixed with the inner surface, the saddle comprising a wall defining a portion of the implant cavity and a slot, the crown comprising a protrusion and a circumferential flange extending outwardly from the protrusion, the circumferential flange extending 360 degrees around the protrusion; and a bone screw shaft comprising a head having a mating element engageable with the crown, wherein the receiver is rotatable relative to the shaft in a transverse plane of the body, and the saddle is movable relative to the crown in a sagittal plane of the body such that the crown is translatable in the slot; and wherein the crown is engaged with the wall in an interference fit, the interference fit including a press assembly having a releasable friction fit.

13. The bone fastener of claim 12, wherein the circumferential flange is engaged with the wall in an interference fit.

14. The bone fastener of claim 12, wherein the crown includes a welding element having a circumferential flange engaged with the wall in an interference fit.

15. The bone fastener of claim 12, wherein the receiver and the shaft are engageable in a snap fit assembly.

16. The bone fastener of claim 12, wherein the slot includes a track defining an arcuate path of the saddle.

17. The bone fastener of claim 12, wherein the mating element includes a flat engageable with the crown, the flat interfacing in a keyed connection such that the shaft is only pivotal relative to the receiver through the transverse plane.

18. A spinal implant system, comprising: a plurality of alternating implant receivers including at least one implant receiver including an inner surface defining an implant cavity, the at least one implant receiver including a crown non-rotatable relative to the inner surface and a saddle defining a portion of the implant cavity and a slot, the crown including a protrusion and a circumferential flange extending 360 degrees around the protrusion; and a bone screw shaft including a head engageable with an implant receiver such that the shaft is compatible with the plurality of implant receivers, wherein the receiver is rotatable relative to the shaft in a transverse plane of the body, and the saddle is movable relative to the crown in a sagittal plane of the body such that the crown is translatable in the slot.

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