Spinal implants and methods of use thereof

Abstract

A surgical coupling member includes a shaft defining an axis and including at least one thread having an external thread form. The external thread form has a front wing and a rear wing. The external thread form defines a pitch and a crest, the crest having a width in the range of about 35% to about 50% of the pitch of the external thread form, wherein the front wing and the rear wing are angled relative to the thread axis in a proximal orientation, and wherein the external thread form is configured to interlock with an internal thread form of an implant receiver. Systems, spinal constructs, implants, and methods of use are disclosed.

Description

Technical Field

[0001] The present disclosure relates generally to medical devices for treating spinal disorders, and more particularly to spinal implant systems including bone fasteners and methods for treating the spine. Background Art

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

[0003] Non-surgical treatments, such as medication, rehabilitation and exercise may be effective, however, may not alleviate the symptoms associated with these conditions. The surgical treatment of these spinal disorders includes correction, fusion, fixation, discectomy, laminectomy and implantable prostheses. As part of these surgical treatments, implants such as bone fasteners, plates, connectors and vertebral rods are generally used to provide stability to the treatment area. These implants can redirect stress while healing occurs and leave the damaged or defective area to restore proper alignment and generally support vertebral members. For example, plates, connectors and / or rods can be attached to the outside of one or more vertebral members via fasteners. The present disclosure describes improvements to these prior arts. Summary of the invention

[0004] In one embodiment, a surgical connection member is provided. The connection member includes a shaft, the shaft defining an axis and including at least one thread having an external thread form. The external thread form has a front wing and a rear wing. The external thread form defines a pitch and a crest, the crest having a width in the range of about 35% to about 50% of the pitch of the external thread form, wherein the front wing and the rear wing are angled relative to the thread axis in a proximal orientation, and wherein the external thread form is configured to interlock with the internal thread form of an implant receiver. The external thread form defines a crest, the crest having a width in the range of about 35% to 50% of the pitch of the external thread form. The front wing and the rear wing are angled relative to the thread axis in a proximal orientation. The external thread form is configured to interlock with the internal thread form of an implant receiver. In some embodiments, systems, spinal constructs, implants, and methods are disclosed.

[0005] In one embodiment, a spinal implant is provided. The spinal implant includes an implant receiver having at least one thread, the thread defining an internal thread form having at least one fillet. The coupling member includes at least one thread defining a thread axis, and an external thread form having a front flank and a rear flank. The front flank and the rear flank are angled relative to the thread axis in a proximal orientation, and the external thread form defines a screw crest having a width within a range of about 35% to 50% of the pitch of the external thread form. The front flank is disposed at a first angle relative to a transverse axis of the at least one thread, and the rear flank is disposed at a second angle relative to the transverse axis. The first angle is greater than the second angle. The external thread form is configured to interlock with the internal thread form.

[0006] In one embodiment, a spinal implant system is provided. The spinal implant system includes at least one bone screw having an implant receiver and a tissue penetrating shaft. The implant receiver includes at least one thread defining an internal thread form having at least one fillet. The fixing screw includes at least one thread defining a thread axis, and an external thread form having a front wing and a rear wing. The front wing and the rear wing are at an angle relative to the thread axis in a proximal orientation. The external thread form defines a screw crest having a width in the range of about 35% to 50% of the pitch of the external thread form. The front wing is set at a first angle relative to the transverse axis of the at least one thread, and the rear wing is set at a second angle relative to the transverse axis. The first angle is greater than the second angle. The external thread form is configured to interlock with the internal thread form. A spinal rod, which is configured to be set together with the implant receiver and engaged with the fixing screw. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present disclosure will become more readily apparent from the specific description accompanying the following drawings, in which:

[0008] Figure 1 is a perspective view of components of one embodiment of a surgical system according to principles of the present disclosure;

[0009] Figure 2 yes Figure 1 A cross-sectional view of the components shown in ;

[0010] Figure 3 is a perspective view of components of one embodiment of a surgical system according to principles of the present disclosure;

[0011] Figure 4 is a side view of components of one embodiment of a surgical system according to principles of the present disclosure;

[0012] Figure 5 is along Figure 4 A cross-sectional view taken along line AA as shown; and

[0013] Figure 6 yes Figure 5 Exploded view of detail B shown. DETAILED DESCRIPTION

[0014] Exemplary embodiments of the disclosed surgical systems and related methods of use are discussed in the context of medical devices for treating musculoskeletal disorders, and more particularly, in the context of spinal implant systems including bone fasteners and methods for treating the spine.

[0015] In certain embodiments, spinal implant system of the present disclosure comprises spinal implant, for example, bone fastener with receiver and set screw.In certain embodiments, set screw is configured to facilitate that set screw engages with receiver.In certain embodiments, set screw is configured to contact receiver and interlock with receiver to reduce the opening of receiver.

[0016] In some embodiments, the set screw includes a thread form with a crest. In some embodiments, the crest includes a selected thickness. In some embodiments, the thickness includes a certain percentage of the pitch. In some embodiments, the thickness of the crest is about 45% of the pitch. In some embodiments, the thickness at the crest is configured to provide an increase in the strength of the set screw or the matching receiver. In some embodiments, the surgical system of the present disclosure includes a set screw configured to withstand increased load capacity. The set screw is configured to resist and / or prevent the opening of the receiver's arms that may occur due to excessive loading. In some embodiments, the opening is due to the set screw deviating from the axis in the receiver, thereby causing thread overload due to reduced thread contact and narrowing of the crest width. In some embodiments, the angles of the rear flank and the front flank are arranged in a proximal orientation relative to the thread axis. In some embodiments, the thread geometry provides a wider crest width on the small diameter of the tulip-shaped head and the large diameter of the set screw. In some embodiments, the increase in crest width helps to resist and / or prevent the shear force generated by the clamping force generated during the engagement of the set screw with the receiver. In some embodiments, the set screw is configured to engage the receiver in a mating manner.

[0017] In some embodiments, the receiver includes internal threads having smooth rounded corners configured to eliminate binding and / or cut into the set screw. In some embodiments, the rounded corners become a load-bearing surface during engagement of the set screw with the receiver. In some embodiments, the arcuate configuration of the corners resists and / or prevents the corners from cutting into the set screw. In some embodiments, this configuration is beneficial when the receiver includes a harder material than the set screw.

[0018] In some embodiments, the thread comprises a leading edge and a trailing edge. In some embodiments, the angles of the leading edge and the trailing edge form a selected thickness of the screw top. In some embodiments, the leading edge is arranged at an angle greater than the angle of the trailing edge. In some embodiments, the angle of the leading edge is about 20 degrees greater than the angle of the trailing edge.

[0019] In some embodiments, the leading edge is disposed at an angle relative to the transverse axis. In some embodiments, the leading edge angle is about 15 degrees relative to the transverse axis. In some embodiments, the trailing edge is disposed at an angle relative to the transverse axis. In some embodiments, the trailing edge angle is about -5 degrees relative to the transverse axis, i.e., a reverse angle of about 5 degrees. In some embodiments, the leading wing edge is about 20 degrees greater than the trailing wing edge angle.

[0020] In some embodiments, the present disclosure can be used to treat spinal disorders, such as degenerative disc disease, disc herniation, osteoporosis, spondylolisthesis, stenosis, scoliosis and other curvature abnormalities, kyphosis, tumors and fractures. In some embodiments, the present disclosure can be used with other skeleton and bone-related applications, including those applications associated with diagnosis and therapy. In some embodiments, the disclosed surgical system can be used alternatively in surgical treatments in which the patient is in a prone or supine position, and / or for various surgical methods for the spine, including anterior, posterior, posterior midline, direct lateral, posterior lateral and / or anterolateral approaches, and for other body regions. The present disclosure can also be used alternatively with procedures for treating the lumbar, cervical, thoracic, sacral and pelvic regions of the spine. The surgical system of the present disclosure can also be used on animals, bone models and other inanimate substrates, such as in training, testing and demonstrations.

[0021] The present disclosure can be more easily understood by the following detailed description of the embodiments performed by reference to the accompanying drawings that form a part of the present disclosure. It should be understood that the present application is not limited to the specific devices, methods, conditions or parameters described and / or shown herein, and the terms used herein are only for the purpose of describing specific embodiments by example, rather than for limitation. In some embodiments, as used in the specification and including the appended claims, the singular forms "a (a)", "an (an)" and "said" include plural numbers, and unless the context clearly stipulates, the reference to a specific numerical value includes at least the specific value. The range can be expressed as from "about" or "approximately" a specific value and / or to "about" or "approximately" another specific value in this article. When expressing this range, another embodiment includes from a specific value and / or to another specific value. Similarly, when the value is expressed as an approximate value by using the antecedent "about", it should be understood that the specific value forms another embodiment. It should also be understood that all spatial references (such as horizontal, vertical, top, upper, lower, bottom, left and right) are only for illustrative purposes and can be changed within the scope of the present disclosure. For example, references to "upper" and "lower" are relative and used only in context and are not necessarily "higher" and "lower."

[0022] The following discussion includes descriptions of surgical systems including one or more spinal implants, related components, and methods of using surgical systems in accordance with the principles of the present invention. Alternative embodiments are disclosed. Reference is made in detail to the exemplary embodiments of the present disclosure illustrated in the accompanying drawings. Figure 1-5 , components of a spinal implant system 10 including a spinal implant, such as coupling members and bone fasteners, are shown.

[0023] The components of the spinal implant system 10 can be made of biologically acceptable materials suitable for medical applications, including metals, synthetic polymers, ceramics and bone materials and / or composites thereof. For example, the components of the spinal implant system 10 can be made of the following materials individually or collectively: stainless steel alloys, commercially pure titanium, titanium alloys, grade 5 titanium, superelastic titanium alloys, cobalt-chromium alloys, superelastic metal alloys (e.g., nitinol, superelastic plastic metals, such as GUM ), ceramics and composites thereof, such as calcium phosphate (e.g., SKELITE TM), thermoplastics such as polyaryletherketones (PAEK), including polyetheretherketones (PEEK), polyetherketoneketones (PEKK) and polyetherketones (PEK), carbon-PEEK composites, PEEK-BaSO4 polymer rubbers, polyethylene terephthalate (PET), fabrics, silicones, polyurethanes, silicone-polyurethane copolymers, polymer rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigid materials, elastomers, rubbers, thermoplastic elastomers, thermosetting elastomers, elastomeric composites, rigid polymers including polyphenylenes, polyamides, polyimides, polyetherimides, polyethylenes, epoxy resins, bone materials including autologous grafts, Plants, allografts, xenografts or transgenic cortical bone and / or cortical cancellous bone, as well as tissue growth or differentiation factors, partially resorbable materials, such as composites of metal and calcium-based ceramics, composites of PEEK and calcium-based ceramics, composites of PEEK and resorbable polymers, fully resorbable materials, for example, calcium-based ceramics such as calcium phosphate, tricalcium phosphate (TCP), hydroxyapatite (HA)-TCP, calcium sulfate or other resorbable polymers such as polyaetide, polyglycolide, polytyrosine carbonate, polycaprolactone and combinations thereof.

[0024] The various components of the spinal implant system 10 may have a material composite material including the above-mentioned materials to achieve various desired characteristics, such as strength, rigidity, elasticity, compliance, biomechanical properties, durability and radiolucency or imaging priority. The components of the spinal implant system 10 may also be made of heterogeneous materials individually or collectively, for example, made of a combination of two or more of the above-mentioned materials. The components of the spinal implant system 10 may be integrally formed, integrally connected or include fastening elements and / or instruments, as described herein.

[0025] Spinal implant system 10 includes a coupling member, such as a fixing screw 12 configured to engage with a bone screw 100, as described herein. Fixing screw 12 includes a portion such as a head 14, and a portion such as a shaft 16. Head 14 includes a tool engagement portion 18, and tool engagement portion 18 is configured to engage a surgical tool or instrument (not shown), as described herein. In some embodiments, portion 18 includes a hexagonal cross section for ease of engagement with a surgical tool or instrument. In some embodiments, head 14 can have an optional cross section, such as, for example, a rectangular, polygonal, hexagonal, elliptical or irregular shape. In some embodiments, portion 18 can have a cross-shaped, Phillips-shaped, square, polygonal or star-shaped cross-sectional configuration, which is configured to be used to place a portion of a corresponding shape of a surgical tool or instrument. In some embodiments, head 14 includes a hollow fracture fixing screw and an internal drive mechanism for removing the fixing screw.

[0026] The shaft 16 extends between the end 20 and the end 22 and defines an axis X1. Figure 1 As shown. Figure 2 1. As shown, axis X2 extends laterally, for example, orthogonal to axis X1. In some embodiments, axis X2 can be alternatively oriented relative to axis X1, for example, at an angle such as an acute angle or an obtuse angle. Shaft 16 includes an outer surface 26. Surface 26 includes threads 28. In some embodiments, surface 26 includes one or more threads 28 configured to enhance fixation with receiver 102, as described herein. In some embodiments, threads 28 are continuous along surface 26. In some embodiments, threads 28 may include a single thread turn or a plurality of discrete threads. In some embodiments, a penetrating element may be located on shaft 16, such as a nail configuration, a barb, an extension element, a raised element, a rib and / or a spike, to facilitate engagement of shaft 16 with bone screw 100.

[0027] like Figure 1 As shown, the thread 28 includes a small diameter D1 and a large diameter D2. The thread 28 includes an external thread form 32. The external thread form 32 defines the profile shape of a complete thread 28. The thread form 32 includes a front flank 34 and a rear flank 36, as shown in FIG. Figure 2 As shown. Figure 1 , 2 6, the external thread form 32 is angled relative to the axis X1 in a proximal and / or reverse angular orientation. For example, the thread form 32, such as the front and / or rear flanks 34, 36, is angled toward the end 20.

[0028] The front wing 34 comprises a surface 38 arranged at an angle α1 relative to the axis X2, such as Figure 2 and 6 In some embodiments, the angle α1 is about 15 degrees relative to the axis X2. In some embodiments, the surface 38 can be oriented in another manner relative to the axis X2, such as by being perpendicular to the axis X2 and / or having another angular orientation relative to the axis X2, such as an acute angle or an obtuse angle.

[0029] The rear flank 36 comprises a surface 50 arranged at an angle α2 relative to the axis X2, such as Figure 2 and 6 In some embodiments, the angle α2 is about -5 degrees relative to the axis X2. In some embodiments, the surface 50 can be alternatively oriented relative to the axis X2, for example, perpendicular and / or at other angles, such as acute or obtuse.

[0030] In some embodiments, the difference between the angle α1 and the angle α2 is greater than the difference Δ1, such as Figure 6In some of these embodiments, angle α1 is greater than angle α2, and in other contemplated embodiments, angle α1 is less than angle α2. In some embodiments, for example, the difference Δ1 is in the range of about 5 degrees to about 20 degrees. In some embodiments, the difference Δ1 is about 20 degrees.

[0031] The threads 28 define a pitch P1 having a length L1 extending between adjacent rear flanks 36. Figure 2 As shown. The front flank 34 and the rear flank 36 converge at the screw top surface C1. In various embodiments, the screw top surface C1 extends along the major diameter D2. The screw top surface C1 includes a width W1 along the major diameter D2. In various embodiments, the width W1 is a percentage of the length L1 of the pitch P1. In some embodiments, the width W1 is a percentage of the length L1 in the range of about 35% to about 50% of the length L1. In some embodiments, the width W1 is about 45% of the length L1. The value of the width W1 is selected to disperse the load applied by the shear force during the engagement of the set screw 12 with the receiver 102. As such, the width W1 is configured to resist and / or prevent the effects of shear forces on the set screw 12 and the receiver 102 during tightening.

[0032] In some embodiments, the width W1 has a predetermined relationship with the pitch P1. In various embodiments, the relationship includes the bone screw 100 being configured such that the width W1 is a preset percentage of the pitch P1, such as the width W1 being between about 40% and about 50% of the pitch P1. In various embodiments, the width W1 is any one of between about 47% and about 43% of the pitch P1, between about 46% and 44% of the pitch P1, and about 45% of the pitch P1.

[0033] like Figure 2 As shown, the screw top surface C1 is disposed at a length L2 from the minor diameter D1. In various embodiments, the screw top surface C1 includes a substantially planar configuration. In various embodiments, the screw top surface C1 is disposed parallel to the axis X1. In some embodiments, the screw top surface C1 can alternatively be oriented relative to the axis X1, such as transversely, and / or at other angles, such as acute or obtuse angles.

[0034] The end portion 20 and the head portion 14 form a cross-section, for example, a neck portion 24 having the head portion 14, such as Figure 1 As shown Figure 2 , 45. In some embodiments, the end 20 includes a reduced diameter portion 60 at the neck 24. In some embodiments, the portion 60 is frangibly connected to the head 14. In some embodiments, the portion 60 is made of a fractured and / or frangible material such that manipulation of the head 14 relative to the shaft 16 can cause fracture at the portion 60 to separate the head 14 from the shaft 16 at a predetermined force and / or torque limit, as described herein. In some embodiments, when force and / or torque is applied to the head 14 and resistance increases, for example due to the fixation of the shaft 16 within the receiver 102, as described herein, the predetermined torque and force limits are approached.

[0035] In some embodiments, the head 14 can break and separate from the neck 24 at a predetermined force or torque limit, which can be in the range of about 7 Newton meters (Nm) to about 12.5 Nm. In some embodiments, the head 14 and / or the shaft 16 can be made of a homogeneous material or made inhomogeneously of different materials, and / or can alternatively be formed of a material having a greater degree of plastic deformability, brittle characteristics, and / or breakaway quality characteristics or properties to facilitate breaking and separation of the head 14 from the shaft 16. In some embodiments, the head 14 includes an inner diameter that facilitates the desired breaking torque.

[0036] End 22 includes a surface 62 including a penetrating element 64 extending distally from surface 62. Element 64 is configured to engage a spinal implant, such as a spinal rod 66, such as Figure 4 and 5 Component 64 is configured to apply force to spinal rod 66 to secure the spinal rod with bone screw 100, as described herein.

[0037] Bone screw 100 includes a receiver 102, such as Figure 3 Receiver 102 includes a pair of spaced arms 104, 106, which define therebetween an implant cavity 108 configured to be used to place spinal rod 66. Arms 104, 106 each extend parallel to axis X3. In some embodiments, arms 104, 106 can be arranged in alternative orientations relative to axis X3, such as transverse, vertical and / or other angular orientations, such as acute or obtuse angles, coaxial and / or can be offset or staggered.

[0038] In various embodiments, the cavity 108 is substantially U-shaped. In some embodiments, all or only a portion of the cavity 108 may have alternative cross-sectional configurations, such as closed, V-shaped, W-shaped, elliptical, rectangular, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, and / or tapered shapes.

[0039] The receiver 102 includes an inner surface 110, such as Figure 3Surface 110 includes threads 112. Threads 112 include a small diameter D3 and a large diameter D4, as shown in FIG. Figure 5 The thread 112 includes an internal thread form 114. The internal thread form 114 defines a profile shape of a complete thread 112. The internal thread form 114 is angled in a distal orientation relative to the axis X3, such as Figure 4 For example, the internal thread form 114 is angled toward the distal end of the receiver 102 .

[0040] Internal thread form 114 includes flank 116 and flank 118, as shown in FIG. Figure 6 The threads 112 define a pitch P2 having a length L4 extending between adjacent flanks 118, as shown in FIG. Figure 6 In some embodiments, the pitch P1 ( Figure 2 ) is approximately equal to the pitch P2. In some embodiments, the pitch P1 is greater than the pitch P2. In some embodiments, the pitch P1 is less than the pitch P2.

[0041] The flank 116 includes a surface 120 extending transverse to the axis X3. The surface 120 is disposed in an orientation that facilitates engagement with the front flank 34 so as to interlock the set screw 12 with the receiver 102. In some embodiments, the surface 120 may be alternatively oriented relative to the axis X3, for example, perpendicular and / or at other angles, such as acute or obtuse.

[0042] The flank 118 includes a surface 150 extending transverse to the axis X3. The surface 150 is disposed in an orientation that facilitates engagement with the rear flank 36 to interlock the set screw 12 with the receiver 102. In some embodiments, the surface 150 may be alternatively oriented relative to the axis X3, for example, perpendicular and / or at other angles, such as acute or obtuse.

[0043] The screw top C2 extends between the flank 116 and the flank 118 and extends along the minor diameter D3. The screw top surface C2 includes a width W2 along the minor diameter D3. The width W2 is a percentage of the length L4 of the pitch P2. In some embodiments, the width W2 is a percentage of the length L1 in the range of about 35% to about 50% of the length L4. In some embodiments, the width W2 is about 45% of the length L4. The width W2 is configured to disperse the load applied by the shear force during the engagement of the set screw 12 with the receiver 102. As such, the engagement of the set screw 12 with the receiver 102 is configured to resist and / or prevent the effect of the shear force on the set screw 12 and the receiver 102 during tightening.

[0044] In some embodiments, width W2 has a predetermined relationship with pitch P2. In various embodiments, the relationship includes bone screw 100 being configured such that width W2 is a preset percentage of pitch P2, such as width W2 being between about 40% and about 50% of pitch P2. In various embodiments, width W2 is any one of between about 47% and about 43% of pitch P2, between about 46% and 44% of pitch P1, and about 45% of pitch P2.

[0045] The screw top surface C2 is set at a length L3 from the major diameter D4. Figure 6 In some embodiments, the distance L3 is greater than the distance L2 by a difference Δ2. These components are configured such that the difference Δ2 is sufficient to provide a gap between the screw top surface C1 and the surface defining the major diameter D4, as shown in FIG. Figure 6 The gap between the top surface C1 and the major diameter D4 facilitates expansion of the threads 28 during engagement of the set screw 12 with the receiver 102. The space between the top surface C1 and the surface defining the major diameter D4 is configured to resist and / or prevent the set screw 12 from opening the arms 104, 106 during engagement of the set screw 12 with the receiver 102.

[0046] In various embodiments, flank 116 merges with crest surface C2 at surface 160. Surface 160 may include an arcuate configuration relative to minor diameter D3 such that surface 160 is circular.

[0047] Flank 118 merges with crest surface C2 at surface 162. Surface 162 includes an arcuate configuration relative to minor diameter D3 such that surface 162 is circular. In some embodiments, one or both of surfaces 160, 162 include an arcuate configuration.

[0048] The arcuate configuration of surfaces 160, 162 prevents surfaces 160, 162 from cutting into set screw 12. For example, when set screw 12 is engaged with receiver 102, surfaces 160, 162 are load bearing surfaces. When a load is applied, the arcuate configuration of surfaces 160, 162 resists and / or prevents surfaces 160, 162 from cutting into set screw 12. In some embodiments, this configuration is particularly beneficial when receiver 102 comprises a harder material than set screw 12.

[0049] Bone screw 100 includes a shaft 180, such as Figure 4 and 5As shown. Shaft 180 is configured to be fixed with tissue (not shown) of a patient. In some embodiments, shaft 180 has a cylindrical cross-sectional configuration and includes an outer surface having a thread defining an external thread form. In some embodiments, the thread may include a single thread turn or a plurality of discrete threads. In some embodiments, an engagement structure may be located on shaft 180, such as a nail configuration, barbs, extension elements, raised elements, and / or spikes, so that shaft 180 engages with tissue such as vertebrae.

[0050] In some embodiments, all or only a portion of shaft 180 may have alternative cross-sectional configurations, such as elliptical, rectangular, triangular, square, polygonal, irregular, uniform, non-uniform, offset, staggered, wavy, arched, variable and / or tapered shapes. In some embodiments, the outer surface of shaft 180 may have alternative surface configurations to enhance fixation with tissue, such as rough, arched, wavy, reticular, porous, semi-porous, concave and / or textured configurations. In some embodiments, all or only a portion of shaft 180 may be arranged with respect to axis X4 in an alternating orientation, such as transverse, vertical and / or other angular orientations, such as acute or obtuse angles, coaxial and / or may be offset or staggered. In some embodiments, all or only a portion of shaft 180 may be hollow.

[0051] In some embodiments, one or more of the bone screws 100 and / or bone fasteners described herein may include, for example, a polyaxial screw, a sagittal angled screw, a pedicle screw, a monoaxial screw, a uniplane screw, a facet screw, a fixation screw, a tissue penetrating screw, a conventional screw, an expansion screw, a wedge, an anchor, a button, a clip, a snap, a friction fastener, a compression fastener, an expansion rivet, a staple, a nail, an adhesive, a post, a fixation plate and / or a fixation post.

[0052] In assembly, operation and use, similar to the systems and methods described herein, spinal implant system 10 includes fixation screw 12 and bone screw 100 as described herein, and is used together with the surgical procedure for treating the spinal disease of one section of the patient's spine as described herein. In some embodiments, the components of spinal implant system 10 are used together with one or more vertebral segments of the spine. In some embodiments, the components of spinal implant system 10 may include one or more bone fasteners, spinal rods, plates, connectors and / or in vivo devices.

[0053] In use, in order to treat the affected part of the spine, the practitioner obtains access to the surgical site in any appropriate manner, such as by the incision and contraction of tissue. In certain embodiments, the parts of spinal implant system 10 can be used for any existing surgical method or technology, including open surgery, micro-open surgery and minimally invasive surgery, including percutaneous surgery implantation. Once the surgical site is reached, specific surgical procedures are performed to treat spinal disorders. The parts of the spinal implant system 10 comprising a set screw 12 and a bone screw 100 are used to enhance surgical treatment. As described herein, the parts of the spinal implant system 10 are delivered or implanted as preassembled devices or can be assembled in situ. The parts of the spinal implant system 10 can be modified, removed or replaced in whole or in part. For example, shaft 180 is fastened to tissue such as vertebrae so that spinal rod 66 is provided with receiver 102 for connection with vertebrae.

[0054] The fixing screw 12 is coupled to the bone screw 100 near the top surface of the receiver 102. The fixing screw 12 is guided along the bone screw 100 by a surgical instrument or tool. Figure 4 The direction indicated by the arrow C in the middle rotates clockwise and Figure 4 The screw 12 is translated in the direction indicated by the arrow D, so that the threads 28 cooperate with the threads 112 to couple the fixation screw 12 with the bone screw 100. As such, the external thread form 32 cooperates with the internal thread form 114 at the same time.

[0055] Translation of the set screw 12 causes the element 64 to engage the spinal rod 66, so that the set screw 12 provides a closure mechanism to dispose the spinal rod 66 within the cavity 108, fix the spinal rod 66 within the receiver 102, and connect the spinal rod 66 to the vertebra. The width W1 at the screw top surface C1 and the width W2 at the screw top surface C2 distribute the load applied by the shear force during the engagement of the set screw 12 with the receiver 102. As such, the widths W1, W2 are configured to resist and / or prevent the effect of the shear force on the set screw 12 and the receiver 102 during tightening. The arcuate surfaces 160, 162 prevent and / or prevent the threads 112 from cutting and / or biting into the surface of the set screw 12 during engagement with the receiver 102.

[0056] As described herein, when the operation is completed, the surgical instruments, components and non-implanted parts of the spinal implant system 10 are removed, and one or more incisions are closed. One or more of the parts of the spinal implant system 10 can be made of a radiolucent material such as a polymer. Radioactive markers can be included for identification under X-rays, fluoroscopy, CT or other imaging techniques. In certain embodiments, the use of surgical navigation, microsurgery and image-guided technology can be used for entering, viewing and repairing spinal deterioration or damage with the aid of the spinal implant system 10.

[0057] In one embodiment, the spinal implant system 10 includes an agent that can be placed, packaged, coated or layered in, on or around the components and / or surfaces of the spinal implant system 10. In some embodiments, the agent can include a bone growth-promoting material, such as a bone graft, to enhance the fixation of the components and / or surfaces of the spinal implant system 10 to the vertebrae. In some embodiments, the agent can include one or more therapeutic agents and / or pharmacological agents for release, including sustained release, to treat, for example, pain, inflammation and degeneration.

[0058] It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be interpreted as limiting, but only as an illustration of various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims attached hereto.

Claims

1. A connecting member, comprising: a shaft defining an axis and comprising at least one thread having an external thread form having a front flank and a rear flank, the external thread form defining a pitch and a crest having a width in the range of 35% to 50% of the pitch of the external thread form, in, The front flank and the rear flank are angled relative to the thread axis in a proximal orientation, wherein the external thread form is configured to interlock with an internal thread form of an implant receiver; wherein the front wing is disposed at a first angle relative to a transverse axis of the at least one thread, and the rear wing is disposed at a second angle relative to the transverse axis, the first angle being greater than the second angle; and Wherein, the first angle is 15 degrees relative to the transverse axis, and the second angle is -5 degrees relative to the transverse axis.

2. The coupling member according to claim 1, wherein: The width is 45% of the pitch of the external thread form.

3. The coupling member according to claim 1, wherein: The external thread form includes a crest surface disposed in a parallel orientation relative to the thread axis.

4. The coupling member according to claim 1, wherein: The external thread form includes a crest surface having a planar configuration.

5. The coupling member according to claim 1, wherein The at least one thread includes a plurality of threads disposed along the shaft.

6. The coupling member according to claim 1, wherein The implant receiver comprises at least one thread having the internal thread form, the at least one thread comprising at least one fillet.

7. The coupling member according to claim 1, wherein: The threads of the implant receiver include a crest having a width in the range of 35% to 50% of the pitch of the internal thread form.

8. The coupling member according to claim 1, wherein The implant receiver includes spaced apart walls, each wall including threads having the internal thread form, each thread including a pair of fillets.

9. A spinal implant comprising: an implant receiver comprising at least one thread defining an internal thread form having at least one fillet; and a coupling member comprising at least one thread defining a thread axis, and an external thread form having a front flank and a rear flank angled relative to the thread axis in a proximal orientation, the external thread form defining a crest having a width in the range of 35% to 50% of the pitch of the external thread form, The front flank is disposed at a first angle relative to a transverse axis of the at least one thread, and the rear flank is disposed at a second angle relative to the transverse axis, the first angle being greater than the second angle, the first angle being 15 degrees relative to the transverse axis, and the second angle being -5 degrees relative to the transverse axis, The external thread form is configured to interlock with the internal thread form.

10. The spinal implant according to claim 9, wherein: The implant receiver includes spaced apart walls, each wall including threads having the internal thread form, each thread including a pair of fillets.

11. The spinal implant according to claim 9, wherein: The width is 45% of the pitch of the external thread form.

12. A spinal implant comprising: at least one bone screw comprising an implant receiver and a tissue penetrating shaft, the implant receiver including at least one thread defining an internal thread form having at least one fillet; A set screw comprising at least one thread defining a thread axis, and an external thread form having an anterior flank and a posterior flank, the anterior flank and the posterior flank being angled relative to the thread axis in a proximal orientation, the external thread form defining a crest, the crest having a width in the range of 35% to 50% greater than a pitch of the external thread form, the anterior flank being disposed at a first angle relative to a transverse axis of the at least one thread, the posterior flank being disposed at a second angle relative to the transverse axis, the first angle being greater than the second angle, the first angle being 15 degrees relative to the transverse axis, and the second angle being -5 degrees relative to the transverse axis, The external thread form is configured to interlock with the internal thread form; and A spinal rod is configured to be disposed with the implant receiver and to engage with the set screw.

13. The spinal implant according to claim 12, wherein: The width is 45% of the pitch of the external thread form.

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