Orthopedic Bone Screws

Abstract

The present disclosure describes a bone screw for use in orthopedic procedures. The bone screw includes a shank having a helical thread and a head also having a helical thread. The shank also includes a first hooking zone having a first thread pitch configured for hooking in cancellous bone and a second hooking zone having a second thread pitch configured for hooking in cortical bone, the first hooking zone extending proximally from a distal end of the screw, and the second hooking zone extending proximally from an interface with the first hooking zone, the first thread pitch and the second thread pitch being compression neutral.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is an international application claiming the benefit of priority from commonly owned and co-pending U.S. Provisional Application No. 63 / 427,279, entitled "ORTHOPEDIC BONE SCREW," filed November 22, 2022, the entire contents of which are incorporated by reference into this disclosure as if fully set forth herein.

[0002] The present disclosure relates generally to bone screws for use in orthopedic surgical procedures, and more particularly to bone screws having a tapered frusto-conical head that decreases proximally. [Background technology]

[0003] Bone screws typically have three main parts: the head, the shank, and the threads. The head of most screws is generally frusto-conical—i.e., resembles a truncated cone, formed by cutting the tip of the cone perpendicular to its height to form circular, parallel inferior and superior bases, the inferior base being the original, wider surface of the cone and the superior surface being the newly formed, narrower surface. The wider base of the frustum comprises the top (or proximal tangent) of the screw and often includes driving features (e.g., a single flute to accept a flat-head screwdriver, or orthogonal cross-hatched flutes to accept a Phillips-style screwdriver). The narrower base of the frustum typically transitions into the shank and may form a separate neck region. Summary of the Invention [Problem to be solved by the invention]

[0004] Various examples of bone screws described herein are suitable for a variety of orthopedic procedures, including, but not limited to, small bone repair (e.g., surgical repair of fractures of the hand, wrist, ankle, and foot, including Bunionplasty® bunion surgery, etc.) and large bone repair (e.g., surgical repair of long bones of the arms and legs). The bone screws described herein may be provided in various lengths and / or diameters (both outer and inner diameters) as needed. The bone screws described herein may be compression or compression-neutral. The bone screws described herein may also be configured for implantation at extreme angles without protruding from the bone. [Means for solving the problem]

[0005] In some embodiments, the orthopedic bone screws described herein include a head, a shank, and a neck located between the head and the shank. The bone screw further includes a proximal end and a distal end. The head is located at / near the proximal end of the bone screw, and the shank extends axially along a longitudinal axis from the neck to the distal end of the bone screw. The head includes a curved outer surface and a helical thread disposed about the curved outer surface.

[0006] In some embodiments, the head has a generally frusto-conical cross-sectional shape, but unlike typical prior art bone screws in which the wider base of the frustum forms the most proximal (or upper) surface of the screw, in the bone screws of the present disclosure, the narrower base of the frustum forms the most proximal (or upper) surface of the bone screw. This orientation may be referred to herein as "inverted cone" or "inverted frusto-conical" to indicate that the orientation of the frusto-conical shape is upside down relative to typical prior art bone screws.

[0007] In some embodiments, the curved outer surface tapers proximally from a wider base to a narrower base. The taper angle, as measured relative to the longitudinal axis (and parallels thereto), may be in the range of 4 to 15 degrees. The taper angle of the curved outer surface may also be characterized in terms of the included angle of the cone defining the frustoconical shape of the head. In such characterization, the included angle may be in the range of 8 to 30 degrees.

[0008] In some embodiments, the head can have an inner diameter at its wider base in the range of 1.75 mm to 9.0 mm and an outer diameter in the range of 2.0 mm to 10.0 mm, the first inner diameter being smaller than the outer diameter (of the helical thread).

[0009] In some embodiments, the head may include an angled surface (also a "chamfer" or "bevel") and a driver recess. The angled surface is formed between the top surface and the outer surface. The top surface has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface does not extend completely across the top of the screw.

[0010] In some embodiments, the head may include an angled surface / chamfer / bevel formed between the top surface and the outer surface such that the width dimension of the top surface is approximately zero (e.g., the angled surface extends completely across the top of the screw).

[0011] In some embodiments, the angled surface may have a bevel angle in the range of 1 to 60 degrees as measured from a plane of the top surface that is generally perpendicular to the longitudinal axis. The angled surface reduces / eliminates the amount of screw material that may extend beyond the edge of the bone structure when the bone screw is implanted at an angle relative to the bone structure.

[0012] In some embodiments, a driver recess is formed in the top surface and angled surface along the longitudinal axis and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobe, torx, etc.).

[0013] In some embodiments, the helical threads on the head may have a pitch (eg, the distance between adjacent threads at any one location) in the range of 0.5 mm to 2.5 mm.

[0014] In some embodiments, the helical thread of the head may have a variable pitch.

[0015] In some embodiments, the bone screw may be compression neutral, in which the helical threads on the head may have the same pitch as the helical threads on the shank, or alternatively, the helical threads on the head may have a pitch that is an even multiple (e.g., 2x) of the pitch of the helical threads on the shank.

[0016] In some embodiments, the bone screw may be a compression screw, in which the helical thread of the head may have a pitch that is different from the pitch of the helical thread on the shank, the pitch of the head being not an even multiple of the pitch of the shank.

[0017] In some embodiments, the head may include cutting flutes formed at the distal end of the helical thread, which serve to remove bone material as the screw is driven into bone, easing the transition from the shank to the head.

[0018] In some embodiments, the helical thread of the head has an outer diameter that remains constant.

[0019] In some embodiments, the helical threads on the head taper outward in the proximal direction such that the outer diameter at the proximal end is larger than the outer diameter near the neck, resulting in an increase in the surface area of ​​the helical threads in contact with the bone from distal to proximal, enhancing the thread's grip into the bone.

[0020] In some embodiments, the helical threads of the head taper inward in the proximal direction so that the outer diameter at the proximal end is smaller than the outer diameter near the neck.

[0021] In some embodiments, the inward taper of the helical thread has the same taper angle as the taper angle of the curved outer surface.

[0022] In some embodiments, the shank is cylindrical and extends from a proximal end adjacent the neck to a distal end of the bone screw. The shank includes a curved outer surface and a helical thread disposed about the curved outer surface.

[0023] In some embodiments, the barrel may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the barrel is smaller than the outer diameter of the head.

[0024] In some embodiments, the helical thread of the barrel may have a pitch in the range of 0.5 mm to 2.5 mm.

[0025] In some embodiments, the barrel may have a pair of helical threads, each having a pitch in the range of 0.5 mm to 5.0 mm.

[0026] In some embodiments, the shaft includes one or more cutting flutes located at the distal end. The cutting flutes serve to remove bone material as the screw is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0027] In some embodiments, the bone screw includes one or more reverse cutting flutes to remove bone material when the screw is removed from the bone.

[0028] In some embodiments, the neck includes a curved outer surface that tapers distally to provide a smooth transition between the inverted nostril and the barrel.

[0029] As additional explanation for the embodiments described below, the present disclosure describes the following embodiments.

[0030] Embodiment 1 is an orthopedic surgical screw at an anatomical target site within a human patient, the screw having a proximal end and a distal end, the screw including a head having a proximal end comprising the proximal end of the screw, a shank having a distal end comprising the distal end of the screw, and a neck extending between the head and the shank, the head, neck, and shank being collinear along a longitudinal axis extending between the proximal end of the head and the distal end of the shank; the head including: a proximal bottom surface at the proximal end of the head, the top surface of the head intersecting the longitudinal axis; the at least one helical thread having a diameter extending from the proximal bottom surface of the head to the distal bottom surface of the head and defining an outer diameter of the head is configured to contact bone forming part of the anatomical target site when the head is implanted in use, thereby enhancing the hooking of the head into the bone, and the at least one helical thread is configured to connect the at least one pin the drive feature is dimensioned to cooperate with the instrument such that the head, the barrel, and the neck can rotate about a longitudinal axis to drive the barrel, the neck, and the head into an anatomical target in a patient; the barrel: includes a curved outer surface having at least one helical thread extending from the proximal end of the barrel toward the distal end of the barrel, the at least one helical thread including at least two hooking zones, the at least two hooking zones including a first hooking zone including a cancellous pitch zone having a first thread pitch configured for hooking in cancellous bone and a second hooking zone including a cortical pitch zone having a second thread pitch configured for hooking in cortical bone, the first hooking zone extending proximally from the distal end of the screw and the second hooking zone extending proximally from an interface with the first hooking zone; the first thread pitch and the second thread pitch are compression neutral.

[0031] Embodiment 2 is the orthopedic surgical screw of embodiment 1, wherein the pitch of at least one helical thread in the first hooking zone is within the range of 0.5 mm to 5 mm.

[0032] Embodiment 3 is the orthopedic surgical screw of embodiment 1 or 2, wherein the pitch of the at least one helical thread in the second hooking zone is half the pitch of the at least one helical thread in the first hooking zone.

[0033] Embodiment 4 is the orthopedic surgical screw of any of Embodiments 1 to 3, wherein the pitch of at least one helical thread in the first hooking zone is 1.5 mm.

[0034] Embodiment 5 is the orthopedic surgical screw of any of Embodiments 1 to 4, wherein the pitch of at least one helical thread in the second hooking zone is 0.75 mm.

[0035] Embodiment 6 is the orthopedic surgical screw of any of Embodiments 1 to 5, wherein the second hooking zone extends between the interface with the first hooking zone and the neck.

[0036] Embodiment 7 is the orthopedic surgical screw of any of Embodiments 1 to 6, wherein the first hooking zone and the second hooking zone each have a length dimension within the range of 10 mm to 30 mm.

[0037] Embodiment 8 is the orthopedic surgical screw of any of Embodiments 1 to 7, wherein the first hooking zone and the second hooking zone may each comprise 10% to 60% of the overall length of the screw.

[0038] Embodiment 9 is the orthopedic surgical screw of any of embodiments 1 to 8, wherein the helical thread of the shaft further includes a third hooking zone extending distally between the neck and an interface with the second hooking zone, the third hooking zone being configured for hooking within cancellous bone.

[0039] A tenth embodiment is the orthopedic surgical screw of any one of the first to ninth embodiments, wherein the third hooking zone and the first hooking zone have the same thread pitch.

[0040] Embodiment 11 is the orthopedic surgical screw of any of Embodiments 1 to 10, wherein the thread pitch of the helical thread of the head is the same as the thread pitch of the helical thread of the shank in the first hooking zone.

[0041] Embodiment 12 is the orthopedic surgical screw according to any one of Embodiments 1 to 11, wherein the pitch of at least one helical thread on the head is within the range of 0.5 mm to 5 mm.

[0042] Embodiment 13 is an orthopedic surgical screw of any of Embodiments 1 to 12, wherein the head includes a chamfered surface extending along the curved outer side from the proximal bottom surface of the head to a predetermined position, the chamfered surface being angled relative to the top surface of the head to define a bevel angle dimensioned such that, when the head is implanted in use, the chamfered surface is positioned flush against the outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating extension of the head beyond the outer surface of the bone when implanted at an angle relative to the bone.

[0043] Embodiment 14 is the orthopedic surgical screw according to any one of Embodiments 1 to 13, wherein the bevel angle of the head is within the range of 1 to 60 degrees.

[0044] Embodiment 15 is an orthopedic surgical screw according to any one of embodiments 1 to 14, wherein the chamfered surface includes a first chamfered surface, and the head further includes a second chamfered surface extending along the curved outer side of the head from the proximal bottom surface of the head to a predetermined position, and the second chamfered surface is bent at an angle relative to the top surface of the head perpendicular to the longitudinal axis and the first chamfered surface to define a second bevel angle.

[0045] Embodiment 16 is the orthopedic surgical screw of any of Embodiments 1 to 15, wherein the second bevel angle of the head is within the range of 1 to 30 degrees.Embodiment 17 is the orthopedic surgical screw of any of Embodiments 1 to 16, wherein the at least one helical thread of the head further comprises a thread surface area and an outer diameter that increases from the distal bottom surface to the proximal bottom surface, such that the thread surface area increases in the distal to proximal direction.

[0046] Embodiment 18 is an orthopedic surgical screw of any of embodiments 1 to 17, wherein the head includes an inverted frustoconical cross-sectional shape defined by an inner diameter that increases from the distal bottom surface to the proximal bottom surface, and a curved outer surface extending between the distal and proximal bottom surfaces tapers relative to the longitudinal axis to define an inverse taper angle.

[0047] Embodiment 19 is the orthopedic surgical screw of any of embodiments 1 to 18, wherein the neck includes microthreads disposed thereon.

[0048] Embodiment 20 is the orthopedic surgical screw of any of embodiments 1 to 19, wherein the shank further comprises microthreads at the interface between the first and second hooking zones.

[0049] Embodiment 21 is the orthopedic surgical screw of any of embodiments 1 to 20, wherein the head further comprises at least one curved surface at the intersection between the helical thread and the upper surface.

[0050] Embodiment 22 is the orthopedic surgical screw of any of embodiments 1 to 21, wherein the head further comprises at least one curved surface at the intersection between the helical thread and the chamfered surface.

[0051] Embodiment 23 is the orthopedic surgical screw of any of embodiments 1 to 22, wherein the helical thread of the shank further comprises a cortical pitch zone at the distal end.

[0052] In some embodiments, the bone screw is cannulated, including a central lumen extending axially throughout the screw, which is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide the bone screw to the correct implantation location. [Effects of the Invention]

[0053] It is important to note that any element or feature shown and described herein with respect to any particular example embodiment may be used in combination, without limitation, with any other feature(s) or element(s) shown and described herein with respect to the other example embodiments.

[0054] The many advantages of the present disclosure will become apparent to those skilled in the art upon reading this specification in conjunction with the accompanying drawings, in which like numerals refer to like elements and in which: [Brief explanation of the drawings]

[0055] [Figure 1] FIG. 1 is a front plan view of a first example of a bone screw according to one embodiment of the present disclosure. [Figure 2] FIG. 2 is a front plan view of the head region of the bone screw of FIG. 1. [Figure 3] FIG. 3 is a side plan view of the head region of FIG. 2. [Figure 4] FIG. 2 is a perspective view of the bone screw of FIG. 1; [Figure 5] FIG. 2 is a top plan view of the bone screw of FIG. 1. [Figure 6] FIG. 2 is a bottom plan view of the bone screw of FIG. 1. [Figure 7] FIG. 10 is a front plan view of a second example of a bone screw according to one embodiment of the present disclosure. [Figure 8] FIG. 8 is a front plan view of the head region of the bone screw of FIG. [Figure 9] FIG. 9 is a side plan view of the head region of FIG. 8. [Figure 10] FIG. 10 is a front plan view of a third example of a bone screw according to an embodiment of the present disclosure. [Figure 11]FIG. 11 is a front plan view of the head region of the bone screw of FIG. [Figure 12] FIG. 12 is a side plan view of the head region of FIG. [Figure 13] FIG. 10 is a front plan view of a fourth example of a bone screw according to an embodiment of the present disclosure. [Figure 14] FIG. 14 is a front plan view of the head region of the bone screw of FIG. 13. [Figure 15] FIG. 15 is a side plan view of the head region of FIG. [Figure 16] FIG. 10 is a front plan view of a fifth example of a bone screw according to an embodiment of the present disclosure. [Figure 17] FIG. 17 is a front plan view of the head region of the bone screw of FIG. [Figure 18] FIG. 18 is a side plan view of the head region of FIG. 17. [Figure 19] FIG. 10 is a front plan view of a sixth example of a bone screw according to an embodiment of the present disclosure. [Figure 20] FIG. 20 is a front plan view of the head region of the bone screw of FIG. [Figure 21] FIG. 21 is a side plan view of the head region of FIG. 20. [Figure 22] FIG. 10 is a front plan view of a seventh example of a bone screw in accordance with an embodiment of the present disclosure. [Figure 23] FIG. 23 is a front plan view of the head region of the bone screw of FIG. [Figure 24] FIG. 24 is a side plan view of the head region of FIG. 23. [Figure 25] FIG. 13 is a front plan view of an eighth example of a bone screw according to an embodiment of the present disclosure. [Figure 26] FIG. 26 is a front plan view of the head region of the bone screw of FIG. [Figure 27] FIG. 27 is a side plan view of the head region of FIG. 26. [Figure 28] FIG. 13 is a front plan view of a ninth example of a bone screw according to an embodiment of the present disclosure. [Figure 29] FIG. 29 is a front plan view of the head region of the bone screw of FIG. 28. [Figure 30] FIG. 30 is a side plan view of the head region of FIG. 29. [Figure 31]FIG. 19 is a front plan view of a tenth example of a bone screw in accordance with an embodiment of the present disclosure. [Figure 32] FIG. 29 is a front plan view of the head region of the bone screw of FIG. 28. [Figure 33] FIG. 32 is a side plan view of the head region of FIG. 31. [Figure 34] FIG. 19 is a front plan view of an eleventh example of a bone screw in accordance with an embodiment of the present disclosure. [Figure 35] FIG. 35 is a front plan view of the head region of the bone screw of FIG. [Figure 36] FIG. 35 is a side plan view of the head region of FIG. 34. [Figure 37] FIG. 26 is a front plan view of a twelfth example of a bone screw in accordance with an embodiment of the present disclosure. [Figure 38] FIG. 38 is a front plan view of the head region of the bone screw of FIG. 37. [Figure 39] FIG. 38 is a side plan view of the head region of FIG. 37. [Figure 40] FIG. 2 is a top view of a representative image of the bone screw of FIG. 1 being used during hallux valgus repair surgery, according to one embodiment of the present disclosure. [Figure 41] FIG. 2 is a plan view of a representative image of the bone screw of FIG. 1 being used to repair a fractured foot bone. [Figure 42] FIG. 32 is a top view of a representative image of the bone screw of FIG. 31 being used during hallux valgus repair surgery, according to one embodiment of the present disclosure. [Figure 43] 2 is a perspective view of a representative image of a plurality of bone screws of FIG. 1 being used to repair a human bone. [Figure 44] 2 is a top view of a representative image of the bone screws of FIG. 1 being used to repair several fractures of the wrist. [Figure 45] FIG. 2 is an enlarged plan view of the head region of the bone screw of FIG. 1. [Figure 46-51] 2A-2C illustrate some examples of possible configurations of the head region of the bone screw of FIG. 1. [Figure 52] FIG. 19 is a front plan view of a tenth example of a bone screw in accordance with an embodiment of the present disclosure. [Figure 53] FIG. 53 is a perspective view of the head region of the bone screw of FIG. 52; [Figure 54] FIG. 54 is a side plan view of the head region of FIG. 53. [Figure 55-58] FIG. 53 is a front plan view of the bone screw of FIG. 52. [Figure 59] FIG. 53 is a perspective view of the bone screw of FIG. 52 implanted to repair two bone fragments. [Figure 60] FIG. 1 is a perspective view of an example insertion tool configured for use with any of the bone screw embodiments disclosed herein, according to one embodiment of the present disclosure. [Figure 61] FIG. 61 is a top plan view of the insertion tool of FIG. 60. [Figure 62] FIG. 61 is a side plan view of the insertion tool of FIG. 60. [Figure 63] 61 is a side plan view of the insertion tool of FIG. 60 coupled with the bone screw of FIG. 52. [Figure 64-65] FIG. 61 is a perspective view of the insertion tool of FIG. 60 and the bone screw of FIG. 52. DETAILED DESCRIPTION OF THE INVENTION

[0056] Exemplary embodiments of the present invention are described below. For clarity, not all features of an actual implementation are described herein. It will, of course, be understood that the development of any such actual implementation will require making numerous implementation-specific decisions to achieve the developer's particular objectives, including compliance with system- and business-related constraints, which may vary from implementation to implementation. Moreover, it will be understood that such a development effort may be complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure. The bone screws and related methods disclosed herein boast various inventive features and components that, both individually and in combination, warrant patent protection.

[0057] Various examples of bone screws described herein are suitable for a variety of orthopedic procedures, including, but not limited to, small bone repair (e.g., surgical repair of fractures of the hand, wrist, ankle, and foot, including Bunionplasty® surgery, talus fracture repair, etc.), large bone repair (e.g., surgical repair of long bones of the arms and legs), and osteotomies. The bone screws described herein may also be used to fixate bones during the healing process or as part of a major repair surgery. The bone screws described herein may be provided in various lengths and / or diameters (both outer and inner diameters) as needed. The bone screws described herein may be compression or compression-neutral.

[0058] 1-6 illustrate an example of a bone screw 10 according to one embodiment of the present disclosure. By way of example, the bone screw 10 includes a head 12, a shank 14, and a neck 16 located between the head 12 and the shank 14. The bone screw 10 further includes a proximal end 18 and a distal end 20. The head 12 is located at / near the proximal end 18 of the bone screw 10, and the shank 14 extends axially along a longitudinal axis L1 (also referred to as the "vertical axis") from the neck 16 to the distal end 20 of the bone screw 10. The head 12 includes a curved outer surface 22 and a helical thread 24 disposed about the periphery of the curved outer surface 22. The head 12 has a generally frusto-conical cross-sectional shape 26; however, unlike typical prior art bone screws in which a wider base 28 of the frustum forms the most proximal (or upper) surface of the thread, in this example, a narrower base 30 of the frustum forms the most proximal (or upper) surface 32 of the bone screw 10. This orientation may be referred to herein as "inverted cone" or "inverted frustoconical" to indicate that the frustoconical orientation is inverted relative to a typical prior art bone screw. The curved outer surface 22 tapers proximally from a wider base 28 to a narrower base 30. By way of example, the curved outer surface 22 tapers at an angle A1 of 5.9° relative to the longitudinal axis L1 (resulting in a cone defining a head shape having an included angle of 11.8°), although the angle A1 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0059] The head 12 may have an inner diameter at the wide base 28 in the range of 1.75 mm to 9.0 mm. The head 12 may have an outer diameter (e.g., the outer diameter of the helical thread 24) in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 24). By way of example, the head 12 of the bone screw 10 shown in FIGS. 1-4 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wide base 28. As a result of the frustoconical shape, the head 12 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0060] The head 12 further includes an angled surface 34 (also known as a "chamfer" or "bevel") and a driver recess 36. The angled surface 34 is formed between the upper surface 32 and the outer surface 22. The upper surface 32 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 34 does not extend completely across the top of the screw 10. In an embodiment, the upper surface 32 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the overall dimensions of the bone screw 10. By way of example, the angled surface 34 may have a bevel angle θ1 in the range of 1 to 60 degrees, measured from the plane of the upper surface 32, which is generally perpendicular to the longitudinal axis L1. By way of example, the bevel angle θ1 of the bone screw 10 shown in FIGS. 1-6 is 50 degrees. The angled surface 34 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when the head is implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 10 is implanted at an angle relative to the bone structure. A driver recess 36 is formed in the upper surface 32 and the angled surface 34 along the longitudinal axis L1 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0061] The helical thread 24 may have a pitch 38 (e.g., the distance between adjacent threads at any one location) in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 24 in this example has a pitch of 1.5 mm. The head 12 may further include cutting flutes 40 formed at the distal end of the helical thread 24, which serve to remove bone material as the screw 10 is driven into bone, facilitating the transition from the shank 14 to the head 12.

[0062] By way of example, the shank 14 is cylindrical and extends from a proximal end adjacent the neck 16 to the distal end 20 of the bone screw 10. The shank 14 includes a curved outer surface 42 and a helical thread 44 disposed about the periphery of the curved outer surface 42. The shank 14 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 14 is smaller than the outer diameter of the head 12. In the example shown and described herein, the shank 14 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 44 may have a pitch 46 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 44 in this example has a pitch of 1.5 mm, which is the same as the pitch of the helical thread 24 of the head 12. Because the head 12 and shank 14 have the same pitch, the bone screw 10 is compression neutral. The body 14 further includes one or more cutting flutes 48 disposed at the distal end 20. The cutting flutes 48 serve to remove bone material as the screw 10 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0063] The neck 16 includes a curved outer surface 50 that tapers distally to provide a smooth transition between the inverted nostril 12 and the barrel 14 .

[0064] By way of example, bone screw 10 may be cannulated, further including a central lumen 52 extending axially throughout screw 10. Central lumen 52 is sized and configured to receive a guidewire (e.g., a K-wire) therethrough to guide bone screw 10 to the correct implantation location.

[0065] 7-9 show an example of a bone screw 110 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 110 includes a head 112, a shank 114, and a neck 116 located between the head 112 and the shank 114. The bone screw 110 further includes a proximal end 118 and a distal end 120. The head 112 is located at / near the proximal end 118 of the bone screw 110, and the shank 114 extends axially along a longitudinal axis L2 (also referred to as the "vertical axis") from the neck 116 to the distal end 120 of the bone screw 110. The head 112 includes a curved outer surface 122 and a helical thread 124 disposed about the periphery of the curved outer surface 122. The head 112 has an inverted frusto-conical cross-sectional shape 126, as described above with respect to the bone screw 10. The curved outer surface 122 tapers proximally from a wider base surface 128 to a narrower base surface 130. By way of example, the curved outer surface 122 tapers at an angle A2 of 5.9° relative to the longitudinal axis L2 (resulting in a cone defining a head shape having an included angle of 11.8°), although the angle A2 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0066] The head 112 may have an inner diameter at the wide base 128 in the range of 1.75 mm to 9.0 mm. The head 112 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 124). By way of example, the head 112 of the bone screw 110 shown in FIGS. 7-9 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wide base 128. As a result of the frustoconical shape, the head 112 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0067] The head 112 further includes an angled surface 134 (also known as a "chamfer" or "bevel") and a driver recess 136. The angled surface 134 is formed between the upper surface 132 and the outer surface 122. The upper surface 132 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 134 does not extend completely across the top of the screw 110. In an embodiment, the upper surface 132 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the overall dimensions of the bone screw 110. By way of example, the angled surface 134 may have a bevel angle θ2 in the range of 1 to 60 degrees, measured from the plane of the upper surface 132, which is generally perpendicular to the longitudinal axis L2. By way of example, the bevel angle θ2 of the bone screw 110 shown in FIGS. 7-9 is 50 degrees. The angled surface 134 positions the head, when implanted during use, generally parallel and flush with the outer surface of the bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 110 is implanted at an angle relative to the bone structure. A driver recess 136 is formed in the upper surface 132 and the angled surface 134 along the longitudinal axis L2 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). The helical thread 124 may have a pitch 138 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 124 in this example has a pitch of 1.5 mm.

[0068] By way of example, the shank 114 is cylindrical in shape and extends from a proximal end adjacent the neck 116 to the distal end 120 of the bone screw 110. The shank 114 includes a curved outer surface 142 and a pair of helical threads 144a, 144b disposed about the periphery of the curved outer surface 142. The shank 114 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 114 is smaller than the outer diameter of the head 112. In the example shown and described herein, the shank 114 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical threads 144a, 144b may have a pitch 146 in the range of 0.5 mm to 5.0 mm. By way of example, the helical threads 144a, 144b in this example each have a pitch (e.g., the distance between adjacent threads of the same helix) of 3.0 mm, but there are two equally spaced helical threads 144a, 144b, making the effective pitch of the bone screw 110 1.5 mm, the same as the pitch of the helical threads 124 of the head 112. Because the bone screw 110 uses a double helix configuration in the shank threads, the bone screw 110 can be driven into a target bone approximately twice as fast as a bone screw having a true pitch of 1.5 mm. Because the head 112 and shank 114 have the same pitch (or effective pitch), the bone screw 110 is compression neutral. The shank 114 further includes one or more cutting flutes 148 disposed at the distal end 120. The cutting flutes 148 serve to remove bone material as the screw 110 is driven into the bone, which eliminates the need to drill pilot holes during surgery.

[0069] Neck 116 includes a curved outer surface 150 that tapers distally to provide a smooth transition between inverted nostril 112 and barrel 114 .

[0070] Bone screw 110 further includes a central lumen extending axially throughout screw 110, similar to central lumen 52 shown and described above with respect to bone screw 10. Central lumen 152 is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 110 to the correct implantation location.

[0071] 10-12 show an example of a bone screw 210 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 210 includes a head 212, a shank 214, and a neck 216 located between the head 212 and the shank 214. The bone screw 210 further includes a proximal end 218 and a distal end 220. The head 212 is located at / near the proximal end 218 of the bone screw 210, and the shank 214 extends axially along a longitudinal axis L3 (also referred to as the "vertical axis") from the neck 216 to the distal end 220 of the bone screw 210. The head 212 includes a curved outer surface 222 and a helical thread 224 disposed about the periphery of the curved outer surface 222. The head 212 has a generally cylindrical shape. The helical thread 224 has an outer diameter that increases in a distal-to-proximal direction. As a result, the surface area of ​​the threads in contact with the bone increases in the distal to proximal direction, enhancing the thread's grip in the bone.

[0072] The head 212 further includes an angled surface 234 (also known as a "chamfer" or "bevel") and a driver recess 236. The angled surface 234 is formed between the upper surface 232 and the outer surface 222. The upper surface 232 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 234 does not extend completely across the top of the screw 210. In an embodiment, the upper surface 232 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 210. By way of example, the angled surface 234 may have a bevel angle θ3 in the range of 1 to 60 degrees, measured from the plane of the upper surface 232, which is generally perpendicular to the longitudinal axis L3. By way of example, the bevel angle θ3 of the bone screw 210 shown in FIGS. 10-12 is 50 degrees. The angled surface 234 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when the head is implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 210 is implanted at an angle relative to the bone structure. A driver recess 236 is formed in the upper surface 232 and the angled surface 234 along the longitudinal axis L3 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0073] Helical thread 224 may have a pitch 238 (e.g., the distance between adjacent threads at any one location) in the range of 0.5 mm to 2.5 mm. By way of example, helical thread 224 in this example has a pitch of 1.5 mm. Thread 224 has an outward taper 225 in the proximal direction of (for example) 10° such that the outer diameter at proximal end 218 is larger than the outer diameter near neck 216, resulting in the surface area of ​​helical thread 224 in contact with bone increasing from distal to proximal, enhancing thread engagement within the bone.

[0074] Illustratively, the shank 214 is cylindrical and extends from a proximal end adjacent the neck 216 to the distal end 220 of the bone screw 210. The shank 214 includes a curved outer surface 242 and a helical thread 244 disposed about the periphery of the curved outer surface 242. The shank 214 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 214 is smaller than the outer diameter of the head 212. In the example shown and described herein, the shank 214 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 244 may have a pitch 246 in the range of 0.5 mm to 2.5 mm. Illustratively, the helical thread 244 in this example has a pitch of 1.5 mm, which is the same as the pitch of the helical thread 224 of the head 212. Because the head 212 and shank 214 have the same pitch, the bone screw 210 is compression neutral. The shank 214 further includes one or more cutting flutes 248 disposed at the distal end 220. The cutting flutes 248 serve to remove bone material as the screw 210 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0075] Neck 216 includes a curved outer surface 250 that tapers distally to provide a smooth transition between inverted nostril 212 and barrel 214 .

[0076] Bone screw 210 further includes a central lumen extending axially throughout screw 210 that is identical to central lumen 52 shown and described above with respect to bone screw 10. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 210 to the correct implantation location.

[0077] 13-15 show an example of a bone screw 310 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 310 includes a head 312, a shank 314, and a neck 316 located between the head 312 and the shank 314. The bone screw 310 further includes a proximal end 318 and a distal end 320. The head 312 is located at / near the proximal end 318 of the bone screw 310, and the shank 314 extends axially along a longitudinal axis L4 (also referred to as the "vertical axis") from the neck 316 to the distal end 320 of the bone screw 310. The head 312 includes a curved outer surface 322 and a helical thread 324 disposed about the periphery of the curved outer surface 322. The head 312 has an inverted frusto-conical cross-sectional shape 326, as described above with respect to the bone screw 10. Curved outer surface 322 tapers proximally from a wider base surface 328 to a narrower base surface 330. By way of example, curved outer surface 322 tapers at an angle A4 of 5.9° relative to longitudinal axis L4 (resulting in a cone defining a head shape having an included angle of 11.8°), although angle A4 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0078] The head 312 may have an inner diameter at the wide base 328 in the range of 1.75 mm to 9.0 mm. The head 312 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 324). By way of example, the head 312 of the bone screw 310 shown in FIGS. 13-15 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wide base 328. As a result of the frustoconical shape, the head 312 has an inner diameter that increases from proximal to distal. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases from distal to proximal, enhancing the thread's engagement within the bone.

[0079] The head 312 further includes an angled surface 334 (also known as a "chamfer" or "bevel") and a driver recess 336. The angled surface 334 is formed between the upper surface 332 and the outer surface 322. The upper surface 332 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 334 does not extend completely across the top of the screw 310. In an embodiment, the upper surface 332 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 310. By way of example, the angled surface 334 may have a bevel angle θ4 in the range of 1 to 60 degrees, measured from the plane of the upper surface 332, which is generally perpendicular to the longitudinal axis L1. By way of example, the bevel angle θ4 of the bone screw 310 shown in FIGS. 13-15 is 50 degrees. The angled surface 334 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when the head is implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 310 is implanted at an angle relative to the bony structure. A driver recess 336 is formed in the upper surface 332 along the longitudinal axis L4 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0080] The helical thread 324 may have a variable pitch ranging from 0.5 mm to 2.5 mm at the distal end of the head 312 and from 1.0 mm to 5.0 mm at the proximal end of the head. By way of example, the helical thread 324 in this example has a pitch 388a of 1.5 mm at the proximal end of the head 312, which tapers to a pitch 388b of 0.75 mm at the distal end of the head. As a result of this graduated pitch, the bone screw 310 is a compression screw because at least a portion of the helical thread 324 is outside the thread groove formed in the bone by the passage of the shank thread 344. The head 312 may further include cutting flutes formed at the distal end of the helical thread 324, which serve to remove bone material as the screw 310 is driven into bone, facilitating the transition from the shank 314 to the head 312.

[0081] By way of example, the shank 314 is cylindrical and extends from the proximal end adjacent the neck 316 to the distal end 320 of the bone screw 310. The shank 314 includes a curved outer surface 342 and a helical thread 344 disposed about the periphery of the curved outer surface 342. The shank 314 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 314 is smaller than the outer diameter of the head 312. In the example shown and described herein, the shank 314 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 344 may have a pitch 346 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 344 in this example has a pitch of 1.5 mm. The shank 314 further includes one or more cutting flutes 348 disposed at the distal end 320. The cutting flutes 348 serve to remove bone material as the screw 310 is driven into the bone, which eliminates the need to drill pilot holes during surgery.

[0082] Neck 316 includes a curved outer surface 350 that tapers distally to provide a smooth transition between inverted nostril 312 and barrel 314 .

[0083] Bone screw 310 further includes a central lumen extending axially throughout screw 310 that is identical to the central lumen shown and described above with respect to bone screw 310. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 310 to the correct implantation location.

[0084] 16-18 show an example of a bone screw 410 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 410 includes a head 412, a shank 414, and a neck 416 located between the head 412 and the shank 414. The bone screw 410 further includes a proximal end 418 and a distal end 420. The head 412 is located at / near the proximal end 418 of the bone screw 410, and the shank 414 extends axially along a longitudinal axis L5 (also referred to as the "vertical axis") from the neck 416 to the distal end 420 of the bone screw 410. The head 412 includes a curved outer surface 422 and a helical thread 424 disposed about the periphery of the curved outer surface 422. The head 412 has an inverted frusto-conical cross-sectional shape 426, as described above with respect to the bone screw 10. The curved outer surface 422 tapers proximally from a wider base 428 to a narrower base 430. By way of example, the curved outer surface 422 tapers at an angle A5 of 5.9° relative to the longitudinal axis L5 (resulting in a cone defining a head shape having an included angle of 11.8°), although the angle A5 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0085] The head 412 may have an inner diameter at the wide base 428 in the range of 1.75 mm to 9.0 mm. The head 412 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 424). By way of example, the head 412 of the bone screw 410 shown in FIGS. 16-18 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wide base 428. As a result of its frustoconical shape, the head 412 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0086] The head 412 further includes an angled surface 434 (also known as a "chamfer" or "bevel") and a driver recess 436. The angled surface 434 is formed between the upper surface 432 and the outer surface 422. The upper surface 432 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 434 does not extend completely across the top of the screw 410. In an embodiment, the upper surface 432 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 410. By way of example, the angled surface 434 may have a bevel angle θ5 in the range of 1 to 60 degrees, measured from the plane of the upper surface 432, which is generally perpendicular to the longitudinal axis L1. By way of example, the bevel angle θ5 of the bone screw 410 shown in FIGS. 16-18 is 50 degrees. Angled surface 434 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when the head is implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when bone screw 410 is implanted at an angle relative to the bony structure. Driver recess 436 is formed in upper surface 432 and angled surface 434 along longitudinal axis L5 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0087] The helical thread 424 may have a pitch 438 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 424 in this example has a pitch of 0.75 mm. The head 412 may further include cutting flutes 440 formed at the distal end of the helical thread 424, which serve to remove bone material as the screw 410 is driven into bone and facilitate the transition from the shank 414 to the head 412.

[0088] Illustratively, the body 414 is cylindrical and extends from a proximal end adjacent the neck 416 to the distal end 420 of the bone screw 410. The body 414 includes a curved outer surface 442 and a helical thread 444 disposed about the curved outer surface 442. The body 414 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the body 414 is smaller than the outer diameter of the head 412. In the example shown and described herein, the body 414 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 444 may have a pitch 446 in the range of 0.5 mm to 2.5 mm. Illustratively, the helical thread 444 in this example has a pitch of 1.5 mm. The bone screw 410 is compression neutral because the pitch 446 of the shank 414 is an even multiple (e.g., 2x) of the pitch 438 of the head 412. The shank 414 further includes one or more cutting flutes 448 disposed at the distal end 420. The cutting flutes 448 serve to remove bone material as the screw 410 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0089] Neck 416 includes a curved outer surface 450 that tapers distally to provide a smooth transition between inverted nostril 412 and barrel 414 .

[0090] 19-21 show an example of a bone screw 510 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 510 includes a head 512, a shank 514, and a neck 516 located between the head 512 and the shank 514. The bone screw 510 further includes a proximal end 518 and a distal end 520. The head 512 is located at / near the proximal end 518 of the bone screw 510, and the shank 514 extends axially along a longitudinal axis L6 (also referred to as the "vertical axis") from the neck 516 to the distal end 520 of the bone screw 510. The head 512 includes a curved outer surface 522 and a helical thread 524 disposed about the periphery of the curved outer surface 522. The head 512 has an inverted frusto-conical cross-sectional shape 526, as described above with respect to the bone screw 10. Curved outer surface 522 tapers proximally from a wider base surface 528 to a narrower base surface 530. By way of example, curved outer surface 522 tapers at an angle A5 of 5.9° relative to longitudinal axis L5 (resulting in a cone defining a head shape having an included angle of 11.8°), although angle A5 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0091] The head 512 can have an inner diameter at the wide base 528 in the range of 1.75 mm to 9.0 mm. The head 512 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 524). By way of example, the head 512 of the bone screw 510 shown in FIGS. 19-21 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wide base 528. As a result of the frustoconical shape, the head 512 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0092] The head 512 further includes an angled surface 534 (also known as a "chamfer" or "bevel") and a driver recess 536. The angled surface 534 is formed between the upper surface 532 and the outer surface 522. The upper surface 532 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 534 does not extend completely across the top of the screw 510. In an embodiment, the upper surface 532 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 510. By way of example, the angled surface 534 may have a bevel angle θ6 in the range of 1 to 60 degrees, measured from the plane of the upper surface 532, which is generally perpendicular to the longitudinal axis L6. By way of example, the bevel angle θ6 of the bone screw 510 shown in FIGS. 19-21 is 50 degrees. Angled surface 534 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when the head is implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when bone screw 510 is implanted at an angle relative to the bony structure. Driver recess 536 is formed in upper surface 532 and angled surface 534 along longitudinal axis L6 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0093] Helical thread 524 may have a pitch 538 in the range of 0.5 mm to 2.5 mm. By way of example, helical thread 524 in this example has a pitch of 1.5 mm. Head 512 may further include cutting flutes 540 formed at the distal end of helical thread 524, which serve to remove bone material as screw 510 is driven into bone and facilitate the transition from shank 514 to head 512.

[0094] By way of example, the shank 514 is cylindrical in shape and extends from a proximal end adjacent the neck 516 to the distal end 520 of the bone screw 510. The shank 514 includes a curved outer surface 542 and a pair of helical threads 544a, 544b disposed about the periphery of the curved outer surface 542. The shank 514 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 514 is smaller than the outer diameter of the head 512. In the example shown and described herein, the shank 514 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical threads 544a, 544b may have a pitch 546 in the range of 0.5 mm to 5.0 mm. By way of example, each of the helical threads 544a, 544b in this example has a pitch (e.g., the distance between adjacent threads of the same helix) of 3.0 mm, but there are two equally spaced helical threads 544a, 544b, making the effective pitch of the bone screw 510 1.5 mm, the same as the pitch of the helical threads 524 of the head 512. Because the bone screw 510 uses a double helix configuration in the shank threads, the bone screw 510 can be driven into the target bone approximately twice as fast as a bone screw having a true pitch of 1.5 mm. Because the head 512 and shank 514 have the same pitch (or effective pitch), the bone screw 510 is compression neutral. The shank 514 further includes one or more cutting flutes 548 disposed on the distal end 520. The cutting flutes 548 serve to remove bone material as the screw 510 is driven into the bone, which eliminates the need to drill pilot holes during surgery.

[0095] Neck 516 includes a curved outer surface 550 that tapers distally to provide a smooth transition between inverted nostril 512 and barrel 514 .

[0096] Bone screw 510 further includes a central lumen extending axially throughout screw 510, similar to central lumen 52 shown and described above with respect to bone screw 10. Central lumen 552 is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 510 to the correct implantation location.

[0097] 22-24 show an example of a bone screw 610 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 610 includes a head 612, a shank 614, and a neck 616 located between the head 612 and the shank 614. The bone screw 610 further includes a proximal end 618 and a distal end 620. The head 612 is located at / near the proximal end 618 of the bone screw 610, and the shank 614 extends axially along a longitudinal axis L7 (also referred to as the "vertical axis") from the neck 616 to the distal end 620 of the bone screw 610. The head 612 includes a curved outer surface 622 and a helical thread 624 disposed about the periphery of the curved outer surface 622. The head 612 has an inverted frusto-conical cross-sectional shape 626, as described above with respect to the bone screw 10. The curved outer surface 622 tapers proximally from a wider base surface 628 to a narrower base surface 630. By way of example, the curved outer surface 622 tapers at an angle A7 of 5.9° relative to the longitudinal axis L7 (resulting in a cone defining a head shape having an included angle of 11.8°), although the angle A7 may be in the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0098] The head 612 can have an inner diameter at the wide base 628 in the range of 1.75 mm to 9.0 mm and an outer diameter at the wide base 628 in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 624). By way of example, the head 612 of the bone screw 610 shown in FIGS. 22-24 has an inner diameter at the wide base 628 of approximately 4.5 mm and an outer diameter of approximately 5.0 mm. As a result of the frusto-conical shape, the head 612 has an inner diameter that increases in a proximal-to-distal direction. The head 624 has a proximal outward taper 625 with a taper angle B7 of approximately 10° (e.g., in the range of 5-30°) such that the outer diameter at the proximal end 618 is larger than the outer diameter near the neck 616; as a result (and in combination with the inverted frusto-conical shape of the head 612), the surface area of ​​the helical thread 624 in contact with the bone increases from distal to proximal, enhancing thread engagement within the bone. In this example embodiment, the combination of the inverted frusto-conical shape of the head 612 and the outward taper 625 of the thread 624 (e.g., angles A7+B7) maximizes the surface area of ​​the thread 624 in contact with the bone.

[0099] The head 612 further includes an angled surface 634 (also known as a "chamfer" or "bevel") and a driver recess 636. The angled surface 634 is formed between the upper surface 632 and the outer surface 622. The upper surface 632 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 634 does not extend completely across the top of the screw 610. In an embodiment, the upper surface 632 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 610. By way of example, the angled surface 634 may have a bevel angle θ7 in the range of 1 to 60 degrees, measured from the plane of the upper surface 632, which is generally perpendicular to the longitudinal axis L7. By way of example, the bevel angle θ7 of the bone screw 610 shown in FIGS. 22-24 is 50 degrees. The angled surface 634 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 610 is implanted at an angle relative to the bone structure. A driver recess 636 is formed in the upper surface 632 and the angled surface 634 along the longitudinal axis L7 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). The helical thread 624 may have a pitch 638 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 624 in this example has a pitch of 0.75 mm.

[0100] Illustratively, the shaft 614 is cylindrical and extends from a proximal end adjacent the neck 616 to the distal end 620 of the bone screw 610. The shaft 614 includes a curved outer surface 642 and a helical thread 644 disposed about the curved outer surface 642. The shaft 614 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shaft 614 is smaller than the outer diameter of the head 612. In the example shown and described herein, the shaft 614 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 644 may have a pitch 646 in the range of 0.5 mm to 2.5 mm. Illustratively, the helical thread 644 in this example has a pitch of 1.5 mm, which is the same as the pitch of the helical thread 624 of the head 612. Because the head 612 and shank 614 have the same pitch, the bone screw 610 is neutral in compression. The shank 614 further includes one or more cutting flutes 648 disposed at the distal end 620. The cutting flutes 648 serve to remove bone material as the screw 610 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0101] Neck 616 includes a curved outer surface 650 that tapers distally to provide a smooth transition between inverted nostril 612 and barrel 614 .

[0102] Bone screw 610 further includes a central lumen extending axially throughout screw 610 that is identical to central lumen 52 shown and described above with respect to bone screw 10. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 610 to the correct implantation location.

[0103] 25-27 show an example of a bone screw 710 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 710 includes a head 712, a shank 714, and a neck 716 located between the head 712 and the shank 714. The bone screw 710 further includes a proximal end 718 and a distal end 720. The head 712 is located at / near the proximal end 718 of the bone screw 710, and the shank 714 extends axially along a longitudinal axis L8 (also referred to as the "vertical axis") from the neck 716 to the distal end 720 of the bone screw 710. The head 712 includes a curved outer surface 722 and a helical thread 724 disposed about the periphery of the curved outer surface 722. The head 712 has an inverted frusto-conical cross-sectional shape 726, as described above with respect to the bone screw 10. The curved outer surface 22 tapers proximally from a wider base surface 28 to a narrower base surface 30. By way of example, the curved outer surface 22 tapers at an angle A1 of 5.9° relative to the longitudinal axis L1 (resulting in a cone defining a head shape having an included angle of 11.8°), although the angle A1 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of the present disclosure.

[0104] The head 712 can have an inner diameter at its wide base 728 in the range of 1.75 mm to 9.0 mm and an outer diameter at its wide base 728 in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 724). By way of example, the head 712 of the bone screw 710 shown in FIGS. 25-27 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at its wide base 728. As a result of its frusto-conical shape, the head 712 has an inner diameter that increases in a proximal-to-distal direction. The head 724 has a proximal outward taper 725 of 10° (for example) such that the outer diameter at the proximal end 718 is larger than the outer diameter near the neck 716. As a result (and in combination with the inverted frusto-conical shape of the head 712), the surface area of ​​the helical thread 724 in contact with the bone increases in a distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0105] The head 712 further includes an angled surface 734 (also known as a "chamfer" or "bevel") and a driver recess 736. The angled surface 734 is formed between the upper surface 732 and the outer surface 722. The upper surface 732 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 734 does not extend completely across the top of the screw 710. In an embodiment, the upper surface 732 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 710. By way of example, the angled surface 734 may have a bevel angle θ8 in the range of 1 to 60 degrees, as measured from the plane of the upper surface 732, which is generally perpendicular to the longitudinal axis L8. By way of example, the bevel angle θ8 of the bone screw 710 shown in FIGS. 25-27 is 50 degrees. The angled surface 734 positions the head generally parallel to and flush with the outer surface of the bone forming part of the anatomical target site when implanted during use, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 710 is implanted at an angle relative to the bone structure. A driver recess 736 is formed in the upper surface 732 and the angled surface 734 along the longitudinal axis L8 and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). The helical thread 724 may have a pitch 738 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 724 in this example has a pitch of 0.75 mm.

[0106] By way of example, the shank 714 is cylindrical in shape and extends from a proximal end adjacent the neck 716 to the distal end 720 of the bone screw 710. The shank 714 includes a curved outer surface 742 and a pair of helical threads 744a, 744b disposed about the periphery of the curved outer surface 742. The shank 714 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shank 714 is smaller than the outer diameter of the head 712. In the example shown and described herein, the shank 714 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical threads 744a, 744b may have a pitch 746 in the range of 0.5 mm to 2.5 mm. By way of example, each of the helical threads 744a, 744b in this example has a pitch (e.g., the distance between adjacent threads of the same helix) of 3.0 mm, but there are two equally spaced helical threads 744a, 744b, making the effective pitch of the bone screw 710 1.5 mm, the same as the pitch of the helical threads 724 of the head 712. Because the bone screw 710 uses a double helix configuration in the shank threads, the bone screw 710 can be driven into the target bone approximately twice as fast as a bone screw having a true pitch of 1.5 mm. Because the pitch 746 of the shank 714 is an even multiple (e.g., 2x) of the pitch 738 of the head 712, the bone screw 710 is compression neutral. The shank 714 further includes one or more cutting flutes 748 disposed at the distal end 720. The cutting flutes 748 serve to remove bone material as the screw 710 is driven into the bone, which eliminates the need to drill pilot holes during surgery.

[0107] Neck 716 includes a curved outer surface 750 that tapers distally to provide a smooth transition between inverted nostril 712 and barrel 714 .

[0108] Bone screw 710 further includes a central lumen extending axially throughout screw 710, similar to central lumen 52 shown and described above with respect to bone screw 10. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 710 to the correct implantation location.

[0109] 28-30 show an example of a bone screw 810 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 810 described herein may be useful in situations where the bone screw 810 is not implanted at an extreme angle. The bone screw 810 includes a head 812, a shank 814, and a neck 816 located between the head 812 and the shank 814. The bone screw 810 further includes a proximal end 818 and a distal end 820. The head 812 is located at / near the proximal end 818 of the bone screw 810, and the shank 814 extends axially along a longitudinal axis L9 (also referred to as the "vertical axis") from the neck 816 to the distal end 820 of the bone screw 810. The head 812 includes a curved outer surface 822 and a helical thread 824 disposed about the periphery of the curved outer surface 822. Head 812 has an inverted frusto-conical cross-sectional shape 826, as previously described with respect to bone screw 10. Curved outer surface 822 tapers proximally from a wider base 828 to a narrower base 830. By way of example, curved outer surface 822 tapers at an angle A9 of 5.9° relative to longitudinal axis L9 (resulting in a cone defining the shape of the head having an included angle of 11.8°), although angle A9 may be within the range of 4-15° (an included angle of 8-30°) without departing from the scope of this disclosure.

[0110] The head 812 can have an inner diameter at its wider, bottom surface 828 in the range of 1.75 mm to 9.0 mm and an outer diameter at its wider, bottom surface 828 in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 824). By way of example, the head 812 of the bone screw 810 shown in FIGS. 28-30 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at its wider, bottom surface 828. As a result of its frustoconical shape, the head 812 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing engagement of the screw within the bone. The head 812 further includes a driver recess 836 formed in its upper surface 832 along the longitudinal axis L9 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). Helical thread 824 may have a pitch 838 (e.g., the distance between adjacent threads at any one location) in the range of 0.5 mm to 2.5 mm. By way of example, helical thread 824 in this example has a pitch of 1.5 mm.

[0111] The bone screw 810 in this embodiment is an example of a bone screw with a "bevel angle" of 0°. This results in a flat head 812, where the top surface 832 and the angled surface 834 are essentially the same surface.

[0112] Illustratively, the shaft 814 is cylindrical and extends from a proximal end adjacent the neck 816 to the distal end 820 of the bone screw 810. The shaft 814 includes a curved outer surface 842 and a helical thread 844 disposed about the curved outer surface 842. The shaft 814 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shaft 814 is smaller than the outer diameter of the head 812. In the example shown and described herein, the shaft 814 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 844 may have a pitch 846 in the range of 0.5 mm to 2.5 mm. Illustratively, the helical thread 844 in this example has a pitch of 1.5 mm, which is the same as the pitch of the helical thread 824 of the head 812. Because the head 812 and shank 814 have the same pitch, the bone screw 810 is neutral in compression. The shank 814 further includes one or more cutting flutes 848 disposed at the distal end 820. The cutting flute(s) 848 serve to remove bone material as the screw 810 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0113] Neck 816 includes a curved outer surface 850 that tapers distally to provide a smooth transition between inverted nostril 812 and barrel 814 .

[0114] Bone screw 810 further includes a central lumen extending axially throughout screw 810. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 810 to the correct implantation location.

[0115] 31-33 show an example of a bone screw 910 according to another embodiment of the present disclosure. By way of example, the bone screw 910 includes a head 912, a shank 914, and a neck 916 located between the head 912 and the shank 914. The bone screw 910 further includes a proximal end 918 and a distal end 920. The head 912 is located at / near the proximal end 918 of the bone screw 910, and the shank 914 extends along a longitudinal axis L from the neck 916 to the distal end 920 of the bone screw 910. 10(also "vertical axis") of the bone screw 10. The head 912 includes a curved outer surface 922 and a helical thread 924 disposed about the periphery of the curved outer surface 922. The head 912 has an inverted frusto-conical cross-sectional shape 926, as described above with respect to the bone screw 10. The curved outer surface 922 tapers proximally from a wider base surface 928 to a narrower base surface 930. By way of example, the curved outer surface 922 may extend axially along the longitudinal axis L. 10 Angle A of 5.9° 10 (a cone defining the shape of the head having an included angle of 11.8°), but angle A 10 can be in the range of 4 to 15 degrees (8 to 30 degrees included angle) without departing from the scope of the present disclosure.

[0116] The head 912 can have an inner diameter at the wider base 928 in the range of 1.75 mm to 9.0 mm and an outer diameter at the wider base 928 in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 924). By way of example, the head 912 of the bone screw 910 shown in FIGS. 31-33 has an inner diameter of approximately 4.5 mm and an outer diameter of approximately 5.0 mm at the wider base 428. As a result of its frusto-conical shape, the head 912 has an inner diameter that increases in a proximal-to-distal direction. The thread 924 has an inward taper 925 in the proximal direction such that the outer diameter at the proximal end 918 is smaller than the outer diameter near the neck 916. By way of example, the inward taper 925 of the thread 924 is parallel to the taper of the curved outer surface 922. As such, the thread 924 extends along the longitudinal axis L. 10 Angle B is 5.9° 10 It tapers at angle B 10 can be in the range of 5 to 15 degrees without departing from the scope of the present disclosure.

[0117] The head 912 further includes an angled surface 934 (also known as a "chamfer" or "bevel") and a driver recess 936. The angled surface 934 is formed between the upper surface 932 and the outer surface 922. The upper surface 932 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 934 does not extend completely across the top of the screw 910. In an embodiment, the upper surface 932 has a width dimension of 0.65 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 910. By way of example, the angled surface 934 is located at a distance from the longitudinal axis L 10 a bevel angle θ in the range of 1 to 60° measured from the plane of the top surface 932, which is approximately perpendicular to 10 By way of example, the bevel angle θ of the bone screw 910 shown in FIGS. 10 is 50°. Angled surface 934 locates the head, when implanted during use, in a generally parallel and flush relationship with the outer surface of the bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when bone screw 910 is implanted at an angle relative to the bony structure. Driver recess 936 defines a longitudinal axis L within upper surface 932 and angled surface 934. 10 , and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.).

[0118] The helical thread 924 may have a pitch 938 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 924 in this example has a pitch of 0.8 mm. The head 912 may further include cutting flutes 940 formed at the distal end of the helical thread 924, which serve to remove bone material as the screw 910 is driven into bone and facilitate the transition from the shank 914 to the head 912.

[0119] By way of example, the shaft 914 is cylindrical and extends from a proximal end adjacent the neck 916 to the distal end 920 of the bone screw 910. The shaft 914 includes a curved outer surface 942 and a helical thread 944 disposed about the curved outer surface 942. The shaft further includes a proximally disposed unthreaded portion 945 to allow for compression. By way of example, the unthreaded portion 945 may comprise approximately two-thirds of the shaft's length, with the distal one-third of the length being threaded. Other configurations are possible depending on the type and location of the fracture being treated. The shaft 914 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shaft 914 is smaller than the outer diameter of the head 912. In the example shown and described herein, the shaft 914 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 944 may have a pitch 946 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 944 in this example has a pitch of 1.5 mm. Because the pitch 946 of the shank 914 is not an even multiple (e.g., 2x) of the pitch 938 of the head 912, the bone screw 910 is a compression screw. The shank 914 further includes one or more cutting flutes 948 disposed at the distal end 920. The cutting flutes 948 serve to remove bone material as the screw 910 is driven into bone, which eliminates the need for drilling pilot holes during surgery.

[0120] Neck 916 includes a curved outer surface 950 that tapers distally to provide a smooth transition between inverted nostril 912 and barrel 914 .

[0121] Bone screw 910 further includes a central lumen extending axially throughout screw 910. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 910 to the correct implantation location.

[0122] 34-36 show an example of a bone screw 1010 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 1010 includes a head 1012, a shank 1014, and a neck 1016 located between the head 1012 and the shank 1014. The bone screw 1010 further includes a proximal end 1018 and a distal end 1020. The head 1012 is located at / near the proximal end 1018 of the bone screw 1010, and the shank 1014 extends along a longitudinal axis L from the neck 1016 to the distal end 1020 of the bone screw 1010. 11 (also "vertical axis") of the bone screw 10. The head 1012 includes a curved outer surface 1022 and a helical thread 1024 disposed about the periphery of the curved outer surface 1022. The head 1012 has an inverted frusto-conical cross-sectional shape 1026, as described above with respect to the bone screw 10. The curved outer surface 1022 tapers proximally from a wider base surface 1028 to a narrower base surface 1030. By way of example, the curved outer surface 1022 may extend axially along the longitudinal axis L. 11 Angle A of 4.5° 11 (a cone defining the shape of the head having an included angle of 9°), but at angle A 11 can be in the range of 4 to 15 degrees (8 to 30 degrees included angle) without departing from the scope of the present disclosure.

[0123] The head 1012 can have an inner diameter at the wide base 1028 in the range of 1.75 mm to 9.0 mm. The head 1012 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 1024). By way of example, the head 1012 of the bone screw 1010 shown in FIGS. 34-36 has an inner diameter of approximately 3.4 mm and an outer diameter of approximately 4.0 mm at the wide base 1028. As a result of the frustoconical shape, the head 1012 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0124] The head 1012 further includes an angled surface 1034 (also known as a "chamfer" or "bevel") and a driver recess 1036. The angled surface 1034 is formed between the upper surface 1032 and the outer surface 1022. The upper surface 1032 has a width dimension greater than zero when measured along the diameter of the head to ensure that the angled surface 1034 does not extend completely across the top of the screw 1010. In an embodiment, the upper surface 1032 has a width dimension of 0.45 mm, although the width dimension may be more or less depending on the overall dimensions of the bone screw 1010. By way of example, the angled surface 1034 is oriented along the longitudinal axis L. 11 a bevel angle θ in the range of 1 to 60° measured from the plane of the top surface 1032, which is approximately perpendicular to 11 By way of example, the bevel angle θ of the bone screw 1010 shown in FIGS. 11 is 50°. The angled surface 1034 positions the head, when implanted during use, generally parallel and flush with the outer surface of the bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 1010 is implanted at an angle relative to the bony structure. A driver recess 1036 is defined within the upper surface 1032 along a longitudinal axis L 11 , and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). By way of example, the helical thread 1024 in this example has a pitch of 1.2 mm.

[0125] By way of example, the body 1014 is cylindrical in shape and extends from a proximal end adjacent the neck 1016 to the distal end 1020 of the bone screw 1010. The body 1014 includes a curved outer surface 1042 and a helical thread 1044 disposed about the periphery of the curved outer surface 1042. The body 1014 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the body 1014 is smaller than the outer diameter of the head 1012. In the example shown and described herein, the body 1014 has an inner diameter of approximately 1.5 mm and an outer diameter of approximately 2.5 mm. The helical thread 1044 may have a pitch 1046 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 1044 in this example has a pitch of 1.2 mm, which is the same as the pitch of the helical thread 1024 of the head 1012. Because the head 1012 and shank 1014 have the same pitch, the bone screw 1010 is compression neutral. The shank 1014 further includes one or more cutting flutes 1048 disposed at the distal end 1020. The cutting flutes 1048 serve to remove bone material as the screw 1010 is driven into bone, which eliminates the need for drilling pilot holes during surgery.

[0126] Neck 1016 includes a curved outer surface 1050 that tapers distally to provide a smooth transition between inverted nostril 1012 and barrel 1014 .

[0127] Bone screw 1010 further includes a central lumen extending axially throughout screw 1010 that is identical to the central lumen shown and described above with respect to bone screw 1010. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 1010 to the correct implantation location.

[0128] 37-39 show an example of a bone screw 1110 according to another embodiment of the present disclosure. By way of example, the bone screw 1110 includes a head 1112, a shank 1114, and a neck 1116 located between the head 1112 and the shank 1114. The bone screw 1110 further includes a proximal end 1118 and a distal end 1120. The head 1112 is located at / near the proximal end 1118 of the bone screw 1110, and the shank 1114 extends along a longitudinal axis L from the neck 1116 to the distal end 1120 of the bone screw 1110. 12 (also "vertical axis") of the bone screw 10. The head 1112 includes a curved outer surface 1122 and a helical thread 1124 disposed about the periphery of the curved outer surface 1122. The head 1112 has an inverted frusto-conical cross-sectional shape 1126, as described above with respect to the bone screw 10. The curved outer surface 1122 tapers proximally from a wider base surface 1128 to a narrower base surface 1130. By way of example, the curved outer surface 1122 may extend axially along the longitudinal axis L. 12 Angle A is 4.4° 12 (a cone defining the shape of the head having an included angle of 8.8°), but angle A 12 can be in the range of 4 to 15 degrees (8 to 30 degrees included angle) without departing from the scope of the present disclosure.

[0129] The head 1112 can have an inner diameter at the wide base 1128 in the range of 1.75 mm to 9.0 mm. The head 1112 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 1124). By way of example, the head 1112 of the bone screw 1110 shown in FIGS. 37-39 has an inner diameter of approximately 3.3 mm and an outer diameter of approximately 4.0 mm at the wide base 1128. As a result of the frustoconical shape, the head 1112 has an inner diameter that increases in the proximal-to-distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the threads in contact with the bone increases in the distal-to-proximal direction, enhancing the thread's engagement in the bone.

[0130] The head 1112 further includes an angled surface 1134 (also known as a "chamfer" or "bevel") and a driver recess 1136. The angled surface 1134 is formed between the upper surface 1132 and the outer surface 1122. The upper surface 1132 has a width dimension greater than zero when measured along the diameter of the head to ensure that the angled surface 1134 does not extend completely across the top of the screw 1110. In an embodiment, the upper surface 1132 has a width dimension of 0.42 mm, although the width dimension may be more or less depending on the outer dimensions of the bone screw 1110. By way of example, the angled surface 1134 is oriented along the longitudinal axis L. 12 a bevel angle θ in the range of 1 to 60° measured from the plane of the top surface 1132, which is approximately perpendicular to 12 By way of example, the bevel angle θ of the bone screw 1110 shown in FIGS. 12 is 50°. The angled surface 1134 positions the head, when implanted during use, generally parallel and flush with the outer surface of the bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 1110 is implanted at an angle relative to the bone structure. A driver recess 1136 is defined within the upper surface 1132 along a longitudinal axis L 12 , and may have any shape suitable for receiving a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). By way of example, the helical thread 1124 in this example has a pitch of 1.0 mm.

[0131] By way of example, the shaft 1114 is cylindrical and extends from a proximal end adjacent the neck 1116 to the distal end 1120 of the bone screw 1110. The shaft 1114 includes a curved outer surface 1142 and a helical thread 1144 disposed about the curved outer surface 1142. The shaft further includes a proximally disposed unthreaded portion 1145 to allow for compression. By way of example, the unthreaded portion 1145 may comprise approximately two-thirds of the shaft's length, with the distal one-third of the length being threaded. Other configurations are possible depending on the type and location of the fracture being treated. The shaft 1114 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the shaft 1114 is smaller than the outer diameter of the head 1112. In the example shown and described herein, the shank 1114 has an inner diameter of approximately 1.5 mm and an outer diameter of approximately 2.5 mm. The helical thread 1144 may have a pitch 1146 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 1144 in this example has a pitch of 1.2 mm. Because the pitch 1146 of the shank 1114 is neither the same as nor an even multiple (e.g., 2x) of the pitch 1138 of the head 1112, the bone screw 1110 is a compression screw. The shank 1114 further includes one or more cutting flutes 1148 disposed at the distal end 1120. The cutting flutes 1148 serve to remove bone material as the screw 1110 is driven into bone, which eliminates the need for drilling pilot holes during surgery.

[0132] The neck 1116 includes a curved outer surface 1150 that tapers distally to provide a smooth transition between the inverted nostril 1112 and the body 1114 .

[0133] The bone screw 1110 further includes a central lumen extending axially throughout the screw 1110, which is identical to the central lumen shown and described above with respect to the bone screw 1110. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide the bone screw 1110 to the correct implantation location.

[0134] The bone screws 10 and various alternatives described herein may be used in any number of orthopedic surgical procedures requiring fixation of at least two bone fragments, such as in the case of a bone fracture. FIG. 40 shows an example of a bone screw 10 being used to secure first and second bone fragments 60, 62 together, for example, during a hallux valgus repair. In this example, the bone screw 10 is inserted so that the proximal end 18 of the bone screw 10 engages the first bone fragment 60 and the distal end 20 of the bone screw 10 engages the second bone fragment 62. The bone screw 10 is positioned so that the head 12 and a portion of the shaft 14 engage the cortical bone 64 while passing through the cancellous bone 66 of one bone fragment 60. The bone screw 10 is further positioned so that the chamfered surface 34 coincides with the edge of the bone, reducing / eliminating any portion of the screw that would otherwise protrude from the bone. When a compressive neutral screw is used, the bone screw 10 maintains the relative positioning of the bone fragments without applying a compressive force.

[0135] The bone screws 10 may be provided in any number of size and length configurations to enable them to be used to address a variety of conditions. FIGS. 41-44 illustrate several examples of the use of the bone screws 10 described herein to fix fractures in several different bone locations. For example, FIG. 41 illustrates a bone screw 10 inserted into a phalange 70 of the foot for the repair or osteotomy of a fracture 72. FIG. 42 illustrates a partially threaded bone screw 910 used to secure a V-shaped notch 73 during a distal metatarsal chevron osteotomy, for example, to correct a hallux valgus deformity. FIG. 43 illustrates a pair of bone screws 10 inserted into a humerus 74 to repair a fracture 76. FIG. 44 illustrates multiple bone screws 10 used to repair several fractures in the wrist region. For example, one bone screw 10 (e.g., a small bone screw 10) has been inserted into a navicular bone 78 to repair a fracture 80. A pair of bone screws 10 are inserted into radius 82 to repair fracture 84 .

[0136] FIG. 45 is an enlarged view of the head 12 of the bone screw 10 previously described with respect to FIGS. 1-6 , particularly illustrating the various angles and surface dimensions of the head 12. While shown and described with respect to the head 12 of the bone screw 10, the following description may be applied to any of the foregoing examples without departing from the scope of this disclosure. As previously described, the head 12 is located at / near the proximal end 18 of the bone screw 10, and the body 14 extends axially along a longitudinal axis L (also known as the “vertical axis”) from the neck 16 to the distal end 20 of the bone screw 10. The head 12 includes a curved outer surface 22 and a helical thread 24 disposed about the periphery of the curved outer surface 22. The head 12 has a generally frustoconical cross-sectional shape, with a wider base 28 of the frustum forming the distal-most boundary or bottom surface of the head 12 and a narrower base 30 of the frustum forming the proximal-most or top surface 32 of the bone screw 10. The curved outer surface 22 tapers proximally from a wider base surface 28 to a narrower base surface 30. By way of example, the curved outer surface 22 tapers at an angle A of 5.9° relative to the longitudinal axis L (or an axis parallel to the longitudinal axis) to form a cone defining a head shape having an included angle θ1 of 11.8°. Angle A may be in the range of 5-15° (and thus, the included angle θ1 may be in the range of 10-30°) without departing from the scope of the present disclosure.

[0137] In embodiments, head 12 is chamfered in the sense that it further includes an angled surface 34 (also known as a "chamfer" or "bevel") that serves to reduce / remove the amount of thread material that may extend beyond the edge of a bone structure when bone screw 10 is implanted at an angle relative to the bone structure. Angled surface 34 is formed between upper surface 32 and outer surface 22. Because of angled surface 34, head 12 has a major height dimension h1, defined as the perpendicular distance between the base of the head (e.g., wider base 28 of the frustum) and upper surface 32 (e.g., narrower base 30 of the frustum), and a secondary height dimension h2, defined as the perpendicular distance between the base of the head and the distal-most intersection 35 between angled surface 34 and outer surface 22.

[0138] The upper surface 32 has a width dimension w defined by the greatest distance between the proximal-most edge of the outer surface 22 and the proximal-most edge 33 of the angled surface 34. In most example embodiments, the width dimension w is greater than zero (e.g., w>0) to ensure that the angled surface 34 does not extend completely across the top of the screw 10. Sometimes, the width dimension w can be equal to zero (e.g., w=0), in which case the proximal-most edge 33 of the angled surface 34 intersects with the proximal-most edge of the outer surface 22. In an example, the upper surface 32 has a width dimension of 0.65 mm, but the width dimension can be more or less depending on the outer dimensions of the bone screw 10 and the bevel angle θ. By way of example, the angled surface 34 can have a bevel angle θ of 0°<θ<85°, measured from a plane of the upper surface 32 that is generally perpendicular to the longitudinal axis L. By way of example, the bevel angle θ of the bone screw 10 shown in FIG. 38 is 50°.

[0139] 46-51 show some examples of possible configurations of the head 12 created by varying the position of the proximal-most edge 33 of the angled surface 34 and the distal-most intersection 35 between the angled surface 34 and the outer surface 22, as well as how their relative positions change the bevel angle θ and the width dimension w of the upper surface 32. For example, FIG. 40 shows an example of a head 12 where w>0 and h2>0. In this example, the bevel angle θ is approximately 50°. FIG. 41 shows an example of a head 12 where w>0 and h2=0. In this example, the bevel angle θ is approximately 65.5°. FIG. 42 shows an example of a head 12 where w=0 and h2=0. In this example, the bevel angle θ is approximately 61.2°. FIG. 43 shows an example of a head 12 where w>0 and h2=0. In this example, the bevel angle θ is approximately 79.5°. Figure 44 shows another example of head 12 where w>0 and h2>0. In this example, the bevel angle θ is approximately 74.5°. Figure 45 shows an example of head 12 where w=0 and h2>0. In this example, the bevel angle θ is approximately 30°. Thus, bone screws of the present disclosure can be provided with various angles of chamfer depending on the surgeon's needs (e.g., insertion angle, etc.) for the particular procedure being performed.

[0140] 52-59 show an example of a bone screw 1210 in accordance with another embodiment of the present disclosure. By way of example, the bone screw 1210 includes a head 1212, a shank 1214, and a neck 1216 located between the head 1212 and the shank 1214. The bone screw 1210 further includes a proximal end 1218 and a distal end 1220. The head 1212 is located at / near the proximal end 1218 of the bone screw 1210, and the shank 1214 extends along a longitudinal axis L from the neck 1216 to the distal end 1220 of the bone screw 1210. 13 (also "vertical axis") of the bone screw 10. The head 1212 includes a curved outer surface 1222 and a helical thread 1224 disposed about the periphery of the curved outer surface 1222. The head 1212 has an inverted frustoconical cross-sectional shape similar to that described above with respect to the bone screw 10. The curved outer surface 1222 tapers proximally from a wider base surface 1228 to a narrower base surface 1230. By way of example, the curved outer surface 1222 may extend axially along the longitudinal axis L. 13 Angle A of 1° 13 (a cone defining the shape of the head having an included angle of 2°), but at angle A 13 may be greater than 1° without departing from the scope of this disclosure.

[0141] The head 1212 can have an inner diameter at the wider bottom surface 1228 in the range of 1.75 mm to 9.0 mm. The head 1212 has an outer diameter in the range of 2.0 mm to 10.0 mm. The first inner diameter is smaller than the outer diameter (of the helical thread 1224). As a result of the frustoconical shape, the head 1212 has an inner diameter that increases in the proximal to distal direction. The outer diameter remains constant, and as a result, the surface area of ​​the thread in contact with the bone increases in the distal to proximal direction, enhancing the thread's engagement in the bone.

[0142] The head 1212 further includes an angled surface 1234 (also known as a "chamfer" or "bevel") and a driver recess 1236. The angled surface 1234 is formed between the upper surface 1232 and the outer surface 1222. The upper surface 1232 has a width dimension greater than zero as measured along the diameter of the head to ensure that the angled surface 1234 does not extend completely across the top of the screw 1210. By way of example, the angled surface 1234 may be formed at a distance from the longitudinal axis L. 13 a bevel angle θ in the range of 1 to 60° measured from the plane of the top surface 1232, which is approximately perpendicular to 13 By way of example, the bevel angle θ of the bone screw 1210 shown in FIGS. 13 is 50°. The angled surface 1234 positions the head, when implanted during use, generally parallel and flush with the outer surface of the bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head extends beyond the outer surface of the bone when the bone screw 1210 is implanted at an angle relative to the bony structure. The driver recess 1236 is oriented within the upper surface 1232 and the angled surface 1234 along a longitudinal axis L 13 , and may have any shape suitable for accepting a driver (e.g., flat head, Phillips, hexalobular, Torx, etc.). In some embodiments (e.g., as shown in FIGS. 52-56), top surface 1234 may be a chamfered surface with a bevel direction generally intersecting the direction of angled surface 1234. By way of example, top surface 1232 may have a bevel angle θ in the range of 1 to 30 degrees. 14 By way of example, the bevel angle θ of the top surface 1232 of the bone screw 1210 shown in FIGS. 14 is 9°.

[0143] The helical thread 1224 may have a pitch 1238 in the range of 0.5 mm to 2.5 mm. By way of example, the helical thread 1224 in this example has a pitch of 1.5 mm. The head 1212 may further include cutting flutes 1240 formed at the distal end of the helical thread 1224, which serve to remove bone material as the screw 1210 is driven into bone and facilitate the transition from the shank 1214 to the head 1212. By way of example, the cutting flutes 1240 may be formed along the longitudinal axis L. 13 In some embodiments, the bevel angle may be between 1° and 30°. By way of example only, the angle of the cutting flutes 1240 shown in Figures 52-54 is 8°.

[0144] In some embodiments, head 1212 may further include a smooth and / or curved surface 1260 at the intersection of helical thread 1224 and angled surface 1234 and / or top surface 1232. By way of example, smooth and / or curved surface 1260 reduces the possibility of nerve damage or other trauma to surrounding tissue by eliminating sharp and / or rough surfaces.

[0145] Illustratively, the body 1214 is cylindrical and extends from a proximal end adjacent the neck 1216 to the distal end 1220 of the bone screw 1210. The body 1214 includes a curved outer surface 1242 and a helical thread 1244 disposed about the curved outer surface 1242. The body 1214 may have an inner diameter in the range of 1.0 mm to 7.5 mm and an outer diameter in the range of 1.5 mm to 8 mm. Preferably, the outer diameter of the body 1214 is smaller than the outer diameter of the head 1212. In the example shown and described herein, the body 1214 has an inner diameter of 3 mm and an outer diameter of approximately 4 mm. The helical thread 1244 may have a pitch 1246 in the range of 0.5 mm to 5.0 mm. Illustratively, the helical thread 1244 in this example has a pitch of 1.5 mm. Because the head 1212 and shank 1214 have the same pitch, the bone screw 1210 is neutral in compression. The shank 1214 further includes one or more cutting flutes 1248 disposed at the distal end 1220. The cutting flutes 1248 serve to remove bone material as the screw 1210 is driven into bone, which eliminates the need to drill pilot holes during surgery.

[0146] 56 , in some embodiments, the shank 1214 may include multiple engagement zones, which may have different thread pitches, for example, to ensure engagement of the screw in different types of bone. In some embodiments, the bone screw 1210 may include three engagement zones: a head zone 1270, a midshaft zone 1272, and a distal zone 1274. By way of example, the head zone 1270 and the distal zone 1274 may be “cancellous pitch zones” having a thread pitch configured for engagement in cancellous bone, while the midshaft zone 1272 may be a “cortical pitch zone” having a thread pitch configured for engagement in cortical bone. In some embodiments, the head zone 1270 and the distal zone 1274 may be cortical pitch zones, while the midshaft zone 1272 may be a cancellous pitch zone. By way of example only, the helical threads 1244 in the head zone 1270 and the distal zone 1274 may have a pitch 1246 in the range of 0.5 mm to 5.0 mm. By way of example, the helical threads 1244 in this example have a pitch of 1.5 mm. To maintain pitch neutrality so that the bone screw 1210 is "compression neutral" in the sense that the helical threads in the different engagement zones cause neither compression nor distraction, the pitch ratio between the cancellous pitch zone(s) and the cortical pitch zone(s) can be any ratio that maintains neutrality, such as 2:1, 1:4, 0.5:1, etc. By way of example only, the pitch of the mid-shaft zone 1272 can be approximately half the pitch of the head zone 1270 and the distal zone 1274. By way of example, the helical threads 1244 in the mid-shaft zone 1272 in this example may have a pitch 1276 of 0.75 mm. Furthermore, the term "compression neutral" as used herein includes not only true compression neutrality as described above, but also insignificant, extremely small compression, e.g., pitch ratios that technically compress but do not substantially affect the performance of bone screw 1210 as a compression neutral screw. By way of example only, such ratios may include (but are not limited to) 2.1 / 1, 4.1 / 1, 0.55 / 1, and / or any ratio within the ranges of (0.45-0.55):1, (1.85-2.15):1, (3.7-4.3):1, or the like.

[0147] In some embodiments, the relative sizes of the snagging zones may vary depending, for example, on the required screw size / length and / or the anatomical target site. For example, as shown in FIG. 57 , in some embodiments, the head zone 1270 may include only the head 1212 of the bone screw 1210 (e.g., that portion of the bone screw between the proximal end 1218 and the neck 1216), and the shank 1214 includes two snagging zones, including a mid-shank zone 1272 (or “proximal zone” 1272) and a distal zone 1274, with the mid-shank zone 1272 extending distally from the neck 1216 to its interface with the distal zone 1274. In some embodiments, the head zone 1270 may have a length dimension within a range of 5 mm to 20 mm. In some embodiments, the mid-shank zone 1272 may have a length dimension within a range of 10 mm to 30 mm. In some embodiments, the distal zone 1274 may have a length dimension within a range of 10 mm to 30 mm. Optionally, in any embodiment, head zone 1270 , mid-shaft zone 1272 , and distal zone 1274 may each comprise between 10% and 60% of the length of bone screw 1210 .

[0148] In some embodiments, the bone screw 1210 may have a cortical pitch zone 1281 at the distal end 1220, and more specifically, at the distal tip 1221, to advantageously provide, for example, minimal snagging within the subchondral bone. In such embodiments, the bone screw 1210 may have three or more snagging zones, with the cortical pitch zone and the cancellous pitch zone alternating. For example, a small cortical pitch zone 1281 at the distal end of the bone screw 1210 may be positioned immediately adjacent to a cancellous pitch zone (e.g., distal zone 1274), followed by a second cortical pitch zone (e.g., mid-shaft zone 1272) immediately adjacent to the cancellous pitch zone, which in turn is followed by a second cancellous pitch zone (e.g., head zone 1270) immediately adjacent to the second cortical pitch zone, and so on. In some embodiments, the second cancellous pitch zone may include the head 1212. In some embodiments, the bone screw 1210 may include four or more pitch zones, alternating between cortical and cancellous pitch zones. In some embodiments, the cortical pitch zone 1281 at the distal end 1220 may include only the distal tip 1221 of the bone screw 1210, as shown by way of example only in FIG. 58 . In some embodiments, the cortical pitch zone at the distal end 1220 may include the distal tip of the bone screw 1210 and a portion of the distal end 1220 of the shank 1214. In some embodiments, the cortical pitch zone at the distal end 1220 may not extend to the distal end of the bone screw 1210.

[0149] In some embodiments, the neck 1216 includes a curved outer surface 1250 that tapers distally to provide a smooth transition between the inverted nostril 1212 and the barrel 1214 .

[0150] Bone screw 1210 may further include a central lumen extending axially throughout screw 1210, similar to central lumen 52 shown and described above with respect to bone screw 10. Central lumen 1252 may be sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 1210 to the correct implantation location.

[0151] In some embodiments, the bone screw 1210 (or any embodiment disclosed herein) may have microthreads 1280 provided on any surface that may otherwise lack threads, including, for example, but not limited to, the neck 1216, the distal end 1220, and any section between the pitch zones (and by way of example only).

[0152] In some embodiments, fixation can be achieved using a headless shank with a single uniform thread pitch or with multiple catch zones with different thread pitches. In some embodiments, the headless shank can be neutral in compression. In some embodiments, the headless shank can be configured to achieve compression and / or distraction.

[0153] 60-65 show an example of an insertion tool 1310 configured for use with any of the bone screws disclosed herein, according to some embodiments. By way of example only, the insertion tool 1310 includes a proximal end 1312, a distal end 1314, and an elongated shaft 1316 extending between the proximal and distal ends. The proximal end 1312 may include a shaped end configured to releasably engage a handle (not shown) to facilitate manipulation of the insertion tool 1310. By way of example only, the handle may be a T-handle, a cylindrical grip handle, or any other commonly used removable handle.

[0154] By way of example only, distal end 1314 includes a distal tip 1318 configured to engage an engagement recess of any of the bone screw embodiments described herein, e.g., engagement recess 1236 of bone screw 1210. Distal tip 1318 may have any shape that complements the engagement recess 1236 of the particular bone screw being used, including, but not limited to, for example, flat head, Phillips, hexalobular, Torx, etc., to enable insertion tool 1310 to apply sufficient torque to the bone screw to drive it into bone.

[0155] By way of example only, the elongated shaft 1316 may have a generally cylindrical body and a flat surface or planar cutout 1320 extending along a substantial portion of the length of the shaft 1316. By way of example, the insertion tool 1310 may be coupled to a bone screw described herein (e.g., bone screw 1210) such that the planar cutout 1320 matches the orientation of the angled surface of the bone screw (e.g., angled surface 1234 of bone screw 1210). In this manner, the planar cutout 1320 provides the user with a visual indication of the orientation and / or directionality of the bone screw 1310 during use. Moreover, the planar cutout 1320 ensures proper orientation of the insertion tool 1310 relative to the bone screw 1210 prior to engagement (e.g., as shown by way of example only in FIG. 65 ). Unlike laser marking or other methods currently used in the art, the flat cutout 1320 cannot be washed away or rubbed off to remove or obscure the visual indication of thread orientation, which represents a significant advantage over existing systems.

[0156] It is important to note that any element or feature shown and described herein with respect to any particular example may be used in combination with any other feature(s) or element(s) shown and described with respect to other examples, without limitation.

Claims

1. 1. An orthopedic surgical screw at an anatomical target site in a human patient, the screw having a proximal end and a distal end, the screw comprising: a head having a proximal end that includes the proximal end of the screw, a shank having a distal end that includes the distal end of the screw, and a neck extending between the head and the shank, wherein the head, neck, and shank are collinear along a longitudinal axis extending between the proximal end of the head and the distal end of the shank; The head portion a proximal bottom surface at the proximal end of the head, the proximal bottom surface including an upper surface of the head intersecting the longitudinal axis; a distal bottom surface at the distal end of the head, and a curved outer surface extending between the proximal bottom surface and the distal bottom surface; at least one helical thread having a diameter extending from the bottom proximal surface of the head to the bottom distal surface of the head and defining an outer diameter of the head, the helical thread being configured to contact bone forming part of the anatomical target site when the head is implanted in use, thereby enhancing the hooking of the head into the bone, the at least one helical thread having at least one pitch; a drive feature dimensioned to cooperate with an instrument to rotate the head, torso, and neck about the longitudinal axis to drive the torso, neck, and head into an anatomical target in a patient; and The body portion is a curved outer surface having at least one helical thread extending from the proximal end of the shank toward the distal end of the shank, the at least one helical thread including at least two hook zones, the at least two hook zones including a first hook zone including a cancellous pitch zone having a first thread pitch configured for hooking in cancellous bone and a second hook zone including a cortical pitch zone having a second thread pitch configured for hooking in cortical bone, the cancellous pitch zone extending proximally from the distal end of the screw and the cortical pitch zone extending proximally from an interface with the cancellous pitch zone; the first thread pitch and the second thread pitch are compression neutral; Including a curved outer surface, Orthopedic surgical screws.

2. The orthopedic surgical screw of claim 1 , wherein the pitch of the at least one helical thread of the first hooking zone is in the range of 0.5 mm to 5 mm.

3. The orthopedic surgical screw according to claim 2 , wherein the pitch of the at least one helical thread of the second hooking zone is half the pitch of the at least one helical thread of the first hooking zone.

4. The orthopedic surgical screw according to claim 2 , wherein the pitch of the at least one helical thread of the first hooking zone is 1.5 mm.

5. The orthopedic surgical screw according to claim 4 , wherein the pitch of the at least one helical thread of the second hooking zone is 0.75 mm.

6. The orthopedic surgical screw according to claim 1 , wherein the second hooking zone extends between the interface with the first hooking zone and the neck.

7. The orthopedic surgical screw of claim 1 , wherein the first and second hooking zones each have a length dimension within a range of 10 mm to 30 mm.

8. The orthopedic surgical screw of claim 1 , wherein the first and second hooking zones can each comprise 10% to 60% of the overall length of the screw.

9. 2. The orthopedic surgical screw of claim 1, wherein the helical thread of the shank further includes a third hooking zone extending distally between the neck and an interface with the second hooking zone, the third hooking zone configured for hooking in cancellous bone.

10. The orthopedic surgical screw according to claim 9 , wherein the third hooking zone and the first hooking zone have the same thread pitch.

11. 2. The orthopedic surgical screw of claim 1, wherein the thread pitch of the helical thread of the head is the same as the thread pitch of the helical thread of the shank within the first engagement zone.

12. The orthopedic surgical screw of claim 1 , wherein the pitch of the at least one helical thread of the head is in the range of 0.5 mm to 5 mm.

13. 2. The orthopedic surgical screw of claim 1, wherein the head includes a chamfered surface extending along the curved outer side from the bottom proximal surface of the head to a predetermined location, the chamfered surface being angled relative to the top surface of the head to define a bevel angle dimensioned such that, when the head is implanted in use, the chamfered surface will be positioned flush along an outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating extension of the head beyond the outer surface of the bone when implanted at an angle relative to the bone.

14. The orthopedic surgical screw of claim 13, wherein the bevel angle of the head is in the range of 1 to 60 degrees.

15. 14. The orthopedic surgical screw of claim 13, wherein the chamfered surface includes the first chamfered surface, and the head further includes a second chamfered surface extending along the curved outer side of the head from the bottom proximal surface of the head to a predetermined location, the second chamfered surface bent at an angle relative to a top surface of the head perpendicular to the longitudinal axis and the first chamfered surface to define a second bevel angle.

16. The orthopedic surgical screw of claim 15, wherein the second bevel angle of the head is within the range of 1 to 30 degrees.

17. 2. The orthopedic surgical screw of claim 1, wherein the at least one helical thread of the head further comprises a thread surface area and an outer diameter that increases from the distal bottom surface to the proximal bottom surface, increasing the thread surface area in a distal-to-proximal direction.

18. 2. The orthopedic surgical screw of claim 1, wherein the head includes an inverted frustoconical cross-sectional shape defined by an inner diameter that increases from the distal bottom surface to the proximal bottom surface, and the curved outer surface extending between the distal and proximal bottom surfaces tapers relative to a longitudinal axis to define a reverse taper angle.

19. The orthopedic surgical screw of claim 1 , wherein the neck includes microthreads disposed thereon.

20. The orthopedic surgical screw of claim 1 , wherein the shank further includes microthreads at an interface between the first and second hooking zones.

21. The orthopedic surgical screw of claim 1 , wherein the head further includes at least one curved surface at an intersection between the helical thread and the upper surface.

22. The orthopedic surgical screw of claim 13 , wherein the head further includes at least one curved surface at an intersection between the helical thread and the chamfered surface.

23. The orthopedic surgical screw of claim 1 , wherein the helical thread of the shank further includes a cortical pitch zone at the distal end.

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