Orthopedic bone screw

Abstract

The present disclosure describes a bone screw for use in orthopedic surgery. The bone screw includes a handle portion having a helical thread and a head portion also having a helical thread. The handle further includes a first gripping region having a first pitch configured for gripping in cancellous bone and a second gripping region having a second pitch configured for gripping in cortical bone, the first gripping region extending proximally from the distal end of the screw and the second gripping region extending proximally from the distal end of the screw. And the second gripping region extends proximally from an interface with the first gripping region; wherein the first pitch and the second pitch are compression neutral.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is an international application claiming the benefit of priority to commonly owned and co-pending U.S. provisional application serial number 63 / 427,279, filed on November 22, 2022, entitled “ORTHOPHOSPHATE BONE SCREW,” the entire contents of which are hereby incorporated by reference into this disclosure as if fully set forth herein. Technical Field

[0003] The present disclosure relates generally to bone screws for use in orthopedic surgery and, more particularly, to a bone screw having a frustoconical head with a tapering taper in a proximal direction. Background Art

[0004] Bone screws typically have three main parts: a head, a shank, and threads. The head of most screws typically has a frustoconical shape, i.e., a frustum resembling a cone, formed by removing the tip of the cone with an incision perpendicular to the height, forming a circular and parallel lower base and upper base, the lower base being the wider original base of the cone and the upper base being the narrower, newly formed surface. The wider base of the frustum includes the top (or proximal-facing surface) of the screw and is typically provided with a drive feature (e.g., a single slot for receiving a flat-head screwdriver, a cross-wire slot for receiving a Phillips-type screwdriver). The narrower base of the frustum typically transitions into the shank and may form a distinctive neck region. Summary of the Invention

[0005] Various examples of bone screws described herein are applicable to various orthopedic surgeries, including but not limited to small bone repair (surgical repair of bone fractures in the hands, wrists, ankles, and feet, including bunion surgery, etc.) and large bone repair (surgical repair of long bones in the arms and legs). Bone screws described herein can be provided in various lengths and / or diameters (large and small) as needed. Bone screws described herein can be compression or compression neutral. Bone screws described herein can also be configured to be implanted at extreme angles without protruding from the bone.

[0006] In some embodiments, the orthopedic bone screws described herein include a head, a shank, and a neck positioned between the head and the shank. The bone screw also includes a proximal end and a distal end. The head is positioned 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 side surface and a helical thread disposed about the curved side surface.

[0007] In some embodiments, the head has a generally frustoconical cross-sectional shape, however, unlike typical prior art bone screws in which the wide base of the frustum forms the most proximal (or top) surface of the screw, in the bone screws of the present disclosure, the narrow base of the frustum forms the most proximal (or top) surface of the bone screw. This orientation may be referred to herein as "reverse conical" or "reverse frustoconical" to indicate that the orientation of the frustoconical shape is vertically flipped relative to a typical prior art bone screw.

[0008] In some embodiments, the curved side surface tapers from a wide base to a narrow base in the proximal direction. The taper angle measured relative to the longitudinal axis (and a line parallel thereto) can be in the range of 4-15°. The taper angle of the curved side surface can also be characterized in terms of the included angle of the cone defining the frustoconical shape of the head. In such a characterization, the included angle can be in the range of 8-30°.

[0009] In some embodiments, the head may have a minor diameter at the wide base in the range 1.75mm to 9.0mm, and a major diameter in the range 2.0mm to 10.0mm.The first minor diameter is smaller than the major diameter (of the helical thread).

[0010] In some embodiments, the head can include an angled surface (also known as a "chamfer" or "bevel") and a driver groove. The angled surface is formed between the top surface and the side surface. The top surface has a width dimension greater than zero, measured along the diameter of the head, to ensure that the angled surface does not extend completely through the top of the screw.

[0011] In some embodiments, the head can include an angled surface / chamfer / bevel formed between the top surface and the side surfaces such that the width dimension of the top surface is approximately zero (eg, the angled surface extends completely across the top of the screw).

[0012] In some embodiments, the angled surface may have an angled angle in the range of 1-60 degrees measured from a plane of the top surface that is generally perpendicular to the longitudinal axis. When the bone screw is implanted at an angle relative to the bone structure, the angled surface reduces / eliminates the amount of screw material that may extend beyond the edge of the bone structure.

[0013] In some embodiments, the driver groove is formed into the top surface and the angled surface along the longitudinal axis and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx, etc.).

[0014] In some embodiments, the helical threads of 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.

[0015] In some embodiments, the helical threads of the head may have a variable pitch.

[0016] In some embodiments, the bone screw can be compression neutral. In this embodiment, the helical thread of the head can have the same pitch as the helical thread of the shank, or alternatively, the helical thread of the head can have a pitch that is an even multiple (e.g., 2x) of the pitch of the helical thread on the shank.

[0017] In some embodiments, the bone screw can be a compression screw. In this embodiment, the helical thread of the head can have a pitch that is different from the pitch of the helical thread on the shank, wherein the head pitch is not an even multiple of the shank pitch.

[0018] In some embodiments, the head may include a cutting flute formed at the distal end of the helical threads that acts to clear bone material as the screw is driven into bone to ease the transition from the stem to the head.

[0019] In some embodiments, the helical threads of the head have a major diameter that remains constant.

[0020] In some embodiments, the helical threads of the head have a proximally oriented outward taper such that the major diameter at the proximal end is larger than the major diameter near the neck, and as a result, the surface area of ​​the helical threads in contact with the bone increases in the distal to proximal direction, thereby enhancing the purchase of the screw into the bone.

[0021] In some embodiments, the helical threads of the head have a proximally directed inward taper such that the major diameter at the proximal end is smaller than the major diameter near the neck.

[0022] In some embodiments, the inward taper of the helical thread has the same taper angle as the taper angle of the curved side surface.

[0023] In some embodiments, the shank is cylindrical in shape and extends from a proximal end adjacent to the neck to a distal end of the bone screw. The shank includes a curved side surface and a helical thread disposed around the curved side surface.

[0024] In some embodiments, the handle may have a minor diameter in the range of 1.0 mm to 7.5 mm and a major diameter in the range of 1.5 mm to 8 mm. Preferably, the major diameter of the handle is smaller than the major diameter of the head.

[0025] In some embodiments, the helical threads of the shank may have a pitch in the range of 0.5 mm to 2.5 mm.

[0026] In some embodiments, the handle may have a pair of helical threads, each helical thread having a pitch in the range of 0.5 mm to 5.0 mm.

[0027] In some embodiments, the handle includes one or more cutting slots disposed at the distal end. The cutting slots serve to clear bone material as the screw is driven into the bone, which avoids the need to drill a pilot hole during surgery.

[0028] In some embodiments, the bone screw includes one or more counter-cutting slots to clear bone material as the screw is removed from the bone.

[0029] In some embodiments, the neck includes curved side surfaces that taper in a distal direction to provide a smooth transition between the reverse tapered head and the handle.

[0030] As additional description to the embodiments described below, the present disclosure describes the following embodiments.

[0031] 14. The repairing screw according to claim 13, wherein the repairing screw has an incision made in accordance with one embodiment of the present invention and an improvement in the amount of repair made therein. The repairing screw has a first end and a second end, the second end of the repairing screw having a first end and a second end. The repairing screw has a first end and a second end, the second end of the repairing screw having a first end and a second end, and a first end. the screw being configured to grasp the head, the handle, and the neck about the longitudinal axis so as to drive the handle, the neck, and the head into the patient's anatomical target; and the handle comprising: a curved side surface having at least one helical thread extending from a proximal end of the handle toward a distal end of the handle, the at least one helical thread comprising at least two gripping regions, the at least two gripping regions comprising a first gripping region and a second gripping region, the first gripping region comprising a cancellous pitch region having a first pitch configured to grasp in cancellous bone, the second gripping region comprising a cortical pitch region having a second pitch configured to grasp in cortical bone, the first gripping region extending proximally from the distal end of the screw, and the second gripping region extending proximally from an interface with the first gripping region; wherein the first pitch and the second pitch are compression neutral.

[0032] Embodiment 2 is the screw for orthopedic surgery according to embodiment 1, wherein the pitch of the at least one helical thread of the first gripping region is in the range of 0.5 mm to 5 mm.

[0033] Embodiment 3 is a screw for orthopedic surgery according to embodiment 1 or 2, wherein the pitch of the at least one helical thread of the second gripping region is half the pitch of the at least one helical thread of the first gripping region.

[0034] Embodiment 4 is the screw for orthopedic surgery of any one of embodiments 1 to 3, wherein the pitch of the at least one helical thread of the first gripping region is 1.5 mm.

[0035] Embodiment 5 is the screw for orthopedic surgery according to any one of embodiments 1 to 4, wherein the pitch of the at least one helical thread of the second gripping region is 0.75 mm.

[0036] Embodiment 6 is a screw for orthopedic surgery according to any one of embodiments 1 to 5, wherein the second gripping region extends between an interface with the first gripping region and a neck.

[0037] Embodiment 7 is a screw for orthopedic surgery according to any one of embodiments 1 to 6, wherein the first gripping area and the second gripping area each have a length dimension in the range of 10 mm to 30 mm.

[0038] Embodiment 8 is the screw for orthopedic surgery according to any one of embodiments 1 to 7, wherein the first gripping area and the second gripping area each comprise between 10% and 60% of the total length of the screw.

[0039] Example 9 is a screw for orthopedic surgery according to any one of Examples 1 to 8, wherein the helical thread of the shank also includes a third gripping area, which extends distally between the neck and the interface with the second gripping area, and the third gripping area is configured to grip in cancellous bone.

[0040] Embodiment 10 is a screw for orthopedic surgery according to any one of embodiments 1 to 9, wherein the third gripping region and the first gripping region have the same pitch.

[0041] Embodiment 11 is a screw for orthopedic surgery according to any one of embodiments 1 to 10, wherein in the first gripping region, the pitch of the helical thread of the head is the same as the pitch of the helical thread of the shank.

[0042] Embodiment 12 is a screw for orthopedic surgery according to any one of embodiments 1 to 11, wherein the pitch of the at least one helical thread of the head is in the range of 0.5 mm to 5 mm.

[0043] Example 13 is a screw for orthopedic surgery according to any one of Examples 1 to 12, wherein the head includes an inclined surface extending from a proximal base of the head along the curved side surface to a predetermined position, wherein the inclined surface is angled relative to the upper surface of the head to define an oblique angle, and the size of the oblique angle is such that when the head is implanted during use, the inclined surface can be positioned along and flush with the outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head will extend beyond the outer surface of the bone when the head is implanted at an angle relative to the bone.

[0044] Embodiment 14 is a screw for orthopedic surgery according to any one of embodiments 1 to 13, wherein the bevel angle of the head is in the range of 1 to 60 degrees.

[0045] Example 15 is a screw for orthopedic surgery according to any one of Examples 1 to 14, wherein the inclined surface includes a first inclined surface, and the head also includes a second inclined surface, the second inclined surface extending from the proximal base of the head along the curved side surface of the head to a predetermined position, wherein the second inclined surface is angled relative to the upper surface of the head perpendicular to the longitudinal axis and the first inclined surface to define a second oblique angle.

[0046] Embodiment 16 is a screw for orthopedic surgery according to any one of embodiments 1 to 15, wherein the second bevel angle of the head is in a range between 1 degree and 30 degrees.

[0047] Example 17 is a screw for orthopedic surgery according to any one of Examples 1 to 16, wherein the at least one helical thread of the head also includes a thread surface area, and the major diameter of the at least one helical thread of the head increases from the distal base to the proximal base to increase the thread surface area in the distal to proximal direction.

[0048] Example 18 is a screw for orthopedic surgery according to any one of Examples 1 to 17, wherein the head includes a reverse frustoconical cross-sectional shape defined by a small diameter that increases from the distal base to the proximal base, and wherein the curved side surface extending between the distal base and the proximal base tapers relative to the longitudinal axis to define a reverse cone angle.

[0049] Embodiment 19 is a screw for orthopedic surgery according to any one of embodiments 1 to 18, wherein the neck includes fine threads disposed thereon.

[0050] Embodiment 20 is a screw for orthopedic surgery according to any one of embodiments 1 to 19, wherein the shank further comprises fine threads at the interface between the first gripping region and the second gripping region.

[0051] Embodiment 21 is a screw for orthopedic surgery according to any one of embodiments 1 to 20, wherein the head further comprises at least one rounded surface at the intersection between the helical thread and the upper surface.

[0052] Embodiment 22 is a screw for orthopedic surgery according to any one of embodiments 1 to 21, wherein the head further comprises at least one rounded surface at the intersection between the helical thread and the inclined surface.

[0053] Embodiment 23 is a screw for orthopedic surgery according to any one of embodiments 1 to 22, wherein the helical threads of the shank further include a cortical pitch region at the distal end.

[0054] In some embodiments, the bone screw is cannulated, comprising a central lumen extending axially through the entire screw. The size and configuration of the central lumen are designed to receive a guide wire (e.g., a K-wire) therethrough to guide the bone screw to the correct implantation position.

[0055] 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 with any other feature or element shown and described with respect to other example embodiments, without limitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] Numerous advantages of the present disclosure will become apparent to those skilled in the art from a reading of this specification in conjunction with the accompanying drawings, wherein like reference numerals are applied to like elements, and wherein:

[0057] Figure 1 is a front plan view of a first example of a bone screw according to an embodiment of the present disclosure;

[0058] Figure 2 yes Figure 1 A front plan view of the head region of the bone screw;

[0059] Figure 3 yes Figure 2 A side plan view of the head region;

[0060] Figure 4 yes Figure 1 Stereoscopic image of bone screw;

[0061] Figure 5 yes Figure 1 a top plan view of a bone screw;

[0062] Figure 6 yes Figure 1 a bottom plan view of the bone screw;

[0063] Figure 7 is a front plan view of a second example of a bone screw according to an embodiment of the present disclosure;

[0064] Figure 8 yes Figure 7 A front plan view of the head region of the bone screw;

[0065] Figure 9 yes Figure 8 A side plan view of the head region;

[0066] Figure 10 is a front plan view of a third example of a bone screw according to an embodiment of the present disclosure;

[0067] Figure 11 yes Figure 10 A front plan view of the head region of the bone screw;

[0068] Figure 12 yes Figure 11 A side plan view of the head region;

[0069] Figure 13 is a front plan view of a fourth example of a bone screw according to an embodiment of the present disclosure;

[0070] Figure 14 yes Figure 13 A front plan view of the head region of the bone screw;

[0071] Figure 15 yes Figure 14 A side plan view of the head region;

[0072] Figure 16 is a front plan view of a fifth example of a bone screw according to an embodiment of the present disclosure;

[0073] Figure 17 yes Figure 16 A front plan view of the head region of the bone screw;

[0074] Figure 18 yes Figure 17 A side plan view of the head region;

[0075] Figure 19 is a front plan view of a sixth example of a bone screw according to an embodiment of the present disclosure;

[0076] Figure 20 yes Figure 19 A front plan view of the head region of the bone screw;

[0077] Figure 21 yes Figure 20 A side plan view of the head region;

[0078] Figure 22 is a front plan view of a seventh example of a bone screw according to an embodiment of the present disclosure;

[0079] Figure 23 yes Figure 22 A front plan view of the head region of the bone screw;

[0080] Figure 24 yes Figure 23 A side plan view of the head region;

[0081] Figure 25 is a front plan view of an eighth example of a bone screw according to an embodiment of the present disclosure;

[0082] Figure 26 yes Figure 25 A front plan view of the head region of the bone screw;

[0083] Figure 27 yes Figure 26 A side plan view of the head region;

[0084] Figure 28 is a front plan view of a ninth example of a bone screw according to an embodiment of the present disclosure;

[0085] Figure 29 yes Figure 28 A front plan view of the head region of the bone screw;

[0086] Figure 30 yes Figure 29 A side plan view of the head region;

[0087] Figure 31 is a front plan view of a tenth example of a bone screw according to an embodiment of the present disclosure;

[0088] Figure 32 yes Figure 28 A front plan view of the head region of the bone screw;

[0089] Figure 33 yes Figure 31 A side plan view of the head region;

[0090] Figure 34 is a front plan view of an eleventh example of a bone screw according to an embodiment of the present disclosure;

[0091] Figure 35 yes Figure 35 Front plan view of the head region of the bone screw. 34;

[0092] Figure 36 yes Figure 34 A side plan view of the head region;

[0093] Figure 37 is a front plan view of a twelfth example of a bone screw according to an embodiment of the present disclosure;

[0094] Figure 38 yes Figure 37 A front plan view of the head region of the bone screw;

[0095] Figure 39 yes Figure 37 A side plan view of the head region;

[0096] Figure 40 is used during bunion repair surgery according to an embodiment of the present disclosure Figure 1 Representative images of bone screws in plan view;

[0097] Figure 41 It is used to repair broken bones of the foot Figure 1 Representative images of bone screws in plan view;

[0098] Figure 42 is used during bunion repair surgery according to an embodiment of the present disclosure Figure 31 Representative images of bone screws in plan view;

[0099] Figure 43 Used to repair humic bone Figure 1 perspective views of representative images of multiple bone screws; and

[0100] Figure 44 yes Figure 1 Plan view of a representative image of multiple bone screws used to repair several fractures in the wrist;

[0101] Figure 45 yes Figure 1 An enlarged plan view of the head region of the bone screw;

[0102] Figures 46-51 Shown Figure 1 Several examples of possible configurations of the head region of a bone screw;

[0103] Figure 52 is a front plan view of a tenth example of a bone screw according to an embodiment of the present disclosure;

[0104] Figure 53 yes Figure 52 A perspective view of the head region of a bone screw;

[0105] Figure 54 yes Figure 53 A side plan view of the head region;

[0106] Figures 55-58 yes Figure 52 Front plan view of the bone screw;

[0107] Figure 59 It is implanted to repair two bone segments. Figure 52 A perspective view of a bone screw;

[0108] Figure 60 is a perspective view of an example of an insertion tool according to an embodiment of the present disclosure, the insertion tool being configured for use with any of the bone screw embodiments disclosed herein;

[0109] Figure 61 yes Figure 60 a top plan view of an insertion tool;

[0110] Figure 62 yes Figure 60 a side plan view of an insertion tool;

[0111] Figure 63 is with Figure 52 Bone screw coupling Figure 60 a side plan view of an insertion tool; and

[0112] Figures 64-65 yes Figure 60 Insertion tool and Figure 52 Perspective view of a bone screw. DETAILED DESCRIPTION

[0113] Illustrative embodiments of the present invention are described below. For the sake of clarity, not all features of an actual implementation are described in this specification. Of course, it should be understood that in the development of any such actual embodiment, many implementation-specific decisions must be made to achieve the developer's specific goals, such as complying with system-related and business-related constraints, which will vary from one implementation to another. Furthermore, it should be understood that such development efforts may be complex and time-consuming, but remain 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 possess various inventive features and components that warrant patent protection, both individually and in combination.

[0114] Various examples of bone screws described herein are suitable for use in various orthopedic surgeries, including but not limited to small bone repair (surgical repair of bone fractures in the hands, wrists, ankles, and feet, including bunion surgery, talar neck fracture repair, etc.), large bone repair (surgical repair of long bones in the arms and legs), and osteotomy. The bone screws disclosed herein can also be used to stabilize bones during the healing process or as part of a larger repair procedure. The bone screws described herein can be provided in various lengths and / or diameters (large and small) as needed. The bone screws described herein can be compression or compression neutral.

[0115] Figures 1 to 6 An example of a bone screw 10 according to one embodiment of the present disclosure is shown. By way of example, the bone screw 10 includes a head 12, a shank 14, and a neck 16 positioned between the head 12 and the shank 14. The bone screw 10 also includes a proximal end 18 and a distal end 20. The head 12 is positioned at / near the proximal end 18 of the bone screw 10, and the shank 14 extends axially from the neck 16 to the distal end 20 of the bone screw 10 along a longitudinal axis L1 (also referred to as a "vertical axis"). The head 12 includes a curved side surface 22 and a helical thread 24 disposed about the curved side surface 22. The head 12 has a generally frustoconical cross-sectional shape 26; however, unlike typical prior art bone screws, in which a wide base 28 of the truncated head forms the most proximal (or top) surface of the screw, in this embodiment, a narrow base 30 of the truncated head forms the most proximal (or top) surface 32 of the bone screw 10. This orientation may be referred to herein as "reverse conical" or "reverse frustoconical" to indicate that the frustoconical orientation is flipped vertically relative to a typical prior art bone screw. The curved side surface 22 tapers in the proximal direction from a wide base 28 to a narrow base 30. By way of example, the curved side surface 22 tapers at an angle A1 of 5.9° relative to the longitudinal axis L1 (resulting in a cone defining the head shape having an included angle of 11.8°), however, the angle A1 may be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0116] The head 12 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 28. The head 12 may have a major diameter (e.g., the outer diameter of the helical thread 24) in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical thread 24). For example, Figure 1-4 The head 12 of the illustrated bone screw 10 has a minor diameter of approximately 4.5 mm at the wide base 28 and a major diameter of approximately 5.0 mm. Due to its frustoconical shape, the head 12 has a minor diameter that increases from proximal to distal. The major diameter remains constant, resulting in an increase in the thread surface area in contact with the bone from distal to proximal, enhancing the screw's grip on the bone.

[0117] The head 12 further includes an angled surface 34 (also a "chamfer" or "bevel") and a driver groove 36. The angled surface 34 is formed between the top surface 32 and the side surface 22. The top surface 32 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 34 does not extend completely through the top of the screw 10. In the present embodiment, the top surface 32 has a width dimension of 0.65 mm, however, the width dimension can be more or less depending on the overall size of the bone screw 10. As an example, the angled surface 34 can have a bevel angle Φ1 in the range of 1-60° measured from the plane of the top surface 32, which plane is generally perpendicular to the longitudinal axis L1. As an example, Figure 1-6 The illustrated bone screw 10 has a bevel angle Φ1 of 50°. When the head is implanted during use, the angled surface 34 is positioned generally parallel to and flush with the outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head would extend beyond the outer surface of the bone when the bone screw 10 is implanted at an angle relative to the bony structure. A driver recess 36 is formed in the top surface 32 and the angled surface 34 along the longitudinal axis L1 and can have any shape suitable for accommodating a driver (e.g., flat head, Phillips type, hexagonal, torx-shaped, etc.).

[0118] The helical threads 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. As an example, the helical threads 24 of this example have a pitch of 1.5 mm. The head 12 may also include a cutting groove 40 formed at the distal end of the helical threads 24 for removing bone material when the screw 10 is driven into bone to simplify the transition from the shank 14 to the head 12.

[0119] As an example, the shank 14 is cylindrical in shape and extends from a proximal end adjacent to the neck 16 to the distal end 20 of the bone screw 10. The shank 14 includes a curved side surface 42 and a helical thread 44 disposed about the curved side surface 42. The shank 14 may have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 14 is smaller than the major diameter of the head 12. In the example shown and described herein, the shank 14 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 44 may have a pitch 46 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 44 of 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 shank 14 also includes one or more cutting grooves 48 disposed at the distal end 20. The cutting slots 48 serve to clear bone material as the screw 10 is driven into the bone, which avoids the need to drill a pilot hole during the surgical procedure.

[0120] The neck 16 includes a curved side surface 50 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 12 and the handle 14 .

[0121] As an example, the bone screw 10 can be cannulated, further comprising a central lumen 52 extending axially through the entire screw 10. The central lumen 52 is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide the bone screw 10 to the correct implantation location.

[0122] Figures 7 to 9 An example of a bone screw 110 according to another embodiment of the present disclosure is shown. By way of example, the bone screw 110 includes a head 112, a shank 114, and a neck 116 positioned between the head 112 and the shank 114. The bone screw 110 also includes a proximal end 118 and a distal end 120. The head 112 is positioned at / near the proximal end 118 of the bone screw 110, and the shank 114 extends axially from the neck 116 to the distal end 120 of the bone screw 110 along a longitudinal axis L2 (also referred to as a "vertical axis"). The head 112 includes a curved side surface 122 and a helical thread 124 disposed about the curved side surface 122. The head 112 has an inverted frustoconical cross-sectional shape 126, as described above with respect to the bone screw 10. The curved side surface 122 tapers in the proximal direction from a wide base 128 to a narrow base 130. As an example, the curved side surface 122 tapers at an angle A2 of 5.9° relative to the longitudinal axis L2 (resulting in a cone defining the shape of the head having an included angle of 11.8°), however the angle A2 may be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0123] The head 112 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 128. The head 112 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical thread 124). As an example, Figure 7-9 The head 112 of the illustrated bone screw 110 has a minor diameter of approximately 4.5 mm and a major diameter of approximately 5.0 mm at a wide base 128. Due to its frustoconical shape, the head 112 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0124] The head 112 further includes an angled surface 134 (also a "chamfer" or "bevel") and a driver groove 136. The angled surface 134 is formed between the top surface 132 and the side surface 122. The top surface 132 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 134 does not extend completely through the top of the screw 110. In the present embodiment, the top surface 132 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 110. As an example, the angled surface 134 can have a bevel angle Φ2 in the range of 1-60° measured from the plane of the top surface 132, which plane is generally perpendicular to the longitudinal axis L2. As an example, Figure 7-9 The bevel angle Φ2 of the bone screw 110 shown is 50°. When the head is implanted during use, the angled surface 134 is positioned approximately parallel to 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 will extend beyond the outer surface of the bone when the bone screw 110 is implanted at an angle relative to the bone structure. A driver groove 136 is formed in the top surface 132 and the angled surface 134 along the longitudinal axis L2 and can have any shape suitable for accommodating a driver (e.g., flat head, Phillips type, hexagonal, plum blossom, etc.). The helical thread 124 can have a pitch 138 in the range of 0.5 mm to 2.5 mm. As an example, the helical thread 124 of this example has a pitch of 1.5 mm.

[0125] As an example, the shank 114 is cylindrical in shape and extends from a proximal end adjacent to the neck 116 to the distal end 120 of the bone screw 110. The shank 114 includes a curved side surface 142 and a pair of helical threads 144a, 144b disposed about the curved side surface 142. The shank 114 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 114 is smaller than the major diameter of the head 112. In the example shown and described herein, the shank 114 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical threads 144a, 144b can have a pitch 146 ranging from 0.5 mm to 5.0 mm. As an example, the helical threads 144a, 144b of this example each have a pitch of 3.0 mm (e.g., the distance between adjacent threads of the same helix), yet there are two evenly spaced helical threads 144a, 144b, such that the effective pitch of the bone screw 110 is 1.5 mm, which is the same as the pitch of the helical thread 124 of the head 112. Because the bone screw 110 uses a double helix configuration in the shank thread, the bone screw 110 can be driven into the target bone at a rate approximately twice that of a bone screw having a true pitch of 1.5 mm. Because the head 112 and the shank 114 have the same pitch (or effective pitch), the bone screw 110 is compression neutral. The shank 114 also includes one or more cutting grooves 148 disposed at the distal end 120. The cutting grooves 148 are used to remove bone material as the screw 110 is driven into the bone, which avoids the need to drill a pilot hole during the surgical procedure.

[0126] The neck 116 includes a curved side surface 150 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 112 and the handle 114 .

[0127] Bone screw 110 also includes a central lumen extending axially through the entire 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.

[0128] Figures 10 to 12An example of a bone screw 210 according to another embodiment of the present disclosure is shown. For example, the bone screw 210 includes a head 212, a shank 214, and a neck 216 positioned between the head 212 and the shank 214. The bone screw 210 also includes a proximal end 218 and a distal end 220. The head 212 is positioned at / near the proximal end 218 of the bone screw 210, and the shank 214 extends axially from the neck 216 to the distal end 220 of the bone screw 210 along a longitudinal axis L3 (also referred to as a "vertical axis"). The head 212 includes a curved side surface 222 and a helical thread 224 disposed about the curved side surface 222. The head 212 has a generally cylindrical shape. The helical thread 224 has a major diameter that increases in the distal-to-proximal direction. As a result, the surface area of ​​the thread in contact with the bone increases in the distal-to-proximal direction, enhancing the screw's grip in the bone.

[0129] The head 212 further includes an angled surface 234 (also a "chamfer" or "bevel") and a driver groove 236. The angled surface 234 is formed between the top surface 232 and the side surface 222. The top surface 232 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 234 does not extend completely through the top of the screw 210. In the present embodiment, the top surface 232 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 210. As an example, the angled surface 234 can have a bevel angle Φ3 in the range of 1-60° measured from the plane of the top surface 232, which plane is generally perpendicular to the longitudinal axis L3. For example, Figure 10-12 The illustrated bone screw 210 has a bevel angle φ3 of 50°. When the head is implanted during use, the angled surface 234 is positioned generally parallel to and flush with the outer surface of a bone forming part of an anatomical target site, thereby reducing or eliminating the extent to which the head would extend beyond the outer surface of the bone when the bone screw 210 is implanted at an angle relative to the bony structure. A driver recess 236 is formed into the top surface 232 and the angled surface 234 along the longitudinal axis L3 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx-shaped, etc.).

[0130] The helical threads 224 can 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. As an example, the helical threads 224 of this example have a pitch of 1.5 mm. The threads 224 have an outward taper 225 that is oriented proximally, for example, by 10°, so that the major diameter at the proximal end 218 is larger than the major diameter near the neck 216. As a result, the surface area of ​​the helical threads 224 that contacts the bone increases in the distal to proximal direction, enhancing the screw's grip in the bone.

[0131] As an example, the shank 214 is cylindrical in shape and extends from a proximal end adjacent to the neck 216 to the distal end 220 of the bone screw 210. The shank 214 includes a curved side surface 242 and a helical thread 244 disposed about the curved side surface 242. The shank 214 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 214 is smaller than the major diameter of the head 212. In the example shown and described herein, the shank 214 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 244 can have a pitch 246 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 244 of 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 handle 214 also includes one or more cutting slots 248 disposed at the distal end 220. The cutting slots 248 serve to clear bone material as the screw 210 is driven into bone, which avoids the need to drill a pilot hole during surgery.

[0132] The neck 216 includes a curved side surface 250 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 212 and the handle 214 .

[0133] Bone screw 210 also includes a central lumen extending axially through the entire screw 210, 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 210 to the correct implantation location.

[0134] Figure 13-15An example of a bone screw 310 according to another embodiment of the present disclosure is shown. By way of example, the bone screw 310 includes a head 312, a shank 314, and a neck 316 positioned between the head 312 and the shank 314. The bone screw 310 also includes a proximal end 318 and a distal end 320. The head 312 is positioned at / near the proximal end 318 of the bone screw 310, and the shank 314 extends axially from the neck 316 to the distal end 320 of the bone screw 310 along a longitudinal axis L4 (also referred to as the "vertical axis"). The head 312 includes a curved side surface 322 and a helical thread 324 disposed about the curved side surface 322. The head 312 has an inverted frustoconical cross-sectional shape 326, as described above with respect to the bone screw 10. The curved side surface 322 tapers in the proximal direction from a wide base 328 to a narrow base 330. As an example, the curved side surface 322 tapers at an angle A4 of 5.9° relative to the longitudinal axis L4 (resulting in a cone defining the shape of the head having an included angle of 11.8°), however the angle A4 can be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0135] The head 312 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 328. The head 312 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical thread 324). As an example, Figure 1 and Figure 2 The head 312 of the bone screw 310 is shown in FIG. Figure 13-15 The head 312 has a minor diameter of approximately 4.5 mm and a major diameter of approximately 5.0 mm at the wide base 328. Due to its frustoconical shape, the head 312 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the surface area of ​​the thread in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0136] The head 312 further includes an angled surface 334 (also a "chamfer" or "bevel") and a driver groove 336. The angled surface 334 is formed between the top surface 332 and the side surface 322. The top surface 332 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 334 does not extend completely through the top of the screw 310. In the present embodiment, the top surface 332 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 310. As an example, the angled surface 334 can have a bevel angle Φ4 in the range of 1-60° measured from the plane of the top surface 332, which plane is generally perpendicular to the longitudinal axis L1. As an example, Figure 13-15The illustrated bone screw 310 has a bevel angle φ4 of 50°. When the head is implanted during use, the angled surface 334 is positioned generally parallel to and flush with the outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head would extend 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 top surface 332 along the longitudinal axis L4 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx-shaped, etc.).

[0137] The helical thread 324 can have a variable pitch ranging from 0.5 mm to 2.5 mm at the distal end of the head 312 and a variable pitch ranging from 1.0 mm to 5.0 mm at the proximal end of the head. By way of example, the helical thread 324 of this example has a pitch 338a of 1.5 mm at the proximal end of the head 312, which tapers to a pitch 338b of 0.75 mm at the distal end of the head. Due to this gradual pitch, the bone screw 310 is a compression screw because at least a portion of the helical thread 324 will be located outside the thread groove formed in the bone by the passage of the shank thread 344. The head 312 may also include a cutting groove formed at the distal end of the helical thread 324, which is used to remove bone material when the screw 310 is driven into the bone, thereby simplifying the transition from the shank 314 to the head 312.

[0138] As an example, the shank 314 is cylindrical in shape and extends from a proximal end adjacent to the neck 316 to the distal end 320 of the bone screw 310. The shank 314 includes a curved side surface 342 and a helical thread 344 disposed about the curved side surface 342. The shank 314 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 314 is smaller than the major diameter of the head 312. In the example shown and described herein, the shank 314 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 344 can have a pitch 346 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 344 of this example has a pitch of 1.5 mm. The shank 314 also includes one or more cutting grooves 348 disposed at the distal end 320. The cutting slots 348 serve to clear bone material as the screw 310 is driven into the bone, which avoids the need to drill a pilot hole during the surgical procedure.

[0139] The neck 316 includes a curved side surface 350 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 312 and the handle 314 .

[0140] Bone screw 310 also includes a central lumen extending axially through the entire screw 310, similar 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.

[0141] Figures 16 to 18 An example of a bone screw 410 according to another embodiment of the present disclosure is shown. By way of example, the bone screw 410 includes a head 412, a shank 414, and a neck 416 positioned between the head 412 and the shank 414. The bone screw 410 also includes a proximal end 418 and a distal end 420. The head 412 is positioned at / near the proximal end 418 of the bone screw 410, and the shank 414 extends axially from the neck 416 to the distal end 420 of the bone screw 410 along a longitudinal axis L5 (also referred to as the "vertical axis"). The head 412 includes a curved side surface 422 and a helical thread 424 disposed about the curved side surface 422. The head 412 has an inverted frustoconical cross-sectional shape 426, as described above with respect to the bone screw 10. The curved side surface 422 tapers in the proximal direction from a wide base 428 to a narrow base 430. As an example, the curved side surface 422 tapers at an angle A5 of 5.9° relative to the longitudinal axis L5 (resulting in a cone defining the shape of the head having an included angle of 11.8°), however the angle A5 can be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0142] The head 412 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 428. The head 412 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 424). For example, Figure 16-18 The head 412 of the illustrated bone screw 410 has a minor diameter of approximately 4.5 mm at the wide base 428 and a major diameter of approximately 5.0 mm. Due to its frustoconical shape, the head 412 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0143] The head 412 further includes an angled surface 434 (also a "chamfer" or "bevel") and a driver groove 436. The angled surface 434 is formed between the top surface 432 and the side surface 422. The top surface 432 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 434 does not extend completely through the top of the screw 410. In the present embodiment, the top surface 432 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 410. As an example, the angled surface 434 can have a bevel angle Φ5 in the range of 1-60° measured from the plane of the top surface 432, which plane is generally perpendicular to the longitudinal axis L1. For example, Figure 16-18 The illustrated bone screw 410 has a bevel angle φ5 of 50°. When the head is implanted during use, the angled surface 434 is positioned generally parallel to and flush with the outer surface of a bone forming part of an anatomical target site, thereby reducing or eliminating the extent to which the head will extend beyond the outer surface of the bone when the bone screw 410 is implanted at an angle relative to the bone structure. A driver recess 436 is formed into the top surface 432 and the angled surface 434 along the longitudinal axis L5 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx, etc.).

[0144] The helical threads 424 may have a pitch 438 in the range of 0.5 mm to 2.5 mm. As an example, the helical threads 424 of this example have a pitch of 0.75 mm. The head 412 may also include a cutting groove 440 formed at the distal end of the helical threads 424 for removing bone material when the screw 410 is driven into the bone to simplify the transition from the handle 414 to the head 412.

[0145] As an example, the shank 414 is cylindrical in shape and extends from a proximal end adjacent to the neck 416 to the distal end 420 of the bone screw 410. The shank 414 includes a curved side surface 442 and a helical thread 444 disposed about the curved side surface 442. The shank 414 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 414 is smaller than the major diameter of the head 412. In the example shown and described herein, the shank 414 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 444 can have a pitch 446 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 444 of this example has a pitch of 1.5 mm. Because the pitch 446 of the shank 414 is an even multiple (e.g., 2x) of the pitch 438 of the head 412, the bone screw 410 is non-compressible. The handle 414 also includes one or more cutting slots 448 disposed at the distal end 420. The cutting slots 448 serve to clear bone material as the screw 410 is driven into bone, which avoids the need to drill a pilot hole during surgery.

[0146] The neck 416 includes a curved side surface 450 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 412 and the handle 414 .

[0147] Figures 19 to 21 An example of a bone screw 510 according to another embodiment of the present disclosure is shown. By way of example, the bone screw 510 includes a head 512, a shank 514, and a neck 516 positioned between the head 512 and the shank 514. The bone screw 510 also includes a proximal end 518 and a distal end 520. The head 512 is positioned at / near the proximal end 518 of the bone screw 510, and the shank 514 extends axially from the neck 516 to the distal end 520 of the bone screw 510 along a longitudinal axis L6 (also referred to as a "vertical axis"). The head 512 includes a curved side surface 522 and a helical thread 524 disposed about the curved side surface 522. The head 512 has an inverted frustoconical cross-sectional shape 526, as described above with respect to the bone screw 10. The curved side surface 522 tapers in the proximal direction from a wide base 528 to a narrow base 530. As an example, the curved side surface 522 tapers at an angle A5 of 5.9° relative to the longitudinal axis L5 (resulting in a cone defining the shape of the head having an included angle of 11.8°), however the angle A5 can be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0148] The head 512 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 528. The head 512 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 524). For example, Figure 19-21 The head 512 of the illustrated bone screw 510 has a minor diameter of approximately 4.5 mm at the wide base 528 and a major diameter of approximately 5.0 mm. Due to its frustoconical shape, the head 512 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0149] The head 512 further includes an angled surface 534 (also a "chamfer" or "bevel") and a driver groove 536. The angled surface 534 is formed between the top surface 532 and the side surface 522. The top surface 532 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 534 does not extend completely through the top of the screw 510. In the present embodiment, the top surface 532 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 510. As an example, the angled surface 534 can have a bevel angle Φ6 in the range of 1-60° measured from the plane of the top surface 532, which plane is generally perpendicular to the longitudinal axis L6. As an example, Figure 19-21 The illustrated bone screw 510 has a bevel angle φ6 of 50°. When the head is implanted during use, the angled surface 534 is positioned substantially parallel to and flush with the outer surface of a bone forming part of an anatomical target site, thereby reducing or eliminating the extent to which the head will extend beyond the outer surface of the bone when the bone screw 510 is implanted at an angle relative to the bony structure. A driver recess 536 is formed in the top surface 532 and the angled surface 534 along the longitudinal axis L6 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx-shaped, etc.).

[0150] The helical threads 524 may have a pitch 538 in the range of 0.5 mm to 2.5 mm. As an example, the helical threads 524 of this example have a pitch of 1.5 mm. The head 512 may also include a cutting groove 540 formed at the distal end of the helical threads 524 for removing bone material when the screw 510 is driven into the bone to simplify the transition from the handle 514 to the head 512.

[0151] As an example, the shank 514 is cylindrical in shape and extends from a proximal end adjacent to the neck 516 to the distal end 520 of the bone screw 510. The shank 514 includes a curved side surface 542 and a pair of helical threads 544a, 544b disposed about the curved side surface 542. The shank 514 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 514 is smaller than the major diameter of the head 512. In the example shown and described herein, the shank 514 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical threads 544a, 544b can have a pitch 546 ranging from 0.5 mm to 5.0 mm. As an example, the helical threads 544a, 544b of this example each have a pitch of 3.0 mm (e.g., the distance between adjacent threads of the same spiral), yet there are two evenly spaced helical threads 544a, 544b, such that the effective pitch of the bone screw 510 is 1.5 mm, which is the same as the pitch of the helical thread 524 of the head 512. Because the bone screw 510 uses a double helix configuration in the shank thread, the bone screw 510 can be driven into the target bone at a rate approximately twice that of a bone screw having a true pitch of 1.5 mm. Because the head 512 and the shank 514 have the same pitch (or effective pitch), the bone screw 510 is compression neutral. The shank 514 also includes one or more cutting grooves 548 disposed at the distal end 520. When the screw 510 is driven into the bone, the cutting grooves 548 serve to clear bone material, which avoids the need to drill a pilot hole during the surgical procedure.

[0152] The neck 516 includes a curved side surface 550 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 512 and the handle 514 .

[0153] Bone screw 510 also includes a central lumen extending axially through the entire 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.

[0154] Figures 22 to 24An example of a bone screw 610 according to another embodiment of the present disclosure is shown. For example, the bone screw 610 includes a head 612, a shank 614, and a neck 616 positioned between the head 612 and the shank 614. The bone screw 610 also includes a proximal end 618 and a distal end 620. The head 612 is positioned at / near the proximal end 618 of the bone screw 610, and the shank 614 extends axially from the neck 616 to the distal end 620 of the bone screw 610 along a longitudinal axis L7 (also referred to as the "vertical axis"). The head 612 includes a curved side surface 622 and a helical thread 624 disposed about the curved side surface 622. The head 612 has an inverted frustoconical cross-sectional shape 626, as described above with respect to the bone screw 10. The curved side surface 622 tapers in the proximal direction from a wide base 628 to a narrow base 630. As an example, the curved side surface 622 tapers at an angle A7 of 5.9° relative to the longitudinal axis L7 (resulting in a cone defining the shape of the head having an included angle of 11.8°), however the angle A7 can be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0155] The head 612 may have a minor diameter at the wide base 628 in the range of 1.75 mm to 9.0 mm and a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 624). As an example, Figure 22-24 The head 612 of the illustrated bone screw 610 has a minor diameter of approximately 4.5 mm at a wide base 628 and a major diameter of approximately 5.0 mm. Due to its frustoconical shape, the head 612 has a minor diameter that increases from proximal to distal. The threads 624 have a proximally oriented outward taper 625 with a taper angle B7 of approximately 10° (e.g., with a range of 5-30°), resulting in a larger major diameter at the proximal end 618 than near the neck 616. As a result (and in combination with the inverse frustoconical shape of the head 612), the surface area of ​​the helical threads 624 that contacts the bone increases from distal to proximal, thereby enhancing the screw's grip in the bone. In this exemplary embodiment, the combination of the inverse frustoconical shape of the head 612 and the outward taper 625 of the threads 624 (e.g., angles A7 + B7) maximizes the surface area of ​​the threads 624 that contacts the bone.

[0156] The head 612 further includes an angled surface 634 (also a "chamfer" or "bevel") and a driver groove 636. The angled surface 634 is formed between the top surface 632 and the side surface 622. The top surface 632 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 634 does not extend completely through the top of the screw 610. In the present embodiment, the top surface 632 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 610. As an example, the angled surface 634 can have a bevel angle Φ7 in the range of 1-60° measured from the plane of the top surface 632, which plane is generally perpendicular to the longitudinal axis L7. As an example, Figure 22-24 The bevel angle Φ7 of the bone screw 610 shown is 50°. When the head is implanted during use, the angled surface 634 is positioned approximately parallel to 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 will extend beyond the outer surface of the bone when the bone screw 610 is implanted at an angle relative to the bone structure. A driver groove 636 is formed in the top surface 632 and the angled surface 634 along the longitudinal axis L7 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, plum blossom, etc.). The helical thread 624 can have a pitch 638 in the range of 0.5 mm to 2.5 mm. As an example, the helical thread 624 of this example has a pitch of 0.75 mm.

[0157] As an example, the shank 614 is cylindrical in shape and extends from a proximal end adjacent to the neck 616 to the distal end 620 of the bone screw 610. The shank 614 includes a curved side surface 642 and a helical thread 644 disposed about the curved side surface 642. The shank 614 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 614 is smaller than the major diameter of the head 612. In the example shown and described herein, the shank 614 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 644 can have a pitch 646 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 644 of 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 compression neutral. The handle 614 also includes one or more cutting slots 648 disposed at the distal end 620. The cutting slots 648 serve to clear bone material as the screw 610 is driven into bone, which avoids the need to drill a pilot hole during the surgical procedure.

[0158] The neck 616 includes a curved side surface 650 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 612 and the handle 614 .

[0159] Bone screw 610 also includes a central lumen extending axially through the entire screw 610, 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 610 to the correct implantation location.

[0160] Figures 25 to 27 An example of a bone screw 710 according to another embodiment of the present disclosure is shown. By way of example, bone screw 710 includes a head 712, a shank 714, and a neck 716 positioned between the head 712 and the shank 714. Bone screw 710 also includes a proximal end 718 and a distal end 720. The head 712 is positioned at / near the proximal end 718 of the bone screw 710, and the shank 714 extends axially from the neck 716 to the distal end 720 of the bone screw 710 along a longitudinal axis L8 (also referred to as a "vertical axis"). The head 712 includes a curved side surface 722 and a helical thread 724 disposed about the curved side surface 722. The head 712 has an inverted frustoconical cross-sectional shape 726, as described above with respect to bone screw 10. The curved side surface 22 tapers in the proximal direction from the wide base 28 to the narrow base 30. As an example, the curved side surface 22 tapers at an angle A1 of 5.9° relative to the longitudinal axis L1 (resulting in a cone defining the head shape having an included angle of 11.8°), however the angle A1 may be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0161] The head 712 may have a minor diameter at the wide base 728 in the range of 1.75 mm to 9.0 mm and a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 724). For example, Figure 25-27 The head 712 of the illustrated bone screw 710 has a minor diameter of approximately 4.5 mm at a wide base 728 and a major diameter of approximately 5.0 mm. Due to the frustoconical shape, the head 712 has a minor diameter that increases in the proximal-to-distal direction. The threads 724 have an outward taper 725 that is oriented proximally by 10° (for example), so that the major diameter at the proximal end 718 is larger than the major diameter near the neck 716. As a result (and in combination with the inverse frustoconical shape of the head 712), the surface area of ​​the helical threads 724 that contacts the bone increases in the distal-to-proximal direction, enhancing the screw's grip in the bone.

[0162] The head 712 further includes an angled surface 734 (also a "chamfer" or "bevel") and a driver groove 736. The angled surface 734 is formed between the top surface 732 and the side surface 722. The top surface 732 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 734 does not extend completely through the top of the screw 710. In the present embodiment, the top surface 732 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 710. As an example, the angled surface 734 can have a bevel angle Φ8 in the range of 1-60° measured from the plane of the top surface 732, which plane is generally perpendicular to the longitudinal axis L8. As an example, Figure 25-27 The bevel angle Φ8 of the bone screw 710 shown is 50°. When the head is implanted during use, the angled surface 734 is positioned approximately parallel to 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 will extend beyond the outer surface of the bone when the bone screw 710 is implanted at an angle relative to the bone structure. A driver groove 736 is formed into the top surface 732 and the angled surface 734 along the longitudinal axis L8 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, plum blossom, etc.). The helical thread 724 can have a pitch 738 in the range of 0.5 mm to 2.5 mm. As an example, the helical thread 724 of this example has a pitch of 0.75 mm.

[0163] As an example, the shank 714 is cylindrical in shape and extends from a proximal end adjacent to the neck 716 to the distal end 720 of the bone screw 710. The shank 714 includes a curved side surface 742 and a pair of helical threads 744a, 744b disposed about the curved side surface 742. The shank 714 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 714 is smaller than the major diameter of the head 712. In the example shown and described herein, the shank 714 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical threads 744a, 744b can have a pitch 746 ranging from 0.5 mm to 2.5 mm. As an example, the helical threads 744a, 744b of this example each have a pitch of 3.0 mm (e.g., the distance between adjacent threads of the same helix). However, the presence of two evenly spaced helical threads 744a, 744b results in an effective pitch of 1.5 mm for the bone screw 710, which is the same as the pitch of the helical thread 724 of the head 712. Because the bone screw 710 utilizes a double helix configuration in the shank threads, the bone screw 710 can be driven into the target bone at approximately twice the rate of a bone screw having an actual pitch of 1.5 mm. Since 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 non-compressible. The shank 714 also includes one or more cutting grooves 748 disposed at the distal end 720. The cutting grooves 748 serve to remove bone material as the screw 710 is driven into the bone, thereby avoiding the need to drill a pilot hole during the surgical procedure.

[0164] The neck 716 includes a curved side surface 750 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 712 and the handle 714 .

[0165] Bone screw 710 also includes a central lumen extending axially through the entire 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.

[0166] Figures 28 to 30An example of a bone screw 810 according to another embodiment of the present disclosure is shown. 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 stem 814, and a neck 816 positioned between the head 812 and the stem 814. The bone screw 810 also includes a proximal end 818 and a distal end 820. The head 812 is positioned at / near the proximal end 818 of the bone screw 810, and the stem 814 extends axially from the neck 816 to the distal end 820 of the bone screw 810 along a longitudinal axis L9 (also referred to as the "vertical axis"). The head 812 includes a curved side surface 822 and a helical thread 824 disposed about the curved side surface 822. The head 812 has a reverse frustoconical cross-sectional shape 826, as described above with respect to the bone screw 10. The curved side surface 822 tapers in the proximal direction from a wide base 828 to a narrow base 830. As an example, the curved side surface 822 tapers at an angle A9 of 5.9° relative to the longitudinal axis L9 (resulting in the cone defining the head shape having an included angle of 11.8°), however, the angle A9 can be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0167] The head 812 may have a minor diameter at the wide base 828 in the range of 1.75 mm to 9.0 mm and a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 824). For example, Figures 28-30 The head 812 of the bone screw 810 shown has a minor diameter of about 4.5mm at a wide base 828, and has a major diameter of about 5.0mm. Due to the truncated cone shape, the head 812 has the minor diameter that increases along the proximal to distal direction. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases along the distal to proximal direction, which strengthens the grip of the screw into the bone. The head 812 also includes a driver groove 836 formed in the top surface 832 along the longitudinal axis L9, and can have any shape (for example, flat head, Phillips type, six heads, plum blossom etc.) that is suitable for receiving the driver. The spiral thread 824 can have a pitch 838 (for example, the distance between adjacent threads at any one position) within the range of 0.5mm to 2.5mm. As an example, the spiral thread 824 of this example has a pitch of 1.5mm.

[0168] The bone screw 810 of this embodiment is an example of a bone screw having a "bevel angle" of 0. This results in a flat head 812 where the top surface 832 and the angled surface 834 are substantially the same surface.

[0169] As an example, the shank 814 is cylindrical in shape and extends from a proximal end adjacent to the neck 816 to the distal end 820 of the bone screw 810. The shank 814 includes a curved side surface 842 and a helical thread 844 disposed about the curved side surface 842. The shank 814 may have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 814 is smaller than the major diameter of the head 812. In the example shown and described herein, the shank 814 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 844 may have a pitch 846 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 844 of 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 compression neutral. The handle 814 also includes one or more cutting slots 848 disposed at the distal end 820. The cutting slots 848 serve to clear bone material as the screw 810 is driven into bone, which eliminates the need to drill a pilot hole during the surgical procedure.

[0170] The neck 816 includes a curved side surface 850 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 812 and the handle 814 .

[0171] The bone screw 810 also includes a central lumen extending axially through the entire screw 810. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide the bone screw 810 to the correct implantation location.

[0172] Figures 31 to 33 An example of a bone screw 910 according to another embodiment of the present disclosure is shown. For example, the bone screw 910 includes a head 912, a handle 914, and a neck 916 positioned between the head 912 and the handle 914. The bone screw 910 also includes a proximal end 918 and a distal end 920. The head 912 is positioned at / near the proximal end 918 of the bone screw 910, and the handle 914 is arranged along the longitudinal axis L. 10 The bone screw 910 is axially extended from the neck 916 to the distal end 920 of the bone screw 910 (also the "vertical axis"). The head 912 includes a curved side surface 922 and a helical thread 924 disposed about the curved side surface 922. The head 912 has a reverse frustoconical cross-sectional shape 926 as described above with respect to the bone screw 10. The curved side surface 922 tapers in the proximal direction from a wide base 928 to a narrow base 930. As an example, the curved side surface 922 is tapered relative to the longitudinal axis L. 10 At an angle of 5.9° 10 The taper (resulting in a cone defining the shape of the head having an included angle of 11.8°) is such that the angle A 10It may be in the range of 4-15° (8-30° included angle) without departing from the scope of the present disclosure.

[0173] The head 912 may have a minor diameter at the wide base 928 in the range of 1.75 mm to 9.0 mm and a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 924). For example, Figures 31-33 The head 912 of the illustrated bone screw 910 has a minor diameter of approximately 4.5 mm at the wide base 428 and a major diameter of approximately 5.0 mm. Due to the frustoconical shape, the head 912 has a minor diameter that increases in the proximal to distal direction. The threads 924 have an inward taper 925 directed proximally such that the major diameter at the proximal end 918 is smaller than the major diameter near the neck 916. As an example, the inward taper 925 of the threads 924 is parallel to the taper of the curved side surface 922. As such, the threads 924 are angled at a 5.9° angle B relative to the longitudinal axis L10. 10 tapering, but angle B 10 It may be in the range of 5-15° without departing from the scope of the present disclosure.

[0174] The head 912 further includes an angled surface 934 (also "chamfer" or "bevel") and a driver groove 936. The angled surface 934 is formed between the top surface 932 and the side surface 922. The top surface 932 has a width dimension greater than zero, measured along the diameter of the head, ensuring that the angled surface 934 does not extend completely through the top of the screw 910. In the present embodiment, the top surface 932 has a width dimension of 0.65 mm, however the width dimension can be more or less depending on the overall size of the bone screw 910. As an example, the angled surface 934 can have a bevel angle φ in the range of 1-60° measured from the plane of the top surface 932. 10 , which is substantially perpendicular to the longitudinal axis L 10 As an example, Figures 31-33 The bevel angle Φ of the bone screw 910 is shown 10 When the head is implanted during use, the angled surface 934 is positioned generally parallel to 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 will extend beyond the outer surface of the bone when the bone screw 910 is implanted at an angle relative to the bone structure. The driver groove 936 is along the longitudinal axis L. 10 Formed into the top surface 932 and angled surface 934 and may have any shape suitable for receiving a driver (eg, flat head, Phillips type, hexagonal, torx, etc.).

[0175] The helical threads 924 may have a pitch 938 in the range of 0.5 mm to 2.5 mm. As an example, the helical threads 924 of this example have a pitch of 0.8 mm. The head 912 may also include a cutting groove 940 formed at the distal end of the helical threads 924 for removing bone material when the screw 910 is driven into the bone to facilitate the transition from the shank 914 to the head 912.

[0176] As an example, the shank 914 is cylindrical in shape and extends from a proximal end adjacent to the neck 916 to the distal end 920 of the bone screw 910. The shank 914 includes a curved side surface 942 and a helical thread 944 disposed about the distal portion of the curved side surface 942. The shank also includes a proximally positioned unthreaded portion 945 to facilitate compression. As an example, the unthreaded portion 945 may comprise approximately two-thirds of the length of the shaft, with the distal third being threaded. Other configurations are possible depending on the type and location of the fracture being treated. The shank 914 may have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 914 is smaller than the major diameter of the head 912. In the example shown and described herein, the shank 914 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 944 may have a pitch 946 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 944 of 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 also includes one or more cutting grooves 948 disposed at the distal end 920. When the screw 910 is driven into the bone, the cutting grooves 948 serve to clear bone material, thereby avoiding the need to drill a pilot hole during the surgical procedure.

[0177] The neck 916 includes a curved side surface 950 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 912 and the handle 914 .

[0178] Bone screw 910 also includes a central lumen extending axially through the entire 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.

[0179] Figures 34 to 36An example of a bone screw 1010 according to another embodiment of the present disclosure is shown. By way of example, the bone screw 1010 includes a head 1012, a handle 1014, and a neck 1016 positioned between the head 1012 and the handle 1014. The bone screw 1010 also includes a proximal end 1018 and a distal end 1020. The head 1012 is positioned at / near the proximal end 1018 of the bone screw 1010, and the handle 1014 is disposed along a longitudinal axis L. 11 The neck 1016 extends axially to the distal end 1020 of the bone screw 1010 (also referred to as the "vertical axis"). The head 1012 includes a curved side surface 1022 and a helical thread 1024 disposed about the curved side surface 1022. The head 1012 has a reverse frustoconical cross-sectional shape 1026 as described above with respect to the bone screw 10. The curved side surface 1022 tapers in the proximal direction from a wide base 1028 to a narrow base 1030. As an example, the curved side surface 1022 is tapered relative to the longitudinal axis L. 11 At an angle of 4.5° 11 tapered (resulting in a cone defining the head shape having an included angle of 9°), whereas angle A 11 It may be in the range of 4-15° (8-30° included angle) without departing from the scope of the present disclosure.

[0180] The head 1012 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 1028. The head 1012 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 1024). As an example, Figures 34-36 The head 1012 of the illustrated bone screw 1010 has a minor diameter of approximately 3.4 mm and a major diameter of approximately 4.0 mm at a wide base 1028. Due to the frustoconical shape, the head 1012 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0181] The head 1012 further includes an angled surface 1034 (also "chamfer" or "bevel") and a driver groove 1036. The angled surface 1034 is formed between the top surface 1032 and the side surface 1022. The top surface 1032 has a width dimension greater than zero, measured along the diameter of the head, ensuring that the angled surface 1034 does not extend completely through the top of the screw 1010. In the present embodiment, the top surface 1032 has a width dimension of 0.45 mm, however the width dimension can be more or less depending on the overall size of the bone screw 1010. As an example, the angled surface 1034 can have a bevel angle φ in the range of 1-60° measured from the plane of the top surface 1032. 11 , which is substantially perpendicular to the longitudinal axis L 11As an example, Figures 34-36 The bevel angle Φ of the bone screw 1010 is shown 11 When the head is implanted during use, the angled surface 1034 is positioned generally parallel to 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 will extend beyond the outer surface of the bone when the bone screw 1010 is implanted at an angle relative to the bone structure. The driver groove 1036 is along the longitudinal axis L. 11 Formed into the top surface 1032 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, torx, etc.).

[0182] By way of example, the helical threads 1024 of this embodiment have a pitch of 1.2 mm. By way of example, the shank 1014 is cylindrical and extends from a proximal end adjacent to the neck 1016 to the distal end 1020 of the bone screw 1010. The shank 1014 includes a curved side surface 1042 and a helical thread 1044 disposed about the curved side surface 1042. The shank 1014 can have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 1014 is smaller than the major diameter of the head 1012. In the example shown and described herein, the shank 1014 has a minor diameter of approximately 1.5 mm and a major diameter of approximately 2.5 mm. The helical thread 1044 can have a pitch 1046 ranging from 0.5 mm to 2.5 mm. As an example, the helical thread 1044 of 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 the shank 1014 have the same pitch, the bone screw 1010 is compression neutral. The shank 1014 also includes one or more cutting grooves 1048 disposed at the distal end 1020. When the screw 1010 is driven into the bone, the cutting grooves 1048 serve to clear bone material, thereby avoiding the need to drill a pilot hole during the surgical procedure.

[0183] The neck 1016 includes a curved side surface 1050 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 1012 and the handle 1014 .

[0184] Bone screw 1010 also includes a central lumen extending axially through the entire screw 1010, similar 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.

[0185] Figures 37 to 39An example of a bone screw 1110 according to another embodiment of the present disclosure is shown. For example, the bone screw 1110 includes a head 1112, a handle 1114, and a neck 1116 positioned between the head 1112 and the handle 1114. The bone screw 1110 also includes a proximal end 1118 and a distal end 1120. The head 1112 is positioned at / near the proximal end 1118 of the bone screw 1110, and the handle 1114 is disposed along a longitudinal axis L. 12 The bone screw 1110 is axially extended from the neck 1116 to the distal end 1120 of the bone screw 1110 (also the "vertical axis"). The head 1112 includes a curved side surface 1122 and a helical thread 1124 disposed about the curved side surface 1122. The head 1112 has a reverse frustoconical cross-sectional shape 1126 as described above with respect to the bone screw 10. The curved side surface 1122 tapers in the proximal direction from a wide base 1128 to a narrow base 1130. As an example, the curved side surface 1122 is axially extended relative to the longitudinal axis L. 12 At an angle of 4.4° 12 tapered (resulting in a cone defining the shape of the head having an included angle of 8.8°), however angle A12 may be in the range of 4-15° (including angles of 8-30°) without departing from the scope of the present disclosure.

[0186] The head 1112 may have a minor diameter in the range of 1.75 mm to 9.0 mm at the wide base 1128. The head 1112 may have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 1124). For example, Figures 37-39 The head 1112 of the bone screw 1110 shown in FIG has a minor diameter of approximately 3.3 mm at a wide base 1128 and a major diameter of approximately 4.0 mm. Due to the frustoconical shape, the head 1112 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the thread surface area in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0187] The head 1112 further includes an angled surface 1134 (also a "chamfer" or "bevel") and a driver groove 1136. The angled surface 1134 is formed between the top surface 1132 and the side surface 1122. The top surface 1132 has a width dimension greater than zero, measured along the diameter of the head, ensuring that the angled surface 1134 does not extend completely through the top of the screw 1110. In the present embodiment, the top surface 1132 has a width dimension of 0.42 mm, however the width dimension can be more or less depending on the overall size of the bone screw 1110. As an example, the angled surface 1134 can have a bevel angle Φ in the range of 1-60° measured from the plane of the top surface 1132. 12 , which is substantially perpendicular to the longitudinal axis L 12As an example, Figures 37-39 The bevel angle Φ of the bone screw 1110 is shown 12 50°. When the head is implanted during use, the angled surface 1134 is positioned approximately parallel to 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 will extend beyond the outer surface of the bone when the bone screw 1110 is implanted at an angle relative to the bone structure. A driver groove 1136 is formed in the top surface 1132 along the longitudinal axis L and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, plum blossom, etc.). As an example, the helical thread 1124 of this example has a pitch of 1.0 mm.

[0188] As an example, the handle 1114 is cylindrical in shape and extends from a proximal end adjacent to the neck 1116 to the distal end 1120 of the bone screw 1110. The handle 1114 includes a curved side surface 1142 and a helical thread 1144 disposed about a distal portion of the curved side surface 1142. The handle also includes a proximally positioned unthreaded portion 1145 to enable compression. As an example, the unthreaded portion 1145 may include approximately two-thirds of the length of the shaft, with the distal third being threaded. Other configurations are possible depending on the type and location of the fracture being treated. The handle 1114 may have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the handle 1114 is smaller than the major diameter of the head 1112. In the example shown and described herein, the handle 1114 has a minor diameter of approximately 1.5 mm and a major diameter of approximately 2.5 mm. The helical thread 1144 can have a pitch 1146 in the range of 0.5 mm to 2.5 mm. As an example, the helical thread 1144 of the present 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 also includes one or more cutting grooves 1148 disposed at the distal end 1120. The cutting grooves 1148 are used to clear bone material as the screw 1110 is driven into the bone, which avoids the need to drill a pilot hole during the surgical procedure.

[0189] The neck 1116 includes a curved side surface 1150 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 1112 and the handle 1114 .

[0190] Bone screw 1110 also includes a central lumen extending axially through the entire screw 1110, similar to the central lumen shown and described above with respect to bone screw 1110. The central lumen is sized and configured to receive a guide wire (e.g., a K-wire) therethrough to guide bone screw 1110 to the correct implantation location.

[0191] The bone screw 10 and the various alternative examples described herein may be used in any number of orthopedic surgical procedures in which at least two bone segments need to be stabilized, such as in the case of a bone fracture. Figure 40 An example of a bone screw 10 used to stabilize first and second bone segments 60, 62 relative to each other, such as during a bunion repair procedure, is shown. In this embodiment, the bone screw 10 is inserted so that the proximal end 18 of the bone screw 10 engages the first bone segment 60 and the distal end 20 of the bone screw 10 engages the second bone segment 62. The bone screw 10 is positioned so that the head 12 and a portion of the shank 14 engage the cortical bone 64 while penetrating the cancellous bone 66 of one bone segment 60. The bone screw 10 is further positioned so that the angled surface 34 aligns with the edge of the bone, thereby reducing or eliminating the portion of the screw that would otherwise protrude from the bone. If a non-compression screw is used, the bone screw 10 maintains the relative positioning of the bone segments without applying a compressive force.

[0192] The bone screw 10 may be provided in any number of size and length configurations to enable the bone screw 10 to be used to address a variety of indications. Figures 41-44 Some exemplary uses of the bone screw 10 described herein for stabilizing fractures in several different bone locations are shown. For example, Figure 41 A bone screw 10 is shown being inserted into a phalanx 70 in the foot to repair a fracture 72 or osteotomy. Figure 42 A partially threaded bone screw 910 is shown for stabilizing the V-shaped cutout 73 during a distal metatarsal spica osteotomy procedure, such as for correcting a bunion deformity. Figure 43 A pair of bone screws 10 are shown inserted into a humerus 74 to repair a fracture 76 . Figure 44 A plurality of bone screws 10 are shown for repairing several fractures in the wrist region. For example, one bone screw 10 (e.g., a small bone screw 10) is inserted into the scaphoid 78 to repair fracture 80. A pair of bone screws 10 is inserted into the radius 82 to repair fracture 84.

[0193] Figure 45 It is about Figure 1-6Detailed description of the head 12 of the bone screw 10 illustrates an enlarged view of the head 12 of the bone screw 10, particularly illustrating various angles and surface dimensions of the head 12. Although illustrated and described with respect to the head 12 of the bone screw 10, the subsequent discussion may apply to any of the above examples without departing from the scope of the present disclosure. As previously described, the head 12 is positioned at / near the proximal end 18 of the bone screw 10, and the shank 14 extends axially from the neck 16 to the distal end 20 of the bone screw 10 along the longitudinal axis L (also referred to as the "vertical axis"). The head 12 includes a curved side surface 22 and a helical thread 24 disposed about the curved side surface 22. The head 12 has a generally frustoconical cross-sectional shape, with a wide base 28 of the truncated head forming the distal-most boundary or base of the head 12 and a narrow base 30 of the truncated head forming the proximal-most end or top surface 32 of the bone screw 10. The curved side surface 22 tapers in the proximal direction from the wide base 28 to the narrow base 30. As an example, the curved side surface 22 tapers at an angle A of 5.9° relative to the longitudinal axis L (or an axis parallel to the longitudinal axis), resulting in a cone defining a head shape having an included angle Φ1 of 11.8°. Angle A may be in the range of 5-15° (and thus included angle Φ1 may be in the range of 10-30°) without departing from the scope of the present disclosure.

[0194] In this embodiment, the head 12 is angled because it also includes an angled surface 34 (also called a "chamfer" or "bevel") that serves to reduce / eliminate the amount of screw material that may extend beyond the edge of the bone structure when the bone screw 10 is implanted at an angle relative to the bone structure. The angled surface 34 is formed between the top surface 32 and the side surface 22. Due to the angled surface 34, the head 12 has a primary height dimension h1 defined as the perpendicular distance between the base of the head (e.g., the wide base 28 of the frustum) and the top surface 32 (e.g., the narrow 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 the angled surface 34 and the side surface 22.

[0195] The top surface 32 has a width dimension w, which is defined by the maximum distance between the proximal edge of the side surface 22 and the proximal edge 33 of the angled surface 34. In most example embodiments, the width dimension w is greater than zero (e.g., w>0), ensuring that the angled surface 34 does not extend completely across the top of the screw 10. In some instances, the width dimension w can be equal to zero (e.g., w=0), in which case the proximal edge 33 of the angled surface 34 intersects the proximal edge of the side surface 22. In the present embodiment, the top surface 32 has a width dimension of 0.65 mm, however, the width dimension can be more or less depending on the overall size of the bone screw 10 and the bevel angle Φ. As an example, the bevel surface 34 can have a bevel angle Φ, where 0°<Φ<85° measured from a plane of the top surface 32 that is generally perpendicular to the longitudinal axis L. As an example, Figure 38 The bevel angle Φ of the bone screw 10 shown in FIG. 5 is 50°.

[0196] Figures 46-51 Several examples of possible configurations of the head 12 are shown, which are produced by varying the positions of the proximal-most edge 33 of the angled surface 34 and the distal-most intersection 35 between the angled surface 34 and the side surface 22, and how their relative positions vary the bevel angle Φ and the width dimension w of the top surface 32. For example, Figure 40 An example of a head 12 is depicted where w > 0 and h2 > 0. In this example, the bevel angle Φ is approximately 50°. Figure 41 An example of a head 12 is depicted where w>0 and h2 = 0. In this example, the bevel angle Φ is approximately 65.5°. Figure 42 An example of a head 12 is depicted where w = 0 and h2 = 0. In this example, the bevel angle Φ is approximately 61.2°. Figure 43 An example of a head 12 is depicted where w>0 and h2 = 0. In this example, the bevel angle Φ is approximately 79.5°. Figure 44 Another example of a head 12 is depicted, where w > 0 and h2 > 0. In this example, the bevel angle Φ is approximately 74.5°. Figure 45 An example of a head 12 is depicted where w=0 and h2>0. In this example, the bevel angle Φ is approximately 30°. In this manner, the bone screws of the present disclosure can be provided with chamfers of various angles, depending on the surgeon's needs for the particular procedure being performed (e.g., insertion angle, etc.).

[0197] Figures 52-59An example of a bone screw 1210 according to another embodiment of the present disclosure is shown. By way of example, bone screw 1210 includes a head 1212, a stem 1214, and a neck 1216 positioned between the head 1212 and the stem 1214. Bone screw 1210 also includes a proximal end 1218 and a distal end 1220. The head 1212 is positioned at / near the proximal end 1218 of the bone screw 1210, and the stem 1214 extends axially from the neck 1216 to the distal end 1220 of the bone screw 1210 along a longitudinal axis L13 (also referred to as a "vertical axis"). The head 1212 includes a curved side surface 1222 and a helical thread 1224 disposed about the curved side surface 1222. The head 1212 has a reverse frustoconical cross-sectional shape similar to the bone screw 10 described above. The curved side surface 1222 tapers in the proximal direction from a wide base 1228 to a narrow base 1230. As an example, the curved side surface 1222 is disposed relative to the longitudinal axis L 13 At an angle of 1° 13 tapered (resulting in a cone defining the head shape having an included angle of 2°), whereas angle A 13 It may be greater than 1° without departing from the scope of the present disclosure.

[0198] The head 1212 can have a minor diameter at the wide base 1228 in the range of 1.75 mm to 9.0 mm. The head 1212 can have a major diameter in the range of 2.0 mm to 10.0 mm. The first minor diameter is smaller than the major diameter (of the helical threads 1224). Due to the frustoconical shape, the head 1212 has a minor diameter that increases from proximal to distal. The major diameter remains constant, and as a result, the surface area of ​​the thread in contact with the bone increases from distal to proximal, enhancing the screw's grip on the bone.

[0199] The head 1212 further includes an angled surface 1234 (also "chamfer" or "bevel") and a driver groove 1236. The angled surface 1234 is formed between the top surface 1232 and the side surface 1222. The top surface 1232 has a width dimension greater than zero measured along the diameter of the head, ensuring that the angled surface 1234 does not extend completely through the top of the screw 1210. By way of example, the angled surface 1234 can have a bevel angle φ in the range of 1-60° measured from the plane of the top surface 1232. 13 , which is substantially perpendicular to the longitudinal axis L 13 By way of example, Figures 52-54 The bevel angle Φ of the bone screw 1210 shown in FIG. 13When the head is implanted during use, the angled surface 1234 is positioned generally parallel to 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 will extend beyond the outer surface of the bone when the bone screw 1210 is implanted at an angle relative to the bone structure. The driver groove 1236 is along the longitudinal axis L. 13 is formed into the top surface 1232 and the angled surface 1234 and can have any shape suitable for receiving a driver (e.g., flat head, Phillips type, hexagonal, plum blossom, etc.). In some embodiments (e.g., as Figures 52 to 56 As shown), the top surface 1234 can be an inclined surface having an inclined direction generally transverse to the direction of the angled surface 1234. As an example, the top surface 1232 can have an inclined angle φ in the range of 1-30°. 14 As an example, Figures 52 to 54 The bevel angle Φ of the top surface 1232 of the bone screw 1210 shown in FIG. 14 It is 9°.

[0200] The helical thread 1224 may have a pitch 1238 in the range of 0.5 mm to 2.5 mm. As an example, the helical thread 1224 of the present example has a pitch of 1.5 mm. The head 1212 may also include a cutting groove 1240 formed at the distal end of the helical thread 1224 for removing bone material when the screw 1210 is driven into the bone to facilitate the transition from the shank 1214 to the head 1212. As an example, the cutting groove 1240 may be oriented relative to the longitudinal axis L. 13 In some embodiments, the angle may be from 1° to 30°. Figures 52-54 The angle of the cut groove 1240 is shown to be 8°.

[0201] In some embodiments, the head 1212 can also include a smooth and / or rounded surface 1260 at the intersection of the helical threads 1224 with the angled surface 1234 and / or the top surface 1232. As an example, the smooth and / or rounded edge 1260 can reduce the possibility of nerve damage or other trauma to surrounding tissue by eliminating sharp and / or rough surfaces.

[0202] As an example, the shank 1214 is cylindrical in shape and extends from a proximal end adjacent to the neck 1216 to the distal end 1220 of the bone screw 1210. The shank 1214 includes a curved side surface 1242 and a helical thread 1244 disposed about the curved side surface 1242. The shank 1214 may have a minor diameter ranging from 1.0 mm to 7.5 mm and a major diameter ranging from 1.5 mm to 8 mm. Preferably, the major diameter of the shank 1214 is smaller than the major diameter of the head 1212. In the example shown and described herein, the shank 1214 has a minor diameter of 3 mm and a major diameter of approximately 4 mm. The helical thread 1244 may have a pitch 1246 ranging from 0.5 mm to 5.0 mm. As an example, the helical thread 1244 of 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 compression neutral. The handle 1214 also includes one or more cutting slots 1248 disposed at the distal end 1220. The cutting slots 1248 serve to clear bone material as the screw 1210 is driven into bone, which avoids the need to drill a pilot hole during surgery.

[0203] refer to Figure 56In some embodiments, the handle 1214 can include multiple gripping regions, which can have varying thread pitches to ensure gripping of the screw, for example, in different bone types. In some embodiments, the bone screw 1210 can have three gripping regions, namely a head region 1270, a mid-shaft region 1272, and a distal region 1274. By way of example, the head region 1270 and the distal region 1274 can be "cancellous pitch regions," having a thread pitch configured for gripping in cancellous bone, while the mid-shaft region 1272 can be a "cortical pitch region," having a thread pitch configured for gripping in cortical bone. In some embodiments, the head region 1270 and the distal region 1274 can be cortical pitch regions, while the mid-shaft region 1272 can be cancellous pitch regions. By way of example only, the helical threads 1244 of the head region 1270 and the distal region 1274 can have a thread pitch 1246 ranging from 0.5 mm to 5.0 mm. By way of example, the helical threads 1244 of this example have a pitch of 1.5 mm. To maintain pitch neutrality, such that the bone screw 1210 is "compression neutral," in that the helical threads in the different grip zones do not cause compression or distraction, the pitch ratio between the cancellous and cortical pitch zones can be any ratio that remains neutral, such as 2:1, 1:4, 0.5:1, etc. By way of example only, the pitch of the mid-shaft region 1272 can be approximately half the pitch of the head region 1270 and the distal region 1274. By way of example, the helical threads 1244 in the mid-shaft region 1272 of this example can have a pitch 1276 of 0.75 mm. Furthermore, the term "compression neutral," as used herein, encompasses not only true compression neutrality, as described above, but also insignificant microcompression, such as pitch ratios that are technically compressive but do not materially affect the performance of the 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 (0.45-0.55):1, (1.85-2.15):1, (3.7-4.3):1, or any ratio within an equivalent range.

[0204] In some embodiments, the relative sizes of the gripping areas vary, for example, depending on the desired screw size / length and / or anatomical target area, etc. For example, Figure 57As shown, in some embodiments, the head region 1270 can include only the head 1212 of the bone screw 1210 (e.g., the portion of the bone screw between the proximal end 1218 and the neck 1216), and the handle 1214 can include two gripping regions, including a mid-shaft region 1272 (or "proximal region" 1272) and a distal region 1274, wherein the mid-shaft region 1272 extends distally from the neck 1216 to an interface with the distal region 1274. In some embodiments, the head region 1270 can have a length dimension ranging from 5 mm to 20 mm. In some embodiments, the mid-shaft region 1272 can have a length dimension ranging from 10 mm to 30 mm. In some embodiments, the distal region 1274 can have a length dimension between 10 mm and 30 mm. Optionally, in any embodiment, each of the head region 1270, the mid-shaft region 1272, and the distal region 1274 can comprise 10% to 60% of the length of the bone screw 1210.

[0205] In some embodiments, bone screw 1210 can have cortical pitch area 1281 at distal end 1220, and more specifically have cortical pitch area 1281 at distal tip 1221, for example, to advantageously provide the minimum grip in subchondral bone.In such embodiment, bone screw 1210 can have three or more gripping areas that alternate between cortical pitch area and cancellous pitch area.For example, the small cortical pitch area 1281 at the distal end of bone screw 1210 can have the cancellous pitch area (for example, distal area 1274) positioned immediately adjacent to the cancellous pitch area, followed by the second cortical pitch area (for example, intermediate shaft area 1272) and the second cancellous pitch area (for example, head area 1270) immediately adjacent to the second cortical pitch area proximal side, and the rest can be deduced by analogy.In certain embodiments, the second cancellous pitch area can include head 1212. In some embodiments, the bone screw 1210 may have four or more pitch regions that alternate between cortical pitch regions and cancellous pitch regions. In some embodiments, the cortical pitch region 1281 at the distal end 1220 may include only the distal tip 1221 of the bone screw 1210, such as only at the distal end 1220. Figure 58 In some embodiments, the cortical pitch region at the distal end 1220 can include the distal tip of the bone screw 1210 and a portion of the distal end 1220 of the handle 1214. In some embodiments, the cortical pitch region at the distal end 1220 may not extend to the distal tip of the bone screw 1210.

[0206] In some embodiments, the neck 1216 includes a curved side surface 1250 that tapers in a distal direction to provide a smooth transition between the reverse tapered head 1212 and the handle 1214 .

[0207] Bone screw 1210 may further include a central lumen extending axially through the entire 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.

[0208] In some embodiments, the bone screw 1210 (or any embodiment disclosed herein) can have microthreads 1280 disposed on any surface that may otherwise be unthreaded, such as but not limited to (and by way of example only) the neck 1216, the distal end 1220, and any spacing between the pitch regions.

[0209] In some embodiments, fixation can be achieved with a headless handle having a single uniform pitch or having multiple gripping areas with different pitches. In some embodiments, the headless handle can be compression neutral. In some embodiments, the headless handle can be configured to achieve compression and / or distraction.

[0210] Figures 60-65 An example of an insertion tool 1310 according to some embodiments is shown that is configured for use with any of the bone screws disclosed herein. By way of example only, the insertion tool 1310 includes a proximal end 1312, a distal end 1314, and an elongated shaft 1316 extending therebetween. The proximal end 1312 can include a shaped end configured to releasably engage a handle portion (not shown) to facilitate operation of the insertion tool 1310. By way of example only, the handle portion can be a T-shaped handle portion, a cylindrical grip handle portion, or any other commonly used removable handle portion.

[0211] By way of example only, the distal end 1314 includes a distal tip 1318 that is configured to engage with the engagement recess of any of the bone screw embodiments described herein, such as the engagement recess 1236 of the bone screw 1210. The distal tip 1318 can have any shape that complements the engagement recess 1236 of the particular bone screw in use, including, for example, but not limited to, a flat head, Phillips type, hexagonal, torx-shaped, etc., to enable the insertion tool 1310 to apply sufficient torque to the bone screw to drive the bone screw into the bone.

[0212] By way of example only, the elongated shaft 1316 can have a generally cylindrical body and flat sides or a planar cut-out portion 1320 extending along a substantial portion of the length of the shaft 1316. For example, the insertion tool 1310 can be coupled to a bone screw described herein (e.g., bone screw 1210) such that the planar cut-out portion 1320 is aligned with the direction of an angled surface of the bone screw (e.g., angled surface 1234 of bone screw 1210). In this manner, the planar cut-out portion 1320 provides a visual indication of the orientation and / or directionality of the bone screw 1310 to the user during use. Furthermore, the planar cut-out portion 1320 ensures that the insertion tool 1310 is properly oriented relative to the bone screw 1210 prior to engagement (e.g., as shown only in FIG. 1 ). Figure 65 (shown by way of example in FIG. 1 ). Unlike laser marking or other methods currently used in the art, the planar cutout 1320 cannot be washed off or worn away to remove or obstruct the visual indication of screw directionality. This represents a significant advantage over existing systems.

[0213] 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 or element shown and described with respect to other examples without limitation.

Claims

1. A screw for performing orthopedic surgery 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 including a proximal end of the screw; a handle having a distal end comprising a distal end of the screw; and a neck extending between the head and the handle, wherein the head, the neck, and the handle are collinear along a longitudinal axis extending between the proximal end of the head and the distal end of the handle; The header includes: a proximal base at a proximal end of the head, the proximal base comprising an upper surface of the head transverse to the longitudinal axis, a distal base at a distal end of the head, and a curved side surface extending between the proximal base and the distal base; at least one helical thread extending from a proximal base of the head to a distal base of the head and having a diameter defining a major diameter of the head, the helical thread being configured to contact bone forming part of the anatomical target site when the head is implanted during use, thereby enhancing grip of the head into the bone, the at least one helical thread having at least one pitch; a drive feature sized to cooperate with the instrument so that the head, handle, and neck can be rotated about the longitudinal axis to drive the handle, neck, and head into an anatomical target of a patient; and the handle comprising: a curved side surface having at least one helical thread extending from a proximal end of the shank toward a distal end of the shank, the at least one helical thread including at least two gripping regions, the at least two gripping regions including a first gripping region and a second gripping region, the first gripping region including a cancellous pitch region having a first pitch configured for gripping in cancellous bone, the second gripping region including a cortical pitch region having a second pitch configured for gripping in cortical bone, the cancellous pitch region extending proximally from the distal end of the screw, and the cortical pitch region extending proximally from an interface with the cancellous pitch region; Wherein the first pitch and the second pitch are compression neutral. 2 . The screw for orthopedic surgery according to claim 1 , wherein the pitch of the at least one helical thread of the first gripping area is in the range of 0.5 mm to 5 mm. 3 . The screw for orthopedic surgery according to claim 2 , wherein the pitch of the at least one helical thread of the second gripping region is half the pitch of the at least one helical thread of the first gripping region.

4. The screw for orthopedic surgery according to claim 2, wherein the pitch of the at least one helical thread of the first gripping area is 1.5 mm. 5 . The screw for orthopedic surgery according to claim 4 , wherein the pitch of the at least one helical thread of the second gripping area is 0.75 mm.

6. The screw for use in orthopedic surgery of claim 1, wherein the second gripping region extends between an interface with the first gripping region and the neck.

7. The screw for orthopedic surgery according to claim 1, wherein the first gripping area and the second gripping area each have a length dimension in the range of 10 mm to 30 mm.

8. The screw for orthopedic surgery according to claim 1, wherein the first gripping area and the second gripping area may each comprise 10% to 60% of the total length of the screw.

9. The screw for orthopedic surgery of claim 1 , wherein the helical thread of the shank further comprises a third gripping region extending distally between the neck and an interface with the second gripping region, the third gripping region being configured for gripping in cancellous bone.

10. The screw for orthopedic surgery according to claim 9, wherein the third gripping area and the first gripping area have the same thread pitch.

11. The screw for orthopedic surgery according to claim 1, wherein in the first gripping region, the pitch of the helical thread of the head is the same as the pitch of the helical thread of the shank.

12. The screw for orthopedic surgery according to 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. A screw for orthopedic surgery according to claim 1, wherein the head includes an inclined surface extending from a proximal base of the head along the curved side surface to a predetermined position, wherein the inclined surface is angled relative to the upper surface of the head to define an oblique angle, the size of the oblique angle being such that when the head is implanted during use, the inclined surface can be positioned along and flush with the outer surface of a bone forming part of the anatomical target site, thereby reducing or eliminating the extent to which the head will extend beyond the outer surface of the bone when the head is implanted at an angle relative to the bone.

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

15. A screw for orthopedic surgery according to claim 13, wherein the inclined surface includes a first inclined surface, and the head further includes a second inclined surface, the second inclined surface extending from the proximal base of the head along the curved side surface of the head to a predetermined position, wherein the second inclined surface is angled relative to the upper surface of the head perpendicular to the longitudinal axis and the first inclined surface to define a second oblique angle. 16 . The screw for orthopedic surgery according to claim 15 , wherein the second bevel angle of the head is in a range between 1 degree and 30 degrees.

17. The screw for orthopedic surgery of claim 1, wherein the at least one helical thread of the head further comprises a thread surface area, and the major diameter of the thread surface area increases from the distal base to the proximal base to increase the thread surface area in the distal to proximal direction.

18. A screw for orthopedic surgery according to claim 1, wherein the head comprises a reverse frustoconical cross-sectional shape defined by a minor diameter that increases from the distal base to the proximal base, and wherein the curved side surfaces extending between the distal base and the proximal base are tapered relative to the longitudinal axis to define a reverse taper angle.

19. The screw for use in orthopedic surgery of claim 1, wherein the neck includes microthreads disposed thereon.

20. The screw for orthopedic surgery of claim 1, wherein the shank further comprises microthreads at an interface between the first gripping region and the second gripping region.

21. The screw for use in orthopedic surgery of claim 1, wherein the head further comprises at least one rounded surface at the intersection between the helical threads and the upper surface.

22. The screw for orthopedic surgery of claim 13, wherein the head further comprises at least one rounded surface at the intersection between the helical thread and the angled surface.

23. The screw for use in orthopedic surgery of claim 1, wherein the helical threads of the shank further comprise a cortical pitch region at the distal end.

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