Bone fixation plate

Abstract

To provide an improved bone fixation plate.SOLUTION: A bone fixation plate is provided that includes a body extending between a proximal end and a distal end. The body includes an upper surface and a lower surface disposed opposite the upper surface. The body includes a slotted aperture extending between the upper and lower surfaces, thereby forming a fastener passage therethrough. The slot tail aperture includes a length extending along a lengthwise axis and a width extending along a widthwise axis. The longitudinal axis extends between a first longitudinal end of the slotted aperture and a second longitudinal end of the slotted aperture. The second lengthwise end is opposite the first lengthwise end. The slot aperture includes a threaded first portion disposed at the first longitudinal end and an unthreaded second portion disposed at the second longitudinal end.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to bone fixation plates, and more particularly to bone fixation plates configured for fixation of the tibia of animals, including dogs. [Background technology]

[0002] Bone fixation plates can be used in tibial osteotomies and other procedures to fix two bone segments together. For example, in a tibial plateau leveling osteotomy (commonly referred to as a "TPLO") procedure, a curvilinear cut is made in the proximal tibia of a dog to separate the metaphysis from the proximal tibia. The metaphysis is then rotated to level the tibial plateau. Finally, the metaphysis is fixed to the proximal tibia with a fixation plate.

[0003] It is generally desirable for practitioners of tibial osteotomies to perform curved cuts as high proximally and as close to the joint between the tibia and the metaphysis as possible. However, conventional bone fixation plates are unable to create such high proximal curved cuts. These high proximal curved cuts are at least partially hindered by the large head size of conventional bone fixation plates. Furthermore, the large head size and hole location limit the ability to manipulate the plate over the bone.

[0004] Additionally, the geometry of conventional bone fixation plates is straight from the head of the plate to the tail of the plate. This limits the fixation of the caudal portion of the proximal tibia after rotation and maximizing central coverage of the midshaft tibia. Furthermore, conventional bone fixation plates do not allow for the implementation of a skin retractor. As a result, longer incisions are required when utilizing conventional bone fixation plates.

[0005] Finally, conventional bone fixation plates have screw holes that are limited or restrictive with respect to how screws inserted therein can be oriented. In other words, conventional bone fixation plates do not allow for multiaxial placement of screws. Summary of the Invention [Problem to be solved by the invention]

[0006] The present invention provides an improved bone fixation plate that allows for a high proximal cut in the tibia while promoting caudal fixation of the plate on the proximal tibia and allowing a location for a skin retractor to engage the plate. [Means for solving the problem]

[0007] According to one aspect of the present disclosure, a bone fixation plate is provided, including a body extending between a proximal end and a distal end. The body includes an upper surface and a lower surface disposed opposite the upper surface. The body includes a slotted aperture extending between the upper and lower surfaces, thereby forming a fastener passage therethrough. The slotted aperture includes a length extending along a longitudinal axis and a width extending along a widthwise axis. The longitudinal axis extends between a first longitudinal end of the slotted aperture and a second longitudinal end of the slotted aperture. The second longitudinal end is opposite the first longitudinal end. The slotted aperture includes a threaded first portion disposed at the first longitudinal end and an unthreaded second portion disposed at the second longitudinal end.

[0008] In any of the aspects or embodiments described above and herein, the length of the slotted aperture may be greater than the width of the slotted aperture.

[0009] In any of the aspects or embodiments described above and herein, the slot aperture may have an open configuration between the first longitudinal end and the second longitudinal end.

[0010] In any of the aspects or embodiments described above and herein, the threaded first portion may have a central axis and may have a conical configuration.

[0011] In any of the aspects or embodiments described above and herein, the threaded first portion may have a central axis and a polyaxial configuration including a plurality of threaded sections having relief pockets disposed between adjacent threaded sections.

[0012] In any of the aspects or embodiments described above and herein, the threaded section may have a conical configuration.

[0013] In any of the aspects or embodiments described above and herein, the threaded first part (TFP) may have a TFP central axis, and the polyaxial configuration may be configured to allow a threaded fastener having a fastener central axis to be disposed on the threaded first part, with the fastener central axis parallel to the TFP central axis and with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections.

[0014] In any of the aspects or embodiments described above and herein, the threaded first part (TFP) may have a TFP central axis, and the polyaxial configuration may be configured to allow a threaded fastener having a fastener central axis to be disposed on the threaded first part with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections, with the fastener central axis at an oblique angle.

[0015] In any of the aspects or embodiments described above and herein, the tilted angle can be up to and including 15 degrees.

[0016] In any of the aspects or embodiments described above and herein, the body may include a head section, a tail section, and a curved section. The head section may include a head section centerline. The head section may be disposed at the proximal end, the tail section may be disposed at the distal end, and the curved section may be disposed between and contiguous with the tail section and the head section. The head section may be oriented toward a caudal side of the body, and the head section centerline may be disposed at a head section angle, which may be greater than zero.

[0017] In any of the aspects or embodiments described above and herein, the tail section may have a tail section centerline that extends along an arcuate path.

[0018] In any of the aspects or embodiments described above and herein, within the tail section, the body may include a caudal side extending between the upper and lower sides and a cranial side extending between the upper and lower sides. The caudal side may be disposed medially of the arcuate path, and the cranial side may be disposed lateral to the arcuate path.

[0019] In any of the aspects or embodiments described above and herein, the tail section may include a first tail aperture and a second tail aperture, each extending between the upper surface and the lower surface. The first tail aperture and the second tail aperture may each have an aperture center axis and a multiaxial configuration including multiple threaded sections with relief pockets disposed between adjacent threaded sections. The first tail aperture may be disposed proximal to the distal end of the body, and the second tail aperture may be disposed between the first tail aperture and the slot aperture.

[0020] In any of the aspects or embodiments described above and herein, the multi-axial configuration of the first and second tail apertures can be configured to allow a respective threaded fastener having a fastener central axis to be disposed in the respective first or second tail aperture at an oblique angle with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections, The oblique angle can be up to and including 15 degrees.

[0021] In any of the aspects or embodiments described above and herein, the curved section may curve caudally away from the tail section causing the head section to project caudally from the tail section.

[0022] In any of the aspects or embodiments described above and herein, the head section may include a head aperture having a head aperture central axis. The head aperture may have a multi-axial configuration including multiple threaded sections with relief pockets disposed between adjacent threaded sections. The multi-axial configuration may allow a threaded fastener having a fastener central axis to be disposed within the head aperture, with the fastener central axis at an oblique angle relative to the head aperture central axis, and may have threaded engagement between the threaded fastener and at least one of the multiple threaded sections. The oblique angle may be up to and including 15 degrees.

[0023] According to one aspect of the present disclosure, a bone fixation plate is provided, including a head section and a tail section. The head section is disposed at a proximal end of the fixation plate. The head section has a first upper surface, a first lower surface opposite the first upper surface, and at least one head aperture extending between the first upper surface and the first lower surface. The head section has a head section centerline bisecting the head section. The tail section is disposed at a distal end of the fixation plate. The tail section includes a second upper surface, a second lower surface, at least one tail aperture, a slot aperture, and a curved section. The second lower surface is opposite the second upper surface. The at least one tail aperture extends between the second upper surface and the second lower surface. The slot aperture extends between the second upper surface and the second lower surface, thereby forming a fastener passage through the head section. The slot aperture has a length extending along a longitudinal axis and a width extending along a width axis. The longitudinal axis extends between a first longitudinal end of the slotted aperture and a second longitudinal end of the slotted aperture. The second longitudinal end is opposite the first longitudinal end. The slotted aperture includes a threaded first portion disposed at the first longitudinal end and an unthreaded second portion disposed at the second longitudinal end. The curved section is disposed between and continuous with the tail section and the head section. The head section is oriented toward the caudal side of the fixation plate. The head section centerline is disposed at a head section angle, the head section angle being greater than zero.

[0024] The foregoing features and elements may be combined in various non-exclusive combinations unless otherwise expressly indicated otherwise. These features and elements, and their operation, will become more apparent in light of the following description and accompanying drawings. It should be understood, however, that the following description and drawings are illustrative and non-limiting in nature. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 is a perspective top view of an embodiment of a fixation plate of the present disclosure. [Figure 2] FIG. 1 is a plan top view of an embodiment of a fixation plate of the present disclosure. [Figure 3] FIG. 3 is a plan top view of the embodiment of the fixation plate of the present disclosure shown in FIG. 2, including the cross-sectional cut lines in this view. [Figure 3A] 4 is a cross-sectional view of the fixation plate shown in FIG. 3 taken along section line AA. [Figure 3B] 4 is a cross-sectional view of the fixation plate shown in FIG. 3 taken along section line BB. [Figure 3C] 4 is a cross-sectional view of the fixation plate shown in FIG. 3 taken along section line CC. [Figure 4] FIG. 4 is an enlarged partial view of the fixation plate shown in FIG. 3, including a slotted tail aperture. [Figure 5] FIG. 1 is a perspective underside view of an embodiment of a fixation plate of the present disclosure. [Figure 6] FIG. 1 is a plan underside view of an embodiment of a fixation plate of the present disclosure. [Figure 7] FIG. 1 is a plan side view of an embodiment of a fixation plate of the present disclosure. [Figure 8] FIG. 1 is a plan proximal end view of an embodiment of a fixation plate of the present disclosure. [Figure 9] FIG. 1 is a plan top view of an embodiment of a fixation plate of the present disclosure. [Figure 10] FIG. 10 is a partial cross-sectional view taken along section line 10-10 shown in FIG. 9. [Figure 11] FIG. 10 is an enlarged partial view of the fixation plate shown in FIG. 9, including a slotted tail aperture. [Figure 12] FIG. 1 is a plan top view of an embodiment of a fracture plate of the present disclosure. [Figure 13] FIG. 13 is a plan side view of the embodiment of the fracture plate shown in FIG. 12. DETAILED DESCRIPTION OF THE INVENTION

[0026] First, it should be noted that in the embodiments described herein, the standard anatomical terms used correspond to the standard anatomical positions of dogs or animals with hindlimb anatomical structures corresponding to those of dogs. The application of the embodiments of the present invention described herein is not limited to dogs or animals with hindlimb anatomical structures corresponding to those of dogs. However, it is envisioned that the present invention may be applied to humans or animals with lower limb anatomical structures corresponding to those of humans, although the standard anatomical positions of humans are different from the standard anatomical positions of dogs. Therefore, the standard anatomical terms used to describe the application of the present invention to dogs or animals with hindlimb anatomical structures corresponding to those of dogs do not correspond to the standard anatomical terms required to describe the application of the present invention to humans or animals with lower limb anatomical structures corresponding to those of humans.

[0027] 1-8, a tibial fixation plate 20 ("fixation plate 20") is illustrated including a proximal end 22, a distal end 24, a caudal side 26, a cranial side 28, a superior surface 30, and an inferior surface 32 (see, e.g., FIG. 3B). In use, the inferior surface 32 generally faces the tibia. The superior surface 30 is opposite the inferior surface 32. The fixation plate 20 may be described as having three longitudinally disposed distinct sections: a head section 34, a curved section 36, and a tail section 38. For ease of description herein, the fixation plate 20 may be described in terms of a body including the aforementioned three distinct sections (i.e., the head section 34, the curved section 36, and the tail section 38) disposed between the proximal end 22 and the distal end 24 and having the caudal side 26, the cranial side 28, the superior surface 30, and the inferior surface 32. The head section 34 extends from the proximal end 22 of the fixation plate 20 toward the distal end 24 of the fixation plate 20. The tail section 38 extends from the distal end 24 of the fixation plate 20 toward the proximal end 22 of the fixation plate 20. The curved section 36 is disposed between and continuous with both the head section 34 and the tail section 38. A tail section-curved section boundary line 40 and a head section-curved section boundary line 42 are shown in FIG. 2 to illustrate each fixation plate 20 section.

[0028] The tail section 38 of the fixation plate 20 is defined by an upper surface 30, a lower surface 32 (see, e.g., FIG. 3B ), a caudal edge surface 44, and a cranial edge surface 46. In a portion of the tail section 38, the caudal edge surface 44 and the cranial edge surface 46 may be disposed equidistant from one another. In some embodiments, the caudal edge surface 44 and the cranial edge surface 46 may converge toward one another at the distal end 24 of the fixation plate 20. In some embodiments, the tail section 38 may include a distal end surface extending between the caudal edge surface 44 and the cranial edge surface 46 at the distal end 24 of the fixation plate 20. The embodiment of the fixation plate 20 shown in FIGS. 1-3 illustrates an example of a fixation plate 20 in which the caudal edge surface 44 and the cranial edge surface 46 converge toward one another proximate the distal end 24. The present disclosure is not limited to this configuration of the tail section 38.

[0029] Some of the figures are shown with orthogonal axes X, Y, and Z to facilitate explanation herein. The tail section 38 may be described as extending along a non-linear tail section centerline (TS centerline 48) that includes a lengthwise component (Y-axis direction) and a widthwise component (X-axis direction); for example, the tail section may be described as being curved. The thickness 50 (see FIG. 3B) of the tail section 38 extends along the Z-axis (the Z-axis perpendicular to the XY plane). The extent to which the tail section 38 may be non-linear (e.g., extending in an arcuate curve in the XY plane) may vary for particular embodiments but is typically selected to create beneficial alignment between the tibia and the tail section 38. FIG. 2 shows a vertical line 52 (parallel to the Y-axis) that intersects the center point of the first tail aperture 58A.

[0030] In the embodiment shown in FIGS. 1-3 , for example, the tail section 38 extends along an arcuate path (i.e., the TS centerline 48) that deviates from a vertical line 52 parallel to the Y-axis. Alternatively, the tail section 38 may extend along a non-linear path that includes a compound curvature, e.g., a collection of arcuate subsections with different curvatures. As another example of a non-linear path, the tail section 38 may extend along a path that includes one or more arcuate subsections and one or more linear sections. These examples of non-linear tail section paths are provided to illustrate possible tail section centerline path configurations and are not intended to be limiting. The Y-axis component of the path of the TS centerline 48 is substantially greater than the X-axis component. The non-linear tail section 38 configuration is oriented such that the caudal side 26 of the tail section 38 is "inside" the arcuate path and the cranial side 28 of the tail section 38 is "outside" the arcuate path. In the XY plane, the TS centerline 48 in the XY plane is equidistant from the caudal edge surface 44 and the cranial edge surface 46. The TS section centerline 48 may be configured as a plane, e.g., the tail section 38 (and TS centerline 48) extends in the XY plane without curvature / deflection in the Z axis direction (except for elements such as recessed channels in the tail section 38, as described herein).

[0031] 1-3C illustrate an embodiment of a fixation plate 20 of the present disclosure that includes an open notch 54 disposed in the tail section 38 at the distal end 24. The open notch 54 may be configured to facilitate engagement of the fixation plate 20 with a surgical tool, such as a Hohmann tissue retractor, or other surgical tool. The present disclosure does not require the open notch 54 to be disposed at the distal end 24 of the fixation plate 20.

[0032] The tail section 38 of the fixation plate 20 includes a tail positioning aperture 56, a first tail aperture 58A, a second tail aperture 58B, and a slotted tail aperture 60. The first tail aperture 58A is disposed adjacent to the distal end 24 of the fixation plate 20, and the slotted tail aperture 60 is disposed adjacent to the curved section 36. The second tail aperture 58B is disposed between the first tail aperture 58 and the slotted tail aperture 60. The first and second tail apertures 58A, 58B and the slotted tail aperture 60 may be centered about the TS centerline 48. The embodiment shown in FIGS. 1-3 illustrates the tail positioning aperture 56 disposed between the first and second tail apertures 58A, 58B. The present disclosure is not limited to disposing the tail positioning aperture 56 between the first and second tail apertures 58A, 58B. The tail positioning aperture 56 is configured to receive a fixation member (not shown; e.g., a pin, screw, or other mechanical structure) for temporarily positioning the fixation plate 20 on the subject's tibia and / or to facilitate a user's visualization of a desired trajectory for a fastener inserted through the head aperture (described below). The tail apertures 58A, 58B allow the tail section 38 to be secured to a bone segment; for example, in a tibial plateau leveling osteotomy or "TPLO" procedure, the tail section 38 of the fixation plate 20 is attached to the distal / epiphyseal segment of the tibia.

[0033] The first and second tail apertures 58A, 58B (as well as the head apertures 96A-C, as described in detail below and shown in FIG. 3) each have a multi-axial configuration having a central axis 158A, 158B (see, e.g., FIG. 3B) that extends through the thickness 50 of the tail section 38 (e.g., along the Z axis). It is understood that the multi-axial aperture configuration greatly enhances a clinician's ability to place a fastener within bone in a desired orientation. More specifically, the multi-axial configuration allows a fastener (e.g., a threaded screw) engaged within the aperture to be aligned with the central axis 158A, 158B of the apertures 58A, 58B (i.e., the central axis of the fastener coincides with the central axis of the tail aperture) or disposed at an oblique angle (e.g., angle A1 as shown in FIG. 3B) from the central axis 158A, 158B of the tail apertures 58A, 58B. In some embodiments, a multi-axis configuration as used in the present disclosure may allow a fastener to be engaged with tail apertures 58A, 58B such that the central axis of the fastener is tilted at an angle (A1) of up to about fifteen degrees (15°) from the central axes 158A, 158B of apertures 58A, 58B. Thus, the multi-axis configuration allows the user to orient the fastener in a range of orientations (at any aperture circumferential position) and select a preferred orientation for the application at hand.

[0034] Each threaded aperture having a multi-axial configuration may include multiple threaded sections 62, with adjacent threaded sections 62 separated from one another by relief pockets 64. In the example fixation plate 20 shown in the figures, first and second tail apertures 58A, 58B are shown having a multi-axial configuration with four (4) threaded sections 62 and four (4) relief pockets 64 (see, e.g., FIG. 3 ). Each relief pocket 64 is disposed opposite another of the relief pockets 64 (i.e., diagonally across the center of the aperture); for example, the relief pockets 64 are disposed at ninety-degree (90°) intervals around the circumference of the apertures 58A, 58B. The present disclosure is not limited to a multi-axial configuration having four (4) threaded sections 62 and four (4) relief pockets 64, but may alternatively include a greater or fewer number of threaded sections 62 and relief pockets 64.

[0035] Each threaded tail aperture 58A, 58B has a first end 66 proximate the upper surface 30 of the tail section 38 and a second end 68 proximate the lower surface 32 of the tail section 38 (see, e.g., FIG. 3B). In the embodiment shown in FIGS. 1-3C, the threaded sections 62 collectively form a conical configuration such that the threaded apertures 58A, 58B have a diameter at the first end 66 (proximate the upper surface 30) that is larger than the diameter at the second end 68 (proximate the lower surface 32). It is understood that the conical configuration of the threaded sections / apertures facilitates intentional misalignment, yet still provides threaded engagement between the threaded sections 62 and fasteners when fastener / aperture misalignment is desired. The present disclosure does not require the threaded apertures 58A, 58B to have a collective conical configuration.

[0036] In some embodiments, first and / or second tail apertures 58A, 58B can be configured to receive at least a portion of the head of a fastener. In the embodiment shown in Figures 1-3C, for example, first and second tail apertures include countersunk portions 70 disposed at first ends 66. The present disclosure does not require first and / or second tail apertures 58A, 58B to include countersunk portions 70, and if included, countersunk portions 70 are not limited to any particular configuration.

[0037] The fixation plate 20 of the present disclosure is not limited to use with any particular type of fastener having first and second tail apertures 58A, 58B. A fastener including a self-tapping tip and a threaded shank (including threads below the head of the fastener) is one example of a fastener that may be used. Specific types of fasteners that may be used include cortical screws and locking screws. The portion of the fastener's threaded shank disposed adjacent the fastener head may include a thread form configured to threadingly engage with the threaded section of the respective first or second tail aperture 58A, 58B, e.g., interlocking threads that avoid cross threads. The entire fastener shank (e.g., other than the self-tapping tip) may have the same thread configuration, or different portions of the fastener shank may have different thread configurations. The threaded engagement between the fastener and the threaded apertures 58A, 58B, and the fastener and bone, allows for positive positioning between the fixation plate 20 and bone.

[0038] A first embodiment of a slot-tail aperture 60 is shown in FIGS. 1-4. As detailed herein, the present disclosure is not limited to this slot-tail aperture embodiment. In the embodiment shown in FIGS. 1-4, the slot-tail aperture 60 is generally oval having a length 61 that is greater than a width 63 and is configured to accept a fastener. The length 61 of the slot-tail aperture 60 extends along a longitudinal axis 72. The width 63 of the slot-tail aperture 60 extends along a width axis 74 that is perpendicular to the longitudinal axis 72. The slot-tail aperture 60 extends through the thickness 50 (see FIG. 3B) of the fixation plate 20 to allow a fastener to pass through the slot-tail aperture 60 and engage the bone segment. The slot-tail aperture 60 is angled to allow compression to be applied to the center of the osteotomy so that all or substantially all of the cut line is compressed. For example, the longitudinal axis 72 is disposed at an angle (A2—see FIG. 4) relative to the Y axis, which may be substantially equal to the angle (A3—see FIG. 2) at which the head section axis is disposed relative to the Y axis, as described below (e.g., A2 is approximately equal to A3). In other words, the longitudinal axis 72 of the slot-tail aperture 60 may be disposed approximately parallel to the head section axis. The length 61 of the slot-tail aperture 60 allows a user to vary the placement of the fastener, for example, to position the fastener in a desired location, for example, oriented more or less toward the cranial side 28 of the tail section 38 (or conversely, the caudal side 26; see FIG. 3, for example), and more or less toward the proximal end 22 of the fixation plate 20 (or conversely, the distal end 24; see FIG. 3, for example), and thus oriented relative to the curved cutting line.

[0039] As shown above, in the TPLO procedure, a curvilinear cut is made in the canine proximal tibia to separate the metaphysis from the proximal tibia, thereby creating an arcuate interface therebetween. The oblique angle A2 of the longitudinal axis 72 of the slot-tail aperture 60 is such that the longitudinal position of the fastener within the slot-tail aperture 60 does not significantly change the orientation of the fastener toward or away from the lateral ends of the arcuate interface. Rather, the longitudinal position of the fastener within the slot-tail aperture 60 primarily changes the position of the fastener relative to a central portion of the arcuate interface. As a result, it is understood that a fastener disposed within the slot-tail aperture 60 more desirably creates compression in the central portion of the arcuate interface rather than the lateral end portions of the interface.

[0040] Embodiments of the present disclosure may include a slot-tail aperture 60 configured to receive a fastener without threaded engagement; i.e., in these embodiments, the slot-tail aperture 60 is unthreaded. The slot-tail aperture 60 may be configured to receive at least a portion of the head of a fastener. In the embodiment shown in FIGS. 1-3C, for example, the slot-tail aperture 60 includes a countersink portion 76 (see FIG. 3B) disposed at the end of the top surface 30 of the slot-tail aperture 60. More specifically, the slot-tail aperture 60 shown in FIGS. 1-4 includes a relatively deep depth (Z-axis) countersink 76 that allows a fastener disposed within the slot-tail aperture 60 to be inclined at a variety of different angular orientations relative to the length axis 72 and / or width axis 74 of the slot-tail aperture 60. Slot tail aperture 60, including countersunk portion 76, may be configured to allow a variety of different fastener types (e.g., having different head configurations) to be used and / or to allow more than one fastener to be disposed within slot tail aperture 60 at a time. However, the present disclosure does not require slot tail aperture 60 to include countersunk portion 76.

[0041] A second embodiment of a slot-tail aperture 160 is shown in FIGS. 9-11. This embodiment of the slot-tail aperture 160 may be configured similarly to the slot-tail aperture 60 shown in FIGS. 1-4, having a generally oval shape with a length 161 greater than a width 163 (see, e.g., FIG. 11). The length 161 of the slot-tail aperture 160 extends along a longitudinal axis 172 between a first longitudinal end 165 and a second longitudinal end 167 opposite the first longitudinal end 165. The width 163 of the slot-tail aperture 160 extends along a width axis 174 perpendicular to the longitudinal axis 172. The slot-tail aperture 160 extends through the thickness 50 of the fixation plate 20 (e.g., along the Z-axis—see FIG. 3B) to allow a fastener to pass through the slot-tail aperture 160 and engage a bone segment. The slot tail aperture 160 may be angled such that the longitudinal axis 172 is disposed at an angle (A2—see FIG. 4) relative to the Y axis, which may be substantially equal to the angle (A3—see FIG. 2) at which the head section axis 84 (e.g., see FIG. 2) is disposed relative to the Y axis, e.g., A2 is approximately equal to A3.

[0042] In this embodiment of slot tail aperture 160, first portion 160A of slot tail aperture 160 is threaded to allow engagement of slot tail aperture 160 with a threaded fastener, and second portion 160B of slot tail aperture 160 is unthreaded to allow a fastener to be received within second portion 160B of slot tail aperture 160. First portion 160A of slot tail aperture 160 is disposed at one longitudinal end (e.g., first longitudinal end 165) of slot tail aperture 160, and second portion 160B of slot tail aperture 160 is disposed at the opposite longitudinal end (e.g., second longitudinal end 167) of slot tail aperture 160. The first and second portions 160A, 160B of the slot-tail aperture 160 may intersect one another to form an open configuration therebetween, e.g., the aperture 160 is continuous between the first and second longitudinal ends 165, 167. Depending on the configuration of the slot-tail aperture 160 (e.g., the length of the slot-tail aperture 160) and the position of the fastener within the slot-tail aperture 160, the open configuration between the first and second portions 160A, 160B may allow a portion of the fastener engaged with the first portion 160A to extend a certain amount into the second portion 160B, or vice versa.

[0043] In some embodiments, the threaded first portion 160A of the slotted tail aperture 160 may be configured in a polyaxial configuration as described herein with respect to the first and second tail apertures 58A, 58B (see, e.g., FIGS. 3 and 3B ) and have a central axis 158C extending through the thickness 50 of the tail section 38 (e.g., along the Z-axis). In a polyaxial configuration, the threaded first portion 160A includes multiple threaded sections 162, with adjacent threaded sections 162 separated from one another by relief pockets 164. The second portion 160B of the slotted tail aperture 160 may be configured to provide a clearance fit with a fastener extending therethrough.

[0044] As shown herein, the multi-axial configuration is understood to greatly enhance a clinician's ability to place a fastener within bone in a desired orientation; for example, the axis of rotation of a fastener engaged within a first threaded portion 160A having a multi-axial configuration can be aligned with or angled from the central axis 158C of the threaded first portion 160A as described herein. In the slot tail aperture 160 shown in FIGS. 9-11, the multi-axial configuration includes three (3) threaded sections 162 and two (2) relief pockets 164. The present disclosure is not limited to this multi-axial configuration; for example, a greater or fewer number of threaded sections 62 and relief pockets 64 may be utilized.

[0045] Slot tail aperture 160 has a first end 166 proximate upper surface 30 of tail section 38 and a second end 168 proximate lower surface 32 of tail section 38 (see, for example, FIG. 3B). In some embodiments, threaded first portion 160B can have the same or similar conical configuration as described herein with respect to threaded apertures 58A, 58B. The present disclosure does not require threaded first portion 160B to have a conical configuration.

[0046] The embodiment of slot tail aperture 160 shown in Figures 9-11 may be configured to receive at least a portion of the head of a fastener in the same or similar manner as described herein with respect to the embodiment of slot tail aperture 60 shown in Figures 1-3C, for example, slot tail aperture 160 may include a countersunk portion 176 disposed at the end of top surface 30 of slot tail aperture 160. However, slot tail aperture 160 does not require countersunk portion 176.

[0047] The embodiment of the slot-tail aperture 160 shown in FIGS. 9-11 provides a clinician with the option of attaching the fixation plate 20 to the subject's bone using a fastener engaged with the threaded first section 160A of the slot-tail aperture 160 or using a fastener engaged with the second section 160B of the slot-tail aperture 160, where the fastener forms a clearance fit with the slot-tail aperture 160. The anatomical configuration of the tibia varies from subject to subject, and this variability is relevant to the method of attaching the fixation plate 20 to the subject's bone during a TPLO procedure. For example, in some instances, the portion of the fixation plate 20 proximal to the slot-tail aperture 160 may be in contact with the subject's bone, while in other instances, that portion of the fixation plate 20 may not be in contact with the subject's bone. The presently disclosed slot-tail aperture 160 with a threaded first section 160A and a clearance fit second section 160B provides the clinician with attachment options that reflect the application at hand. For example, if the portion of fixation plate 20 proximate slot tail aperture 160 is spaced from the subject bone, a clinician may prefer to use a threaded thread engagement (via threaded first section 160A) rather than a compression screw, which may be subjected to undue stress in such an application. Conversely, if the portion of fixation plate 20 proximate slot tail aperture 160 is in contact with the subject bone, a clinician may prefer to use a compression screw (via threaded first section 160B) to achieve the benefits associated with compressing the TPLO curve cut.

[0048] In some embodiments, the lower surface 32 of the tail section 38 can be arcuate. For example, in the embodiment shown in Figures 3A, 5, and 6, the lower surface 32 of the tail section 38 is curved in the width direction, e.g., curved along the X-axis. In some embodiments, both the lower surface 32 and the upper surface 30 of the tail section 38 can be curved in the width direction. The arcuate shape of the lower surface 32 can be selected to complement the general shape of the tibia.

[0049] In some embodiments, tail section 38 may include a plurality of recessed channels 78 that intersect lower surface 32 and caudal edge surface 44, and a plurality of recessed channels 78 that intersect lower surface 32 and cranial edge surface 46. See, for example, FIGS. 5 and 6. Recessed channels 78 reduce the surface area of ​​lower surface 32, thereby reducing the potential contact area between lower surface 32 of fixation plate 20 and the tibia when fixation plate 20 is secured in place.

[0050] 1-3 , the head section 34 is disposed at the proximal end 22 of the fixation plate 20. The head section 34 is substantially diamond-shaped and is at least partially defined by a first proximal edge surface 80 and a second proximal edge surface 82 oriented to intersect each other. The head section 34 may be substantially symmetrical about a head section centerline 84 (HS centerline 84—see FIG. 2 ). As described herein, embodiments of the head section 34 may have complex and / or asymmetric configurations. Thus, the statement that the head section 34 may be “substantially symmetrical” about the HS centerline 84 should not be construed as requiring the head section 34 to have perfectly symmetrical halves on either side of the HS centerline 84. The head section 34 (and thus the HS centerline 84) is disposed at an angle toward the caudal side 26 of the fixation plate 20. The HS centerline 84 bisects the head section 34 and is disposed at an angle A3 relative to a vertical line 52 (parallel to the Y-axis) shown intersecting the center point of the first tail aperture 58. The angle A3 at which the head section 34 is angled can range from approximately fifteen degrees (15°) to approximately thirty-five degrees (35°). As can be seen in FIGS. 3B and 7, the head section 34 deviates from the XY plane in the Z-axis direction. FIG. 7 shows the head section 34 deviating at an angle A4. The angle A4 is shown in FIGS. 3B and 7 to illustrate a typical angular deviation of the head section 34. The angle A4 at which the head section 34 is angled can range from approximately twenty degrees (20°) to approximately forty-five degrees (45°). As described herein, the head section 34 has a complex curved shape, and the degree of angular deviation (in the Z-axis direction) from the XY plane may vary across the head section 34, i.e., the angle A4 may vary across the head section 34.

[0051] The head section 34 is anatomically contoured to reflect the contour of the tibia and to facilitate attachment of the fixation plate 20 to a portion of the tibia after rotation. The contouring includes angular disposition of the head section 34 along angles A3 and A4 and may also include a contoured lower surface 32 to reflect the surface geometry of the tibia. The contouring of the head section 34 may be asymmetric. The contouring of the head section 34 also allows the fixation plate 20 to be placed in multiple positions on the tibia to achieve desired fixation after rotation. The shape of the head section 34 also enables significant causal fixation in osteotomies. In a preferred embodiment, the head section 34 is contoured to reflect the average contour of the tibia after TPLO curve cutting and rotation has occurred, based on a database containing a clinically sufficient amount of empirical data.

[0052] In the embodiment shown in FIGS. 1-3 , the first and second proximal edge surfaces 80, 82 are connected to one another by a connecting edge surface 86. See, e.g., FIGS. 2 and 3 . The HS centerline 84, which bisects the head section 34, may also bisect the connecting edge surface 86; see, e.g., FIG. 2 . The first proximal edge surface 80 transitions to the fixation plate curved section 36 via a first transition edge surface 88, and the second proximal edge surface 82 transitions to the fixation plate curved section 36 via a second transition edge surface 90. As shown in FIGS. 1-3 , the connecting edge surface 86, the first transition edge surface 88, and the second transition edge surface 90 may be arcuate. The width of the head section 34 may be described as extending along a line 92 perpendicular to the HS centerline 84. The width of head section 34 may increase from proximal end 22 of fixation plate 20 (e.g., at connecting edge surface 86) to a maximum value (e.g., approximately at first and third head apertures 96A, 96C) and then decrease to curved section 36 of fixation plate 20, thus creating a substantially diamond-shaped configuration. Head section 34 shown in Figures 1-3 is a non-limiting example of a head section 34 that may be used in fixation plate 20 of the present disclosure.

[0053] The head section 34 includes a head positioning aperture 94, a first head aperture 96A, a second head aperture 96B, and a third head aperture 96C. The head apertures 96A-C enable the head section 34 to be fixed to a tibial segment (e.g., the medial segment). The head positioning aperture 94 is configured to receive a fixation member (not shown; e.g., a pin, screw, or other mechanical structure) for temporarily positioning the fixation plate 20 on the subject's tibia and / or to facilitate a user's visualization of the desired trajectory for a screw inserted through the head aperture. The first head aperture 96A is disposed caudal to the HS centerline 84, adjacent to a first lateral "point" of the diamond shape. See, for example, FIG. 2 . The third head aperture 96C is disposed cranial to the HS centerline 84, adjacent to a second lateral "point" of the diamond shape, opposite the first lateral point. The head positioning aperture 94 may be disposed between the first and third head apertures 96A, 96C, generally aligned with the HS centerline 84. The present disclosure is not limited to disposing the head positioning aperture 94 between the first and third head apertures 96A, 96C. The second head aperture 96B is disposed at the proximal end 22 of the fixation plate 20, generally aligned with the HS centerline 84, and is disposed closer to the proximal end 22 but centrally relative to the first and third head apertures 96A, 96C.

[0054] The first, second, and third head apertures 96A-C may have a multi-axial configuration as described above with respect to the first and second tail apertures 58A, 58B, for example, a multi-axial configuration that allows a fastener engaged within the head apertures 96A-C to be aligned with or disposed at an oblique angle from the central axis of the head apertures 96A-C. The multi-axial configuration includes multiple threaded sections 62 having adjacent threaded sections 62 separated from one another by relief pockets 64 (e.g., as described herein with respect to the first and second tail apertures 58A, 58B), where the threaded sections 62 may collectively form a conical configuration, or the like. Each of the head apertures 96A-C may also be configured to receive at least a portion of the head of a fastener in the manner described above with respect to the tail apertures 58A, 58B.

[0055] 3B, 3C, 5, 6, and 8, in some embodiments of the present disclosure, one or more thread angle limiting protrusions 98 (“SAR protrusions 98”) may be disposed proximate any or all of the first, second, and third head apertures extending from the underside 32 of the head section 34. As explained above, the multi-axial configuration of the head apertures 96A-C allows fasteners (e.g., threaded screws) engaging within the head apertures 96A-C to be disposed at an angle A1 (see, e.g., FIG. 3B) oblique to the central axis of the head apertures 96A-C, where the angle A1 may be up to approximately fifteen degrees (15°) from the central axis of the head apertures 96A-C. The SAR protrusions 98 are configured to limit the amount of angle (A1) at which the fastener central axis may be oblique to the central axis of the head apertures 96A-C in a predetermined region of each head aperture 96A-C. In other words, each SAR protrusion 98 is positioned to limit the fastener cant angle in a given region of its respective head aperture 96A-C. In regions of head apertures 96A-C without a SAR protrusion 98, fasteners may cant at an otherwise possible cant angle A1. The SAR protrusions 98 function to prevent fasteners from being inserted into regions of the tibial portion where fastener penetration may be problematic, for example, in a direction toward the articulation with the femur.

[0056] The SAR projections 98 include a circumferentially extending length 100, a width 102, and a height 104. See, for example, FIGS. 6 and 8 . The circumferential length 100 extends a predetermined portion of the outer diameter of each head aperture 96A-C. The circumferential length 100 may be selected based on the region of the tibia, with a preference to completely avoid tilted fastener placement, or to avoid tilted fastener placement beyond a predetermined tilt angle. For example, in the region of the head aperture where the SAR projections 98 are disposed, the SAR projections 98 may be configured to prevent any fastener tilt, i.e., in the region of the head aperture 96A-C where the SAR projections 98 are disposed, fasteners may only be oriented so that their central axes coincide with the central axes of the respective head apertures 96A-C. Alternatively, in the region of the head aperture 96A-C in which the SAR protrusion 98 is disposed, the SAR protrusion 98 may be configured to allow limited fastener cant, i.e., in the region of the head aperture 96A-C in which the SAR protrusion 98 is disposed, the fastener may be allowed to be oriented with its central axis canted at a percentage of the maximum allowable fastener cant angle possible anywhere around the head aperture 96A-C in which the SAR protrusion 98 is not present (e.g., 50% of A1, or only about 7.5 degrees cant if the maximum allowable cant angle anywhere is 15 degrees, etc.).

[0057] 3C, 5, 6, and 8, the SAR protrusions 98 associated with the first head aperture 96A are disposed on the caudal side 26 of the first head aperture 96A, the SAR protrusions 98 associated with the second head aperture 96B are disposed on the proximal end 22 of the second head aperture 96B (see FIG. 6), and the SAR protrusions 98 associated with the third head aperture 96C are disposed on the cranial side 28 of the third head aperture 96C. In this exemplary embodiment, each of these SAR protrusions 98 has a length 100 that is approximately one-third of the circumference of the respective head aperture periphery at the lower surface 32. In this exemplary embodiment, each of these SAR protrusions 98 has a height 104 sufficient to limit the fastener tilt angle to that desired within that region, e.g., having a range of A1 that is less than a maximum value that includes A1=0.

[0058] The configuration of the SAR protrusions 98 (e.g., circumferentially extending length, width, and height) shown in Figures 3C, 5, 6, and 8 is an example of a SAR protrusion 98 configuration, and the present disclosure is not limited thereto. The positioning of the SAR protrusions 98 shown in Figures 3C, 5, 6, and 8 is an example of a SAR protrusion 98 positioning, and the present disclosure is not limited thereto. The example of the SAR protrusions 98 shown in Figures 3C, 5, 6, and 8 includes a single SAR protrusion 98 per head aperture 96A-C. In alternative embodiments, the present disclosure may include two or more SAR protrusions 98 per head aperture 96A-C. Example SAR protrusions 98 are described above as being associated with head apertures 96A-C. In some embodiments, the present disclosure may include one or more SAR protrusions 98 associated with tail apertures 58A, 58B.

[0059] As described above, the curved section 36 of the fixation plate 20 is disposed between and continuous with both the head section 34 and the tail section 38. The tail section-curved section boundary line 40 and the head section-curved section boundary line 42 shown in FIG. 2 are included to illustrate approximate boundaries between the respective fixation plate sections 34, 36, 38. The curved section 36 curves caudally away from the tail section 38. The curvature of the curved section 36 in the XY plane is typically selected to match the desired orientation of the head section 34 described above (e.g., HS centerline angle A3—see FIG. 2 ). The curved section 36 may also deviate in the Z-axis direction from the XY plane of the tail section 38 to again match the desired orientation of the head section 34 described above (e.g., HS centerline angle A4—see FIG. 3B ).

[0060] The fixation plate 20 may comprise a variety of different materials. For example, in some embodiments, the fixation plate 20 may comprise surgical implant grade 316L stainless steel, or titanium, or a polymeric material (e.g., a bioabsorbable polymer), or the like, or any combination thereof. In some embodiments, the fixation plate 20 may include one or more materials that support and stimulate bone growth, or pharmaceutical or other healing compounds, or the like, and any combination thereof. In some embodiments, the fixation plate 20 may include a radiolucent material so that only the bone growth and not the fixation plate 20 itself is visible when an x-ray is taken.

[0061] The present disclosure is not limited to using the multi-axial configuration described herein on fixation plates 20 utilized in TPLO procedures. Referring to Figures 12 and 13, a fracture plate 120 (i.e., an alternative type of fixation plate 20) is illustrated including a length 122 (Y-axis), a width 124 (X-axis), and a thickness 126 (Z-axis), and multiple slotted apertures 260, each having a first portion 260A and a second portion 260B with a multi-axial configuration that are identical or substantially identical to a slotted tail aperture 160 described herein having a threaded first portion 160A, and a second portion 160B described herein (see, e.g., Figures 9-11). In this example, all of the apertures shown on the fracture plate 120 are shown as slotted apertures 260 with a multi-axial configuration, although this is not required. As shown herein, the axis of rotation of a fastener engaged within a first portion 260A of a slotted aperture having a multi-axial configuration can be aligned with or angled from the central axis of the fastener aperture. Each slotted aperture 260 having a multi-axial configuration can include multiple threaded sections 62, with adjacent threaded sections 62 separated from one another by relief pockets 64, such as the configuration shown in FIGS. 3A-C. The present disclosure is not limited to the fracture plate configuration of the fixation plate 20 shown in FIGS. 12 and 13, and the presently disclosed slotted aperture 260 having a first portion 260A having a multi-axial configuration can be utilized with other types of fixation plates.

[0062] While the principles of the disclosure have been described above with reference to specific devices and methods, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the disclosure.

[0063] The singular forms "a," "an," and "the" refer to one or more than one unless the context clearly dictates otherwise. For example, the term "comprising a specimen" includes one or more specimens and is considered equivalent to the phrase "comprising at least one specimen." The term "or" refers to a single element of the described alternative elements or a combination of two or more elements unless the context clearly dictates otherwise. As used herein, "comprises" means "includes." Thus, "comprising A or B" means "including A, B, or A and B," without excluding additional elements. Furthermore, the term "coupled" does not exclude the presence of intermediate elements between coupled items. Also, references to attached, fixed, connected, or the like can include permanent, removably, temporarily, partially, completely, and / or any other possible attachment options.

[0064] It should be noted that various connections between elements are shown in the description and drawings, the contents of which are incorporated by reference into this disclosure. These connections are general and, unless otherwise specified, may be direct or indirect, and this specification is not intended to be limiting in this respect. A coupling between two or more entities may refer to a direct connection or an indirect connection. An indirect connection may incorporate one or more intervening entities or spaces / gaps between the entities that are coupled to each other.

[0065] Furthermore, no element, component, or method step in this disclosure is intended to be disclosed to the public, regardless of whether that element, component, or method step is expressly recited in a claim. No claim element herein shall be construed under the provisions of 35 U.S.C. 112(f) unless the element is expressly recited using the phrase "means for."

[0066] While various inventive aspects, concepts, and features of the present disclosure may be described and illustrated herein as being embodied in combination in exemplary embodiments, these various aspects, concepts, and features may be used in many embodiments individually or in various combinations and subcombinations. Unless expressly excluded herein, all such combinations and subcombinations are intended to be within the scope of the present application. Furthermore, although various alternative embodiments of various aspects, concepts, and features of the present disclosure (such as alternative materials, structures, configurations, methods, devices, and alternatives with respect to components, shape, fit, function, etc.) may be described herein, such descriptions are not intended to be a complete or exhaustive list of available alternative embodiments, whether currently known or later developed. Those skilled in the art may readily employ one or more of the inventive aspects, concepts, and features in additional embodiments and applications within the scope of the present application, even in embodiments not explicitly disclosed herein. For example, in the exemplary embodiments described above in the Detailed Description section of the present specification, elements are described as individual units and shown separately from one another for ease of description. In alternative embodiments, such elements may be configured as combined elements.

[0067] Additionally, while some features, concepts, or aspects of the present disclosure may be described herein as being preferred configurations or methods, such description is not intended to imply that such features are necessary or essential unless expressly so stated. Furthermore, while example or representative values ​​and ranges may be included to aid in understanding the current application, such values ​​and ranges should not be construed in a limiting sense, and only significant values ​​or ranges are intended when explicitly stated.

[0068] Descriptions of exemplary methods or processes are not limited to including every step required in every instance, nor should the order in which steps are presented be construed as necessary or mandatory unless expressly stated. The words used in the claims have their full ordinary meaning and are not limited in any way by the description of the embodiments herein.

Claims

1. 1. A bone fixation plate comprising: a body extending between a proximal end and a distal end, the body including an upper surface and a lower surface disposed opposite the upper surface; the body includes a slotted aperture extending between the upper surface and the lower surface thereby forming a fastener passage therethrough, the slotted aperture having a length extending along a longitudinal axis and a width extending along a widthwise axis, the longitudinal axis extending between a first longitudinal end of the slotted aperture and a second longitudinal end of the slotted aperture, the second longitudinal end being opposite the first longitudinal end; the slotted aperture including a threaded first portion disposed at the first longitudinal end and an unthreaded second portion disposed at the second longitudinal end.

2. The bone fixation plate of claim 1 , wherein the length of the slotted aperture is greater than the width of the slotted aperture.

3. The bone fixation plate of claim 2 , wherein the slotted aperture has an open configuration between the first longitudinal end and the second longitudinal end.

4. The bone fixation plate of claim 1 , wherein the threaded first portion has a central axis and has a conical configuration.

5. 2. The bone fixation plate of claim 1, wherein the threaded first portion has a central axis and a polyaxial configuration including a plurality of threaded sections having relief pockets disposed between adjacent threaded sections.

6. The bone fixation plate of claim 5 , wherein the threaded section has a conical configuration.

7. 6. The bone fixation plate of claim 5, wherein the threaded first portion (TFP) has a TFP central axis, and the polyaxial configuration is configured to allow a threaded fastener having the fastener central axis to be disposed in the threaded first portion, with a fastener central axis parallel to the TFP central axis and with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections.

8. 6. The bone fixation plate of claim 5, wherein the threaded first portion (TFP) has a TFP central axis, and the polyaxial configuration is configured to enable a threaded fastener having the fastener central axis to be disposed on the threaded first portion with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections with the fastener central axis at an oblique angle.

9. The bone fixation plate of claim 8 , wherein the oblique angle is up to and including 15 degrees.

10. the body including a head section, a tail section, and a curved section; the head section includes a head section centerline; the head section is disposed at the proximal end, the tail section is disposed at the distal end, and the curved section is disposed between and contiguous with the tail section and the head section; The bone fixation plate of claim 1 , wherein the head section is oriented toward a caudal side of the body, the head section centerline is disposed at a head section angle, the head section angle being greater than zero.

11. The bone fixation plate of claim 10 , wherein the tail section has a tail section centerline that extends along an arcuate path.

12. within the tail section, the body including a caudal side extending between the upper surface and the lower surface, and a cranial side extending between the upper surface and the lower surface; The bone fixation plate of claim 11 , wherein the caudal surface is disposed medially of the arcuate pathway and the cranial surface is disposed laterally of the arcuate pathway.

13. the tail section includes a first tail aperture and a second tail aperture, each extending between the upper surface and the lower surface; the first tail aperture and the second tail aperture each have an aperture central axis and a multi-axial configuration including a plurality of threaded sections having relief pockets disposed between adjacent threaded sections; 12. The bone fixation plate of claim 11, wherein the first tail aperture is disposed proximal to the distal end of the body and the second tail aperture is disposed between the first tail aperture and the slot aperture.

14. 14. The bone fixation plate of claim 13, wherein the polyaxial configuration of the first and second tail apertures is configured to enable a respective threaded fastener having a fastener center axis to be disposed in the respective first or second tail aperture at an oblique angle with threaded engagement between a threaded fastener and at least one of the plurality of threaded sections, the oblique angle being up to and including 15 degrees.

15. The bone fixation plate of claim 10 , wherein the curved section curves caudally away from the tail section causing the head section to project caudally from the tail section.

16. 11. The bone fixation plate of claim 10, wherein the head section includes a head aperture having a head aperture central axis, the head aperture having a multi-axial configuration including a plurality of threaded sections with relief pockets disposed between adjacent threaded sections, the multi-axial configuration allowing a threaded fastener having the fastener central axis to be disposed within the head aperture with the fastener central axis at an oblique angle relative to the head aperture central axis, with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections, the oblique angle being up to and including 15 degrees.

17. 1. A bone fixation plate comprising: a head section disposed at a proximal end of the fixation plate, the head section having a first upper surface, a first lower surface opposite the first upper surface, and at least one head aperture extending between the first upper surface and the first lower surface, the head section having a head section centerline bisecting the head section; a tail section disposed at a distal end of the fixation plate, the tail section comprising: a second upper surface; and a second lower surface opposite the second upper surface; and at least one tail aperture extending between the second upper surface and the second lower surface; a tail section having a slotted aperture extending between the second upper surface and the second lower surface, thereby forming a fastener passageway through the head section, the slotted aperture having a length extending along a longitudinal axis and a width extending along a widthwise axis, the longitudinal axis extending between a first longitudinal end of the slotted aperture and a second longitudinal end of the slotted aperture, the second longitudinal end being opposite the first longitudinal end, the slotted aperture including a threaded first portion disposed at the first longitudinal end and an unthreaded second portion disposed at the second longitudinal end; a curved section disposed between the tail section and the head section and continuous with the tail section and the head section; A bone fixation plate, wherein the head section is oriented toward a caudal side of the fixation plate, the head section centerline is disposed at a head section angle, the head section angle being greater than zero.

18. the length of the slotted aperture is greater than the width of the slotted aperture; 18. The bone fixation plate of claim 17, wherein the threaded first portion has a central axis and a polyaxial configuration including a plurality of threaded sections having relief pockets disposed between adjacent threaded sections.

19. 19. The bone fixation plate of claim 18, wherein the threaded first portion (TFP) has a TFP central axis, and the polyaxial configuration is configured to enable a threaded fastener having the fastener central axis to be disposed on the threaded first portion with threaded engagement between the threaded fastener and at least one of the plurality of threaded sections with the fastener central axis at an oblique angle.

20. The bone fixation plate of claim 19 , wherein the oblique angle is up to and including 15 degrees.

Images