Contoured bone plate with locking screws for bone compression, particularly across the tarsometatarsal joint

Abstract

A method of applying a bone plate across two different portions of a tarsometatarsal joint or metatarsal can include placing a bone plate across the separation between two bone portions. The bone plate can have at least two fixation holes and a bend between the holes. A locking screw can be inserted through one or both holes having a head thread and a shaft thread, the shaft thread having a pitch greater than the pitch of the head thread. The locking screw can be screwed into the underlying bone portion until the bend of the bone plate is deformed.

Description

[Technical Field]

[0001] Related Articles This application claims the benefit of U.S. Provisional Patent Application No. 63 / 138,726, filed January 18, 2021, the entire contents of which are incorporated herein by reference.

[0002] Technical Field The present disclosure relates to bone plates and methods for fixing bones using bone plates, including compressing opposing bone ends together using the bone plate. [Background technology]

[0003] background Bones, such as those of the foot, may be anatomically misaligned. In certain situations, surgical intervention is required to precisely align the bones to reduce patient discomfort and improve the patient's quality of life. Surgical intervention may involve amputating one or more of the misaligned bones and then physically realigning the bones to an anatomically corrected position. A bone plate or multiple bone plates may be used to hold the bones in the anatomically corrected position and may help prevent the bones from returning to their misaligned position. Summary of the Invention

[0004] overview Generally, the present disclosure is directed to bone plates and screws, systems incorporating bone plates and screws, and methods of using bone plates. In some examples, bone plate systems and techniques are described for facilitating compression (e.g., angular compression) between opposing ends of two bone portions to which the bone plate is attached, which may be different parts of the same bone or two different bones separated by a joint. The force generated by the plating system may be distributed asymmetrically across the faces of the bone ends pressed together, for example, so that there is more force on the side of the bone end opposite the plate than on the side of the bone end closer to the plate. This may help to facilitate angular correction of the bone portions relative to one another and / or promote healing (e.g., fusion) between the bone portions in the correct orientation.

[0005] In some implementations, the bone plate includes an elongated body having a length greater than its maximum width and thickness. For example, the bone plate may have a length sized to span the tarsometatarsal joint, which separates the metatarsal bone from the opposing cuneiform bone. The bone plate may include a bend that displaces a portion of the bone plate positionable over the joint between two bone portions away from the joint. As a result, the bone plate may include a first end that contacts one bone portion and a second end that contacts a second bone portion, with an intermediate portion between the two ends displaced from one or both bone portions and / or the joint between the two bone portions.

[0006] To secure the bone plate to the bone portions, the bone plate can include a plurality of fixation holes extending therethrough, including at least one fixation hole positionable on a first bone portion and at least one additional fixation hole positionable on a second bone portion. One or more of these fixation holes can include threading partially or completely surrounding the fixation hole to facilitate engagement with threading on the head of a locking screw insertable through the fixation hole and into the underlying bone.

[0007] At least one locking screw may be used to both secure the locking plate to the underlying bone portion and achieve compression between the ends of the two bone portions secured together with the bone plate, according to some examples. The locking screw is configured to both engage with and deform the bone plate when driven beyond its initial engagement position within the bone plate. For example, when an arch within the bone plate is physically deformed toward a flat or non-bent profile (e.g., resulting in a residual arch with a lower height after deformation), the underside of the plate may be placed under tension and the upper side of the plate may be placed under compression. As a result, a moment force having an asymmetrically distributed magnitude may be applied across the end faces of the bone being compressed. When used, the locking screw may be configured to engage with the bone plate and deform the bone plate by controlling the compression ratio of the locking screw. The compression ratio of the bone screw may be controlled by adjusting the pitch of the threads on the screw head relative to the pitch of the threads on the screw shaft and / or by controlling the lead of the head relative to the lead of the shaft.

[0008] Conventional bone plate systems utilize one of two different types of screws: compression screws or locking screws. Compression screws are screws that have a threaded shaft but no threaded head. In use, compression screws are driven until the head of the screw contacts the bone plate and can then be driven further into the bone to compress the bone plate. In contrast, locking screws have both a threaded head and a threaded shaft. However, locking screws are generally designed to be screwed in without causing any compression on the bone plate until the threaded head engages with mating threads on the bone plate.

[0009] According to some examples of the present disclosure, a bone plate is provided with one or more locking screws that achieve both meshing between the screw head and the mating threads around the fixation holes on the bone plate and compression of the bone plate during rotation. The pitch of the threads on the screw shaft may be sufficiently greater than the pitch of the threads on the screw head to achieve both meshing and compression. Additionally or alternatively, the lead of the threads on the shaft may be greater than the lead of the threads on the head so as to generate a compressive force when the locking screw is inserted into the underlying bone. In either case, as the threads on the screw head mesh with the mating threads around the fixation holes in the rotational direction, the threads on the shaft can continue to pull the bone plate, engaged with the threads on the head, downward toward the bone. As a result, the bending portion of the bone plate can deform (e.g., elastically and / or plastically) toward the bone portion to which it is fixed.

[0010] In some examples, the bone plate is provided with one or more locking screws configured for both engagement with and compression of the bone plate. The bone plate has a bent portion. The bent portion may be a region of the bone plate between opposing ends of the bone plate that is non-planar with one or both ends (e.g., prior to deformation and / or installation). The bent portion may be offset from the ends in one or more planes. For example, when one end of the bone plate is placed in contact with one bone portion and a second end of the bone plate is placed in contact with the other bone portion, the bent portion may define a gap between the bone-facing surface of the bone plate at the bent portion and the surface of the underlying bone(s). This gap may be reduced or eliminated through flattening of the bent portion upon installation of one or more locking screws also configured to achieve compression.

[0011] With the bent portion of the bone plate positioned above the joint between the two bone portions to be fixed together, one or more locking screws configured for compression may be installed through corresponding fixation holes in the bone plate and into the underlying bone. Once the one or more locking screws are installed, the bent portion in the bone plate may deform toward the joint between the two bone portions. As the bone plate is deformed from the initial bend to a reduced bend profile, the bone plate may function as a spring, providing a distributed load across the end faces of the bones that are pressed together, e.g., with a force on the cortex of the bone opposite the plate that is greater than the force on the cortex of the bone closest to the plate. As a result, the force provided by the tensioned bone plate may be angled, helping to reinforce bone realignment performed, for example, prior to fixation using the bone plate.

[0012] In some examples, a bone plate having a curved portion may be placed over the joint between two adjacent bone portions to be fixed, and one or more locking screws configured for compression may be placed through fixation holes in the bone plate and into the underlying bone portion. One or more additional screws (e.g., compression screws, locking screws not configured for compression) may also be placed through one or more fixation holes in the bone plate and into one or more underlying bone portions.

[0013] Additionally or alternatively, one or more drive pins may be used to assist in the installation and pre-compression of the bone plate prior to the installation of the screws. In use, the drive pin may include a threaded head, a shaft, and an enlarged region having a cross-sectional area larger than the cross-sectional area of ​​the fixation hole into which the head of the drive pin is inserted. One or more drive pins may be installed into the underlying bone portion through the fixation hole of the bone plate, for example, by threading the distal head of the one or more drive pins into the underlying bone portion. As the drive pins are driven deeper into the underlying bone portion, the enlarged region of the drive pin may press against the upper surface of the bone plate adjacent the corresponding fixation hole. This may compress the bone plate toward the bone portion to which it is being fixed. One or more individual drive pins may then be removed and the corresponding screws installed to complete the installation process.

[0014] In yet a further example, a bone plate having a bent portion may be pre-deformed (e.g., pre-compressed) before or simultaneously with placement over the joint between two adjacent bone portions to be fixed (and before installation of any screws or, optionally, drive pins). For example, using manual manipulation and / or a bending tool, the bent portion of the plate may be compressed toward a more planar shape and held in compression while being placed over the joint between the bone portions to be fixed. Bone screws and / or drive pins may then be placed through the fixation holes of the bone plate while held in compression. One exemplary bending tool that may be used is a pair of plate bending arms inserted through fixation holes on either side of the apex of the bent portion (e.g., into drill guides placed in the fixation holes), which are then used to manipulate the bone plate.

[0015] In one example, a method of applying a bone plate across a tarsometatarsal joint is described. The method includes positioning the bone plate across the tarsometatarsal joint, which separates the metatarsals from the cuneiform bones. The bone plate has a first fixation hole, a second fixation hole, and a bend between the first and second fixation holes. Positioning the bone plate across the tarsometatarsal joint includes positioning the bend over the tarsometatarsal joint using a gap between the bone-facing surface of the bone plate and the tarsometatarsal joint. The method also includes inserting a locking screw through the first fixation hole. The locking screw has a head with a head thread and a shaft with a shaft thread. The shaft thread has a pitch greater than the pitch of the head thread, and the first fixation hole includes threads for engaging with the head thread. The method includes threading a locking screw into the metatarsal or cuneiform bone beneath the first fixation hole until the head threads of the locking screw engage the threads defined by the first fixation hole, and further threading the locking screw into the metatarsal or cuneiform bone, thereby deforming a bent portion of the bone plate toward the tarsometatarsal joint.

[0016] In another example, an orthopedic fixation system is described. The system includes a bone plate having a length defining a longitudinal axis extending from a proximal end of a body to a distal end of the body. The bone plate has an upper surface and a bone-facing surface opposite the upper surface, and includes a first fixation hole extending through the body and a second fixation hole extending through the body. The length of the bone plate is sized to traverse the tarsometatarsal joint with one of the first and second fixation holes positioned over a metatarsal bone and the other of the first and second fixation holes positioned over a cuneiform bone. At least the first fixation hole includes threads, and the bone plate includes a bend that offsets a portion of the bone plate between the first and second fixation holes relative to a portion of the bone plate defining the first and second fixation holes. The system also includes a locking screw having a head with a head thread and a shaft with a shaft thread, the shaft thread having a pitch greater than the pitch of the head thread. The locking screw exhibits a compression ratio defined by the pitch of the shaft thread divided by the pitch of the head thread. The locking screw is configured to be inserted into at least one of the metatarsal and cuneiform bones through the first fixation hole, with the head thread engaged with the threads defined by the first fixation hole. The compression ratio is effective to deform the bone plate when the head thread is fully engaged with the threads defined by the first fixation hole and the screw is further rotated.

[0017] In another example, a method is described that includes tensioning a bone plate having first fixation holes, second fixation holes, and a bend between the first and second fixation holes by bending the bone plate toward a flat profile relative to the bend, thereby providing a tensioned bone plate. The method includes placing the tensioned bone plate across a tarsometatarsal joint separating a metatarsal from a cuneiform bone and inserting a locking screw through the first fixation hole. The locking screw has a head with a head thread and a shaft with a shaft thread. The shaft thread has a pitch greater than the pitch of the head thread, and the first fixation hole includes threads for engaging with the head thread. The method also includes threading the locking screw into the metatarsal or cuneiform bone beneath the first fixation hole until the head threads of the locking screw engage the threads defined by the first fixation hole.

[0018] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will become apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a side view of an exemplary bone plate that can be used to achieve both fixation and compression across two bone portions. [Figure 2] FIG. 1 is a top view of an exemplary bone plate that can be used to achieve both fixation and compression across two bone portions.

[0020] [Figure 3] FIG. 3 is a side view of an exemplary locking screw that can be used with the bone plate of FIGS. 1 and 2.

[0021] [Figure 4] 3 is a diagram of the exemplary bone plate of FIGS. 1 and 2 secured to a first bone portion and a second bone portion across a joint between the two bone portions.

[0022] [Figure 5] 3A and 3B illustrate an exemplary application of the bone plate of FIGS. 1 and 2 using first and second locking screws. [Figure 6A] 3A and 3B illustrate an exemplary application of the bone plate of FIGS. 1 and 2 using first and second locking screws. [Figure 6B] 3A and 3B illustrate an exemplary application of the bone plate of FIGS. 1 and 2 using first and second locking screws.

[0023] [Figure 7] FIG. 1 is a flow diagram illustrating an exemplary technique for installing a bone plate system according to the present disclosure.

[0024] [Figure 8] FIG. 10 is a side view of an exemplary drive pin that can be used to assist in attaching a bone plate to a bone.

[0025] [Figure 9] 9 is a side view of the exemplary bone plate showing the exemplary drive pin of FIG. 8 inserted through the fixation hole of the bone plate.

[0026] [Figure 10] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint. [Figure 11] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint. [Figure 12] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint. [Figure 13] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint. [Figure 14] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint. [Figure 15] 1 illustrates exemplary procedural steps for attaching a bone plate to the medial cuneiform bone and the first metatarsal bone separated by the tarsometatarsal joint.

[0027] [Figure 16] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 17] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 18] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 19] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 20] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 21] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS. [Figure 22] 10-15 illustrate exemplary procedural steps that may be performed after the procedural steps described with respect to FIGS.

[0028] [Figure 23] 10 illustrates exemplary procedural steps for pre-tensioning a bone plate prior to installation. [Figure 24] 10 illustrates exemplary procedural steps for pre-tensioning a bone plate prior to installation. DETAILED DESCRIPTION OF THE INVENTION

[0029] Detailed Description The present disclosure generally relates to bone plates, systems, and kits including one or more bone plates and screws, as well as methods of using one or more bone plates and corresponding screws. In an exemplary application, a bone plate and screw system according to the present disclosure may be useful for internal fixation of one or more bones during surgical procedures, such as bone alignment, osteotomy, fixation procedures, fracture repair, and / or other procedures in which one or more bones are set in a desired position. Such procedures may be performed on bones of the foot or hand, for example, where the bones are relatively small compared to bones in other parts of the human anatomy (e.g., adjacent bones separated by a joint or different portions of a single bone). In one example, a procedure utilizing an embodiment of a bone plate and screw system may be performed to correct alignment between a metatarsal (e.g., the first metatarsal) and a cuneiform (e.g., the medial cuneiform), such as hallux valgus correction. An example of such a procedure is the Lapidus procedure. In another example, a procedure may be performed by correcting the alignment of a metatarsal (e.g., the first metatarsal). An example of such a procedure is a base metatarsal osteotomy procedure.

[0030] Exemplary screw configurations and methods of installing bone plate and screw systems according to the present disclosure will be described in more detail with respect to Figures 3-24. However, an exemplary bone plate that may be used in accordance with the present disclosure will first be described with respect to Figures 1 and 2.

[0031] 1 and 2 are side and top views, respectively, of an exemplary bone plate 10 that can be used to achieve both fixation and compression across two bone portions. The bone plate 10 defines a body 12 having a central longitudinal axis 14. The body of the bone plate 10 has a top surface 16 and a bone-facing surface 18, the bone-facing surface 18 being opposite the top surface 16 of the body 12. In some implementations, the bone plate 10 is positioned such that the bone-facing surface 18 interfaces with and / or contacts one or both bone portions along at least a portion of the length of the longitudinal axis 14. For convenience, "bone-facing surface" refers to the side of the bone plate that generally faces the bone when the plate is placed over one or more bones, regardless of whether there are two or more surfaces that contact the bone when the bone plate 10 is applied.

[0032] The body 12 of the bone plate 10 can define a distal region 20 at or near a first end 22 and a proximal region 24 at or near a second end 26 opposite the first end of the body. The distal region 20 can be separated from the proximal region 24 by an intermediate region 28. For example, the bone plate 10 can include one or more fixation holes extending through the thickness of the body 12. In these examples, the body 12 can include one or more fixation holes in the distal region 20, one or more additional fixation holes in the proximal region 24, and an intermediate region 28 without any fixation holes disposed between the distal region 20 and the proximal region 24.

[0033] In the example shown in FIGS. 1 and 2 , the distal region 20 of the bone plate 10 has at least one fixation hole, shown as two fixation holes 30 and 32. The proximal region 24 also has at least one fixation hole, also shown as two fixation holes 34 and 36. The first fixation hole 30 extending through the body 12 in the distal region 20 is the fixation hole closest to the intermediate region 28 on the distal side of the bone plate, which may include a bend that offsets the intermediate region from the underlying bone surface, as described. The second fixation hole 34 extending through the body 12 in the proximal region 24 is the fixation hole closest to the intermediate region 28 on the proximal side of the bone plate. The third fixation hole 32 in the illustrated example is located between the first fixation hole 30 and the first end 22 of the bone plate. The fourth fixation hole 36 in this example is located between the second fixation hole 34 and the second end 26 of the bone plate.

[0034] Each feature described as a fixation hole may be an opening extending through the thickness of body 12 sized to receive a corresponding screw. Each fixation hole may typically have a circular cross-sectional shape, but may have other cross-sectional shapes without departing from the scope of this disclosure. The fixation holes may extend perpendicularly through the thickness of body 12 or may be tapered (e.g., so that the hole is larger adjacent top surface 16 than on the adjacent bone-facing surface 18). In yet other examples, the fixation holes may extend at a non-perpendicular angle through the thickness of body 12 and / or may be configured for polyaxial screw alignment.

[0035] Although bone plate 10 is illustrated as being configured with four fixation holes 30, 32, 34, and 36, the bone plate may include fewer or more fixation holes. For example, distal region 20 and proximal region 24 of bone plate 10 may each include fewer fixation holes (e.g., one) and / or more fixation holes (e.g., three, four). The dimensions (e.g., length) of distal region 20 and proximal region 24 can be adjusted to accommodate the particular number of fixation holes included. Furthermore, although the fixation holes on bone plate 10 are illustrated as being coaxial with one another along longitudinal axis 14 of the bone plate, the bone plate may include one or more branches, each including fixation holes extending away from the longitudinal axis. As a result, one or more fixation holes in these branches(es) may be non-colinear with the remaining coaxially arranged fixation holes. For example, in various examples, the bone plate 10 may include at least one branch extending outward from the longitudinal axis 14 of the bone plate to define at least one of a Y-shaped, L-shaped, T-shaped, U-shaped, and / or other shaped profile.

[0036] Bone plate 10 may include a bend 40. Bend 40 may be a portion of bone plate 10 that is out of one or more planes in which first fixation holes 30 and second fixation holes 34 are disposed. In some examples, first end 22 and second end 26 of bone plate 10 are coplanar (e.g., such that the ends of the bone plate can be disposed in the same plane). Bend 40 may offset at least a portion of bone plate 10 from the plane in which first end 22 and second end 26 are disposed.

[0037] As will be explained, when bone plate 10 including bend 40 is placed across a joint between two bone portions, at least a portion of distal region 20 (e.g., including first end 22) may contact one bone portion and at least a portion of proximal region 24 (e.g., including second end 26) may contact the other bone portion. Bend 40 may elevate a portion of bone plate 10 from the surface of one or both bone portions across the joint. As a result, a gap may exist between bone-facing surface 18 of bone plate 10 in the region of the bend and the underlying bone portion. The size of this gap may be reduced (optionally, without eliminating the gap) upon insertion of one or more screws and / or compression of the bone plate.

[0038] The bend 40 of the bone plate 10 may curve the distal region 20 toward the proximal region 24 around the intermediate region 28. For example, the bend 40 may reduce the distance between the first end 22 and the second end 26 compared to when the body 12 is flat or planar. The bend 40 may be defined by a sharp transition (e.g., V-shaped) or a radius of curvature. The radius of the bend 40 may vary or be constant as a function of longitudinal position on the body 12 and / or may be concentrated in one or more portions of the body, such as the portion of the body between the proximal region 20 and the distal region 24. In some examples, the bend 40 is defined by a radius of curvature ranging from about 10° to about 45°, e.g., from about 15° to about 35°. In other examples, the bend 40 may be defined by a radius of curvature ranging from 45° to 135°, e.g., from about 75° to about 105°. Other bend angles are possible.

[0039] When bone plate 10 is configured to have a bend, the entire length of the bone plate may be bent (e.g., to define a radius of curvature), or only one region of the bone plate may be bent out-of-plane relative to the remainder of the bone plate. Thus, when describing bone plate 10 as having a bend 40 in an intermediate region 28 between proximal region 20 and distal region 24, it should be understood that the bend may or may not be isolated to that region. Rather, bend 40 may define an apex in intermediate region 28 between first fixation hole 30 and second fixation hole 34, such that, for example, the peak of the bone plate and / or the maximum offset relative to the first and second fixation holes (and / or first and second ends) is within this region. Depending on the application, the apex of the bend 40 may be positioned along the length of the bone plate 10 so that when the bone plate is placed across a joint separating bone portions, the apex is substantially centered over the joint (e.g., within ±3 mm of the joint, such as ±2 mm of the joint, or ±1 mm of the joint).

[0040] Bone plate 10 can be formed from any suitable biocompatible material or combination of materials, such as stainless steel, nitinol, titanium, and / or a polymeric material (e.g., polyetheretherketone or PEEK). Bend 40 can be formed by manufacturing bone plate 10 to include a bend (e.g., by casting or machining a starting portion of the bone plate that includes bend 40). Alternatively, bone plate 10 can be fabricated as a flat plate that is then bent (e.g., plastically deformed) to create bend 40.

[0041] The bone plate 10 can have a variety of features and configurations. For example, the width of the bone plate 10 can be constant along its length or can vary such that one or more regions of the bone plate have a greater width than one or more other regions of the bone plate. For example, in some implementations, the bone plate 10 can have a greater width in regions including fixation holes and a narrower width in regions between adjacent fixation holes. Additionally or alternatively, the thickness of the bone plate 10 can be constant along its length or can vary such that one or more regions of the bone plate have a greater thickness than one or more other regions of the bone plate. For example, the bone plate 10 can include pads projecting downwardly from the remainder of the bone-facing surface 18 (e.g., in the regions of the fixation holes) and / or channels recessed relative to the remainder of the bone-facing surface to define a different thickness along its length. Exemplary bone plate features that can be used are described in U.S. Pat. No. 10,245,088, entitled "Bone Plating System and Method," the entire contents of which are incorporated herein by reference.

[0042] Bone fasteners may be used to secure the bone plate 10 to the underlying bone portion. As briefly mentioned above, at least one of the bone fasteners used to secure the bone plate to the underlying bone portion may be configured as a locking screw configured to achieve both engagement and compression with the bone plate, thereby deforming the bent portion 40 toward the underlying bone surface.

[0043] FIG. 3 is a side view of an exemplary locking screw 50 that can be used with the bone plate 10 of FIGS. 1 and 2. The locking screw 50 extends from a proximal end 52 to a distal end 54. The locking screw 50 includes a head 56 and a shaft 58. The head 56 of the locking screw 50 includes threads 60 that partially or completely surround the head for engaging with mating threads surrounding a fixation hole in the bone plate 10 into which the locking screw is intended to be inserted. The threads 60 may be referred to as head threads for purposes of explanation. The shaft 58 of the locking screw 50 includes threads 62 that partially or completely surround the shaft for engaging with a bone portion underlying the fixation hole in the bone plate 10 into which the locking screw 50 is intended to be inserted. The threads 62 may be referred to as shaft threads for purposes of explanation.

[0044] Threads 60 and 62 may each be a helical structure used to convert rotary motion into linear motion or force. Threads 60 and 62 may each be defined by threads of material wrapped around an inner cylinder or cone of material in the form of a helix to define a straight thread or a tapered thread, respectively.

[0045] The locking screw 50 can be characterized by both lead and pitch. Lead is the distance along the axis of the screw covered by one complete revolution (360°) of the screw. Pitch is the distance from the crest of one thread to the next. In some examples, the locking screw 50 is configured as a single-lead screw, e.g., such that there is only one thread wrapped around the body of the screw. When configured in this manner, the locking screw advances axially a distance equal to the pitch or spacing between adjacent threads along the axis of the screw for each full revolution (360°) of the body of the screw. In other examples, the locking screw 50 is configured as a multiple-lead screw, such as a double-lead screw, triple-lead screw, or quadruple-lead screw, such that the locking screw advances axially a multiple of the pitch or spacing between adjacent threads for each full revolution of the body of the screw. In other words, the pitch and lead may be equal for a single lead thread, but the lead may be the pitch or spacing between adjacent threads multiplied by the number of threads for a multiple lead thread (e.g., pitch x 2 for a double lead thread, pitch x 3 for a triple lead thread).

[0046] According to some implementations of the present disclosure, the locking screw 50 is configured to be inserted through a fixation hole in the bone plate 10 and driven into the underlying bone portion. The locking screw can be configured with a compression ratio greater than 1.0. As used herein, the term "compression ratio" refers to the shaft thread pitch multiplied by the number of shaft thread starts, the sum of which is divided by the head thread pitch multiplied by the head thread starts. This can be expressed as the following formula:

number

[0047] In practice, the head threads 60 may typically be single-start threads. In such a configuration, if the shaft threads 62 define single-start threads, the compression ratio may be the pitch of the shaft threads 62 divided by the pitch of the head threads 60. If the shaft threads 62 define double-start threads, the compression ratio may be twice the pitch of the shaft threads 62 divided by the pitch of the head threads 60.

[0048] The differential pitch and / or start between the head threads 60 and the shaft threads 62 may be selected to be effective for delivering a compressive force to the bone plate 10 when the locking screw 50 is inserted into the bone plate. For example, when the bone plate 10 is secured to one bone portion with a bone fastener, the locking screw 50 may be inserted through a fixation hole across a joint into another bone portion. When the head threads 60 of the locking screw 50 engage with mating threads surrounding the fixation hole of the bone plate into which the screw is inserted, the shaft threads 62 may continue to pull the screw into the underlying bone. As a result, the bent portion 40 of the bone plate 10 may be deformed by bending toward the bone portion. As the locking screw 50 continues to be threaded into the fixation hole of the bone plate 10, the bent portion 40 may further deform. The locking screw 50 may be inserted into the underlying bone until the head 56 is fully seated within the receiving opening defined by the fixation hole of the bone plate.

[0049] The specific compression ratio effective to achieve compression of the bone plate 10 during use may vary based on, for example, the thickness of the plate. Generally, the compression ratio may be greater than 1.0. As a result, one rotation (360°) of the locking screw 50 may cause the screw shaft to traverse an axial distance greater than the axial distance traveled by the screw head seated within the mating threads defined by the fixation hole. As a result, the bone plate 10 may deform a distance toward the underlying bone into which the locking screw 50 is inserted to accommodate the difference in the length of shaft-to-head travel due to the compression ratio.

[0050] FIG. 3 illustrates a head 56 having an exemplary pitch 64 and a shaft 58 having an exemplary pitch 66. The compressive force generated by having different pitches and / or thread starts between the head and shaft can be characterized by a compression ratio, as discussed above. In some implementations, the locking screw 50 exhibits a compression ratio greater than 1.0, e.g., greater than 1.5, e.g., greater than 1.6, greater than 1.7, greater than 1.75, greater than 1.9, greater than 2.1, greater than 2.3, greater than 2.5, or greater than 3.0. For example, the locking screw 50 may have a compression ratio ranging from 1.45 to 3.5, such as from 1.5 to 2.5. A locking screw exhibiting such a compression ratio may be effective in deforming a bent portion 40 of a bone plate 10, the bone plate having a thickness of less than 5 mm, e.g., less than 3 mm, or less than 2 mm, in the region of the bend. For example, bone plate 10 may have a thickness in the range of 1 mm to 2 mm (e.g., at least in the region of bend 40) and may be deformed by a locking screw having a compression ratio greater than 1.5. In some implementations, a locking screw having any one of the aforementioned compression ratios has a single-start head thread and a single-start shaft thread, such that the compression ratio is provided by a shaft thread having a larger pitch than the head thread.

[0051] Bone plate 10 can include at least one fixation hole extending through body 12 at distal region 20 of the bone plate and at least one fixation hole extending through the body and proximal region 24 of the bone plate. In use, at least two fixation elements can be used to secure the bone plate to two different bone portions; for example, intermediate region 28 of the bone plate can bridge a joint or gap between two bone portions. For example, as described with respect to FIGS. 1 and 2 , bone plate 10 can include at least first fixation hole 30 and second fixation hole 34, which in the illustrated example further includes third fixation hole 32 and fourth fixation hole 36. Bone plate 10 can be engaged to underlying bone portions using, for example, a single locking screw configured as described with respect to FIG. 3 to achieve compression in conjunction with the bone plate. At least one locking screw (e.g., at least two locking screws so configured) configured with a high compression ratio, such as a compression ratio of greater than 1.5, can be used to secure the bone plate to the underlying bone portion. One or more other fixation elements having a different configuration than the increased compression ratio locking screw 50 may be inserted through other fixation holes in the bone plate. When two or more locking screws 50 are used, the two or more locking screws may have the same configuration (e.g., the same compression ratio) as one another, or may have different configurations (e.g., different compression ratios) that are still consistent with the locking screws 50 as described herein.

[0052] A bone plate fixation system including bone plate 10 can include at least one locking screw 50 (e.g., two, three, or four locking screws 50) that exhibits an effective compression ratio to deform the bent portion 40 of the bone plate during use. The bone plate fixation system can include one or more other mechanical fixation elements having a configuration different from the locking screw 50 that are insertable through other fixation holes in the bone plate to complete attachment to the underlying bone portion. Any suitable fixation elements, such as screws, pins, rivets, spikes, etc., having a configuration different from the locking screw 50, can be used for these other attachment elements.

[0053] For example, the bone plate fixation system can include at least one locking screw 50 that exhibits a compression ratio effective to deform the bend of the bone plate 10 during use, and at least one other screw (e.g., two, three, four, or more) that is a non-locking screw and / or a locking screw that exhibits a compression ratio less than that of the locking screw 50. For example, the bone plate fixation system can include one or more locking screws having a compression ratio less than 1.5, such as less than 1.45, less than 1.25, or less than 1.2. For example, the bone plate fixation system can include one or more locking screws having a compression ratio at least 0.05 less than the compression ratio exhibited by the locking screw 50 configured as described with respect to FIG. 3, such as at least 0.1, at least 0.25, or at least 0.5. In some examples, the bone plate fixation system can include one or more locking screws having a compression ratio of 1.0.

[0054] In one implementation, a bone plate fixation system includes a bone plate 10, at least two locking screws 50 that exhibit a compression ratio effective to deform a bend 40 in the bone plate, and at least two additional locking screws having a compression ratio less than that of the locking screws 50 (e.g., a compression ratio that does not result in substantial or any bending of the bone plate). In these systems, at least one locking screw 50 may be placed through a fixation hole on the distal region 20 of the bone plate 10, and at least one locking screw 50 may be placed through a fixation hole on the proximal region 24 of the bone plate. In these examples, at least one or two other locking screws having a lower compression ratio than the locking screws 50 may be placed through the remaining fixation holes on the distal region 20 and / or proximal region 24 of the bone plate.

[0055] FIG. 4 illustrates a bone plate 10 secured to a first bone portion 70 and a second bone portion 72 across a separation 74 (referred to herein for purposes of illustration as a "joint 74") between the two bone portions. The first bone portion 70 and the second bone portion 72 may be different portions of the same bone (e.g., a metatarsal), in which case the separation 74 may be a cut line between the two bone portions (e.g., where an osteotomy or shortening procedure has been performed) or a fracture. Alternatively, the first bone portion 70 and the second bone portion 72 may be different bone portions, in which case the separation 74 may be a joint, such as a metatarsal and a cuneiform bone separated by a tarsometatarsal joint. In the particular example of FIG. 4, the first bone portion 70 is shown as a metatarsal and the second bone portion 72 is shown as a cuneiform bone.

[0056] It should be understood that references to different features or elements in this disclosure as first, second, third, etc. are for convenience only and are not intended to impose an order of operations unless otherwise specified. For example, while bone plate 10 is described as including first fixation hole 30 positionable on first bone portion 70 and second fixation hole 34 positionable on second bone portion 72, it should be understood that in different examples, the first bone portion may be a metatarsal or cuneiform bone. Furthermore, during installation, an initial screw may be placed through second fixation hole 34 instead of first fixation hole 30. Accordingly, other orders of installation and placement of components may be used and should not be limited to the specific examples described.

[0057] 4 , bone plate 10 is shown bridging across a joint 74 with first and third fixation holes 30, 32 positioned over an underlying first bone portion 70 (e.g., a metatarsal) and second and fourth fixation holes 34, 36 positioned over an underlying second bone portion 72 (e.g., a cuneiform). When bone plate 10 is installed using at least one locking screw 50 and at least one other fixation element not configured as a locking screw 50 (e.g., a non-locking screw or a locking screw with a lower compression ratio), the at least one locking screw can be inserted through any one of the fixation holes in the bone plate. However, in some implementations, locking screw 50 may be installed through one or both fixation holes closest to the joint 74 separating the two bone portions.

[0058] 4, one locking screw 50A may be placed through the first fixation hole 30 and / or one locking screw 50B may be placed through the second fixation hole 34. The locking screws 50A, 50B may exhibit an effective compression ratio to deform the plate 10 at least in the region of the bend 40. Utilizing one or more locking screws with a relatively high compression ratio through one or more fixation holes closest to the intermediate region 28, including the apex of the bend 40, may be useful, for example, to help deform the bend toward the underlying bone surface by delivering compression closest to where the bone plate is desired to be deformed.

[0059] One or more other fixation holes of bone plate 10, such as one or more fixation holes located proximally and / or distally to the fixation hole nearest intermediate region 28, may be secured to the underlying bone portion using screws having a different configuration than locking screws 50A, 50B. For example, one locking screw 76A may be placed through third fixation hole 32 and / or one locking screw 76B may be placed through fourth fixation hole 36. Locking screws 76A, 76B may exhibit a lower compression ratio than each of locking screws 50A and 50B (e.g., when at least two locking screws 50 are utilized).

[0060] A bone plate fixation system including a non-planar bone plate, such as bone plate 10 having a bend 40, and one or more locking screws 50 that can mate with the bone plate and generate sufficient compressive force to deform the non-planarity of the bone plate during installation can be useful to help compress bone portions fixed together using the bone plate. When bone plate 10 is initially placed over a joint separating two bone portions, with the distal region 20 at least partially contacting a first bone portion 70 and the proximal region 24 at least partially contacting a second bone portion 72, a gap may exist between the bone-facing surface of the bone plate and the underlying bone portion. When one or more locking screws 50 are installed into the underlying bone through one or more corresponding fixation holes in bone plate 10, the bend 40 can deform (e.g., plastically and / or elastically) toward the underlying bone portion. This can create a residual spring force that compresses the ends of the bone portions together. For example, physically compressing the bend 40 from an initial apex height to a reduced apex height can place the upper side of the bone plate in compression and the lower side of the bone plate in tension, creating a moment force of asymmetrically distributed magnitude across the end faces of the bones being compressed. In implementations where the bone plate system is applied dorsally to two bone portions (e.g., across the metatarsophalangeal joint or across the tarsometatarsal joint), this can tend to plantarflex the distal bone portion relative to the proximal bone portion, thereby compressing the bone ends across the joint to promote healing (e.g., union) and reinforcing any joint realignment performed prior to fixation.

[0061] 5 and 6 illustrate an exemplary application of the bone plate 10 using first and second locking screws 50A, 50B. FIG. 5 shows the bone plate 10 positioned over a joint 74 (e.g., the tarsometatarsal joint) separating a first bone portion 70 (e.g., the first metatarsal) from a second bone portion 72 (e.g., the medial cuneiform) prior to installation of the locking screws. FIG. 6A shows the bone plate 10 after installation of the first and second locking screws 50A, 50B. FIG. 6B is a force diagram that schematically illustrates an exemplary distributed load that may be applied across a joint by the bone plate 10 after deformation. The bone plate 10 of FIG. 5 is shown with an optional drill guide threaded into the fixation holes of the bone plate.

[0062] During installation, bone plate 10 can be positioned across joint 74, for example, with the apex of bend 40 substantially centered over the joint. First fixation hole 30 can be positioned over an underlying first bone portion 70, and second fixation hole 34 can be positioned over an underlying second bone portion 72. For example, distal region 20 can at least partially contact first bone portion 70, proximal region 24 can at least partially contact second bone portion 72, and bend 40 can be elevated above the surface of one or both bone portions. As a result, a gap 80 can exist between bone-facing surface 18 of bone plate 10 and the joint line defined by the end of the bone below bend 40. The size of the gap 80 may vary depending on, for example, the degree of bend 40, and in some examples is at least 1 mm, e.g., at least 1.5 mm, at least 1.75 mm, at least 2 mm, at least 2.25 mm, at least 2.5 mm, at least 3 mm, at least 3.5 mm, at least 4 mm, or at least 5 mm.

[0063] A clinician may attach the bone plate 10 to the first and second bone portions 70, 72 by inserting one or more locking screws 50A, 50B into one or more corresponding fixation holes in the bone plate. For example, the clinician may insert a first locking screw 50A through the first locking hole 30 and thread the locking screw into the underlying first bone portion 70. The clinician may continue to advance the first locking screw 50A until the head threads on the locking screw partially, but not fully, engage with the mating threads extending around the first locking hole 30 (e.g., such that the head threads on the locking screw partially engage with the mating threads but can continue to be advanced downwardly relative to the mating threads). If the opposite side of the bone plate 10 is already secured to the second bone portion 72 using a fixation element, the clinician may further thread the first locking screw 50A into the first bone portion 70. After the head threads of the locking screw initially engage with the mating threads on the fixation hole, as the shaft threads of the first locking screw 50A advance downwardly into the first bone portion 70, the compression ratio provided by the differential configuration of the head threads and shaft threads can create a compressive force that deforms the flexion portion 40 toward the joint 74.

[0064] Depending on the sequence of operations, before or after placing the first locking screw 50A into the first bone portion 70, the clinician can insert the second locking screw 50B through the second fixation hole 34 and thread the locking screw into the underlying second bone portion 72. The clinician may continue to advance the second locking screw 50B until the head threads on the locking screw are partially or fully engaged with the mating threads extending around the second fixation hole 34 (e.g., the head threads on the locking screw are partially engaged with the mating threads but can continue to be advanced against the mating threads, or are fully seated with the locking threads). The clinician can then thread the second locking screw 50B into the second bone portion 72. After the head threads of the locking screw initially engage with the mating threads on the fixation hole, as the shaft threads of the second locking screw 50B advance downwardly into the second bone portion 72, the compression ratio provided by the differential configuration between the head and shaft threads can create a compressive force that deforms (e.g., further deforms) the flexion portion 40 toward the joint 74.

[0065] As the bent portion 40 of the bone plate 10 is deformed toward the facing surface of the underlying bone portion and / or joint 74, the bent portion may flatten. For example, if the bent portion 40 is characterized by a radius of curvature, the radius of curvature may be smaller when the bent portion is undeformed ( FIG. 5 ) and larger when the bent portion is deformed ( FIG. 6A ) after installation compared to before installation. In some installations, the bent portion 40 of the bone plate 10 is bent downward toward the facing surface of the underlying bone portion until the bone-facing surface of the bone plate contacts the bone portion in a region that formally defines the apex of the bend. In other installations, such as that shown in FIG. 6A , the bent portion 40 of the bone plate is bent toward the facing surface of the underlying bone portion, but a residual gap 80 remains between the bone-facing surface 18 of the bone plate 10 and the joint line defined by the end of the bone below the bent portion 40. In some examples, the size of the gap 80 after installation of the bone plate 10 may be less than 2 mm, such as less than 1.75 mm, less than 1.5 mm, less than 1 mm, less than 0.75 mm, or less than 0.5 mm.

[0066] As shown in FIGS. 5 and 6 , the first and second fixation holes 30 and 34 may be oriented relative to one another such that axes extending through the geometric centers of each fixation hole converge to define a convergent angle 90. After screws are placed through the first and second fixation holes 30 and 34, the angle 90 may decrease, representing a flattening of the bend 40. However, the first and second fixation holes, and correspondingly, the first and second screws passing through the fixation holes, may be inclined at a convergent angle relative to one another. This may be useful to help generate a force that presses the end of the first bone portion 70 against the end of the second bone portion 72, the force having a distributed magnitude that is greater in a portion of the bone portion opposite the side on which the bone plate 10 is placed (e.g., the opposite cortex of the bone portion) and smaller on the side on which the bone plate is placed.

[0067] In some examples, the difference between the angle 90 before deformation and the angle 90 after deformation is 90 degrees or less, such as 60 degrees or less, 45 degrees or less, 30 degrees or less, or 20 degrees or less. For example, the angle 90 before deformation may be in the range of 15 degrees to 90 degrees, such as 20 degrees to 45 degrees. After deformation, the angle 90 may be in the range of 0 degrees to 45 degrees, such as 5 degrees to 15 degrees. In one particular example, the angle 90 may be in the range of 20 degrees to 30 degrees before deformation and in the range of 5 degrees to 15 degrees after deformation.

[0068] When the bend or arch of the bone plate 10 is physically deformed toward a flattened or non-bent profile (e.g., resulting in complete flattening of the plate or a residual bend or arch of less height after deformation), the underside of the plate may be placed under tension and the upper side of the plate may be placed under compression. As a result, a moment force having an asymmetrically distributed magnitude may be applied across the end faces of the bone being compressed. FIG. 6B shows an exemplary triangular distributed load profile that may be generated across the end faces of the bone portions by deformation of the bone plate. The asymmetrically distributed force pressing the end faces of the bone portions together may be greater on the side of the bone portion opposite the side in contact with the bone plate 10 (e.g., the cortex) than on the side of the bone portion not in contact with the bone plate (e.g., the cortex). FIG. 6B shows an exemplary asymmetric force distribution with force vectors 92 of different magnitudes across the depth of the joint between two bone portions.

[0069] Features described as screws, including locking screw 50, can be formed from any suitable biocompatible material or combination of materials, such as stainless steel, nitinol, titanium, and / or a polymeric material (e.g., polyetheretherketone or PEEK). The screws may be monoaxial and / or polyaxial. Furthermore, the screws may be cannulated or non-cannulated and / or self-tapping or non-self-tapping. In some examples, one or more of the screws are cannulated (e.g., all of the screws). In other examples, one or more of the screws are not cannulated (e.g., all of the screws).

[0070] The screws, including the locking screw 50, and the bone plate 10 may be sized based on the desired use of the plating system. In some examples, each screw used with the bone plate 10 is sized to be inserted into the metatarsal and / or cuneiform bones of a human foot. For example, each screw may have a length ranging from 8 mm to 18 mm, e.g., 10 mm to 16 mm, or 12 mm to 14 mm. When screws intended for insertion into both the metatarsal and cuneiform bones are provided, the screws may be the same size, or one may be longer than the other (e.g., 1 mm, 2 mm, or more). The diameter of the screw shaft may vary, but in some examples, the diameter ranges from 2 mm to 4 mm, e.g., 2.5 mm to 3.2 mm.

[0071] FIG. 7 is a flow diagram illustrating an exemplary technique for attaching a bone plate system according to the present disclosure. The technique of FIG. 7 includes performing an optional bone realignment procedure to realign a first bone portion 70 relative to a second bone portion 72, which is then fixed using the bone plate system (100). The bone realignment procedure may include realigning a metatarsal relative to a cuneiform bone, e.g., realigning the first metatarsal relative to the medial cuneiform bone, or may include realigning other bone portions relative to each other. For example, the realignment procedure may include realigning the second metatarsal relative to the middle cuneiform bone, the third metatarsal relative to the lateral cuneiform bone, the proximal phalanges relative to the metatarsal bones across the metatarsophalangeal joint, or even other bone portions relative to each other.

[0072] For example, to correct the alignment of a first bone portion (e.g., a metatarsal bone) relative to a second bone portion (e.g., a cuneiform bone), a clinician may surgically access the joint between the two bone portions. Once accessed, the clinician may prepare the end surfaces of the two bone portions. The clinician can prepare the end of each bone to promote fusion of the bone ends across the joint following realignment. Bone preparation may include using a tissue removal instrument to apply force to the end surface of the bone to create a blunt bone surface to promote subsequent fusion. Exemplary tissue removal instruments that can be used include, but are not limited to, saws, rotary drilling instruments, rongeurs, reamers, osteotomes, curettes, etc. The tissue removal instrument may be applied to the end surface of the bone being prepared to remove cartilage and / or bone. For example, the tissue removal instrument may be applied to the end surface to remove cartilage (e.g., all of the cartilage) down to the subchondral bone. Additionally or alternatively, tissue removal instruments may be applied to cut, fenestrate, mortar, and / or otherwise reshape bone end surfaces and / or to create bleeding bone surfaces to promote fusion. When a cutting operation is performed to remove a bone end, the cut may be performed freehand with the aid of a cutting guide having a guide surface positionable over the portion of the bone to be cut. When a cutting guide is used, the cutting instrument may be inserted relative to the guide surface (e.g., between a slot defined between two guide surfaces) to guide the cutting instrument for bone removal.

[0073] Either before or after preparing one or both ends of the bone segments, the clinician may move one bone segment (e.g., a metatarsal) in at least one plane, such as the transverse plane, to close the intermetatarsal angle between the bone segment (e.g., the first metatarsal) and an adjacent bone (e.g., the second metatarsal), and / or in the frontal plane to reposition a sesamoid bone. In some instances, the clinician moves the bone segments in multiple planes, such as the transverse plane, the frontal plane, and / or the sagittal plane. The clinician may or may not utilize a bone placement guide to facilitate the movement of the bone segments. Once the bone segments have been moved to the desired position, the clinician can optionally provisionally fix the moved position (e.g., by inserting k-wires through the moved bone segment into the adjacent bone segment) and then permanently fix the moved position using one or more bone plate systems as described herein. Details of exemplary bone realignment instruments and techniques that can be used in conjunction with the present disclosure are described in U.S. Patent No. 9,622,805, entitled "BONE POSITIONING AND PREPARING GUIDE SYSTEMS AND METHODS," issued April 18, 2017, the entire contents of which are incorporated herein by reference.

[0074] In some applications, regardless of whether the clinician performs the particular bone realignment technique described above, the clinician temporarily or provisionally fixates the first bone portion 70 relative to the second bone portion 72 before attaching the bone plate 10 across the joint separating the two bone portions. The clinician may press the end surfaces of the first bone portion 70 and the second bone portion 72 together, for example, by manual pressure and / or using a compression tool physically attached to both the first and second bone portions. For example, the clinician may attach a compression tool to the first bone portion 70 using one or more fixation pins and may also attach a compression tool to the second bone portion using one or more fixation pins. The compression tool may have a mechanism (e.g., a threaded rod, rack and pinion) that pushes pins inserted through the two bone portions to compress the end surfaces of the two bone portions together. Additional details regarding exemplary compressor structures that may be used in accordance with the present disclosure are described in U.S. Patent Application Publication No. 2020 / 0015856, filed January 16, 2020, and entitled "COMPRESSOR-DISTRACTOR FOR ANGULARLY REALIGNING BONE PORTIONS," the entire contents of which are incorporated herein by reference.

[0075] In some implementations, the clinician inserts one or more fixation pins through the end faces of the first bone portion 70 and the second bone portion 72 in addition to, or instead of, compressing the end faces with a compression tool. The fixation pins may be k-wires, olive wires (e.g., pins with enlarged cross-sectional areas), or other fixation pin structures. The fixation pin cross joint 74 between the first bone portion 70 and the second bone portion 72 can help temporarily fixate and / or compress the end faces of the two bone portions prior to installing the bone plate 10 for osmotic fixation (and subsequent fusion of the bone faces). When used, the one or more fixation pins can be removed from the end faces of the two bone portions across the joint between the bone portions after installing the bone plate 10 (e.g., after installing at least one fixation element through the bone plate into each of the first bone portion 70 and the second bone portion 72).

[0076] With further reference to FIG. 7 , an exemplary technique includes placing a bone plate 10 across a joint separating two bone portions (102). The bone plate 10 may include a first fixation hole 30, a second fixation hole 34, and a bend 40 between the first and second fixation holes. Placing the bone plate across the joint may involve, for example, positioning the bend 40 over the joint with the distal region 20 of the bone plate contacting the first bone portion and the proximal region 24 of the bone plate contacting the second bone portion. As a result of the presence of the bend, a gap 80 may exist between the bone-facing surface 18 of the bone plate and the underlying surface and / or epiphysis of the joint.

[0077] The technique of FIG. 7 may also include inserting a locking screw 50 through a first fixation hole in the bone plate (104). The locking screw 50 can have a head with head threads and a shaft with shaft threads. The shaft threads may be configured to provide a compression ratio greater than 1.0, such as greater than 1.5, relative to the head threads. The head threads may be configured (e.g., sized and / or shaped) to engage with corresponding mating threads surrounding the first fixation hole. A clinician may insert the locking screw through the first fixation hole by advancing the distal end of the screw through the opening defined by the first fixation hole and beginning to thread the locking screw shaft into the underlying bone. In different examples, a hole may or may not be pre-drilled in the bone prior to inserting the screw.

[0078] With the distal end of the locking screw 50 inserted through the first fixation hole in the bone plate 10, the clinician can thread the locking screw into the underlying bone (106). Using hand force or the aid of a rotary drill instrument, the clinician can rotate the locking screw 50 in either a clockwise or counterclockwise direction (depending on the thread pattern) to advance the screw axially downward into the bone portion underlying the fixation hole in the bone plate. The clinician can continue to thread the locking screw 50, advancing the screw axially into the bone portion. When the head threads on the head of the locking screw contact the mating threads surrounding the first fixation hole, the head threads may intersect with the mating threads surrounding the first fixation hole, thereby engaging the threads.

[0079] With the head threads at least partially engaged with the mating threads defined by the first fixation hole, the technique of Figure 7 includes further threading the locking screw 50 into the first fixation hole and the underlying bone. When the bone plate 10 is already secured to other bone portions across a joint, further rotation of the locking screw 50 can deform the bone plate (e.g., the bending portion 40 of the bone plate). The bone plate can deform by bending toward the joint and the underlying bone.

[0080] Before and / or after installing the locking screw 50 through the first fixation hole of the bone plate, the clinician can install one or more fixation elements, such as one or more locking screws, through one or more additional fixation holes in the bone plate. For example, before or after installing the locking screw 50 into the first bone portion through the first fixation hole, the clinician can install another locking screw (which may or may not have a relatively high compression ratio) into the second bone portion through the second fixation hole. The clinician can install one or more additional screws, such as one or more additional locking screws (which may or may not have a relatively high compression ratio), through other fixation holes in the bone plate, such as the third fixation hole and the fourth fixation hole.

[0081] As described herein, a bone plate fixation system applied across a joint separating the ends of two bone portions can help compress the end surfaces of the two bone portions together to promote fusion. In some instances, the plate fixation system creates asymmetric compression, in which the distal cortex of the bone ends is compressed more than the proximal cortex. In some applications, such as when a bone plate is applied to the dorsal surface of the bone portions, this can help plantarflex the realigned bone portions, reinforcing the correct realignment in the sagittal plane while facilitating fusion. Additionally, or alternatively, when a bone plate is applied to the medial surface of the bone portions, it can bias the realigned bone portions laterally, helping to reinforce the correct realignment in the transverse plane (e.g., biasing to close the intermetatarsal angle) while promoting fusion.

[0082] A variety of different instruments and additional or alternative techniques can be used to facilitate installation of the bone plate fixation system as described herein. For example, one or more drive pins (e.g., plate tack pins, drill pins) may be used to help facilitate installation of the bone plate 10. When used, the drive pins can be inserted through fixation holes in the bone plate and into the underlying bone. In some instances, the drive pins include a threaded distal region and can be rotationally driven into the underlying bone by threading. In either case, the drive pin can enter or drill a hole in the bone portion underlying the fixation hole into which the drive pin is inserted.

[0083] In some implementations, the drive pin may include an enlarged region having a cross-sectional area larger than that of the fixation hole. As the drive pin is advanced into the underlying bone, the region of the larger cross-sectional area may press against the upper side of the bone plate 10 (e.g., either directly against the upper side or indirectly via a drill guide extending above the upper surface). Continued rotation of the drive pin may cause the enlarged cross-sectional area to deform the bend 40 by compressing the bend toward the surface of the underlying joint and / or bone portion. As a result, the bone plate may be partially or fully deformed toward the desired degree of compression by the drive pin. The drive pin may then be removed from the fixation hole, and a locking screw may be inserted through the fixation hole and into the underlying bone. Another fixation device (e.g., a pin, screw, etc.) may be placed through one or more adjacent holes before removing the drive pin to help hold the bone plate in compression for installation of the locking screw.

[0084] When the bone plate 10 is pre-deformed using a drive pin prior to installation of one or more screws, the screws used to secure the bone plate to the underlying bone portion may or may not include a locking screw 50 exhibiting a relatively high compression ratio. In some applications using a drive pin for pre-deformation, at least one (and optionally all) of the fixation elements used to secure the deformed bone plate to the underlying bone may be a non-locking or locking screw configured with a lower compression ratio (e.g., a compression ratio of less than 1.5, or a compression ratio of 1.0, etc., that is ineffective to substantially deform the plate upon installation). However, in some implementations, a locking screw 50 with an increased compression ratio can be installed (e.g., through one or both fixation holes closest to the joint 74) to help secure the bone plate to the underlying bone portion.

[0085] FIG. 8 is a side view of an exemplary drive pin 120 that can be used to assist in attaching a bone plate to a bone. For example, the drive pin 120 may be connected to a driver (e.g., an impact driver, a rotary driver, a drill) that uses the drive pin 120 to apply force to drill a hole in the bone underlying the bone plate. Additionally or alternatively, a clinician utilizing the drive pin 120 can apply force through a manual instrument to drive the drive pin. In either case, after using the drive pin 120 to create a hole and / or orient the bone plate, the drive pin can be removed from the bone and bone plate. A bone fixation member (e.g., a bone screw) can then be inserted into the opening formed by the drive pin 120 to permanently secure the bone plate to the bone.

[0086] In the illustrated example, the drive pin 120 defines a body extending from a proximal end 122 to a distal end 124. The body defines multiple regions of differing cross-sectional thicknesses, shown in the illustrated example as at least three regions of differing cross-sectional thicknesses. For example, the body of the drive pin 120 may define a bone penetration region 126 adjacent the distal end, a drive region 128 adjacent the proximal end, and a bone plate orientation region 130 between the bone penetration and drive regions. The bone penetration region 126 can have a smaller cross-sectional thickness than the bone plate orientation region 130. The bone plate orientation region 130 can have a smaller cross-sectional thickness than the drive region 128, or in other implementations, can have a cross-sectional thickness that is the same as or greater than the drive region 128.

[0087] Configuring the drive pin 120 with multiple cross-sectional thicknesses can be useful to provide different functionality while limiting unnecessary trauma to the bone into which the drive pin is engaged. For example, the bone penetration region 126 can be relatively small to minimize bone damage and facilitate insertion of the distal end of the drive pin. The bone plate orientation region 130 can be sized complementary to the diameter of the fixation hole in the bone plate into which the drive pin is inserted. This can provide a close fit between the drive pin and the bone plate, for example, to precisely rotate the bone plate around the drive pin to orient the bone plate during installation. The drive region 128 can be sized larger for engagement with a driver used in the process. In some configurations, the drive pin 120 is provided as part of a kit that includes other drive instruments (e.g., pins, k-wires) and has the same diameter as one or more of those other instruments to provide a uniform drive connection size across the instruments. In other words, drive pin 120 may be part of a kit having one or more (and optionally two or more) other instruments (e.g., when all components of the kit are contained within a sterile case), each instrument having a shaft of substantially the same diameter, and each instrument configured to couple to the same driver for driving the instrument.

[0088] 8, the bone-penetrating region 126 may be threaded to facilitate rotational driving (threading) of the drive pin into the underlying bone. When threaded, the threads on the bone-penetrating region 126 may define any suitable pitch, which may be the same as or different from the pitch on the shaft threads of the locking screw 50, which may be inserted through the fixation hole after removal of the drive pin. The distal end 124 of the drive pin 120 may have a trocar or other tip (e.g., a self-tapping tip) for initiating penetration of the drive pin 120 into the underlying bone.

[0089] Although drive pin 120 is shown as including a threaded bone penetration region 126 and an unthreaded plate orientation region 130, the drive pin need not have two separate regions. Rather, if bone penetration region 126 and plate orientation region 130 are configured with the same cross-sectional size, the threads may optionally extend to also encompass the region of the drive pin that functions as the plate orientation region.

[0090] In general, the drive pin 120 can have any desired cross-sectional shape, including polygonal shapes, arcuate shapes, and combinations thereof. In some configurations, at least the bone penetration region 126, the drive region 128, and the bone plate orientation region 130 of the drive pin have a circular cross-sectional shape.

[0091] While drive pin 120 can have a variety of different sizes, in some examples, bone penetration region 126 has a diameter ranging from 0.1 mm to 2 mm, and / or bone plate orientation region 130 has a diameter ranging from 0.5 mm to 3 mm, and / or drive region 128 has a diameter ranging from 1.6 mm to 3.7 mm. For example, bone penetration region 126 may have a diameter ranging from 1 mm to 2 mm, and bone plate orientation region 130 may have a diameter ranging from 1 mm to 2 mm.

[0092] The drive pin 120 can have one or more regions of a cross-sectional thickness different from the bone penetration region 126, the drive region 128, and the bone plate orientation region 130. For example, in the illustrated example, the drive pin 120 includes a fourth region 132 having a cross-sectional thickness greater than at least the bone penetration region 126 and the bone plate orientation region 130. In the illustrated configuration, the fourth region 132 also has a cross-sectional thickness greater than the drive region 128. The fourth region 132 is disposed proximal to the bone plate orientation region 130 and can have a cross-sectional thickness greater than the bone plate fixation hole diameter and / or the cross-sectional thickness of a drill guide into which the drive pin 120 is configured to be inserted. The fourth region 132 can function as a feature that limits the downward insertion depth of the drive pin 120 as the drive pin 120 is being inserted through a bone plate and / or drill guide. If included, the fourth region 132 may be integral with the remainder of the drive pin body (e.g., permanently formed therewith) or may be part of a multi-piece assembly that is separately attachable to the drive pin.

[0093] The fourth region 132 can have any desired cross-sectional shape (e.g., circular, spherical, rectangular, triangular, elliptical), and the cross-sectional shape may be the same as or different from the cross-sectional shape of adjacent sections of the drive pin. In some examples, the fourth region 132 has a cross-sectional thickness ranging from 1.5 mm to 12 mm, e.g., from 2 mm to 5 mm. Further details regarding exemplary drive pin techniques and devices that may be used are described in U.S. Patent Application Publication No. 2020 / 0015870, filed July 12, 2019, and entitled "MULTI-DIAMETER BONE PIN FOR INSTALLING AND ALIGNING BONE FIXATION PLATE WHILE MINIMIZING BONE DAMAGE," the entire contents of which are incorporated herein by reference.

[0094] 9 is a side view of bone plate 10 showing drive pin 120 inserted through second fixation hole 34 of the bone plate. In the illustrated configuration, a drill guide 140 is threaded into the threaded opening defined by the fixation hole. As shown in this example, the threads surrounding the bone penetration region terminate at the proximal end just before where the drive pin intersects with the bone plate when the drive pin is fully inserted and the enlarged region abuts the drill guide (or, in other configurations, the top surface of the bone plate itself).

[0095] 10-15 are perspective views illustrating exemplary procedural steps that may be used to install a bone plate on two bone portions separated by a joint according to the present disclosure. In particular, FIGS. 10-15 illustrate exemplary procedural steps for attaching bone plate 10 to a medial cuneiform bone 70 and a first metatarsal bone 72 separated by a tarsometatarsal joint, for example, after preparing the ends of the two bones, realigning the first metatarsal bone relative to the cuneiform bone, and / or provisionally fastening the bone portions together.

[0096] 10, bone plate 10 can be positioned across the tarsometatarsal joint, which separates metatarsal bone 72 from cuneiform bone 70. In the orientation shown, bone plate 10 is positioned on the dorsal side (e.g., dorsal-most half, dorsal-most quarter) of the two bones. In other applications, bone plate 10 may be positioned in other locations along the surfaces of the two bones, such as on the medial side (e.g., medial-most half, medial-most quarter) of the two bones and / or on the dorsal-medial side of the two bones.

[0097] 11 , a first drive pin 120A can be inserted through a first fixation hole 30 located closest to the region of the bone plate 10 that defines the apex of the bend. The drive pin 120A can be rotationally driven through the first fixation hole and into the underlying bone (wedge bone 70). As the drive pin drills axially into the bone, the enlarged region of the drive pin can contact the top surface of the bone plate (e.g., the top surface of a drill guide extending above the bone plate). Continued rotation of the drive pin 120A can cause the enlarged region of the drive pin to press against the bone plate, at least partially deforming the bend by compressing it, resulting in a relative flattening of the bone plate.

[0098] As shown in FIG. 12 , the second drive pin 120B can be inserted through a second fixation hole 34 located on the opposite side of the joint from the first drive pin 120A. The second fixation hole 34 can be positioned closest to the region of the bone plate 10 that defines the apex of the bend opposite the first fixation hole 30. The second drive pin 120B can be rotationally driven through the second fixation hole into the underlying bone (metatarsal 72). Again, as the drive pin drills axially into the bone, the enlarged region of the drive pin can contact the top surface of the bone plate (e.g., the top surface of a drill guide extending above the bone plate). Continued rotation of the drive pin 120B can press the enlarged region of the drive pin against the bone plate, further deforming the bend of the bone plate that was initially deformed upon insertion of the first drive pin 120A. Full insertion of the second drive pin 120B can complete the deformation of the bone plate 10 to the desired degree of compression.

[0099] To hold the bone plate 10 for screw insertion, a third fixation pin 150 may be inserted into a fixation hole in the bone plate adjacent to the fixation hole into which the screw is desired to be inserted, as shown in FIG. 13 . In this example, the third fixation pin 150 is inserted through the third fixation hole 32 of the bone plate 10 into the underlying bone. The third fixation pin may be configured similarly to the drive pin 120 or may be a different pin configuration, such as, for example, an olive drive threaded plate tack or other pin. The third fixation pin 150 may be applied to maintain the deformation and compression of the bone plate 10 (and the position of the bone plate). In other examples, the technique may proceed without installing the third fixation pin 150. The first drive pin 120A may be removed, while the second fixation pin 120B (or a screw through the opposite fixation hole) remains in place.

[0100] In either case, the first drive pin 120A can be removed from the first fixation hole 30 to open the fixation hole for installation of a locking screw, as shown in Figure 14. After the first drive pin 120A is removed, a locking screw 50 (or other type of fixation element as described herein) can be threaded through the first fixation hole 30 and into the underlying bone.

[0101] With the locking screw 50 installed through the first fixation hole 30, the third fixation pin 150 (if used) can be removed from the cuneiform bone 70 to secure the bone plate 10 to the metatarsal bone 72. Additionally, the second drive pin 120B can be removed from the metatarsal bone 72, and a screw can be threaded into the second fixation hole 34 to secure the bone plate to the metatarsal bone. The screw inserted through the second fixation hole 34 can be a locking screw 50 or a different type of threaded structure or other fixation element, as described herein. In some examples, a fixation pin (e.g., the third fixation pin 150) is inserted through the fourth fixation hole 36 before removing the second drive pin 120B.

[0102] 15 shows the bone plate 10 attached across the tarsometatarsal joint separating the medial cuneiform 70 from the first metatarsal 72. The bone plate is attached to the medial cuneiform 70 and the first metatarsal 72 using screws inserted through the first and second fixation holes 30, 34 of the bone plate. Depending on the configuration of the bone plate 10 in the procedure being performed, the clinician may proceed to fully attach the bone plate by, for example, placing screws through the third fixation hole 32 and the fourth fixation hole 36 into the underlying bone.

[0103] However, in some applications, a clinician may desire to install multiple bone plates across a joint rather than installing only a single bone plate. The multiple bone plates may be positioned at different locations around the joint to provide a biplanar plate fixation construct. In these applications, each bone plate and / or screw may be configured and installed in accordance with the present disclosure, or one bone plate system may be different from the other. In some such applications, a clinician may proceed to begin installation of a second bone plate before completing installation of a first bone plate. For example, a clinician may begin installation of a second bone plate after securing the first bone plate through the first fixation holes 30 and the second fixation holes 34, but before installing screws through other fixation holes (e.g., the third and / or fourth fixation holes 32, 36).

[0104] For example, Figures 16-22 illustrate exemplary treatment steps that may be performed before, after, or instead of the treatment steps described with respect to Figures 10-15. As shown in Figure 16, bone plate 10B can be placed across the tarsometatarsal joint, which separates metatarsal bone 72 from cuneiform bone 70. In the orientation shown, bone plate 10B is placed on the medial side of the two bones (e.g., medial most half, medial most quarter), although it can also be placed in other locations around the bones.

[0105] 17 , a first drive pin 120A can be inserted through a first fixation hole 30 located closest to the region of the bone plate 10B that defines the apex of the bend. The drive pin 120A can be rotationally driven through the first fixation hole 30 and into the underlying bone (wedge bone 70). As the drive pin drills axially into the bone, the enlarged region of the drive pin can contact the top surface of the bone plate (e.g., the top surface of a drill guide extending above the bone plate). Continued rotation of the drive pin 120A can cause the enlarged region of the drive pin to press against the bone plate, at least partially deforming the bend by compressing it and resulting in a relative flattening of the bone plate.

[0106] As shown in FIG. 18 , the second drive pin 120B can be inserted through a second fixation hole 34 located on the opposite side of the joint from the first drive pin 120A. The second fixation hole 34 can be located closest to the region of the bone plate 10 that defines the apex of the bend opposite the first fixation hole 30. The second drive pin 120B can be rotationally driven through the second fixation hole into the underlying bone (metatarsal 72). Again, as the drive pin drills axially into the bone, the enlarged region of the drive pin can contact the top surface of the bone plate (e.g., the top surface of a drill guide extending above the bone plate). Continued rotation of the drive pin 120B can press the enlarged region of the drive pin against the bone plate, further deforming the bend of the bone plate that was initially deformed upon insertion of the first drive pin 120A. Full insertion of the second drive pin 120B can complete the deformation of the bone plate 10B to the desired degree of compression.

[0107] To hold the bone plate 10 in place for screw insertion, a third fixation pin 150 may be inserted into a fixation hole in the bone plate adjacent to the fixation hole into which the screw is desired to be inserted, as shown in FIG. 19 . In this example, the third fixation pin 150 is inserted through the third fixation hole 32 of the bone plate 10 into the underlying bone. The third fixation pin may be configured similarly to the drive pin 120 or may be a different pin configuration, such as, for example, an olive drive threaded plate tack or other pin. The third fixation pin 150 may be applied to maintain the deformation and compression of the bone plate 10B (and the position of the bone plate). In other examples, the technique may proceed without installing the third fixation pin 150. The first drive pin 120A may be removed, while the second fixation pin 120B (or a screw through the opposite fixation hole) remains in place.

[0108] In either case, the first drive pin 120A can be removed from the first fixation hole 30 to open the fixation hole for installation of a locking screw, as shown in Figure 20. After the first drive pin 120A is removed, a locking screw 50 (or other type of fixation element as described herein) can be threaded through the first fixation hole 30 and into the underlying bone.

[0109] With the locking screw 50 installed through the first fixation hole 30, the third fixation pin 150 (if used) can be removed from the cuneiform bone 70 to secure the bone plate 10 to the metatarsal bone 72. Additionally, the second drive pin 120B can be removed from the metatarsal bone 72, and a screw can be threaded into the second fixation hole 34 to secure the bone plate to the metatarsal bone. The screw inserted through the second fixation hole 34 can be a locking screw 50 or a different type of threaded structure or other fixation element, as described herein. In some examples, a fixation pin (e.g., the third fixation pin 150) is inserted through the fourth fixation hole 36 before removing the second drive pin 120B.

[0110] 21 shows a bone plate 10B attached dorsally across the tarsometatarsal joint separating the medial cuneiform 70 from the first metatarsal 72. The bone plate is attached to the medial cuneiform 70 and the first metatarsal 72 using screws inserted through the first and second fixation holes 30, 34 of the bone plate.

[0111] It may be useful for various reasons to secure a first bone plate 10 with a single screw connecting the bone plate to an underlying bone portion (e.g., metatarsal 72) and then attach a second bone plate 10B before completing the installation of the first bone plate 10. With only a single screw securing the first bone plate 10 to the bone portion, the bone portion may be further manipulable during installation of the second bone plate 10B. For example, the clinician may be able to pivot the metatarsal 72 about the single screw connecting the first bone plate 10 to the metatarsal. This may provide a degree of mobility or freedom for the clinician to adjust the position of the first metatarsal in the transverse, frontal, and / or sagittal planes before or simultaneously with the installation of the second bone plate 10B. Additionally or alternatively, this arrangement provides mobility, allowing the bend 40 of the second bone plate 10B (if so configured) to deform to provide additional stiffening correction of the bone portion (e.g., biasing the metatarsal bones laterally to close the intermetatarsal angle).

[0112] Once the second bone plate 10B is attached to the medial cuneiform 70 and first metatarsal 72 using screws inserted through the first and second fixation holes 30, 34 of the bone plate, the clinician can proceed to fully install the first and / or second bone plate 10B. For example, the clinician can complete installation by placing screws through the third and fourth fixation holes 32, 36 of the first and / or second bone plate 10B into the underlying bone, as shown in FIG. 22 .

[0113] It should be understood that the foregoing description of exemplary procedural steps described in connection with FIGS. 10-22 is illustrative of the present invention, and that the procedure may be modified in accordance with the disclosure. For example, a clinician may install the medial bone plate before installing the dorsal bone plate, or may install only a single bone plate. As another example, a clinician may insert an initial drive pin and / or locking screw through the first fixation hole into the first metatarsal 72 instead of the medial cuneiform 70, as described in this example. As a further example, the installation procedure may be modified to incorporate one or more additional fixation elements that may be used in addition to or instead of the described bone plate fixation systems and techniques. Exemplary additional fixation elements that may be used include, but are not limited to, lag screws, pins, and / or staples inserted across the separation between two bone portions, such as across the tarsometatarsal joint (e.g., through the first tarsometatarsal joint and into the second metatarsal), and / or staples inserted across the tarsometatarsal joint.

[0114] When a bone plate fixation system according to the present disclosure is applied to both the dorsal and medial sides of the metatarsal and cuneiform bones, the two bone plates can reinforce the realignment introduced during the bone realignment procedure. For example, a bone plate attached to the dorsal side of the metatarsal and cuneiform bones can apply an asymmetrically distributed force that is greater on the plantar side of the joint than on the dorsal side of the joint, which can tend to plantarflex the metatarsal. A bone plate attached to the medial side of the metatarsal and cuneiform bones can apply an asymmetrically distributed force that is greater on the lateral side of the joint than on the medial side of the joint, which can bias the distal end of the metatarsal laterally and tend to close the intermetatarsal angle between the metatarsal to which the bone plate is attached and the adjacent metatarsal.

[0115] As described above, bone plate 10 may be placed on two bone portions to be fixed together. The bone plate may be placed on the bone portions in an undeformed state, for example, before compressing the bent portion 40. Once the bone plate is placed on one or both bone portions, it may be deformed, for example, by inserting one or more locking screws and / or drive pins or equivalent compression-threaded elements through the fixation holes in the bone plate. This may deform the bent portion of the bone plate toward a flatter profile.

[0116] In yet a further example, the bone plate 10 having the bent portion 40 may be pre-tensioned (e.g., pre-compressed) prior to or simultaneously with placement over the joint between two adjacent bone portions to be fixed. For example, using manual manipulation and / or a bending tool, the bent portion 40 of the plate may be compressed toward a more planar shape and held in compression while being placed over the joint between the bone portions to be fixed. While held in compression, one or more drive pins and / or fixation elements (e.g., screws) may be inserted through the fixation holes in the bone plate and into the underlying bone portions.

[0117] In these examples, the bone plate 10 may have a configuration and may be deformed according to any of the shape profiles and configurations described above, with the deformation occurring at least partially before attachment of the bone plate to one or both of the underlying bone portions. In these applications, at least one (and optionally all) fixation elements used to secure the pre-deformed bone plate to the underlying bone portions may be non-locking or locking screws configured with a lower compression ratio (e.g., a compression ratio of less than 1.5, or a compression ratio of 1.0, etc., that is ineffective to substantially deform the plate upon installation). However, in some implementations, a locking screw 50 with an increased compression ratio can be installed (e.g., through one or both fixation holes closest to the joint 74) to help secure the pre-deformed bone plate to the underlying bone portions.

[0118] 23 and 24 illustrate one exemplary embodiment in which an instrument is used to pre-deform the bone plate 10 prior to installation. FIG. 23 shows the bone plate 10 connected to a bending instrument 160, shown in the illustrated example as a plate bending arm, prior to compression. The plate bending arms 160 are inserted through fixation holes in the drill guide 140 and / or bone plate on either side of the bending portion 40. The handles can be squeezed together as shown in FIG. 24 to deform the bending portion of the bone plate 40 and pre-compress the bone plate. The handles can be squeezed together in the direction indicated by the force vector arrow 162, for example, by one hand of a clinician grasping both handles and squeezing them together.

[0119] Once pre-compressed, the relatively flat plate can be placed over the two bone portions to be fastened together and held to one or both bone portions using a drive pin or other fixation feature. The plate flexion arms 160 can then be removed, the screw holes prepared, and screws driven through the fixation holes in the plate and into the underlying bone.

[0120] If the bone plate 10 is pre-compressed prior to installation, the screws used to secure the plate to the underlying bone portions may or may not include locking screws 50 as described above, which have a relatively high compression ratio. In some implementations, all of the screws utilized to secure the bone plate to the underlying bone portions may be non-locking screws or locking screws with a lower compression ratio.

[0121] In some implementations, components of the bone plate systems described herein (e.g., one or more bone plates, screws, and / or other fixation elements) may be provided as part of a kit. The kit may be a disposable, single-use surgical kit. The terms "disposable" and "single-use" are meant to convey that the surgical kit, along with all components included in the surgical kit, are intended for use with only one surgical patient. After the surgical procedure on a surgical patient is complete, any components not implanted in the surgical patient can be disposed of using conventional methods.

[0122] The kit can include a sterile container that can house various surgical supplies. The container can be sterilized using any suitable sterilization means (e.g., exposure to ethylene oxide, steam autoclave, gamma irradiation). In one example, various surgical items can be placed in the container, and the container and the various surgical items contained therein can be sterilized in a single step. The sterile container can be partially or fully enclosed in packaging that can serve to protect the container as well as seal and maintain the sterility of the container. The packaging and / or sterile container can be made of a transparent material, such as a suitable polymer, so that the surgical items contained within the container can be viewed.

[0123] A disposable, single-use kit can include all or any combination of one or more of the described surgical articles. The items included in the kit can vary depending on the particular surgical procedure for which the kit is intended to be used. Other kit embodiments can include two or more sterile packages with different components within each sterile package. For example, a first sterile package containing bone plates, fasteners, and pins can be provided with a second sterile package containing instruments such as plate manipulation and / or bone preparation instruments. Such kits can also be provided in a modular form with components grouped together in separate sterile packages that are selected to provide a complete kit for the desired surgical procedure.

[0124] Various examples have been described. These and other examples are within the scope of the following claims. [Configuration 1] 1. An orthopedic fixation system comprising: a bone plate having a length defining a longitudinal axis extending from a proximal end of the body to a distal end of the body, the bone plate having a top surface and a bone-facing surface opposite the top surface, the bone plate including a first fixation hole extending through the body and a second fixation hole extending through the body, the length of the bone plate sized to traverse a separation with one of the first fixation hole and the second fixation hole positioned on a first bone portion and the other of the first fixation hole and the second fixation hole positioned on a second bone portion, at least the first fixation hole including threads, and the bone plate including a bend that offsets a portion of the bone plate between the first fixation hole and the second fixation hole relative to a portion of the bone plate defining the first fixation hole and the second fixation hole; a locking screw having a head with head threads and a shaft with shaft threads, the locking screw having a compression ratio greater than 1.0, the locking screw configured to be inserted through the first fixation hole into at least one of the first bone portion and the second bone portion, the head threads engaging the threads defined by the first fixation hole, the compression ratio effective to deform the bone plate when the head threads partially engage the threads defined by the first fixation hole and the screw is further rotated; 1. An orthopedic fixation system comprising: [Configuration 2] 2. The system of claim 1, wherein the first bone portion and the second bone portion are two different bones, and the separation portion is a joint between the two different bones. [Configuration 3] 3. The system of claim 1 or 2, wherein the first bone portion is a metatarsal or cuneiform bone, the second bone portion is the other of the metatarsal or cuneiform bones, and the joint is a tarsometatarsal joint. [Configuration 4] 4. The system of any one of aspects 1-3, wherein at least one of the first bone portion and the second bone portion includes a metatarsal. [Configuration 5] 2. The system of claim 1, wherein the first bone portion and the second bone portion are two portions of the same bone. [Configuration 6] 6. The system of claim 5, wherein the first bone portion and the second bone portion are two portions of a metatarsal bone, and the separation portion is a cut between the two portions. [Configuration 7] 7. The system of any one of configurations 1 to 6, wherein the compression ratio is greater than 1.5, e.g., greater than 1.7, greater than 1.9, greater than 2.1, or greater than 2.3. [Configuration 8] 8. The system of any one of configurations 1-7, wherein the second fixation hole also includes threading, the locking screw comprising a first locking screw, further comprising a second locking screw, the second locking screw having a head with head threads and a shaft with shaft threads, the shaft threads having a pitch greater than a pitch of the head threads, the compression ratio of the second locking screw being greater than 1.5, the second locking screw configured to be inserted through the second fixation hole into the other of the metatarsal and the cuneiform bone, the head threads of the second locking screw engaged with the threads defined by the second fixation hole. [Configuration 9] 9. The system of any one of configurations 1-8, wherein the bone plate has a length defining a longitudinal axis, the bone plate further comprising a third fixation hole disposed between the first fixation hole and a first end of the bone plate, and a fourth fixation hole disposed between the second fixation hole and a second end of the bone plate. [Configuration 10] 10. The system of configuration 9, further comprising a third screw configured to be inserted through the third fixation hole and a fourth screw configured to be inserted through the fourth fixation hole, each of the third screw and the fourth screw being a non-locking screw or a locking screw exhibiting a compression ratio of less than 1.5. [Configuration 11] 11. The system of any one of configurations 9-10, wherein the first fixation hole, the second fixation hole, the third fixation hole, and the fourth fixation hole are coaxial with one another along the longitudinal axis of the bone plate. [Configuration 12] 12. The system of any one of configurations 1-11, wherein the bend that offsets the portion of the bone plate between the first fixation hole and the second fixation hole is defined by a radius of curvature that offsets the portion of the bone plate between the first fixation hole and the second fixation hole in one dimension. [Configuration 13] 13. The system of any one of configurations 1-12, wherein the bone plate and the locking screw are included in a sterile container as part of a kit. [Configuration 14] 1. A method of applying a bone plate across a separation between a first bone portion and a second bone portion, the method comprising: positioning a bone plate across a separation between a first bone portion and a second bone portion, the bone plate having a first fixation hole, a second fixation hole, and a bend between the first fixation hole and the second fixation hole, and positioning the bone plate across the separation includes positioning the bend over the separation with a gap between a bone-facing surface of the bone plate and the separation; inserting a locking screw through the first fixation hole, the locking screw having a head with head threads and a shaft with shaft threads, the locking screw having a compression ratio greater than 1.0, and the first fixation hole including threads for engaging the head threads; threading the locking screw into the first bone portion below the first fixation hole until the head threads of the locking screw partially engage the threads defined by the first fixation hole; further threading the locking screw into the first bone portion, thereby deforming the bend in the bone plate toward the separation portion; A method comprising: [Configuration 15] 15. The method of claim 14, wherein the first bone portion and the second bone portion are two different bones, and the separation portion is a joint between the two different bones. [Configuration 16] 16. The method of claim 14 or 15, wherein the first bone portion is a metatarsal or cuneiform bone, the second bone portion is the other of the metatarsal or cuneiform bones, and the joint is a tarsometatarsal joint. [Configuration 17] 17. The method of any one of aspects 14 to 16, wherein at least one of the first bone portion and the second bone portion comprises a metatarsal bone. [Configuration 18] 15. The method of claim 14, wherein the first bone portion and the second bone portion are two portions of the same bone. [Configuration 19] 19. The method of claim 18, wherein the first bone portion and the second bone portion are two portions of a metatarsal bone, and the separation portion is a cut between the two portions. [Configuration 20] 20. The method of any one of aspects 14 to 19, wherein the compression ratio of the locking screw is at least 1.5. [Configuration 21] 21. The method of any one of aspects 14 to 20, wherein the compression ratio is greater than 1.7, e.g., greater than 1.9, greater than 2.1, or greater than 2.3. [Configuration 22] 22. The method of any one of aspects 14 to 21, wherein the bone plate defines a thickness in the range of 1.0 mm to 2 mm. [Configuration 23] 23. The method of any one of aspects 14 to 22, further comprising provisionally fixing the first bone portion to the second bone portion by inserting at least a fixation pin through an end face of the first bone portion and into an end face of the second bone portion prior to threading the locking screw into the first bone portion. [Configuration 24] 24. The method of any one of aspects 14-23, further comprising inserting a screw through the second fixation hole and threading the screw into the second bone portion below the second fixation hole. [Configuration 25] The second screw also comprises a head having head threads and a shaft having shaft threads, the second screw having a compression ratio greater than 1.0; the second fixation hole includes threads for engaging the head threads of the second screw; Driving the second screw into the second bone portion includes driving the second screw until the head threads of the second screw partially engage the threading defined by the second fixation hole; and further driving the second screw into the second bone portion. 25. The method of claim 24, comprising: [Configuration 26] the gap between the bone-facing surface of the bone plate and the separation portion is at least 1.75 mm; further threading the locking screw into the first bone portion, thereby deforming the bend in the bone plate toward the separation portion, reducing the gap to a distance of less than 1.5 mm; 26. The method of any one of claims 14 to 25, comprising: [Configuration 27] 27. The method of any one of aspects 14 to 26, wherein deforming the bend in the bone plate toward the separation includes establishing an asymmetric distributed load across an end of the first bone portion and an end of the second bone portion, the asymmetric distributed load having a greater magnitude on a side of the first bone portion and the second bone portion opposite a side on which the bone plate is positioned. [Configuration 28] 28. The method of any one of aspects 14-27, wherein the bone plate has a length defining a longitudinal axis, the first fixation hole is spaced from the second fixation hole, the first fixation hole is on one side of the separation portion, and the second fixation hole is on the other side of the separation portion. [Configuration 29] 29. The method of claim 28, wherein the bone plate further comprises a third fixation hole disposed between the first fixation hole and a first end of the bone plate, and a fourth fixation hole disposed between the second fixation hole and a second end of the bone plate. [Configuration 30] 30. The method of claim 29, wherein the first fixation hole, the second fixation hole, the third fixation hole, and the fourth fixation hole are coaxial with one another along the longitudinal axis of the bone plate. [Configuration 31] 31. The method of any one of aspects 28-30, wherein the bone plate further comprises at least one branch extending outward from the longitudinal axis of the bone plate to define at least one of a Y-shape, an L-shape, a T-shape, and a U-shape. [Configuration 32] Prior to inserting the locking screw through the first fixation hole: further comprising threading a drive pin through the first fixation hole and into the first bone portion below the first fixation hole, the drive pin extending from a proximal end to a distal end, the drive pin including threads adjacent the distal end and an enlarged region spaced proximally from the distal end, the enlarged region having a cross-sectional size greater than a cross-sectional size of the first fixation hole; 32. The method of any one of aspects 14 to 31, wherein threading the drive pin through the first fixation hole comprises threading the drive pin through the first fixation hole and into the first bone portion below the first fixation hole at least until the enlarged region presses against an upper side of the bone plate, thereby deforming the bent portion of the bone plate toward the separation portion. [Configuration 33] 33. The method of any one of aspects 14-32, wherein the bone plate has a length defining a longitudinal axis, the first fixation hole is spaced from the second fixation hole, the first fixation hole is on one side of the separation and the second fixation hole is on the other side of the separation, the bone plate further comprising a third fixation hole disposed between the first fixation hole and a first end of the bone plate, and a fourth fixation hole disposed between the second fixation hole and a second end of the bone plate. [Configuration 34] inserting a first drive pin through the first fixation hole into the first bone portion; inserting a second drive pin through the second fixation hole into the second bone portion; inserting a third drive pin through the third fixation hole into the first bone portion; removing the first drive pin from the first fixation hole before inserting the locking screw into the first fixation hole, wherein inserting the locking screw through the first fixation hole comprises inserting the locking screw through the first fixation hole with the second drive pin inserted through the second fixation hole and the third drive pin inserted through the third fixation hole; 34. The method of claim 33, comprising: [Configuration 35] the captive screw comprises a first captive screw and further comprises a second captive screw, the second captive screw having a head with head threads and a shaft with shaft threads, the second captive screw having a compression ratio greater than 1.0, the second fixation hole including threads for engaging the head threads of the second captive screw; inserting the second locking screw through the second fixation hole and threading the second locking screw into the second bone portion below the second fixation hole until the head threads of the second locking screw engage the threads defined by the second fixation hole; 35. The method of any one of configurations 33 and 34, further comprising, after inserting the first and second locking screws, inserting a third screw through the third fixation hole into the first bone portion and a fourth screw through the fourth fixation hole into the second bone portion. [Configuration 36] the compression ratios of the first and second captive screws are each at least 1.5; each of the third screw and the fourth screw is a non-locking screw or a locking screw exhibiting a compression ratio of less than 1.5; 36. The method according to claim 35. [Configuration 37] the first bone portion is a metatarsal or a cuneiform bone, the second bone portion is the other of the metatarsal or cuneiform bones, and the joint is a tarsometatarsal joint; and prior to positioning the bone plate across the tarsometatarsal joint, preparing the end of the metatarsal; preparing the end of the cuneiform bone; 37. The method of any one of aspects 14-36, further comprising: moving the metatarsal bone at least in the transverse plane to close an intermetatarsal angle between the metatarsal bone and an adjacent metatarsal bone. [Configuration 38] 38. The method of claim 37, wherein positioning the bone plate across the tarsometatarsal joint includes positioning the bone plate on at least one of the dorsal and medial sides of the metatarsal and cuneiform bones. [Configuration 39] 39. The method of claim 37 or 38, wherein the metatarsal is a first metatarsal and the cuneiform is a medial cuneiform. [Configuration 40] 40. The method of any one of aspects 37-39, wherein positioning the bone plates across the tarsometatarsal joint comprises positioning a first bone plate dorsally of the tarsometatarsal joint and positioning a second bone plate medially of the tarsometatarsal joint, the first bone plate and the second bone plate each comprising the first fixation hole on one side of the tarsometatarsal joint, the second fixation hole on the other side of the tarsometatarsal joint, a third fixation hole between the first fixation hole and a first end of the bone plate, and a fourth fixation hole disposed between the second fixation hole and a second end of the bone plate. [Configuration 41] the first bone plate is installed by inserting the locking screw into one of the first fixation hole and the second fixation hole of the first bone plate and inserting a secondary screw into the other of the first fixation hole and the second fixation hole of the first bone plate; the second bone plate is installed by inserting the locking screw through one of the first and second fixation holes of the second bone plate and inserting a secondary screw through the other of the first and second fixation holes of the second bone plate prior to inserting screws through the third and fourth fixation holes of the first bone plate. 41. The method of claim 40. [Configuration 42] 1. A method comprising: tensioning a bone plate having a first fixation hole, a second fixation hole, and a bend between the first fixation hole and the second fixation hole by bending the bone plate toward a flat profile relative to the bend, thereby providing a tensioned bone plate; placing the tensioned bone plate across the tarsometatarsal joint separating the metatarsal bones from the cuneiform bones; Inserting a screw through the first fixation hole, the screw having a head with head threads and a shaft with shaft threads, the first fixation hole including threads for engaging the head threads; threading the locking screw into the metatarsal or cuneiform bone below the first fixation hole until the head threads of the locking screw engage the threads defined by the first fixation hole; A method comprising:

Claims

1. 1. An orthopedic fixation system comprising: a bone plate having a body and a length defining a longitudinal axis extending from a proximal end of the body to a distal end of the body, the bone plate having a top surface and a bone-facing surface opposite the top surface, the bone plate including a first fixation hole extending through the body and a second fixation hole extending through the body, the length of the bone plate sized to traverse a separation with one of the first fixation hole and the second fixation hole positioned on a first bone portion and the other of the first fixation hole and the second fixation hole positioned on a second bone portion, at least the first fixation hole including threads, and the bone plate including a bend that offsets a portion of the bone plate between the first fixation hole and the second fixation hole relative to a portion of the bone plate defining the first fixation hole and the second fixation hole; a locking screw having a head with head threads and a shaft with shaft threads, the locking screw having a compression ratio greater than 1.0, the locking screw configured to be inserted into at least one of the first bone portion and the second bone portion through the first fixation hole, the head threads engaging the threads defined by the first fixation hole, the compression ratio effective to deform the bone plate as the head threads partially engage the threads defined by the first fixation hole and the screw is further rotated, the compression ratio being: (shaft thread pitch x number of shaft threads) / (head thread pitch x number of head threads) a captive screw defined by:

1. An orthopedic fixation system comprising:

2. The system of claim 1 , wherein the first bone portion and the second bone portion are two different bones, and the separation is a joint between the two different bones.

3. 3. The system of claim 2, wherein the first bone portion is a metatarsal or cuneiform bone, the second bone portion is the other of the metatarsal or cuneiform bone, and the joint is a tarsometatarsal joint.

4. The system of claim 1 , wherein at least one of the first bone portion and the second bone portion includes a metatarsal bone.

5. The system of claim 1 , wherein the first bone portion and the second bone portion are two portions of the same bone.

6. 6. The system of claim 5, wherein the first bone portion and the second bone portion are two portions of a metatarsal bone, and the separation is a cut between the two portions.

7. 7. The system of claim 1, wherein the compression ratio is greater than 1.5, such as greater than 1.7, greater than 1.9, greater than 2.1, or greater than 2.

3.

8. 4. The system of claim 3, wherein the second fixation hole also includes threads, and the locking screw is a first locking screw configured to be inserted into one of the metatarsal and the cuneiform bone through the first fixation hole, and the system further comprises a second locking screw, the second locking screw having a head with head threads and a shaft with shaft threads, the shaft threads having a pitch greater than the pitch of the head threads, the compression ratio of the second locking screw being greater than 1.5, and the second locking screw configured to be inserted into the other of the metatarsal and the cuneiform bone through the second fixation hole, the head threads of the second locking screw engaged with the threads defined by the second fixation hole.

9. 9. The system of claim 1, wherein the bone plate has a length defining a longitudinal axis, and the bone plate further comprises a third fixation hole disposed between the first fixation hole and a first end of the bone plate, and a fourth fixation hole disposed between the second fixation hole and a second end of the bone plate.

10. 10. The system of claim 9, further comprising a third screw configured to be inserted through the third fixation hole and a fourth screw configured to be inserted through the fourth fixation hole, wherein each of the third screw and the fourth screw is a non-locking screw or a locking screw exhibiting a compression ratio of less than 1.

5.

11. 11. The system of claim 9 or 10, wherein the first fixation hole, the second fixation hole, the third fixation hole, and the fourth fixation hole are coaxial with one another along the longitudinal axis of the bone plate.

12. 12. The system of claim 1, wherein the bend that offsets the portion of the bone plate between the first fixation hole and the second fixation hole is defined by a radius of curvature that offsets the portion of the bone plate between the first fixation hole and the second fixation hole in one dimension.

13. 13. The system of claim 1, wherein the bone plate and the locking screw are included in a sterile container as part of a kit.

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