Patent Description:
This disclosure relates generally to devices and methods for positioning and/or preparing bones.

Bones, such as the bones of a foot, may be anatomically misaligned. In certain circumstances, surgical intervention is required to correctly align the bones to reduce patient discomfort and improve patient quality of life.

The following drawings are illustrative of particular embodiments of the present invention and, therefore, in no way limit the scope of the invention. The drawings are not necessarily to scale (unless otherwise stated) and are intended for use in conjunction with the explanations in the following detailed description. Embodiments of the invention will hereinafter be described with respect to the appended drawings, wherein like numerals denote like elements.

The following detailed description is exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides practical illustrations for implementing exemplary embodiments of the present invention. Examples of constructions, materials, and dimensions are provided for selected elements, and all other elements employ that which is known to those of ordinary skill in the field of the invention. Those skilled in the art will recognize that many of the noted examples have a variety of suitable alternatives.

Embodiments of the invention include a bone positioning guide of positioning bones in a medical procedure. In an exemplary application, embodiments of the bone positioning guide can be useful during a surgical procedure, such as a bone alignment, osteotomy, fusion procedure, and/or other procedures where one or more bones are to be prepared (e.g., cartilage or bone removal and/or cut). Such a procedure can be performed, for example, on bones (e.g., adjacent bones separated by a joint or different portions of a single bone) in the foot or hand, where bones are relatively smaller compared to bones in other parts of the human anatomy. In one example, a procedure utilizing an embodiment of the bone positioning guide can be performed to correct an alignment between a metatarsal (e.g., a first metatarsal) and a second metatarsal and/or a cuneiform (e.g., a medial, or first, cuneiform), such as in a bunion correction surgery. An example of such a procedure is a Lapidus procedure (also known as a first tarsal-metatarsal fusion). In another example, the procedure can be performed by modifying an alignment of a metatarsal (e.g., a first metatarsal). An example of such a procedure is a basilar metatarsal osteotomy procedure.

<FIG> shows a side perspective view of a bone positioning guide <NUM> in accordance with an embodiment of the invention. The bone positioning guide <NUM> can be useful for positioning a bone (e.g., orientating and/or translating) during a medical procedure. In some embodiments, the bone positioning guide includes a bone engagement member, a tip, a mechanism to urge the bone engagement member and the tip towards each other (e.g. moving the bone engagement member towards the tip, moving the tip towards the bone engagement member, or moving both simultaneously), and an actuator to actuate the mechanism. When the mechanism is actuated it causes a first bone engaged with the bone engagement member to move to correct an alignment in more than one plane with respect to a second bone in contact with the tip. In some embodiments, the correction in more than one plane includes a correction about an axis in a frontal plane.

In the embodiment of <FIG>, bone positioning guide <NUM> includes a main body member <NUM> and a shaft <NUM>, and the bone engagement member <NUM> is connected to the shaft and the tip <NUM> is connected to the main body member. In general, the main body member <NUM> can be sized and shaped to clear anatomy or other instrumentation (e.g., pins and guides) while positioned on a patient. In the embodiment of <FIG>, the main body member <NUM> includes a generally C-shaped configuration with a first end <NUM> and a second end <NUM>. In some embodiments, the main body is sized and configured to engage bones of a human foot. In addition, although bone positioning guide <NUM> is illustrated as being formed of two components, main body member <NUM> and shaft <NUM>, the guide can be fabricated from more components (e.g., <NUM>, <NUM>, or more) that are joined together to form the guide.

A shaft <NUM> can be movably connected to the main body member <NUM> proximate its first end <NUM>. In some embodiments, the shaft <NUM> includes threads <NUM> that engage with the main body member <NUM> such that rotation of the shaft translates the shaft with respect to the main body member. In other embodiments, the shaft can slide within the main body member and can be secured thereto at a desired location with a set screw. In yet other embodiments, the shaft can be moved with respect to the main body by a ratchet mechanism. In the embodiment shown, the shaft moves along an axis that intersects the tip <NUM>. In other embodiments, such as that described with respect to <FIG>, the shaft <NUM> and/or bone engagement member <NUM> is offset from tip <NUM>.

As shown in <FIG>, embodiments of the bone positioning device can have a bone engagement member <NUM>. In some embodiments, the bone engagement member includes a surface <NUM> configured to contact a bone, such as a metatarsal or a cuneiform. In the embodiment shown, the surface <NUM> is concave. Such a surface is adapted to promote surface contact with a generally cylindrical bone, such as a metatarsal. Other embodiments of surface shapes include planar surfaces and V-shaped surfaces. When using a concave or V-shaped bone engagement member <NUM>, the sidewalls of the concavity or V-shaped groove may be symmetrical or asymmetrical. In a symmetrical configuration, the bottom of the concavity or groove can be centered between upwardly extending sidewalls configured to receive a bone. Each sidewall can extend upwardly to the same height and/or at the same slope. In the asymmetrical configuration, one sidewall can have a different configuration than the opposing sidewall. For example, one of the sidewalls may extend upwardly from the bottom of the concavity or groove to a lower height than the opposing sidewall. As another example, one sidewall may extend upwardly at a different angle than the opposing sidewall. The asymmetrical configuration can be useful for applying a force that is biased laterally instead of only being linear toward tip <NUM>.

In some embodiments, bone engagement member <NUM> includes a pin or a clamp. Independent of whether bone engagement member <NUM> includes such pin or clamp, the bone engagement member can engage an anatomical feature of a bone, such as a ridge (e.g., a medial ridge of a first metatarsal). In such embodiments, the engagement generally prohibits rotational movement of the bone with respect to the bone engagement member. In other embodiments, bone may be allowed to rotate with respect to the bone engagement member.

In the embodiment shown, the bone engagement member <NUM> is provided on an end of the shaft <NUM>. In the embodiment of the shaft shown having threads <NUM>, the bone engagement member <NUM> can be rotatably coupled to the shaft <NUM>. In such embodiments, as the shaft is rotated relative to the main body member the bone engagement member <NUM> may or may not rotate with respect to the main body member even as it translates with respect to the main body member along with the shaft <NUM> and rotates with respect to the shaft. The bone engagement member may oscillate about the shaft <NUM>, but generally does not rotate with respect to bone after contact with the bone.

<FIG> depict a tip <NUM> of bone positioning guide <NUM>, which can be at a second end <NUM> of the main body member opposite the first end. The tip <NUM> can be useful for contacting a bone, generally a bone distinct from a bone contacting the bone engagement member. For example, if the bone engagement member is in contact with a first metatarsal, the tip can be in contact with a metatarsal other than the first metatarsal (e.g., the second, third, fourth, or fifth metatarsal). In some embodiments, the tip is tapered to facilitate percutaneous insertion and contact with bone. The tip can also include a textured surface <NUM>, such as serrated, roughened, cross-hatched, knurled, etc., to reduce slippage between the tip and bone. In the embodiment shown, the tip further includes a stop <NUM> to limit a depth of insertion. The shape of the tip can be configured to stably contact bone. For example, <FIG> shows a side view of the bone positioning guide with a generally straight tip <NUM>, while <FIG> shows a side view of the bone positioning guide with a nonlinear tip <NUM> (e.g., a tip that is angled or curved). In some embodiments, the tip is configured to restrict translational movement between it and a bone, but to allow rotational movement between it and the bone.

As shown in <FIG>, bone positioning guide <NUM> can also include an actuator (e.g., a knob or a handle) <NUM> to actuate the mechanism, in this embodiment associated with the shaft. In the embodiment shown, the actuator can be useful for allowing a user to rotate the shaft with respect to the main body member <NUM>. Also as shown in <FIG>, the actuator, shaft, and bone engagement member may include a cannulation <NUM> to allow the placement of a fixation wire (e.g., K-wire) through these components and into contact with or through a bone engaged with the bone engagement member. For example, the fixation wire can be placed into the bone engaged with bone engagement member <NUM> to fix the position of the bone engagement member with respect to the bone. In another example, the fixation wire can be placed through the bone in contact with the bone engagement member and into an adjacent bone to maintain a bone position of the bone in contact with the bone engagement member and the adjacent bone.

In other embodiments, the mechanism to urge the bone engagement member and the tip towards each other can include a tenaculum or tong structure. In such embodiments, the guide can include a first shaft pivotably connected to a second shaft. A first end of each shaft can include an actuator, such as a handle. A second end of the first shaft can include a bone engagement member, as described above. And a second end of the second shaft can include a tip, as described above. In use, the actuator can be actuated (e.g., squeezed together) to move the bone engagement member and the tip closer together to position bone. Other embodiments of this type may include another set of shafts and another pivoting connection such that the bone engagement member and tip translate towards each other when the actuator is actuated.

In other embodiments, the mechanism to urge the bone engagement member and the tip towards each other can include a rack and pinion structure. In such embodiments, the rack can include a tip, as described above. And the pinion can include a bone engagement member, as described above, and an actuator (e.g., a knob). In use, the actuator can be actuated (e.g., turned about an axis generally perpendicular to a direction of travel) to move the bone engagement member and the tip closer together to position bone.

Embodiments of the bone positioning guide may include any suitable materials. In certain embodiments, the bone positioning guide is fabricated from a radiolucent material such that it is relatively penetrable by X-rays and other forms of radiation, such as thermoplastics and carbon-fiber materials. Such materials are useful for not obstructing visualization of bones using an imaging device when the bone positioning guide is positioned on bones.

Embodiments of the bone positioning guide can be useful in operation for positioning a bone or bones during a medical procedure. Bone positioning can be useful, for instance, to correct an anatomical misalignment of bones and maintain an anatomically aligned position, such as in a bone alignment and/or fusion procedure. In some embodiments, the bone positioning guide is capable of reducing an angle between the first metatarsal and the second metatarsal from over <NUM> degrees (e.g., up to about <NUM> degrees) to about <NUM> degrees or less (e.g., to about <NUM>-<NUM> degrees), including to negative angles of about -<NUM> degrees. In some embodiments, the bone positioning guide is also capable of rotating the first metatarsal about its long axis with respect to the medial cuneiform from a rotational angle of over <NUM> degrees to a rotational angle of less than <NUM> degrees (e.g., to about <NUM> to <NUM> degrees).

In some embodiments, a bone preparation guide may be provided to facilitate the preparation of a bone. The bone preparation guide can be provided with a bone positioning guide, or either device can be provided or used independently. An example of a bone preparation guide <NUM> is shown in <FIG>. In some embodiments, the bone preparation guide <NUM> includes a body <NUM> defining a first guide surface <NUM> to define a first preparing plane and a second guide surface <NUM> to define a second preparing plane. A tissue removing instrument (e.g., a saw, rotary bur, osteotome, etc., not shown) can be aligned with the surfaces to remove tissue (e.g., remove cartilage or bone and/or make cuts to bone). The first and second guide surfaces <NUM>, <NUM> can be spaced from each other by a distance, (e.g., between about <NUM> millimeters and about <NUM> millimeters, such as between about <NUM> and about <NUM> millimeters). In the embodiment shown, the first and second guide surfaces are parallel, such that cuts to adjacent bones using the guide surfaces will be generally parallel.

In some embodiments, as shown in <FIG>, a first facing surface <NUM> is positioned adjacent the first guide surface <NUM> and/or a second facing surface <NUM> is positioned adjacent the second guide surface <NUM>. In such embodiments, the distance between the first guide surface and the first facing surface defines a first guide slot, and the distance between the second guide surface and the second facing surface defines a second guide slot. Each slot can be sized to receive a tissue removing instrument to prepare the bone ends. The first and second slots may be parallel or skewed. In the illustrated embodiment, the facing surfaces each contain a gap, such that the surface is not a single, continuous surface. In other embodiments, the facing surfaces can be a single, continuous surface lacking any such gap.

An opening <NUM> can be defined by the body <NUM> between the first and second guide surfaces. The opening can be an area between the guide surfaces useful for allowing a practitioner to have a visual path to bones during bone preparation and/or to receive instruments. In the embodiment shown, the opening extends across the body and a distance from a surface <NUM> opposite of the first facing surface <NUM> to a surface <NUM> opposite of the second facing surface <NUM>.

The embodiment shown also includes a first end <NUM> extending from the body <NUM> in a first direction and a second end <NUM> extending from the body in a second direction. The second direction can be different than the first direction (e.g., an opposite direction). As shown, each of the first end and the second end can include at least one fixation aperture <NUM> configured to receive a fixation pin (not shown in <FIG>) to secure the guide to a bone. As shown, such apertures may extend through the end at a vertical or skewed angle relative to a top surface of the guide.

The bone preparation guide <NUM> can also include a first adjustable stabilization member <NUM> engaged with the first end <NUM>. In some embodiments, the bone preparation guide can include a second adjustable stabilization member <NUM> engaged with the second end <NUM>. Each of the members can be threaded and engage a threaded aperture defined by the ends. The elevation of each end can be adjusted with respect to a bone by adjusting the stabilization member. In some embodiments, as shown, the stabilization members are cannulated such that they can receive a fixation pin.

As shown in <FIG> and <FIG>, the bone preparation guide can also include a spacer <NUM> extending downward from the body <NUM> and configured to be placed into a joint. In some embodiments, the spacer <NUM> is selectively engageable with the body. The spacer can have a first portion <NUM> configured to extend into a joint space and a second portion <NUM> engageable with the body <NUM>. In the embodiment shown, the spacer can be received within opening <NUM>, such that the spacer extends from the body in between the first and second guide surfaces. Such a spacer can be useful for positioning the body at a desired position with respect to a joint and for properly positioning the guide with respect to bones to be cut in more than one plane (e.g., three planes selected from more than one of a frontal plane, a transverse plane, and a sagittal plane). The distance between the spacer and the first guide surface can define a length of tissue removal (e.g., bone or cartilage to be cut) from a first bone, and the distance between the spacer and the second guide surface can define a length of tissue removal (e.g., bone or cartilage to be cut) from a second bone.

As shown in <FIG>/B and <NUM>, the bone preparation guide can also include a tissue removal location check member <NUM> engageable with the body <NUM> and configured to extend to a first bone and a second bone. The tissue removal location check member can have a first portion <NUM> configured to extend into contact with first and second bones and a second portion <NUM> engageable with the body. In the embodiments shown in <FIG> and <FIG>, the tissue removal location check member extends from the body at both the first and second guiding surfaces. In other embodiments, such as the embodiment shown in <FIG>, separate tissue removal location check members are provided for independent insertion into respective slots of the guide. Accordingly, embodiments of tissue removal location check members are useful for allowing a practitioner to see where a tissue removing instrument guided by the surfaces will contact the bone to be prepared.

Embodiments of the bone preparation guide can be useful in operation for guiding a preparation of a bone or bones at a targeted anatomy. Bone preparation can be useful, for instance, to facilitate contact between leading edges of adjacent bones, separated by a joint, or different portions of a single bone, separated by a fracture, such as in a bone alignment and/or fusion procedure.

Examples of methods (not claimed) are used for temporarily fixing an orientation of a bone or bones, for example, prior to or in conjunction with permanently fixing the orientation of the bone or bones. In general, the method of positioning a bone includes the steps of moving a bone from an anatomically misaligned position to an anatomically aligned position with respect to another bone and preparing an end of the moved bone and a facing end of another bone. In some embodiments, the end of at least one of the moved bone and the other bone is prepared after moving the bone into the aligned position. In certain embodiments, the bone is anatomically aligned in more than one plane with respect to another bone by applying a force to one bone at a single location, such that the bone both translates and rotates in response to the force. In certain embodiments, the moving step can be accomplished with a bone positioning device and/or the preparing step can be accomplished with a bone preparation guide, as described herein.

<FIG> depict fontal views of a bone positioning guide <NUM> on a foot <NUM> having a first metatarsal <NUM>, a medial cuneiform <NUM>, a second metatarsal <NUM>, and a third metatarsal <NUM>. <FIG> depicts a foot <NUM> with an uncorrected bunion deformity, while <FIG> depicts the foot <NUM> with an alignment corrected by the bone positioning guide <NUM>. Solid line L1 represents the starting location of the bone positioning guide <NUM> and dotted line L2 represents the finishing location of the bone positioning guide. As shown, as the bone positioning guide <NUM> is actuated it rotates with the first metatarsal <NUM> about an axis extending through the frontal plane as it pushes the first metatarsal <NUM> laterally in the transverse plane and plantarly in the sagittal plane. Accordingly, in this example, the position of the first metatarsal <NUM> is corrected with respect to the second metatarsal <NUM> generally in three planes by actuating a single bone positioning guide <NUM> to urge a bone engagement member <NUM> toward a tip <NUM>. <FIG> shows a top view of a foot <NUM> with an uncorrected bunion deformity, while <FIG> shows a top view of the foot <NUM> with an alignment corrected by the bone positioning guide <NUM>, emphasizing the rotational correction in the frontal plane and the lateral correction in the transverse plane.

<FIG> show three sequential images of a bone positioning guide <NUM> on a foot <NUM> positioning a first metatarsal <NUM> with respect to a second metatarsal <NUM>. <FIG> represents the beginning of the procedure, <FIG> the middle, and <FIG> the end. The orientation of the pins <NUM> is useful for visualizing the amount of rotation of the first metatarsal <NUM> in each image. With respect to <FIG>, it can be seen the bone positioning guide <NUM> and the first metatarsal <NUM> are rotating in the frontal plane in response to actuation of bone positioning guide <NUM>. Further, the angle between the first metatarsal <NUM> and second metatarsal <NUM> is reduced, as the space that can be seen between the first and second metatarsals in <FIG> is eliminated in <FIG>.

Each of the three potential planes of deformity will now be described in isolation. <FIG> show frontal plane views of a foot <NUM>. In <FIG>, the foot <NUM> is normal, while in <FIG> the foot is depicted with an uncorrected bunion deformity showing an isolated axial rotation of the first metatarsal <NUM>. Solid line L3 indicates the alignment of the first metatarsal <NUM> relative to ground, while dotted line L4 in <FIG> indicates the extent of axial rotation in the frontal plane.

<FIG> show transverse plane views of a foot <NUM>. In <FIG>, the foot <NUM> is normal, while in <FIG> the foot is depicted with an uncorrected bunion deformity showing an isolated transverse plane first metatarsal <NUM> deviation. Solid line L5 indicates the alignment of the second metatarsal <NUM> and solid line L6 indicates the proper alignment of the first metatarsal <NUM> relative to the second metatarsal <NUM>. The angle between these two lines forms the intermetatarsal angle (IMA). Dotted line L7 in <FIG> indicates the extent of transverse deviation.

<FIG> show sagittal plane views of a foot <NUM>. In <FIG>, the foot <NUM> is normal, while in <FIG> the foot is depicted with an uncorrected bunion deformity showing an isolated sagittal deviation of the first metatarsal <NUM>. Solid line L8 indicates the proper alignment of the first metatarsal <NUM>, while dotted line L9 in <FIG> indicates the extent of sagittal deviation.

A specific method (not claimed) includes the steps of engaging a bone engagement member with a first bone, placing a tip of the bone positioning guide in apposition to a second bone, the second bone being different from the first bone, and moving the bone engagement member with respect to the tip to change the position of the first bone with respect to the second bone in more than one plane. In some embodiments, after alignment, at least one of an end of the first bone and a facing end of a third bone are prepared (e.g., only the end of the first bone or both the end of the first bone and the end of the second bone), optionally using a preparation guide.

Example of the method (not claimed) includes the step of mobilizing a joint for a corrective procedure. For example, after creating surgical access to the joint and before moving the bones into an aligned position, tissue can be released to allow a bone, such as a metatarsal, to rotate freely. In some embodiments, obstructing bone may be excised (e.g., a dorsolateral flare of the metatarsal base, a plantar flare of the metatarsal base (sometimes referred to as a plantar condyle), part of an end of a metatarsal facing a cuneiform, or osteophyte) to further promote free rotation by creating relatively flat surfaces with respect to a frontal plane. An example of a dorsolateral flare F on a first metatarsal <NUM> of a foot <NUM> is shown in <FIG>. An example of a plantar flare PF on a first metatarsal <NUM> is shown in <FIG> also depicts a medial ridge MR, which, in some embodiments, can be engaged by the bone engaging member of a bone positioning guide.

Examples of methods (not claimed) can also include steps performed after preparing the ends of the bones. For example, the ends of the bones may be placed in apposition and optionally compressed together and the position of the bones can be fixed with one or more bone fixation devices (e.g., compressing bone screw, bone plate, bone staple, external fixator, intramedullary implant or nail) prior to a closing of the surgical access to the joint.

An exemplary method (not claimed) will now be described with respect to <FIG> depicting a foot <NUM> having a first metatarsal <NUM>, a medial cuneiform <NUM>, and a second metatarsal <NUM>. Note, unless otherwise indicated, the steps described need not be carried out in the order described.

After customary surgical preparation and access, a bone preparation instrument <NUM> can be inserted into the joint (e.g., first tarsal-metatarsal joint) to release soft tissues and/or excise the plantar flare from the base of the first metatarsal <NUM>, as shown in <FIG>. Excising the plantar flare may involve cutting plantar flare off the first metatarsal <NUM> so the face of the first metatarsal is generally planar. This step helps to mobilize the joint to facilitate a deformity correction. In some embodiments, the dorsal-lateral flare of the first metatarsal may also be excised to create space for the deformity correction (e.g., with respect to rotation of the first metatarsal). In certain embodiments, a portion of the metatarsal base facing the medial cuneiform can be removed during this mobilizing step.

An incision can be made and a tip <NUM> of a bone positioning guide <NUM> can be inserted on the lateral side of a metatarsal other than the first metatarsal <NUM>, such as the second metatarsal <NUM>. As shown in <FIG>, the tip can be positioned proximally at a base of the second metatarsal <NUM> and a third metatarsal <NUM> interface. A surface of a bone engagement member <NUM> can be placed on the proximal portion of the first metatarsal <NUM>. In some embodiments, the bone engagement member engages a medial ridge of the first metatarsal <NUM>. As shown, the main body member <NUM> of the positioning guide can be generally perpendicular to the long axis of the second metatarsal <NUM>.

As depicted in <FIG>, the actuator <NUM> can be actuated to extend the shaft <NUM> to reduce the angle (transverse plane angle between the first metatarsal and the second metatarsal) and rotate the first metatarsal about its axis (frontal plane axial rotation). The first metatarsal <NUM> can be properly positioned with respect to the medial cuneiform <NUM> by moving the bone engagement member <NUM> with respect to the tip <NUM>. In some embodiments, such movement simultaneously pivots the first metatarsal with respect to the cuneiform and rotates the first metatarsal about its longitudinal axis into an anatomically correct position to correct a transverse plane deformity and a frontal plane deformity. In certain embodiments, main body member <NUM> rotates in a generally lateral direction during this step. In some embodiments, fixation pins (not shown in <FIG>) can be inserted into the bones prior to the positioning step (e.g., freehand or using apertures in the guide as a template), and can be used to impart additional force (transverse, sagittal, and/or frontal plane rotational) to the first metatarsal <NUM>, if desired. The bone positioning guide <NUM> can hold the desired position of the first metatarsal <NUM> with respect to the second metatarsal <NUM>. After the desired correction is achieved, a fixation wire <NUM> can be inserted through a cannulation in the shaft <NUM> and driven into the first metatarsal <NUM> and the second metatarsal <NUM> to hold the corrected position.

As depicted in <FIG>, a joint spacer <NUM> can be positioned within the joint between the first metatarsal and the medial cuneiform.

As shown in <FIG>, a bone preparation guide <NUM> can be placed over the joint spacer <NUM> and engaged with the joint spacer to set a position and orientation of the bone preparation guide relative to the joint. As shown, the bone preparation guide <NUM> can be positioned proximal to the bone positioning guide <NUM> in longitudinal alignment with the long axis of the first metatarsal <NUM> and the medial cuneiform <NUM>, generally on the dorsal or dorsal-medial surface. In other embodiments, the spacer <NUM> is positioned after the guide <NUM> is provisionally placed on the bones. In yet other embodiments, bone preparation guide <NUM> and joint spacer <NUM> are placed simultaneously. In still other embodiments, bone preparation guide <NUM> is placed on the bones without using joint spacer <NUM> to aid with positioning.

As depicted in <FIG> and <FIG>, one or more fixation pins <NUM> can be inserted into apertures of the bone preparation guide <NUM> to secure the guide to the first metatarsal <NUM> and the medial cuneiform <NUM>. As shown, some pins <NUM> can be inserted at an angle or in a converging orientation to help prevent movement of the bone preparation guide <NUM> during a tissue removing step. As shown, two of the pins <NUM>, one on the first metatarsal and one on the medial cuneiform, are parallel to allow the bone preparation guide <NUM> to be removed from the foot without removing all the pins. After insertion of the pins <NUM>, the spacer <NUM> can optionally be removed in embodiments having a selectively engageable spacer (e.g., a joint spacer <NUM> that is physically removable from bone preparation guide <NUM>).

In some embodiments, the location of the intersection of the tissue removing instrument and the bone to be prepared is confirmed before bone preparation. In one embodiment, a tissue removing instrument location check member can be engaged with the preparation guide to visually confirm where a tissue removal instrument will contact the bone. In another embodiment, a tissue removal instrument is engaged with the preparation guide to visually confirm where the instrument will contact the bone. In either embodiment, such visual confirmation can include the use of an imaging device, such as an X-ray. If the position of the preparation guide is correct, additional fixation pins may be inserted through the apertures (e.g., angled apertures) to further fix the position of the preparation guide with respect to the first metatarsal and the medial cuneiform. In some embodiments, the spacer is reattached prior to further bone preparation steps.

In some embodiments, the end of the first metatarsal <NUM> facing the medial cuneiform <NUM> can be prepared with a tissue removing instrument <NUM> guided by a guide surface of bone preparation guide <NUM> (e.g., inserted through a slot defined by a first guide surface and a first facing surface). In some embodiments, the first metatarsal <NUM> end preparation is done after the alignment of the bones, e.g., by actuating bone positioning guide <NUM> before preparing the end of first metatarsal <NUM>. In other embodiments, the first metatarsal <NUM> end preparation is done before the alignment of the bones, e.g., by preparing the end of the first metatarsal <NUM> before actuating bone positioning guide <NUM>.

In addition, as shown in <FIG>, the end of the medial cuneiform <NUM> facing the first metatarsal <NUM> can be prepared with the tissue removing instrument <NUM> guided by a guide surface of bone preparation guide <NUM> (e.g., inserted through a slot defined by a second guide surface and a second facing surface). In some embodiments, the medial cuneiform <NUM> end preparation is done after the alignment of the bones. In yet other embodiments, the medial cuneiform <NUM> end preparation is done before the alignment of the bones. In embodiments that include cutting bone or cartilage, the cuneiform cut and the metatarsal cut can be parallel, conforming cuts. In the specific embodiment shown in <FIG>, a saw blade can be inserted through a first slot to cut a portion of the medial cuneiform and the saw blade can be inserted through a second slot to cut a portion of the first metatarsal (e.g., in some embodiments the medial cuneiform can be cut before the first metatarsal). Accordingly, in the embodiment shown, the cuts to both the first metatarsal and the medial cuneiform were preformed after the first metatarsal was positioned.

Any angled/converging pins can be removed and the bone preparation guide <NUM> can be lifted off the parallel pins <NUM>, as shown in <FIG>. The parallel pins can be referred to as "reference pins" which can serve as a reference in later steps to ensure that the corrected alignment of the first metatarsal <NUM> has been maintained. The joint spacer can also be removed before, after, or simultaneously with the bone preparation guide. In some embodiments, the bone positioning guide <NUM> is also removed from the foot.

The tissue (e.g., bone or cartilage slices) from the first metatarsal and the medial cuneiform can be removed from the joint site and the joint surfaces can be fenestrated, if desired. If the bone positioning guide was taken off the foot, it can be put back on, as shown in <FIG>, before the additional steps discussed below.

After preparation, the ends of the two bones can be placed in apposition and optionally compressed together by provisionally fixating the joint. For example, the two bones may be placed in apposition by placing the cut end of the first metatarsal <NUM> in abutment with the cut end of the medial cuneiform <NUM>. In some examples, the cut end of the first metatarsal <NUM> is placed adjacent to, and optionally in contact with, the cut end of the medial cuneiform <NUM>.

As shown in <FIG>, a compression pin, such as a threaded olive pin <NUM> can be inserted through the first metatarsal <NUM> and into the medial cuneiform <NUM> to provide compression and provisional fixation between the first metatarsal and the medial cuneiform. Additional compression pins can be inserted to provide additional stability. As shown, the parallel reference pins should be aligned during this step. In some embodiments, a practitioner checks for alignment of the parallel reference pins prior to insertion of the compression pin, and, if they are not aligned, adjusts the position of the first metatarsal until desired alignment is achieved.

Although they can be left in place, in some embodiments the parallel reference pins and bone positioning guide can be removed and a bone fixation device (e.g., two bone plates positioned in different planes, as shown) can be applied to stabilize the joint for fusion. <FIG> shows a first bone plate <NUM> positioned on a dorsal-medial side of the first metatarsal and medial cuneiform and a second bone plate <NUM> positioned on a medial-plantar side of the first metatarsal and the medial cuneiform. In other embodiments, such as the embodiment shown in <FIG>, the second bone plate <NUM> can be a helical bone plate positioned from a medial side of the cuneiform to a plantar side of the first metatarsal across the joint space. The plates can be applied with the insertion of bone screws.

As shown in <FIG>, the compression pin can be removed and the incision can be closed.

<FIG> A/B and 29A/B include examples of anatomically misaligned metatarsals and metatarsals that have been anatomically aligned using methods (not claimed) and/or instruments in accordance with the invention. <FIG> shows a left foot pre-operation and post-operation, while <FIG> shows a right foot pre-operation and post-operation. As can be seen from a comparison of the pre-operative images to the post-operative images, the patients' intermetatarsal angle (IMA) was significantly reduced. <FIG> show the correction of an axial rotation in a frontal rotational plane. <FIG> shows a pre-operative image and a post-operative image of a right foot. Drawings of a metatarsal <NUM> are also provided to illustrate the rotation. The rotation of the metatarsal can be seen by the position of sesamoid bones <NUM>, which are depicted as having been rotated under the first metatarsal <NUM> in the post-operative drawing. <FIG> shows pre-operative views of a left foot <NUM> and a right foot <NUM>. Again, by comparing the location of the sesamoid bones <NUM> with respect to a reference location, such as ground, the planter surface of the foot, and/or a cuneiform, it can be seen this patient's metatarsal is rotated out of alignment.

Examples of methods (not claimed) can be useful for positioning a bone or bones. Bone positioning can be useful, for instance, to correct an anatomical misalignment of bones and maintain an anatomically aligned position, such as in a bone alignment and/or fusion procedure. In some embodiments, an "anatomically aligned position" means that an angle of a long axis of a first metatarsal relative to a long axis of a second metatarsal is about <NUM> degrees or less in the transverse plane or sagittal plane. In certain embodiments, anatomical misalignment can be corrected in both the transverse plane and the frontal plane. In the transverse plane, a normal intermetatarsal angle ("IMA") between a first metatarsal and a second metatarsal is less than about <NUM> degrees. An IMA of between about <NUM> degrees and about <NUM> degrees is considered a mild misalignment of the first metatarsal and the second metatarsal. An IMA of greater than about <NUM> degrees is considered a severe misalignment of the first metatarsal and the second metatarsal. In some embodiments, methods (not claimed) are capable of anatomically aligning the bone(s) by reducing the IMA from over <NUM> degrees to about <NUM> degrees or less (e.g., to an IMA of about <NUM>-<NUM> degrees), including to negative angles of about -<NUM> degrees or until interference with the second metatarsal, by positioning the first metatarsal at a different angle with respect to the second metatarsal.

With respect to the frontal plane, a normal first metatarsal will be positioned such that its crista prominence is generally perpendicular to the ground and/or its sesamoid bones are generally parallel to the ground and positioned under the metatarsal. This position can be defined as a metatarsal rotation of <NUM> degrees. In a misaligned first metatarsal, the metatarsal is axially rotated between about <NUM> degrees to about <NUM> degrees or more. In some embodiments, methods (not claimed) are capable of anatomically aligning the metatarsal by reducing the metatarsal rotation from about <NUM> degrees or more to less than <NUM> degrees (e.g., to about <NUM> to <NUM> degrees) by rotating the metatarsal with respect to the medial cuneiform.

While various embodiments of bone positioning and preparing guide systems and methods (not claimed) have been described, it should be appreciated that the concepts of the disclosure can be altered in practice, e.g., based on the needs of the clinician, the patient undergoing the bone repositioning procedure, the specific anatomy being treated, and/or the target clinical outcome. As one example, the described systems and techniques may be modified to utilize a fulcrum about which rotation and/or pivoting of one bone relative to another bone occurs via bone positioning guide <NUM>. The fulcrum can establish and/or maintain space between adjacent bones being compressed between bone engagement member <NUM> and tip <NUM> of bone positioning guide <NUM>, preventing lateral translation or base shift of the bones during rotation and pivoting.

<FIG> illustrates a portion of a foot having a bunion caused by a misaligned first metatarsal <NUM> relative to second metatarsal <NUM>. <FIG> shows the foot of <FIG> after being anatomically aligned to correct the misalignment using bone positioning guide <NUM>. As shown, first metatarsal <NUM> has been rotated counterclockwise in the frontal plane (from the perspective of a patient, clockwise from the perspective of a frontal observer) and also pivoted in the transverse plane (e.g., such that the angle <NUM> between the first metatarsal <NUM> and second metatarsal <NUM> is reduced). Rotation and pivoting of first metatarsal <NUM> can cause the base <NUM> of first metatarsal <NUM> to shift relative to medial cuneiform <NUM>. In general, it is desirable that the offset 354A between first metatarsal <NUM> and medial cuneiform <NUM> be reduced to zero (e.g., such that there is substantially no offset) after rotation and pivoting. As shown in the illustrated application of <FIG>, however, the base <NUM> of first metatarsal <NUM> abutting medial cuneiform <NUM> has shifted toward second metatarsal <NUM>. This results in a transverse offset 354B of first metatarsal <NUM> toward second metatarsal <NUM>, causing base compression between first metatarsal <NUM> and second metatarsal <NUM>.

To help avoid the base shift and offset 354B observed in <FIG>, a clinician can insert a fulcrum in the notch between first metatarsal <NUM> and second metatarsal <NUM> at the base of the metatarsals (e.g., adjacent respective cuneiform) before actuating bone positioning guide <NUM>. The fulcrum can provide a point about which first metatarsal <NUM> can rotate and/or pivot while helping minimize or avoid base compression between the first metatarsal and the second metatarsal. In addition, use of the fulcrum may cause first metatarsal <NUM> and medial cuneiform <NUM> to be better angled relative to the guide slots of bone preparation guide <NUM> (once installed), providing a better cut angle through the guide slots then without use of the fulcrum. This can help reduce or eliminate unwanted spring-back, or return positioning, of first metatarsal <NUM> after removing bone positioning guide <NUM>.

<FIG> illustrates a bone positioning operation in which a fulcrum <NUM> is positioned at an intersection between a first bone and a second bone, where the first bone is being realigned relative to the second bone. In particular, <FIG> illustrates fulcrum <NUM> being positioned between first metatarsal <NUM> and second metatarsal <NUM>. Fulcrum <NUM> may be positioned distally of bone preparation guide <NUM> between first metatarsal <NUM> and second metatarsal <NUM> as shown in <FIG> or, in other applications, proximally of the guide (e.g., at the ends of the first and second metatarsals abutting the medial and intermediate cuneiform bones, respectively).

When used, the clinician can insert fulcrum <NUM> between first metatarsal <NUM> and second metatarsal <NUM> (or other adjacent bones, when not performing a metatarsal realignment) at any time prior to actuating bone positioning guide <NUM>. In different embodiments, fulcrum <NUM> can be inserted between first metatarsal <NUM> and second metatarsal <NUM> before or after inserting joint spacer <NUM> and/or placing bone preparation guide <NUM> over the joint being operated upon. In one embodiment, the clinician prepares the joint being operated upon to release soft tissues and/or excise the plantar flare from the base of the first metatarsal <NUM>, as discussed above. Either before or after installing bone positioning guide <NUM> over adjacent bones, for example with bone engagement member <NUM> positioned in contact with the medial ridge of the first metatarsal <NUM> and tip <NUM> positioned in contact with second metatarsal <NUM>, the clinician inserts fulcrum <NUM> at the joint between the first metatarsal and the second metatarsal. The clinician can subsequently actuate bone positioning guide <NUM> (e.g., rotate knob <NUM>). In the case of a left foot as shown in <FIG>, actuation of bone positioning guide <NUM> causes the first metatarsal <NUM> to rotate counterclockwise in the frontal plane (from the perspective of a patient) and also pivot in the transverse plane about the fulcrum. In the case of a right foot (not shown), actuation causes the first metatarsal to rotate clockwise in the frontal plane (from the perspective of a patient) and also pivot in the transverse plane about the fulcrum. Thus, for both feet, actuation of bone positioning guide <NUM> can supinate the first metatarsal in the frontal plane and pivot the first metatarsal in the transverse plane about fulcrum <NUM>. While use of fulcrum <NUM> can minimize or eliminate base compression between adjacent bones being operated upon, in other embodiments as discussed above, the described systems and techniques can be implemented without using the fulcrum.

In instances in which fulcrum <NUM> is used, any suitable mechanical instrument can be used for the fulcrum. <FIG> is a perspective view of one example instrument that can be used as fulcrum <NUM>. In this embodiment, fulcrum <NUM> has a generally rectangular shape and tapers in thickness along at least a portion of the length from the trailing end <NUM> to the leading end <NUM>. Fulcrum <NUM> may be sized sufficiently small so that it does not interfere with placement of bone preparation guide <NUM> on the joint being worked upon. In some embodiments, the clinician is provided a system containing multiple different size fulcrums and allowed to choose the specific sized fulcrum desired for the specific procedure being performed. <FIG> illustrates an example kit or system of different sized fulcrums, labeled with exemplary "width x thickness" sizes, that may be provided to a clinician in such an embodiment. In some examples, fulcrum <NUM> has a width ranging from <NUM> millimeters to <NUM> millimeters (e.g., about <NUM> millimeters to about <NUM> millimeters) and a thickness ranging <NUM> millimeter to <NUM> millimeters (e.g., about <NUM> millimeters to about <NUM> millimeters), although fulcrums with different dimensions can be used. While <FIG> and <FIG> illustrate one example style of fulcrum, other mechanical instruments providing a fulcrum functionality can be used without departing from the scope of the disclosure. For instance, as alternative examples, a surgical pin or screw driver head may be used as fulcrum <NUM>.

As discussed above, bone positioning guide <NUM> can have a variety of different configurations, including a configuration in which bone engagement member <NUM> is laterally offset from tip <NUM>. <FIG> is a perspective view of bone positioning guide <NUM> showing an example arrangement in which bone engagement member <NUM> is laterally offset from tip <NUM>. In this embodiment, the first end <NUM> of main body member <NUM> is laterally offset from an axis <NUM> extending through shaft <NUM> and a geometric center of bone engagement member <NUM>. In particular, in the illustrated configuration, tip <NUM> is offset laterally in the direction of the cuneiform relative to bone engagement member <NUM>. As a result, when bone positioning guide <NUM> is actuated, e.g., by rotating knob <NUM>, a moment can be created by the offset tip. This can cause the end of the first metatarsal <NUM> adjacent the proximal phalange to pivot toward the second metatarsal <NUM> and close angle <NUM>, e.g., while the opposite end of the first metatarsal adjacent the medial cuneiform pivots away from the second metatarsal. This can also help avoid base compression between the first and second metatarsals.

As discussed above with respect to <FIG> and <FIG>, a joint spacer <NUM> can be positioned in a joint between a first metatarsal and a medial cuneiform before placing bone preparation guide <NUM> over the joint spacer. Bone preparation guide <NUM> can have an opening <NUM> (<FIG>) sized to receive joint spacer <NUM>. In some examples, opening <NUM> of bone preparation guide <NUM> is size and/or shaped indexed to joint spacer <NUM> such that there is substantially no, or no, relative movement between the guide and spacer (once bone preparation guide <NUM> is placed over joint spacer <NUM>). This can arrangement can ensure that bone preparation guide <NUM> is positioned precisely at the location where guided by joint spacer <NUM>.

In practice, once bone preparation guide <NUM> is placed over joint spacer <NUM>, the guide slots of the bone positioning guide may not be perfectly aligned with the ends of the bones (e.g., first metatarsal <NUM> and medial cuneiform <NUM>) to be cut through the guide slots. Accordingly, in other configurations, opening <NUM> of bone preparation guide <NUM> may not be sized and/or shaped and/or indexed to joint spacer <NUM>. In other words, opening <NUM> of bone preparation guide <NUM> may have a different cross-sectional size and/or shape than the cross-sectional size and/or shape of joint spacer <NUM>. In these configurations, bone preparation guide <NUM> may actuate or rotate about an axis extending through the length of joint spacer <NUM>. As a result, after the clinician places bone preparation guide <NUM> over joint spacer <NUM>, the clinician may rotate bone preparation guide <NUM> around joint spacer <NUM> until the guide slots of the bone preparation guide are better aligned with the ends of the bones to be cut (e.g., first metatarsal <NUM> and medial cuneiform <NUM>). Depending on the configuration of opening <NUM> of bone preparation guide <NUM> and the configuration of joint spacer <NUM>, the guide may rotate freely (e.g., <NUM> degrees) around the joint spacer (e.g., seeker) or within a bounded angular range (e.g., from plus <NUM> degrees to minus <NUM> degrees from a normal position).

<FIG> illustrates one example configuration of a joint spacer <NUM> that can allow bone preparation guide <NUM> to rotate around the spacer (e.g., seeker). As shown in the illustrated example, joint spacer <NUM> has a proximal portion <NUM> having a cylindrical cross-section and a distal portion <NUM> having a rectangular cross-section. A leading edge of the distal portion <NUM> is insertable into the joint between the first metatarsal <NUM> and the medial cuneiform <NUM>. Once bone preparation guide <NUM> is inserted over joint spacer <NUM>, body <NUM> of the guide (<FIG>) may be positioned about the proximal portion <NUM>. This can allow the guide to be rotated around the proximal portion.

In other configurations, opening <NUM> of bone preparation guide <NUM> may be size and/or shape indexed to the cross-sectional size and/or shape of joint spacer <NUM> but still provide relative rotation between the two components. For example, opening <NUM> may have a circular cross-section sized and shaped to receive proximal portion <NUM> of joint spacer <NUM> from <FIG>. Because both opening <NUM> of bone preparation guide <NUM> and proximal portion <NUM> of joint spacer <NUM> have circular cross-sections in such an embodiment, the two components may rotate relative to each other. <FIG> is a perspective view of an example configuration of bone preparation guide <NUM> having an opening <NUM> with circular cross-sectional shape. <FIG> is a perspective view of the example bone positioning guide of <FIG> shown with joint spacer <NUM> from <FIG> inserted into the guide.

Claim 1:
A metatarsal correction system comprising:
a bone preparation guide (<NUM>) comprising a body (<NUM>) defining a guide surface (<NUM>, <NUM>) configured to be positioned over an end of a bone, the guide surface (<NUM>, <NUM>) being configured to guide a tissue removing instrument for cutting the end of the bone, wherein the bone is at least one of a first metatarsal (<NUM>) and a medial cuneiform (<NUM>);
a bone positioning guide (<NUM>) configured to be positioned on a medial side of the first metatarsal (<NUM>) and on a lateral side of a metatarsal (<NUM>, <NUM>) other than the first metatarsal, the bone positioning guide comprising a mechanism that is configured to be operated to move the first metatarsal in at least a transverse plane to close an intermetatarsal angle between the first metatarsal and a second metatarsal; and
a fixation device (<NUM>, <NUM>) positionable across a tarsal-metatarsal joint separating the first metatarsal (<NUM>) from the medial cuneiform (<NUM>), the fixation device being configured to fixate a moved position of the first metatarsal relative to the medial cuneiform for fusion.