# Patent

## Title
Devices and method of achieving bone fusion

## Abstract

A method for fusing bones using a guide pin and a fastener is disclosed. The method includes inserting a guide pin into two bones. The guide pin including at least one radial marking. The method also including imaging the two bones and guide pin and analyzing the position of the at least one radial marking of the guide pin relative to the two bones. In addition, the method includes selecting a fastener, inserting a drill over the guide pin, drilling an opening through at least one of the two bones, and inserting the fastener into the opening. The guide pin may include an exterior surface with a first end and a second end, a cutting edge at the first end, and at least one radial marking near the first end. A system including a guide pin, a fastener, and a drill is also disclosed.

## Background
FIELD OF THE INVENTION
The present invention relates generally to general surgery, orthopaedic implants used for achieving bone fusion. More specifically, but not exclusively, the present invention relates to a method for achieving bone fusion using guide pins and fasteners.
BACKGROUND OF THE INVENTION
Bone fusion techniques generally leave the physician unable to view the positioning or location of the fusion implants during the surgical procedure and may result in decreased probability of fusion at the desired location or in the desire position. Generally, in small bone surgery screws are used across a joint or fracture site and the surgeon will need to use inaccurate depth gages, depth probes or other tools in an attempt to determine what size screw is needed after an opening in the bones has been drilled. Current methods generally include trial and error for placement of the screw and determining proper screw length.
SUMMARY OF THE INVENTION
Aspects of the present invention provide a guide pin and bone fastener for use in a method of fusing bones.
In one aspect, provided herein is a guide pin that includes an exterior surface with a first end and a second end, a cutting edge on at least the first end, and at least one radial marking near the first end.
In another aspect, provided herein is a system for bone fusion including a guide pin, fastener, and drill. The guide pin has an exterior surface with at least one cutting end. The guide pin also includes at least one radial marking near the at least one cutting end. The fastener includes a head portion with a superior end and an inferior end and a shaft portion that has a smooth end and a threaded end. The smooth end of the shaft portion is joined to the inferior end of the head portion. The drill is configured to slidingly engage the exterior surface of the guide pin to drill an opening.
In yet another aspect, provided herein is a surgical method for fusing bones that includes the steps of inserting a guide pin into two bones. The guide pin has at least one radial marking. The method also includes the step of imaging the two bones and the guide pin and the step of analyzing the position of the at least one radial marking of the guide pin relative to the two bones. In addition, the method includes the step of selecting a fastener, inserting a drill over the guide pin, drilling an opening through at least one of the two bones, and inserting the fastener into the opening.
These, and other objects, features and advantages of this invention will become apparent from the following detailed description of the various aspects of the invention taken in conjunction with the accompanying drawings.



BRIEF DESCRIPTION OF DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and together with the detailed description herein, serve to explain the principles of the invention. The drawings are only for purposes of illustrating preferred embodiments and are not to be construed as limiting the invention. It is emphasized that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. The foregoing and other objects, features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of one embodiment of a guide pin, in accordance with an aspect of the present invention;
FIG. 2 is a side view of the guide pin of FIG. 1, in accordance with an aspect of the present invention;
FIG. 3 is a side view of the first end of the guide pin of FIG. 1, in accordance with an aspect of the present invention;
FIG. 4 is a top perspective view of one embodiment of a fastener, in accordance with an aspect of the present invention;
FIG. 5 is a bottom perspective view of the fastener of FIG. 3, in accordance with an aspect of the present invention;
FIG. 6 is a side view of the fastener of FIG. 3, in accordance with an aspect of the present invention;
FIG. 7 is a side view of the guide pin of FIG. 1 aligned with the fastener of FIG. 3, in accordance with an aspect of the present invention;
FIG. 8 is a medial view of the bones of a right foot with the guide pin of FIG. 1 inserted through two bones, in accordance with an aspect of the present invention;
FIG. 9 is a lateral view of the right foot of FIG. 8, in accordance with an aspect of the present invention;
FIG. 10 is a posterior view of the right foot of FIG. 9 with the fastener of FIG. 4 inserted over the guide pin of FIG. 1, in accordance with an aspect of the present invention;
FIG. 11 is a posterior view of the right foot of FIG. 9 after removal of the guide pin, in accordance with an aspect of the present invention;
FIG. 12 is a medial view of the right foot of FIG. 11, in accordance with an aspect of the present invention; and
FIG. 13 depicts one embodiment of a surgical method for using the guide pin of FIG. 1 to insert a fastener, in accordance with an aspect of the present invention.



DETAILED DESCRIPTION FOR CARRYING OUT THE INVENTION
Generally stated, disclosed herein is one embodiment of a guide pin and a fastener. Further, a surgical method for using the guide pin and fastener is discussed.
In this detailed description and the following claims, the words proximal, distal, anterior, posterior, medial, lateral, superior and inferior are defined by their standard usage for indicating a particular part of a bone or implant according to the relative disposition of the natural bone or directional terms of reference. For example, “proximal” means the portion of a device or implant nearest the torso, while “distal” indicates the portion of the device or implant farthest from the torso. As for directional terms, “anterior” is a direction towards the front side of the body, “posterior” means a direction towards the back side of the body, “medial” means towards the midline of the body, “lateral” is a direction towards the sides or away from the midline of the body, “superior” means a direction above and “inferior” means a direction below another object or structure.
Similarly, positions or directions may be used herein with reference to anatomical structures or surfaces. For example, as the current devices and methods are described herein with reference to use with the bones of the foot, the bones of the foot, ankle and lower leg may be used to describe the surfaces, positions, directions or orientations of the devices, instrumentation and methods. Further, the devices and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to one side of the body for brevity purposes. However, as the human body is relatively symmetrical or mirrored about a line of symmetry (midline), it is hereby expressly contemplated that the device and methods, and the aspects, components, features and the like thereof, described and/or illustrated herein may be changed, varied, modified, reconfigured or otherwise altered for use or association with another side of the body for a same or similar purpose without departing from the spirit and scope of the invention. For example, the devices and methods, and the aspects, components, features and the like thereof, described herein with respect to the right foot may be mirrored so that they likewise function with the left foot. Further, the devices and methods, and the aspects, components, features and the like thereof, disclosed herein are described with respect to the foot for brevity purposes, but it should be understood that the devices and methods may be used with other bones of the body having similar structures, for example the upper extremity, and more specifically, with the bones of the wrist, hand, and arm.
Referring to the drawings, wherein like reference numerals are used to indicate like or analogous components throughout the several views, and with particular reference to FIGS. 1-3, there is illustrated an exemplary embodiment guide pin 100. The guide pin 100 may be, for example, a cylindrical rod including a first end 102 and a second end 104. The terms “guide pin,” “cylindrical rod,” “guide wire,” and “pin” may be used interchangeably herein as they essentially describe the same device. The first end 102 may include a tip 106 and the tip 106 may be a sharp cutting point. The tip 106 may penetrate a patient's soft tissue and/or bone. In alternative embodiments, the guide pin 100 may have a tip 106 at the first end 102 and the second end 104. The guide pin 100 as shown in FIGS. 1-3 may also include a smooth exterior surface 110. In alternative embodiments, the exterior surface 110 may include threads (not shown) adjacent to the tip 106.
The guide pin 100 may also include at least one circumferential indentation, notch, radial marking or recess 108 near the first end 102. The terms “indentation,” “notch,” “radial marking” and “recess” may be used interchangeably herein as they essentially describe the same structure. In the depicted embodiments, the guide pin 100 includes three recesses 108, although any number of recesses is contemplated, for example, two or four recesses 108. In one embodiment the recesses 108 may be positioned at a distance (A), for example, about 5 mm to 20 mm, at a distance (B), for example, about 10 mm to 30 mm, and at a distance (C), for example, about 20 mm to 40 mm from the tip 106 of the guide pin 100, as shown in FIG. 3. In the depicted embodiment, shown in FIGS. 1-3, the distances of the recesses 108 from the tip 106 may be 16 mm for (A), 20 mm for (B) and 32 mm for (C). The distances (A), (B), and (C) may be measured from the tip 106 to the distal end of the recesses 108, or the side of the recesses 108 closest to the second end 104. The distances (A), (B), and (C) may correspond, for example, to the various thread lengths of a given sized bone screw, described in greater detail below, that may be used for insertion across the joint. The guide pin 100 may also be used to measure the overall length of the screw that is needed for insertion into the bones or across a joint or bone fracture, as described in greater detail below. Thus, the overall length of the screw and the thread length of the screw may be selected using the guide pin 100 to ensure the two bone fragments are adequately compressed and joined together. In addition, the recesses 108 may have a width of, for example, 1 mm to 3 mm and may be recessed a depth of, for example, about 0.20 mm to 0.50 mm from the exterior surface 110. The recesses 108 may also be circumferential around the guide pin 100 or only extend around a portion or partially around the guide pin 100. The guide pin 100 may also be used as a drill guide for inserting a drill into a patient's bone or across a patient's joint.
By way of specific example, the guide pin 100 may be of the type described above with reference to FIGS. 1-3, but may only include, for example, two recesses 108 positioned at distances (B) and (C). The distances (B) and (C) may correspond, for example, to two different size thread lengths of a given sized bone screw, as described in greater detail below. In this embodiment if neither of the recesses 108 at distances (B) or (C) crosses the joint space, then a bone screw with a shorter thread length than the thread lengths corresponding to distances (B) and (C) will be selected.
Referring now to FIGS. 4-6, a fastener 200 is shown. The terms “bone screw,” “fastener,” “fixator,” “elongate member,” and “screw” may be used interchangeably herein as they essentially describe the same type of device. The bone screw 200 may include a head portion 202 and a shaft portion 212. The head portion 202 may include a superior end 204 and an inferior end 206. The superior end 204 of the head portion 202 may have a tool engagement opening 208 and a cannulation or center hole 210, as shown in FIG. 4. The tool engagement opening 208 may have a multi-lobed shape as shown in FIG. 4, although other polygonal shapes are also contemplated. The shaft portion 212 may include a smooth end 214 and a threaded end 216 for engaging a patient's bone, as seen in FIGS. 10-12. The bone screw 200 may be, for example, available in multiple sizes with threaded ends 216 of various lengths to correspond to the distances (A), (B), and (C) of the guide pin 100. By way of specific example, as shown in FIG. 7, the threaded end 216 of fastener 200 corresponds to the distance (C) of the guide pin 100. The threaded end 216 of the shaft portion 212 may also include at least one cutting tip 218, as shown in FIG. 5, to assist in insertion into the patient's bone. In the embodiment shown in FIG. 5, the threaded end 216 includes four cutting tips 218.
A surgical method using the guide pin 100 and fastener 200 is shown in FIGS. 8-13. As shown in FIG. 8, after exposure of the surgical site, a guide pin 100 is inserted into two adjacent bones in the foot 300, for example, through the calcaneous bone 310 and into the talus bone 320 crossing the joint space between the bones. After insertion of the guide pin 100, at least one image, for example, using fluoroscopy, may be taken of the bones 310, 320 and the guide pin 100. The at least one image may be used to check the position of the guide pin 100, the position of the radial markings 108, and to ensure that the guide pin 100 crosses the space between the bones 310, 320. The image will be used to determine the location of the recesses 108 relative to the joint space, for example, the joint space between the bones 310, 320. The location of the recesses 108 will then be analyzed to determine the necessary thread length 216 of the bone screw 200 for insertion, alignment, and adequate compression across the joint. The positioning of the recesses 108 of the guide pin 100 allows the surgeon to determine the thread length of the screw. For example, as shown in FIG. 8, the recesses 108 at distance A, B and C all extend through the joint space and into the bone 320. Based on the positioning of the recess 108 at distance C, a screw having a thread length 216 of distance C, as shown in FIG. 7, should be selected to ensure the threads of the screw all extend past the bone joint space. Next, a depth gauge may be aligned with the portion of the guide pin 100 extending out of the patient's incision or the screw entry point after the desired position of the guide pin 100 is obtained. The depth gauge may be used to measure the overall length of the screw that is needed. A screw may then be selected based on the measurements for the thread length 216 and overall screw length for insertion into a bone or across a joint as well as to ensure proper fusion orientation of the bones.
Once the bone screw 200 is selected, a drill may be inserted over the guide pin 100 and guided along the exterior surface 110 of the guide pin 100 from the second end 104 to the first end 102 to create an opening 112 for insertion of a bone screw 200, as shown in FIG. 9. A drill guide and/or tissue protector, not shown, may also be used during the insertion of the guide pin 100 and/or during the drilling of the opening 112 to assist in guiding the insertion of the guide pin 100 and the screw 200 as well as to protect the surrounding soft tissue. After the opening 112 is drilled, the drill may be removed and the drill guide as well as the tissue protector may be removed. Then the selected bone screw 200 may be inserted into the opening 112 by aligning the cannulation 210 of the bone screw 200 with the guide pin 100 and threading the screw 200 into the bones over the guide pin 100, as shown in FIG. 10. As the screw 200 is inserted into the patient's bones 310, 320 a compression force across the joint or fracture should be maintained. Once the bone screw 200 is fully inserted into the patient's bones 310, 320, the guide pin 100 may be removed. As shown in FIG. 12, the bone screw 200 will pass through the joint between the bones 310, 320 to hold the bones 310, 320 in a desired position for bone fusion.
Referring now to FIG. 13, the surgical method may include inserting a guide pin across the space between two bones 400. Next an image of the bone joint space and guide pin may be taken 410. The method may also include analyzing the depth and position of the radial markings of the guide pin 420 to determine the necessary thread length of the fastener to ensure proper bone positioning post implantation. Then a fastener may be selected 430 using the measured thread length and a drill may be selected and inserted over the guide pin to drill an opening in the bones 440. After the opening is drilled the selected fastener may be inserted into the bones and across the joint through the opening 450.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has”, and “having”), “include” (and any form of include, such as “includes” and “including”), and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes,” or “contains” one or more steps or elements possesses those one or more steps or elements, but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes,” or “contains” one or more features possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed.
The invention has been described with reference to the preferred embodiments. It will be understood that the architectural and operational embodiments described herein are exemplary of a plurality of possible arrangements to provide the same general features, characteristics, and general system operation. Modifications and alterations will occur to others upon a reading and understanding of the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations.

## Claims

1. A guide pin, comprising:
an exterior surface with a first end and a second end;
a cutting edge on at least the first end; and
at least three radiolucent radial markings positioned between the first end and a midpoint of the exterior surface, wherein the at least three radiolucent radial markings comprises:
a first radiolucent radial marking positioned a first distance from the cutting edge;
a second radiolucent radial marking positioned a second distance from the cutting edge; and
a third radiolucent radial marking positioned a third distance from the cutting edge;
wherein the first radiolucent radial marking is positioned nearest the cutting edge, the third radiolucent radial marking is positioned farthest from the cutting edge, and the second radiolucent radial marking is positioned between the first radiolucent radial marking and the third radiolucent radial marking;
wherein the distance between the first radiolucent radial marking and the second radiolucent radial marking is smaller than the distance between the second radiolucent radial marking and the third radiolucent radial marking; and
wherein the at least three radiolucent radial markings comprise:
a center section with a first end and a second end extending a distance therebetween, wherein the distance defines a width;
a first beveled portion extending from the exterior surface of the guide pin to the first end of the center section; and
a second beveled portion extending from the exterior surface of the guide pin to the second end of the center section.

2. The guide pin of claim 1, wherein the cutting edge includes a pointed tip.

3. The guide pin of claim 1, wherein the first radiolucent radial marking has a distance ranging from about 5 mm to 20 mm from the pointed tip of the cutting edge.

4. The guide pin of claim 1, wherein the second radiolucent radial marking has a distance ranging from about 10 mm to 30 mm from the pointed tip of the cutting edge.

5. The guide pin of claim 1, wherein the third radiolucent radial marking has a distance from about 20 mm to 40 mm from the pointed tip of the cutting edge.

6. The guide pin of claim 1, wherein the width of the at least three radiolucent radial markings ranges from about 1 mm to 3 mm and the center section of the at least one radiolucent radial marking is recessed to a depth ranging from 0.20 mm to 0.50 mm.

7. The guide pin of claim 1, wherein the exterior surface forms a first cylinder with a first diameter, the center section forms a second cylinder with a second diameter, and the second diameter is smaller than the first diameter; and
wherein the center section and the exterior surface are positioned to extend parallel to each other.

8. The guide pin of claim 1, wherein the center section is cylindrical.

9. The guide pin of claim 1, wherein the at least three radiolucent radial markings are visible using fluoroscopy when inserted into at least one bone.