EXTRACORPOREAL BONE COMPRESSING LINK AND APPARATUS AND METHOD USING SAME

Abstract

An extracorporeal bone compressing link and apparatus and method using same. Active devices that incorporate the extracorporeal bone compressing link can transport and compress bone through external means by acting on conventional bone fasteners including but not limited bone fasteners including but not limited to screws, pins or wires that penetrate through the skin and fixate into bone.

Claims

1. An extracorporeal link for connecting percutaneous bone fasteners comprising an element wherein: (a) the element comprises a plurality of transverse holes, wherein (i) the plurality of transverse holes are located about the element, and (ii) each transverse hole in the plurality of transverse holes is capable of allowing a bone fastener to pass through the transverse hole in the plurality of transverse holes to secure to one or more bone segments; (b) the element is configured in a first configuration; (c) the element is operable for being held under force in a second configuration; and (d) the element is operable to move toward the first configuration after being released from the force, wherein (i) the movement toward the first configuration is capable of applying moments and forces to the bone fastener by mis-aligning the link fastener holes, and (ii) the moments and forces capable of being applied to the bone fastener are operable to act through the skin to transport and compress the one or more bone segments.

2. The extracorporeal link of claim 1, wherein the extracorporeal link is operatively positioned in a plurality of bone fragments.

3. The extracorporeal link of claim 1, wherein the material comprises one or more cross-sectional geometries.

4. The extracorporeal link of claim 1, wherein (a) each transverse hole in the plurality of transverse holes is capable of guiding the bone fastener, and (b) the bone fastener is positioned through the extracorporeal link, skin, and the bone.

5. The extracorporeal link of claim 1, wherein the movement toward the first configuration after being released from the force operatively positions the bone fastener to fixate, move or compress the bone at a desired direction.

6. The extracorporeal link of claim 1, wherein the extracorporeal link is held by a restraining instrument in a sterile kit.

7. The extracorporeal link of claim 6, wherein the restraining instrument comprises a restrainer selected from a group consisting of pliers, power screws, sliding platens, forceps, needle drivers, and pin tower tubes.

8. The extracorporeal link of claim 6, wherein the sterile kit comprises the extracorporeal link, the restraining instrument, a plurality of bone fasteners, and a plurality of pin tower tubes.

9. The extracorporeal link of claim 1, wherein the extracorporeal link is operatively connected to a protective cover.

10. The extracorporeal link of claim 9, wherein the protective cover comprises a material selected from a group consisting of plastic, rubber, latex, foam and combinations thereof.

11. The extracorporeal link of claim 9, wherein the protective cover is movable and operates to cover cut bone fasteners or release other shape changing features of the link.

12. The extracorporeal link of claim 9, wherein the protective cover can act on the link to increase or decrease the magnitude of the moments and forces applied to the bone fastener.

13. The extracorporeal link of claim 12, wherein the protective cover is movable or contains an adjustor that acts on the link to increase or decrease the magnitude of the moments and forces applied to the bone fastener.

14. The extracorporeal link of claim 13, wherein the protector cover contains the adjustor, and the adjustor is a screw.

15. An apparatus for percutaneous bone fastening comprising: (a) an extracorporeal link, wherein (i) the extracorporeal link comprises a plurality of transverse holes, (ii) the plurality of transverse holes are located about the extracorporeal link, (iii) each transverse hole in the plurality of transverse holes is capable of allowing a bone fastener to pass through the transverse hole in the plurality of transverse holes to secure to one or more bone segments, (iv) the extracorporeal link is capable of being configured in a first configuration, and (v) the extracorporeal link is configured in a second configuration; and (b) a restraining instrument, wherein (i) the extracorporeal link is operatively positioned by the restraining instrument, (ii) the operative positioning of the instrument holds the extracorporeal link in the second configuration, and (iii) when released from the operative positioning of the restraining instrument, the extracorporeal link operably moves toward the first configuration to apply moments and forces to the bone fastener by mis-aligning the traverse holes.

16. The apparatus of claim 15, wherein the movement toward the first configuration is capable of applying moments and forces to the bone fastener.

17. The apparatus of claim 16, wherein the moments and forces capable of being applied to the bone fastener are operable to act through the skin to transport and compress the one or more bone segments.

18. The apparatus of claim 15, wherein the restraining instrument comprises a restrainer selected from a group consisting of pliers, power screws, sliding platens, forceps, needle drivers, and pin tower tubes.

19. A method for using an extracorporeal link for connecting percutaneous bone fasteners, the method comprising: (a) selecting an element, wherein (i) the element comprises a plurality of transverse holes, (ii) the plurality of transverse holes are located about the element, (iii) each transverse hole in the plurality of transverse holes is capable of allowing a bone fastener to pass through the transverse hole in the plurality of transverse holes to secure to one or more bone segments, and (iv) the element is configured in a first configuration; (b) restraining the element in a second configuration, wherein the element is restrained using external force; (c) positioning the element near, but not proximate to, one or more bone segments; (d) passing a plurality of bone fasteners through the plurality of transverse holes; and (e) releasing the element from the external force, wherein (i) responsive to releasing the element from the external force, the element moves toward the first configuration, (ii) the movement toward the first configuration applies moments and forces to the plurality of bone fasteners by mis-aligning the link fastener holes, and (iii) the moments and forces being applied to the plurality of bone fasteners act through the skin to transport and compress the one or more bone segments.

20. The method of claim 19, wherein the positioning of the element adjusts the moments and forces being applied to the plurality of bone fasteners.

21. The method of claim 19, wherein the external force is applied by a restraining instrument.

22. The method of claim 19, wherein the restraining instrument comprises a restrainer selected from a group consisting of pliers, power screws, sliding platens, forceps and needle drivers and pin tower tubes.

23. A method for making an extracorporeal link for connecting percutaneous bone fasteners, the method comprising: (a) selecting a material, wherein (i) the material comprises a memory-shape metal, and (ii) the material is in a first configuration; (b) cooling the material, wherein (i) the material is operable for being reconfigured to a second configuration, (ii) the material is capable of remaining in the second configuration absent an external force, and (iii) the material is capable of moving toward the first configuration at an elevated temperature; (c) responsive to cooling the material, reconfiguring the material into the second configuration; (d) responsive to reconfiguring the material, restraining the material in a restraining instrument, wherein the restraining instrument restrains the material in the second configuration at the elevated temperature; and (e) containing the extracorporeal link within a cover for protecting the extracorporeal link.

24. The method of claim 23, wherein the material is selected from the group consisting of nitinol. plastic, spring steel, and strong and highly elastic materials.

25. The method of claim 23, wherein the materials is nitinol.

26. The method of claim 23, wherein the cover comprises a characteristic selected from the group consisting of being operable (a) to move to hide a bone fastener, (b) to release shape changing features of the extracorporeal link, (c) to hold antibiotic impregnated dressing, (d) to facilitate the release of the link from the second configuration to the first configuration, and (e) combinations thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Other advantages of the present invention will be apparent from the following detailed description of the invention in conjunction with embodiments as illustrated in the accompanying drawings, in which:

[0051] FIG. 1A depicts a perspective view of a two pin link in the unstressed as manufactured first shape.

[0052] FIG. 1B depicts a perspective view of a two pin link in the retained and stressed second shape.

[0053] FIG. 2A depicts a perspective view of a three pin link in the unstressed as manufactured first shape.

[0054] FIG. 2B depicts a perspective view of a three pin link in the retained and stressed second shape.

[0055] FIG. 3A depicts a perspective view of a four pin link in the unstressed as manufactured first shape.

[0056] FIG. 3B depicts a perspective view of a four pin link in the retained and stressed second shape.

[0057] FIG. 4A depicts a side view of a two pin link with sliding cover containing a link in the stressed second shape.

[0058] FIG. 4B depicts an orthogonal view of a two pin link with sliding cover containing a link in the stressed second shape.

[0059] FIG. 4C depicts an orthogonal view of a two pin link with sliding cover open and containing a link in the first shape.

LIST OF REFERENCE NUMERALS

[0060] 1 Link member with two pins [0061] 2 Link member with three pins [0062] 3 Link member with four pins [0063] 4 Link movable cover [0064] 5 Link movable cover closed with link in a second shape [0065] 6 Link movable cover open with link in a second shape and one side of the cover outline but transparent.

DETAILED DESCRIPTION OF THE INVENTION

[0066] The present invention relates to a shape changing link that is used external to the body to act on bone fasteners.

[0067] In particular, in certain embodiments, the shape changing link that is used external to the body to act on bone fasteners includes the link that can receive a plurality of bone fasteners as displayed in FIGS. 1A, 1B, 2A, 2B, 3A, and 3B.

[0068] When fabricated, the link is formed in the first unstressed shape, as displayed in FIGS. 1A, 2A, and 3A (showing links members 1, 2, and 3, respectively). When instrument held, the link is in the stressed recoverable second shape, as displayed in FIGS. 1B, 2B, and 3B. When held wire, pin or other fasteners can be inserted through the holes, slots or openings in the link, through skin and into bone. When released from the instrument the link acts to recover its first unstressed shape thus acting to apply moments and forces on the k-wire or pin. The forces and moments are created by the mis-alignment of holes or slots on the bottom and the top of the link and through bowing and shortening of the link. The link acting on the k-wire or pin causes the tips of the bone fastener to move or if restrained by bone, forces to be applied to bone.

[0069] Height of the link above bone when the link is released from the stressed recoverable second shape toward the first unstressed shape effects the force or moments applied to the bone fastener. Since the fasteners can be inserted through holes in the link the height of the link above bone is adjustable. As the height of height above bone decreases, the magnitude of the moments applied to the fasteners, a property of the link, remains constant and bone fixation forces increase. Thus, by setting the height of the link above bone at a pre-determined distance bone fixation forces can be controlled to a pre-determined amounts for any given link. The magnitudes of moments applied to the bone fasteners can be set through the design of the link.

[0070] Generally, the fixation requirements are to stabilize and compress healing bone. On occasion the clinical need is to distract the bones and the link can be fabricated to either compress or distract. The link can have a plurality of k-wires or pins and act on the pins in a plurality of directions. The link can accept its pins or wires in a plurality of shape changing holes to fixate a multitude of bones, bone fragments and bone anatomies.

[0071] The ability to program the link shape change to act on bone through the skin provides an endless number of link geometries acting on a plurality of fasteners, wires and pins to program the bone movement or compression to meet unique clinical needs. In certain embodiments, the pins, wires and screws can be pulled together in a linear fashion, to a central location or some other location driven by the link design and pin placement strategy.

[0072] Due to the link being external to the body and not skin contacting the material for the link can be most any material that exhibits elastic behavior. In some embodiments, the materials include, but are not limited to, nitinol, titanium, stainless steel, polyethylene, polypropylene, polyester ether ketone, Teflon® and nylon. This convenience allows a manufacturing cost reduction, a wide range of elastic properties, designs and bone compressing options.

[0073] In clinical use, the link is held in a surgical instrument in a second shape. This held shape is strained from its initial relaxed first shape, has the link pin holes aligned with one another and with the desired bony location of the pin. The instrument held link can act as a guide for the placement of the pins or wires. The surgeon will introduce each pin or wire through the link, skin and into bone. X-ray visualization enhances planning and placement of the link and its fixation pins or wires. Once all pins or wires are placed the surgeon releases the restraining instrument allowing the link to change shape, act on the pins or wires and compress the bony structures.

[0074] The instrument with link allows the surgeon to vary the distance of the link above the skin and provides the surgeon the ability to adjust the bone fixation force by releasing the link at different locations on the pins. This change in the point of moment application of the link on the pin changes the force applied to bone. The shorter the distance between the link and the bone the higher force imparted to the bone by the moment created by the link.

[0075] The pins, wires or other bone fastener, such as a screw can be used with the link. If a screw the portion acted on by the link is unthreaded or threaded. If unthreaded the link height can be adjusted in the same manner as if a pin. If threaded the link may have threads and as the screw is advanced bone is fixated and the link and screw are fastened to each other in an adjustable manner.

[0076] The link at the point of penetration of a pin, wire or screw can be capped to cover the exposed end of the pin, wire or screw of have a movable cover that protects the fastener. This avoids any catching of the externalized fixation on things in the environment such as bandages, clothing, furniture etc.

[0077] When bone healing has occurred the link can be removed. To remove the link the instrument is re-applied to the link and activated to return the link to its strained second shape. This re-aligns the pin holes with the pins, removes any shortening or lengthening force and allows the link to be slid off the pins or wires. Once the link is removed the wires or pins are removed by turning and pulling on the pins with a driver. Once the pins or wires are removed the small skin penetration holes heal with only a bandage covering.

[0078] Due to the simple and minimally invasive nature of this invention failure to obtain the desired bone fusion result is not catastrophic for the link and wire placement trauma is very low and its use does not preclude a more invasive device and fixation techniques at a later date.

[0079] To provide for a number of link shapes, pin hole placements and pin types the instrument that strains the link may by fabricated with multi-link compatible designs or replaceable heads specific to each link design. In this manner a single instrument that acts to strain the link can be used for many link designs.

[0080] The instrument must deform the link into its stressed second shape and retain it in this shape during use and if desired storage. It may compress, stretch or align the pin holes of the link. The instrument's operation can be based on mechanical designs including but not limited to single or multiple action pliers, power screw driven compressing devices (vice, clamp, pivoting levers for example), sliding or rotating mechanism, forceps, needle drivers and other instruments that releases the link into the stressed second shape. See FIGS. 1B, 2B, and 3B.

[0081] The simple and disposable nature of the instruments, link, fasteners, pins and wires may allow the link system to be fully contained in a sterile kit. This minimizes disease transmission, provides convenience, assures all components are available and speeds the operative procedure. The common availability of sterile k-wires and pins and the external nature of the link and its instrument can allow this type of system to be used with sterile pins and wires and a non-sterile link and instrument.

[0082] The link can take many designs and a plurality of pins or wires. Accordingly, in certain embodiments, the link may have a plurality of pin holes distributed on the link in a fashion so that their orientation includes but is not limited to triangular, square, linear, or circular.

[0083] In some embodiments, the link can be designed to change shape in a plurality of directions so as to pull together, push apart, pull in a single direction or a plurality of directions. In such an embodiment, this allows multiple pins in a single bone or in multiple bones to meet variable clinical requirements for fixation. Thus, in some embodiments, the pin orientation relative to each other includes but is not limited to parallel, divergent or convergent when being placed through the link while it is being held in its stressed second shape.

[0084] A two pin link 1 is shown in FIGS. 1A and 1B. A three pin link 2 that deflects its pins and compression along a single axis is shown in FIGS. 2A and 2B. A four pin link 3 that deflects its pins along a single axis is shown in FIGS. 3A and 3B changes shape in only one direction causing two sets of pins to come together. A link with multiple linearly oriented bone fastener holes provide surgical flexibility in where to insert the bone fixation pins. A link with transverse oriented pin holes can provide multi-axial rotational resistance to enhance fixation.

[0085] A link restraining, release and removal instrument is used to manipulate the link. All designs restrain and release while others also allow engagement with a deployed link and its removal from the pins or wires. Levers rotating about a fulcrum not limited to pliers, needle drivers, and forceps can restrain, release and engage the link for removal.

[0086] Links made of superelastic nitinol limit the geometry of the links that can be cost effectively fabricated. Thin plates and tubing can be cost effectively fabricated with high superelastic behavior. Nitinol links can be held in a second stressed shape with an instrument.

[0087] Links of any design can be protected with a cover (such as the sliding covers 4, 5, and 6 shown in FIGS. 4A, 4B, and 4C, respectively) that protects the end of the pins, link and that can be movable to release the link to its first shape allowing multiple direction of force and moment application. This cover can be fabricated of materials not limited to plastic, rubber, foam, or latex and fastened to or stretched over the link and pins.

[0088] This cover can act on the link to adjust the moments and forces applied to the bone fasteners. The cover can have features that push on the link so as to deform it. This deformation may be caused by the cover geometry and movement or screws can thread through the cover to push on the link to increase or decrease the moments of forces applied to the bone fasteners.

[0089] Although the extracorporeal bone compressing link of the present invention has been describe in connection with the shown embodiments, it is not intended to be limited to the specific forms set forth herein, but, on the contrary it is intended to cover such modifications, alternatives and equivalents as can reasonably be included within the scope and spirit of the invention as defined by the appended claims.

[0090] Additional variations of these embodiments will be obvious to those of ordinary skill in the art. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description. Only those claims specifically reciting “means for” or “step for” should be construed in the manner required under the sixth paragraph of 35 U.S.C. § 112.

[0091] While embodiments of the invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit and teachings of the invention. The embodiments described and the examples provided herein are exemplary only, and are not intended to be limiting. Many variations and modifications of the invention disclosed herein are possible and are within the scope of the invention. The scope of protection is not limited by the description set out above, but is only limited by the claims which follow, that scope including all equivalents of the subject matter of the claims.

[0092] Amounts and other numerical data may be presented herein in a range format. It is to be understood that such range format is used merely for convenience and brevity and should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a numerical range of approximately 1 to approximately 4.5 should be interpreted to include not only the explicitly recited limits of 1 to approximately 4.5, but also to include individual numerals such as 2, 3, 4, and sub-ranges such as 1 to 3, 2 to 4, etc. The same principle applies to ranges reciting only one numerical value, such as “less than approximately 4.5,” which should be interpreted to include all of the above-recited values and ranges. Further, such an interpretation should apply regardless of the breadth of the range or the characteristic being described. The symbol “—” is the same as “approximately”.

[0093] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the presently disclosed subject matter belongs. Although any methods, devices, and materials similar or equivalent to those described herein can be used in the practice or testing of the presently disclosed subject matter, representative methods, devices, and materials are now described.

[0094] Following long-standing patent law convention, the terms “a” and “an” mean “one or more” when used in this application, including the claims.

[0095] Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in this specification are approximations that can vary depending upon the desired properties sought to be obtained by the presently disclosed subject matter.

[0096] As used herein, the term “and/or” when used in the context of a listing of entities, refers to the entities being present singly or in combination. Thus, for example, the phrase “A, B, C, and/or D” includes A, B, C, and D individually, but also includes any and all combinations and subcombinations of A, B, C, and D.

REFERENCES

[0097] U.S. Pat. No. 10,537,370, entitled “Bone Intramedullary Fixation Scaffold,” issued Jan. 21, 2020 to William Casey Fox (“Fox '370 Patent”). [0098] U.S. Pat. No. 10,448,979, entitled “Shape Changing Bone Implants And Method Of Use For Enhancing Healing,” issued Oct. 22, 2019 to William Casey Fox (“Fox '979 Patent”). [0099] U.S. Pat. No. 10,123,831, entitled “Bone Compression Device And Method,” issued Nov. 13, 2018 to Mathew P. Gephart.