BONE STABILIZER AND STIMULATOR IMPLANT

Abstract

A dual function bone implant provides both stabilization and stimulation for bone healing. The implant includes a fixation or stabilization hardware body, with an electromagnetic field generator mounted in or on the body. The hardware body stabilizes the bone, while the electromagnetic field generator stimulates bone growth and fusion by producing an electromagnetic field at the bone site.

Description

BACKGROUND OF THE INVENTION

Implants are well-known for use in stabilizing bone structures. Such implants take many forms, such as a cage, a plate, a rod, a crosslink, and/or spinous process clamp. It is also known that bone growth can be stimulated by exposure to electromagnetic fields which can be generated by an implanted device or an externally worn device. Both types of stimulators have problems. An implanted stimulator introduces an additional foreign object into the patient. Implanted stimulators also increase surgery time and potential complications. External bone stimulators require patient compliance, and have electromagnetic fields which are farther away from the healing site, compared to an implanted stimulator, thus weakening the field at the bone healing site.

Therefore, there is a need for improved bone stimulation and stabilization which overcomes the problems of the prior art.

Accordingly, a primary objective of the present invention is the provision of a combination bone stabilizer and stimulator implant.

A further objective of the present invention is the provision of a dual function bone implant having stabilization and growth enhancing electromagnetic fields.

A further objective of the present invention is the provision of a single implant device and for bone stabilization which produces an electromagnetic field adjacent the bone for hastened healing.

A further objective of the present invention is a provision of a bone implant for stabilization and stimulation which minimizes foreign matter in the body, decreases operative time and potential complications, and eliminates patient compliance issues.

Still another objective of the present invention is the provision of an implant device which is economical to manufacture and safe and efficacious in use.

These and other objectives become apparent from the following description of the invention.

SUMMARY OF THE INVENTION

The bone stabilizing and stimulating implant of the present invention includes a fixation body having an electromagnetic field generator mounted therein. The fixation body may take various forms, such as a plate, a rod, a crosslink, a cage, or spinous process clamp. The electromagnetic field generator may be an electric current source, such as a battery, or a magnet, preferably made from a rare earth metal, such as neodymium iron boron. The dual function device is implanted into the patient's body adjacent the bone so that the fixation hardware stabilizes the bone and the electromagnetic field generator is adjacent the bone healing site to maximize the electromagnetic field effect to enhance bone growth.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a first embodiment of the bone stabilization and stimulation implant according to the present invention.

FIG. 2 is another perspective view of the first embodiment of the implant, shown from the opposite side as FIG. 1.

FIG. 3 is a sectional view of the first embodiment taken along line 3-3 of FIG. 1.

FIG. 4 is a perspective view of a second embodiment of the bone stabilization and stimulation implant according to the present invention.

FIG. 5 is another perspective view of the second embodiment of the invention, taken from the opposite side as FIG. 4.

FIG. 6 is a sectional view of the second embodiment taken along line 6-6 of FIG. 4.

FIG. 7 is a perspective view of a third embodiment of the bone stabilization and stimulation implant of the present invention.

FIG. 8 is a sectional view of the third embodiment, taken along line 8-8 of FIG. 7.

FIG. 9 is a perspective view of a fourth embodiment of the bone stabilization and stimulation implant according to the present invention.

FIG. 10 is a sectional view of the fourth embodiment of the implant, taken along line 10-10 of FIG. 9.

FIG. 11 is a perspective view of a fifth embodiment of the bone stabilization and stimulation implant, according to the present invention.

FIG. 12 is a sectional view of the fifth embodiment taken along lines 12-12 of FIG. 11.

FIG. 13 shows a sixth embodiment of the bone stabilization and stimulation implant, according to the present invention.

FIG. 14 is a sectional view taken along lines 14-14 of FIG. 13.

FIG. 15 shows an assembly utilizing the third and fifth embodiments of the implant from FIGS. 7 and 11.

FIG. 16 is a perspective view of a seventh embodiment of a bone stabilization and stimulation implant, according to the present invention.

FIG. 17 is a perspective view of the second embodiment of the implant and its electromagnetic field.

FIG. 18 is a perspective view of the fourth embodiment and its electromagnetic field.

FIG. 19 is a perspective view of the sixth embodiment of the implant, with its electromagnetic field.

FIG. 20 is a schematic view showing the anode and cathode of an electric current source used in the first, third, and fifth implant embodiments.

FIG. 21 is a perspective view of a seventh embodiment of the bone stabilization and stimulation implant, according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The implant of the present invention includes a hardware or fixation body of various embodiments, such as a plate 10, a crosslink 20, a rod 30, a crosslink and rod assembly 40, a cage 50, and a spinous process clamp 60. The general shape of the hardware body may vary from that shown in the drawings without departing from the scope of the present invention.

Each embodiment of the implant also includes an electromagnetic field generator mounted on the hardware body. This electromagnetic field generator can be an electrical current source, such as a battery 12 mounted in the hardware body with wire leads 14 extending through the body and beyond. Alternatively, the electromagnetic field generator can be a magnet 16 secured in the hardware body. Preferably, the magnet is a rare earth metal, such as neodymium iron boron.

The battery 12 and electrical wiring 14 are shown in the drawings to be embedded in the hardware body. Alternatively, the battery and wires can be fixed to the exterior of the body. Similarly, the magnet is shown in the drawings as being embedded in the hardware body, but could alternatively be fixed to the exterior of the body. Such external positioning or mounted of the electromagnetic field generator to the hardware body may simplify manufacturing and eliminate concerns of weakening the body by providing a solid body without hollow channels or pockets for the electromagnetic field generator.

Each embodiment of the invention has the dual function of bone stabilization and stimulation. The hardware body provides the stabilization function, while the electromagnetic field generator provides the stimulation function.

FIGS. 1-3 show a cervical plate 10 having a battery 12 mounted therein with wire leads 14 extending from the battery. The plate 10 includes convention holes 18 for receipt of conventional screws.

FIGS. 4-6 also show a cervical plate 10 with a magnet 16 mounted therein. The cervical plate implants of FIGS. 1-3 and FIGS. 4-6 function identically to one another.

FIGS. 7-8 show a crosslink hardware body 20 having a battery 12 mounted therein with wire leads 14 extending from the battery.

FIGS. 9-10 show the crosslink 20 with a magnet 16 mounted therein, rather than the battery 12 and wires 14.

FIGS. 11-12 show a rod 30 with a battery 12 mounted therein and wire leads 14 extending from the battery 12.

FIGS. 13-14 show the hardware rod 30 with a magnet 16 mounted therein.

FIG. 15 shows a plurality of crosslinks 20 and rods 30 assembled together to form a frame with the batteries 12 and wires 14. It is understood that this assembly can also use magnets, rather than the batteries and wires. Also, the assembly can be extended with additional crosslinks and rods, if needed.

FIG. 16 shows a corpectomy cage 50 having a magnet 52 mounted therein. The magnet 52 has the same bone stimulation function as the magnet 16, but may have a different shape. The magnet 52 creates an electromagnetic field, represented by the broken lines in FIG. 16 and the reference numeral 60.

FIGS. 16-19 show electromagnetic fields 60 generated by the battery 12 or the magnet 16 in the cervical plate 10, crosslink 20, rod 30, and cage 50, respectively.

FIG. 20 shows a schematic of the electric current source, including the battery 12 and the wires 14, with the opposite anode 70 and cathode 72 ends.

FIG. 21 shows the magnet 16 used in a spinous process clamp 60. It is understood that a battery 12 can also be used with the clamp 60, similar to the use of the battery 12 on the other hardware devices 10, 20, 30, 40 and 50. The magnet 16 is shown to be co-axial with the clamp axle, but the magnet 16 can be set in any position in the clamp 60.

The various embodiments of the implant of the present invention increases the chances of bone healing after surgery or trauma. The implants help promote bone healing by adding structural support from the hardware or fixation body, and bone growth and fusion stimulation from the electromagnetic field generator. This single apparatus provides multiple functions, as compared to the prior art separate apparatus for each function. The single implant minimizes the amount or volume of foreign objects implanted into the patient, while decreasing operation times and complications. The implant of the present invention also eliminates any need for patient compliance, as with prior art external bone stimulators. The implants also position the electromagnetic field as close as possible to the bone healing site, which is not possible with the prior art stimulators which are separate from the stabilization hardware. The dual function implant also minimizes the surgical invasiveness, which was more extensive with the separate, single function prior art implants which increased operation time, increased potential for infection and/or patient discomfort, and had the potential for movement from the desired position.

The process for implanting the dual function implants of the present invention is identical to the prior art implantation process used for convention bone stabilization or fixation hardware.

The invention has been shown and described above with the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. From the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives.

Claims

1. A bone stimulator and stabilization implant comprising: a fixation body for bone stabilization; andan electro-magnetic field generator mounted to the body to produce an electro-magnetic field for bone growth stimulation.

2. The implant of claim 1 wherein the body is a corpectomy cage.

3. The implant of claim 1 wherein the body is a cervical plate.

4. The implant of claim 1 wherein the body is a rod.

5. The implant of claim 1 wherein the body is a cross link.

6. The implant of claim 1 wherein the body is a spinous process clamp.

7. The implant of claim 1 wherein the generator is a battery.

8. The implant of claim 7 wherein the battery is wired to an electrical current source.

9. The implant of claim 1 wherein the generator is a magnet.

10. The implant of claim 9 wherein the magnet is neodymium iron boron.

11. An implantable device for bone stabilization and stimulation, comprising: a fixation hardware member implantable to an internal site adjacent bone; anda source on the hardware member for generating electro-magnetic waves adjacent the bone to stimulate bone growth.

12. The implantable device of claim 11 wherein the body is a corpectomy cage.

13. The implantable device of claim 11 wherein the body is selected from a group comprising a cervical plate, a rod, a cross link, a corpectomy cage, and a spinous process clamp.

14. The implantable device of claim 11 wherein the generator is a battery.

15. The implantable device of claim 14 wherein the battery is wired to an electrical current source.

16. The implantable device of claim 11 wherein the generator is a magnet.

17. The implantable device of claim 16 wherein the magnet is neodymium iron boron.

18. A method of stimulating bone growth, comprising: implanting fixation hardware adjacent bone;generating an electro-magnetic field from the hardware to intersect with the bone and thereby enhance bone growth.

19. The method of claim 18 wherein the electro-magnetic field is generated with a magnet imbedded in the hardware.

20. The method of claim 18 wherein the electro-magnetic field is generated with a battery imbedded in the hardware.

21. The method of claim 18 wherein the electro-magnetic field is generated by an electrical current source.