Method for the delivery of electrical current to promote bone growth between adjacent bone masses

• US 7,455,672 B2
• Filed: 07/31/2003
• Issued: 11/25/2008
• Est. Priority Date: 05/27/1994
• Status: Expired due to Fees

• Current Assignee: Gary K. Michelson
• Original Assignee: Gary K. Michelson
• Inventors: Michelson, Gary Karlin
• Primary Examiner(s): Brown; Michael A.
• Application Number:
  US10/631,309
• Publication Number:
  US 20040024400A1
• Time in Patent Office: 1,944 Days
• Field of Search: 606 60- 62, 606 69- 77, 606/246, 606/279, 623/16.1, 623/17.3, 607 50- 52
• US Class Current: 606/60
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 17/7074 Tools specially adapted for spinal fixation operations other than for bone removal or filler handling A61B17/7062, A61B17/808, A61B17/8858 take precedence; for spinal image producing devices A61B90/36, A61B34/20; markers A61B90/39
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61B 2090/036 abutting on tissue or skin
• CPC Class Codes: A61F 2/30744 End caps, e.g. for closing an endoprosthetic cavity
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/44 for the spine, e.g. vertebrae, spinal discs
• CPC Class Codes: A61F 2/442 Intervertebral or spinal discs, e.g. resilient non-disc-shaped intervertebral inflatable pockets A61F2/441; non-disc-shaped intervertebral fusion implants A61F2/4455
• CPC Class Codes: A61F 2/4455 for the fusion of spinal bodies, e.g. intervertebral fusion of adjacent spinal bodies, e.g. fusion cages intervertebral discs A61F2/442
• CPC Class Codes: A61F 2/446 having a circular or elliptical cross-section substantially parallel to the axis of the spine, e.g. cylinders or frustocones
• CPC Class Codes: A61F 2/447 substantially parallelepipedal, e.g. having a rectangular or trapezoidal cross-section
• CPC Class Codes: A61F 2/4603 for insertion or extraction of endoprosthetic joints or of accessories thereof
• CPC Class Codes: A61F 2/4611 of spinal prostheses
• CPC Class Codes: A61F 2002/2821 Bone stimulation by electromagnetic fields or electric current for enhancing ossification
• CPC Class Codes: A61F 2002/2835 Bone graft implants for filling a bony defect or an endoprosthesis cavity, e.g. by synthetic material or biological material
• CPC Class Codes: A61F 2002/30062 (bio)absorbable, biodegradable, bioerodable, (bio)resorbable, resorptive
• CPC Class Codes: A61F 2002/30143 hexagonal
• CPC Class Codes: A61F 2002/30153 rectangular
• CPC Class Codes: A61F 2002/30158 trapezoidal
• CPC Class Codes: A61F 2002/30179 : X-shaped
• CPC Class Codes: A61F 2002/30235 : tubular, e.g. sleeves
• CPC Class Codes: A61F 2002/30261 : parallelepipedal
• CPC Class Codes: A61F 2002/3037 : Translation along the common longitudinal axis, e.g. piston
• CPC Class Codes: A61F 2002/30398 : Sliding
• CPC Class Codes: A61F 2002/30405 : made by screwing complementary threads machined on the parts themselves
• CPC Class Codes: A61F 2002/30433 : using additional screws, bolts, dowels, rivets or washers e.g. connecting screws
• CPC Class Codes: A61F 2002/30507 : using a threaded locking member, e.g. a locking screw or a set screw
• CPC Class Codes: A61F 2002/30556 : for adjusting thickness
• CPC Class Codes: A61F 2002/30579 : with mechanically expandable devices, e.g. fixation devices
• CPC Class Codes: A61F 2002/30593 : hollow
• CPC Class Codes: A61F 2002/30599 : stackable
• CPC Class Codes: A61F 2002/30604 : modular
• CPC Class Codes: A61F 2002/30774 : internally-threaded
• CPC Class Codes: A61F 2002/30777 : Oblong apertures
• CPC Class Codes: A61F 2002/30785 : parallel
• CPC Class Codes: A61F 2002/30787 : inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30789 : perpendicular with respect to each other
• CPC Class Codes: A61F 2002/30797 : internally-threaded
• CPC Class Codes: A61F 2002/30836 : knurled
• CPC Class Codes: A61F 2002/30841 : Sharp anchoring protrusions for impaction into the bone, e.g. sharp pins, spikes
• CPC Class Codes: A61F 2002/30843 : Pyramidally-shaped
• CPC Class Codes: A61F 2002/30845 : with cutting edges
• CPC Class Codes: A61F 2002/3085 : with a threaded, e.g. self-tapping, bone-engaging surface, e.g. external surface
• CPC Class Codes: A61F 2002/30879 : Ribs
• CPC Class Codes: A61F 2002/30904 : serrated profile, i.e. saw-toothed
• CPC Class Codes: A61F 2002/3092 : having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/448 : comprising multiple adjacent spinal implants within the same intervertebral space or within the same vertebra, e.g. comprising two adjacent spinal implants
• CPC Class Codes: A61F 2002/4485 : comprising three or more adjacent spinal implants
• CPC Class Codes: A61F 2002/449 : comprising multiple spinal implants located in different intervertebral spaces or in different vertebrae
• CPC Class Codes: A61F 2002/4619 : for extraction
• CPC Class Codes: A61F 2002/4627 : with linear motion along or rotating motion about the instrument axis or the implantation direction, e.g. telescopic, along a guiding rod, screwing inside the instrument
• CPC Class Codes: A61F 2002/4629 : connected to the endoprosthesis or implant via a threaded connection
• CPC Class Codes: A61F 2002/4681 : by applying mechanical shocks, e.g. by hammering
• CPC Class Codes: A61F 2210/0004 : bioabsorbable
• CPC Class Codes: A61F 2220/0025 : Connections or couplings between prosthetic parts, e.g. between modular parts; Connecting elements
• CPC Class Codes: A61F 2220/0033 : made by longitudinally pushing a protrusion into a complementary-shaped recess, e.g. held by friction fit
• CPC Class Codes: A61F 2220/0041 : using additional screws, bolts, dowels or rivets, e.g. connecting screws
• CPC Class Codes: A61F 2230/0017 : Angular shapes
• CPC Class Codes: A61F 2230/0019 : rectangular
• CPC Class Codes: A61F 2230/0026 : trapezoidal
• CPC Class Codes: A61F 2230/0058 : X-shaped
• CPC Class Codes: A61F 2230/0069 : cylindrical
• CPC Class Codes: A61F 2230/0082 : parallelepipedal
• CPC Class Codes: A61F 2250/0009 : for adjusting thickness
• CPC Class Codes: A61F 2250/0063 : Nested prosthetic parts
• CPC Class Codes: A61F 2310/00023 : Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00179 : Ceramics or ceramic-like structures
• CPC Class Codes: A61F 2310/00796 : Coating or prosthesis-covering structure made of a phosphorus-containing compound, e.g. hydroxy(l)apatite
• CPC Class Codes: A61N 1/0551 : Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/205 : for promoting a biological process

Abstract

An electrical bone growth promotion apparatus and method for the delivery of electrical current to an implant surgically implanted within the intervertebral space between two adjacent vertebrae of the spine to promote bone growth and the fusion process to areas adjacent to the implant is disclosed. The apparatus of the present invention comprises a self contained implant having a surgically implantable, renewable power supply and related control circuitry for delivering electrical current directly to the implant and thus directly to the area in which the promotion of bone growth is desired. The desired areas of bone growth promotion may be controlled by conducting negative charge only to the desired location of bone growth promotion.

Claims

1. A method for promoting bone growth between at least two adjacent bone masses with an implant surgically implanted in the area to be joined, said method comprising the steps of:

providing the implant having opposed first and second surfaces for placement between and in contact with the adjacent bone masses, a mid-longitudinal axis, and a hollow chamber between the first and second surfaces, the hollow chamber being adapted to hold bone growth promoting material, the hollow chamber being along at least a portion of the mid-longitudinal axis of the implant, each of the first and second surfaces having at least one opening in communication with the hollow chamber into which bone from the adjacent bone masses grows;

placing the implant between the adjacent bone masses and in contact with the adjacent bone masses to be joined by bone growth; and

energizing the implant with an energizer to promote bone growth from adjacent bone mass to adjacent bone mass through the first and second surfaces and through at least a portion of the hollow chamber at the mid-longitudinal axis of the implant.

2. The method of claim 1, wherein the energizing step includes using an energizer that is at least in part within the hollow chamber of the implant.

3. The method of claim 1, wherein the energizing step includes using an energizer that is at least in part between the first and second surfaces of the implant that are placed between and in contact with the adjacent bone masses.

4. The method of claim 1, wherein the energizing step includes energizing the implant from a point external to a patient'"'"'s body.

5. The method of claim 1, wherein the energizing step includes providing negative charge to a first portion of the implant.

6. The method of claim 1, further comprising the step of providing positive charge to a second portion of the implant to inhibit bone growth in an area adjacent to the second portion.

7. The method of claim 1, wherein the energizing step includes generating an electromagnetic wave.

8. The method of claim 1, wherein the energizing step includes generating electromagnetic energy.

9. The method of claim 1, wherein the energizing step includes generating a magnetic field.

10. The method of claim 1, wherein the energizing step includes delivering intermittent pulses of current.

11. The method of claim 1, wherein the energizing step includes delivering of one of an alternating current, a direct current, and a sinusoidal current.

12. The method of claim 1, wherein the energizing step comprises utilizing the energizer that includes one of an electromagnetic wave generator, an electromagnetic energy generator, and a magnetic field generator.

13. The method of claim 1, wherein the energizing step comprises utilizing the energizer that is an electromagnetic field generator positioned external to a patient'"'"'s body and is inductively coupled to the implant.

14. The method of claim 1, wherein the energizing step includes energizing the implant with an electromagnetic field so that the implant emits an electromagnetic field.

15. The method of claim 1, further comprising the step of accessing the hollow chamber through an access opening in the implant.

16. The method of claim 15, further comprising the step of utilizing a cap for closing the access opening of the hollow chamber.

17. The method of claim 16, wherein the energizer attaches to the cap.

18. The method of claim 1, wherein the providing step includes providing the implant with a coil wrapped around at least a portion of the implant, the coil being electrically conductive.

19. The method of claim 18, wherein at least a portion of the coil is in the form of an external thread on at least a portion of the first and second surfaces of the implant.

20. The method of claim 19, wherein the external thread is energized by the energizer.

21. The method of claim 19, wherein the external thread conducts electromagnetic energy to the interior space of the implant.

22. The method of claim 1, wherein the providing step includes providing the implant having a passage between at least two of the openings through the implant such that the passage communicates with each of the adjacent bone masses to be joined, and having a conductive coil disposed about the passage and coupled to the energizer.

23. The method of claim 1, wherein the providing step includes providing the implant with the first and second surfaces of the implant being at least in part arcuate.

24. The method of claim 23, wherein the providing step includes providing the implant that is generally cylindrical.

25. The method of claim 1, wherein the providing step includes providing the implant with the first and second surfaces of the implant being at least in part planar.

26. The method of claim 1, wherein the placing step includes inserting the implant to fit entirely between the adjacent bone masses.

27. The method of claim 1, wherein the providing step includes providing the implant comprising a material other than bone.

28. The method of claim 1, wherein the providing step includes providing the implant comprising bone.

29. The method of claim 28, wherein the bone includes cortical bone.

30. The method of claim 1, wherein the providing step includes providing the implant comprising bone growth promoting material.

31. The method of claim 30, wherein the bone growth promoting material is at least in part bone.

32. The method of claim 30, wherein the bone growth promoting material is a material other than bone.

33. The method of claim 30, wherein the bone growth promoting material includes at least one of bone morphogenetic protein and hydroxyapatite.

34. The method of claim 1, further comprising the step of coating the implant with a bone growth promoting substance.

35. The method of claim 1, wherein the implant is combined with bone growth promoting material.

36. The combination of claim 35, wherein the bone growth promoting material is at least in part bone.

37. The combination of claim 35, wherein the bone growth promoting material is a material other than bone.

38. The combination of claim 35, wherein the bone growth promoting material includes at least one of bone morphogenetic protein and hydroxyapatite.

39. The method of claim 1, wherein the providing step includes providing the implant comprising a material that is a source of osteogenesis.

40. The method of claim 1, wherein the implant is combined with a material that intrinsically participates in the growth of bone from one of the adjacent bone masses to the other of the adjacent bone masses.

41. The method of claim 1, wherein the implant is an interbody spinal fusion implant.

42. The method of claim 1, wherein the implant is for fusion of a joint in the body.

43. The method of claim 1, wherein the adjacent bone masses are vertebral bodies.

44. The method of claim 1, wherein the adjacent bone masses are broken portions of the same bone.