Surgical bone screw construction

• US 20090125072A1
• Filed: 03/21/2008
• Published: 05/14/2009
• Est. Priority Date: 11/13/2007
• Status: Active Grant

• Current Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Original Assignee: Warsaw Orthopedic Incorporated (Medtronic Plc)
• Inventors: Neubardt, Seth L.
• Granted Patent: US 8,348,983 B2
• Time in Patent Office: Days
• US Class Current: 606/305
• CPC Class Codes: A61B 17/8625 Shanks, i.e. parts contacting bone tissue
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/4893 Nerves

Abstract

A surgical bone screw includes an elongate body having a proximal end, a distal end, a threaded portion on the circumference of the body, and a passage extending between the proximal and the distal ends of the body. An electrical conductor is disposed in the passage between the proximal and the distal ends of the screw body. The conductor has a first terminal at the proximal end and a second terminal at the distal end. The conductor and both of the terminals are electrically insulated from surrounding portions of the screw body. When the screw is driven into bone tissue and a stimulating current is applied to the first terminal, the current is directed substantially through the conductor to flow into tissue adjacent to the second terminal at the distal end, without shunting by other tissue that surrounds the screw body.

Claims

1. A surgical bone screw, comprising:

an elongate screw body having a proximal end, a distal end opposite the proximal end, a threaded portion on the circumference of the body, and a passage extending between the proximal and the distal ends of the body;

an electrical conductor disposed inside the passage and extending between the proximal and the distal ends of the screw body, wherein opposite ends of the conductor are terminated at a first terminal at the proximal end of the body, and at a second terminal at the distal end; and

the electrical conductor and the first and the second terminals are arranged to be electrically insulated from surrounding portions of the screw body;

so that when the screw is driven into bone tissue and a stimulating current is applied to the first terminal, the current is directed substantially through the conductor to flow into tissue adjacent the second terminal, without shunting by other tissue that surrounds the screw body.

2. A bone screw according to claim 1, wherein the first terminal is formed and arranged to contact an electrical terminal associated with a drive bit.

3. A bone screw according to claim 1, including a radio frequency identifier (RFID) device fixed to a part of the screw body.

4. The bone screw of claim 3, wherein the RFID device is constructed and arranged to contain information concerning at least one of an associated screw size, a screw identification number, and a patient.

5. A bone screw according to claim 1, wherein the proximal end of the screw body includes a polyaxial head extension, and the first terminal is exposed on said extension.

6. A bone screw according to claim 5, wherein the first terminal is formed and arranged to contact a terminal associated with a drive bit.

7. A bone screw according to claim 5, including a radio frequency identifier (RFID) device fixed to a part of the polyaxial head extension.

8. The bone screw of claim 7, wherein the RFID device is constructed and arranged to contain information concerning at least one of an associated screw size, a screw identification number, and a patient.

9. A bone screw according to claim 1, wherein the second terminal is disposed in the vicinity of a bottom tip of the screw body.

10. A bone screw according to claim 1., wherein the second terminal is disposed at a known angular position on the circumference of the distal end of the screw body, and at a known distance from a bottom tip of the body.

11. The bone screw of claim 10, including a marker on the circumference of the proximal end of the screw body, and the marker has an angular position corresponding to that of the second terminal on the circumference of the distal end of the screw body.

12. A bone screw according to claim 1, wherein the electrical conductor is in the form of a rod or wire.

13. A bone screw according to claim 1, wherein the electrical conductor is in the form of a tube.

14. A bone screw according to claim 1, wherein the passage extends internally of the screw body.

15. A bone screw according to claim 1, wherein the passage is in the form of a channel or groove that is formed in the outer circumference of the screw body.

16. A surgical bone screw, comprising:

an elongate screw body having a screw head at a proximal end of the body, a screw tip at a distal end of the body opposite the proximal end, and a threaded portion on the circumference of the body; and

an electrically insulated coating applied on the outer periphery of the screw body except at certain exposed portions in the regions of the screw head and the screw tip;

so that when the screw is driven into bone tissue and a stimulating current is applied to an exposed portion at the screw head, the current is directed substantially within the screw body and flows into tissue adjacent an exposed portion at the screw tip, without shunting by other tissue surrounding the screw body.

17. A bone screw according to claim 16, wherein a first exposed portion at the screw head is located and dimensioned to contact a terminal associated with a drive bit.

18. A bone screw according to claim 16, including a radio frequency identifier (RFID) device fixed on or within a part of the screw body.

19. The bone screw of claim 18, wherein the RFID device is constructed and arranged to contain information concerning at least one of an associated screw size, a screw identification number, and a patient.