Bone saw blade guide with magnet

• US 5,817,097 A
• Filed: 11/07/1997
• Issued: 10/06/1998
• Est. Priority Date: 08/03/1995
• Status: Expired due to Fees

• Current Assignee: Synvasive Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Synvasive Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Mills, Oliver S., Howard, Michael J., White, Thomas V., Hedley, Anthony K.
• Primary Examiner(s): Buiz, Michael Powell
• Assistant Examiner(s): REIP, DAVID OWEN
• Application Number:
  US08/967,268
• Time in Patent Office: 333 Days
• Field of Search: 606/79, 606/82, 606/86, 606/87, 606/88, 606/89
• US Class Current: 606/87
• CPC Class Codes: A61B 17/15 Guides therefor arrangements for guiding straight saw blades in general B23D51/025
• CPC Class Codes: A61B 17/155 Cutting femur
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/1728 for holes for bone plates or plate screws
• CPC Class Codes: A61B 17/1764 for the knee
• CPC Class Codes: A61B 2017/1602 Mills

Abstract

A surgical saw blade guide or milling instrument guide comprising a guide body having a guiding surface thereon, and containing a magnet therein which exerts attractive force in a direction toward the guide body for attracting a bone saw blade or milling instrument to the guiding surface. The surgical saw blade guide or milling instrument guide can comprise a plurality of magnets and the magnet or magnets can themselves form part of the guiding surface. Also, a method of cutting a bone comprising the steps of magnetically attracting a surgical bone saw blade or milling instrument to a surgical saw blade guide or milling instrument guide containing a magnet, actuating a bone saw coupled to the bone saw blade or actuating a milling instrument, advancing the bone saw blade or milling instrument into the bone thereby cutting the bone, and detaching the saw blade or milling instrument from the guide.

Claims

1. A surgical cutting guide for use with a surgical instrument having a known width and formed of magnetic material comprising

a guide body having a connector on one surface thereof for detachably connecting the guide body to a bone having a bone portion to be cut, said guide body further including a separate guiding surface having a length which is at least substantially equal in length to the bone portion to be cut and a magnet forming part of said separate guiding surface having a dimension at least equal to the known width and positioned to be substantially in alignment with the bone portion to be cut and to magnetically attract and exert an attractive force on the surgical instrument in a direction towards the guide body for attracting the surgical instrument to and slideably against the guiding surface.

2. The surgical cutting guide of claim 1, wherein the guide body comprises coated steel, stainless steel, aluminum, plastic, titanium or cobalt-chrome.

3. The surgical cutting guide of claim 1, wherein the magnet is selected from the group consisting of alnicos, ceramics and rare earths.

4. The surgical cutting guide of claim 1, wherein the magnet is selected from the group consisting of samarium-cobalt and neodymium-iron-boron.

5. The surgical cutting guide of claim 1, wherein the magnet comprises material having a Maximum energy Product (BHmax) of between about 0.5 Megagauss Oersteds and about 45 Megagauss Oersteds (MGO).

6. The surgical cutting guide of claim 1, wherein the magnet is completely embedded in the guide body and is enclosed by a cover formed of a material which minimally reduces magnetic flux exerted by the magnet on the surgical instrument.

7. The surgical cutting guide of claim 1, wherein the magnet is a plurality of magnets.

8. The surgical cutting guide of claim 1, wherein the magnet exerts the attractive force in a direction substantially normal to the blade guiding surface.

9. The surgical cutting guide of claim 1, wherein the magnet is removable from the guide body.

10. The surgical cutting guide of claim 1, wherein the guide body further comprises a magnet cover.

11. The surgical cutting guide of claim 10, wherein the cover is selected from the group consisting of coated steel, stainless steel, aluminum and plastic.

12. The surgical cutting guide of claim 1, wherein said connector comprises at least one bone connector coupled to the guide body for reversibly attaching the guide body to said bone having a bone portion to be cut.

13. The surgical cutting guide of claim 12, wherein the at least one bone connector is a bone pin.

14. The surgical cutting guide of claim 1, wherein the separate guiding surface is selected from the group consisting of coated steel, stainless steel, titanium, aluminum and plastic.

15. The surgical cutting guide of claim 1, wherein the guide body is configured to cut a femur for implanting a unit of a prosthetic knee.

16. The surgical cutting guide of claim 1, wherein the guide body is configured to cut a tibia for implanting a unit of a prosthetic knee.

17. A surgical saw blade guide kit comprising the surgical cutting guide of claim 1 and a plurality of magnets, wherein each magnet is configured to removably fit within the guide body.

25. A method of cutting a bone comprising the steps of:

a) providing the surgical cutting guide of claim 1;

b) reversibly attaching with a connector the surgical cutting guide to the bone having a portion to be cut;

c) placing the surgical instrument having a magnetic material against the guide surface such that the surgical instrument is attracted to and slideably against the guiding surface by the magnet;

d) advancing the surgical instrument into the bone, thereby cutting the portion of the bone to be cut; and

e) removing the surgical instrument from the guiding surface.

26. The method of claim 25, wherein the step of reversibly attaching to a bone having a portion to be cut includes a bone which is selected from the group consisting of the scapula, humerus, ulna, radius, pelvis, femur, tibia, fibula, patella, talus and calcaneus.

18. A surgical cutting guide for use with a surgical instrument having a known width and formed of a magnetic material comprising a guide body having a separate guiding surface thereon having a length which is at least substantially equal in length to a bone portion of a bone to be cut, said guide body further having at least one bone connector coupled to the guide body on a surface other than the guiding surface for reversibly attaching the guide body to said bone having a bone portion to be cut, said guide body containing in the guiding surface a magnet having a dimension at least equal to the known width and substantially in alignment with the bone portion to be cut and wherein said magnet exerts an attractive force in a direction towards the guide body for attracting the surgical instrument to and slideably against the guiding surface.

19. A method of cutting a bone comprising the steps of

a) detachably connecting with a connector a surgical cutting guide to a bone having a bone portion to be cut wherein the surgical cutting guide comprises a guide body having a separate guiding surface having a length which is at least substantially equal in length to the bone portion to be cut;

b) magnetically attracting a surgical instrument having a known width and formed of a magnetic material to the surgical guide wherein the guiding surface contains a magnet therein having a dimension at least equal to the known width and positioned to be in alignment with the bone portion to be cut, the magnet exerting an attractive force on the surgical instrument in a direction towards the guide body and slideably against the guiding surface;

c) advancing the surgical instrument into the bone having a portion to be cut, thereby cutting the bone portion to be cut; and

d) removing the surgical instrument from the guiding surface.

20. The method of claim 19, comprising the additional step of

detaching the surgical cutting guide from the bone having a portion to be cut upon completion of cutting thereof.

21. The method of claim 19, wherein the step of detachably connecting the connector to a bone having a portion to be cut includes a bone which is selected from the group consisting of the scapula, humerus, ulna, radius, pelvis, femur, tibia, fibula, patella, talus and calcaneus.

22. A method of cutting a bone comprising the steps of:

a) reversibly attaching with a connector a surgical cutting guide to the bone having a portion to be cut, wherein the surgical cutting guide comprises a guide body having a separate guiding surface thereon having a length which is at least substantially equal in length said bone having a portion to be cut and wherein the connector is used for reversibly attaching the guide body to the bone having a portion to be cut, the guide body containing a magnet which exerts an attractive force on a surgical instrument having formed of a magnetic material and wherein said magnet has a dimension at least equal to the known width and positioned to be in alignment with the bone portion to be cut, said magnet exerting said attractive force in a direction towards the guiding surface for attracting the surgical instrument to and slideably against the guiding surface;

b) placing the surgical instrument against the guiding surface such that the surgical instrument is attracted to the guiding surface by the magnet;

c) advancing the surgical instrument into the bone portion to be cut, thereby cutting the bone; and

d) removing the surgical instrument from the guiding surface.

23. The method of claim 22, comprising the additional step of actuating a bone saw coupled to the surgical instrument before step b).

24. The method of claim 22, wherein the step of reversibly connecting to a bone includes a bone which is selected from the group consisting of the scapula, humerus, ulna, radius, pelvis, femur, tibia, fibula, patella, talus and calcaneus.