Surgical cutting instrument with movable, inner and outer tubular members

• US 5,269,798 A
• Filed: 02/19/1992
• Issued: 12/14/1993
• Est. Priority Date: 02/19/1992
• Status: Expired due to Fees

• Current Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Linvatec Corporation (Jefferies Financial Group, Inc.)
• Inventors: Winkler, Rance A.
• Primary Examiner(s): KRUTER, JEROME
• Application Number:
  US07/836,961
• Time in Patent Office: 664 Days
• Field of Search: 604/22, 604/265, 606/170, 606/171, 606/174, 30/345
• US Class Current: 606/170
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments

Abstract

A surgical cutting instrument formed of relatively movable, cooperating, inner and outer elongate tubular members wherein one of the inner and outer tubular members is made of a gall-resistant material providing an elongate bearing surface along substantially the entire length of the surgical cutting instrument to allow the inner and outer tubular members to be mounted with virtually no gap therebetween for precision cutting without wear or abrasion, metal flaking, galling and seizure and while permitting the other of the inner and outer tubular members to be made from 300 Series stainless steel. When the outer member is made from gall-resistant material, the inner member made from 300 Series stainless steel can be provided with an elongate bearing surface therealong formed by surface hardening the inner member or coating the inner member with thin, dense chromium. The outer tubular member can be made of 300 Series stainless steel with the inner tubular member including a distal tip made from gall-resistant material, a body made from 300 Series stainless steel joined to the distal tip and a bearing surface extending along the body. A biocompatible lubricant can be disposed between the inner and outer members to increase wear and galling resistance of the surgical cutting instrument, and a sleeve bearing on the inner tubular member allows the surgical cutting instrument to withstand increased radial or side loads.

Claims

1. A surgical cutting instrument comprising

an elongate outer tubular member having a distal end, an inner diameter and an opening at said distal end for receiving anatomical tissue;

an elongate inner tubular member disposed within said outer tubular member and having a distal end, an outer diameter and a cutting surface at said distal end for cooperating with said opening to cut tissue, at least said inner member distal end including said cutting surface being made from gall-resistant material in its entirety;

a bearing layer on said inner member extending from said gall-resistant material toward said proximal end; and

means for mounting said inner and outer tubular members for relative movement to position said cutting surface to engage tissue through said opening, said gall-resistant material and said bearing layer together forming a bearing surface along substantially the entire length of the surgical cutting instrument to permit said inner diameter to be substantially the same as said outer diameter.

2. A surgical cutting instrument as recited in claim 1 wherein said bearing layer includes a surface hardened case.

3. A surgical cutting instrument as recited in claim 2 wherein the depth of said case measured radially on said inner tubular member is at least 33 micrometers and said case has a hardness of substantially 1000 to 1200 HV at a depth of 33 micrometers.

4. A surgical cutting instrument as recited in claim 3 wherein said case includes carbon infused into said inner tubular member.

5. A surgical cutting instrument as recited in claim 1 wherein said bearing layer includes a coating of chromium along said outer diameter.

6. A surgical cutting instrument as recited in claim 5 wherein the depth of said coating measured radially on said inner tubular member is substantially 0.0001 to 0.0002 inch.

7. A surgical cutting instrument as recited in claim 6 wherein said coating is formed by electrodeposition.

8. A surgical cutting instrument as recited in claim 1 wherein said gall-resistant material includes a gall-resistant, austenitic stainless steel alloy.

9. A surgical cutting instrument as recited in claim 1 wherein said inner and outer tubular members each include a proximal end and said means for mounting includes a handpiece receiving said proximal ends.

10. A surgical cutting instrument as recited in claim 1 wherein a gap is disposed between said inner diameter and said outer diameter and the width of said gap measured radially with said inner and outer tubular members is substantially 0.00075 inch or less.

11. A surgical cutting instrument comprising

an elongate outer tubular member having a distal end, a proximal end and an opening at said distal end for receiving anatomical tissue;

an elongate inner tubular member having a cylindrical body, a cylindrical tip joined to said body, a distal end on said tip, a proximal end on said body and a cutting surface on said tip for engaging anatomical tissue, said inner tubular member being disposed within said outer tubular member to permit relative movement between said inner and outer tubular members to position said cutting surface to engage tissue through said opening, said distal end and tip being formed of gall-resistant material in its entirety and said body being formed of 300 Series stainless steel in its entirety; and

an elongate bearing surface secured on said body and extending from said distal tip toward said proximal end substantially the entire length of said inner tubular member.

12. A surgical cutting instrument as recited in claim 11 wherein said bearing surface includes a coating of chromium on the outer diameter of said body.

13. A surgical cutting instrument as recited in claim 12 wherein the depth of said coating measured radially on said body is substantially 0.0001 to 0.0002 inch.

14. A surgical cutting instrument as recited in claim 13 wherein said coating is formed on said body by electrodeposition.

15. A surgical cutting instrument as recited in claim 11 wherein said bearing surface includes a hardened case on the outer diameter of said body.

16. A surgical cutting instrument as recited in claim 15 wherein the depth of said case measured radially on said body is at least 33 micrometers and said case has a hardness of substantially 1000 to 1200 HV at a depth of 33 micrometers.

17. A surgical cutting instrument as recited in claim 16 wherein said case includes carbon infused into said inner tubular member.

18. A surgical cutting instrument as recited in claim 17 further including a lubricant coating on said case.

19. A surgical cutting instrument as recited in claim 11 wherein said distal tip is joined to said body at a weld junction.

20. A surgical cutting instrument as recited in claim 11 wherein said distal tip is joined to said body at a brazing junction.

23. A surgical cutting instrument as recited in claim 15 wherein said tubing is made from tetrafluoroethylene.

24. A surgical cutting instrument as recited in claim 23 wherein said sleeve bearing is disposed on said inner tubular member proximal end.

21. A surgical cutting instrument comprising

an elongate outer tubular member having a distal end, a proximal end and an opening at said distal end for receiving anatomical tissue;

an elongate inner tubular member having a cylindrical body, a cylindrical tip joined to said body, a distal end on said tip, a proximal end on said body and a cutting surface on said tip for engaging anatomical tissue, said inner tubular member being disposed within said outer tubular member to permit relative movement between said inner and outer tubular members to position said cutting surface to engage tissue through said opening, said tip being formed of gall-resistant material in its entirety and said body being formed of 300 Series stainless steel in its entirety;

an elongate bearing surface secured on said body and extending from said distal tip toward said proximal end substantially the entire length of said inner tubular member; and

a sleeve bearing disposed on said inner member.

22. A surgical cutting instrument as recited in claim 21 wherein said sleeve bearing includes a length of thin-walled tubing heat-shrunk on said inner tubular member.

25. A surgical cutting instrument comprising

an elongate outer tubular member having a distal end, a proximal end and an opening at said distal end for receiving anatomical tissue;

an elongate inner tubular member having a cylindrical body, a cylindrical tip joined to said body at a junction, a distal end on said tip, a proximal end on said body and cutting surface on said tip for engaging anatomical tissue, said distal tip having a length from said distal end to said junction of substantially 0.625 to 0.650 inch, said inner tubular member being disposed within said outer tubular member to permit relative movement between said inner and outer tubular members to position said cutting surface to engage tissue through said opening, said tip being formed of gall-resistant material in its entirety and said body being formed of 300 Series stainless steel in its entirety;

an elongate bearing surface secured on said body and extending from said distal tip toward said proximal end substantially the entire length of said inner tubular member.

26. A surgical cutting instrument comprising

an outer elongate tubular member having a distal end and a cutting port at said distal end for receiving anatomical tissue;

an inner tubular member having a distal end and a cutting surface at said distal end for engaging tissue in said cutting port, said inner tubular member being mounted in said outer tubular member to permit relative movement between said inner and outer tubular members to allow said cutting surface to engage tissue in the cutting port, the outer diameter of said inner tubular member being substantially the same as the inner diameter of said outer tubular member; and

a biocompatible lubricant disposed between said inner and outer tubular members, said lubricant including a white, food-grade grease.

27. A surgical cutting instrument as recited in claim 34 and further including an elongate bearing surface disposed on one of said inner and outer tubular members extending substantially the entire length of the surgical cutting instrument and wherein said lubricant is disposed between said bearing surface and the other of said inner and outer tubular members.

28. A surgical cutting instrument comprising

an outer elongate tubular member having a distal end and a cutting port at said distal end for receiving anatomical tissue;

an inner tubular member having a distal end and a cutting surface at said distal end for engaging tissue in said cutting port, said inner tubular member being mounted in said outer tubular member to permit relative movement between said inner and outer tubular members to allow said cutting surface to engage tissue in the cutting port, the outer diameter of said inner tubular member being substantially the same as the inner diameter of said outer tubular member; and

a biocompatible grease lubricant disposed between said inner and outer tubular members.