Surgical instrument

• US 5,322,505 A
• Filed: 07/29/1992
• Issued: 06/21/1994
• Est. Priority Date: 02/07/1990
• Status: Expired due to Term

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: Smith & Nephew Holdings Incorporated (Smith & Nephew PLC)
• Inventors: Krause, Kenneth W., Sample, Philip B., Crowell, Richard
• Primary Examiner(s): Pellegrino, Stephen C.
• Assistant Examiner(s): Lewis, William W.
• Application Number:
  US07/921,563
• Time in Patent Office: 692 Days
• Field of Search: 606/167, 606/170, 606/171, 606/180, 128/750-757, 604/22
• US Class Current: 604/24
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments
• CPC Class Codes: A61B 2017/2904 curved, but rigid
• CPC Class Codes: A61B 2017/320032 Details of the rotating or oscillating shaft, e.g. using a flexible shaft
• CPC Class Codes: A61M 25/0054 with regions for increasing flexibility
• CPC Class Codes: A61M 25/0138 having flexible regions as a result of weakened outer material, e.g. slots, slits, cuts, joints or coils
• CPC Class Codes: Y10T 29/49986 Subsequent to metal working
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material
• CPC Class Codes: Y10T 408/03 Processes

Abstract

A surgical instrument that includes a rigid outer member within which is disposed a hollow inner member having rigid proximal and distal ends and a region disposed between the rigid proximal and distal ends that is relieved to render such region relatively flexible. The flexible region is integral with a portion of the proximal end disposed adjacent to the flexible region. The inner member transmits force (such as torsion) applied to its proximal end to move a cutting implement disposed at its distal end and cause it to cut tissue admitted through an opening in the distal region of the outer member. In another aspect, a region of the inner member is weakened (e.g., by relieving an integral region of the member) with respect to the remainder of the inner member to cause this region to break if the force (e.g., torque) applied to the inner member exceeds a predetermined threshold. In yet another aspect, the flexible region is relieved by forming openings therein, and pliable material (such as silicone rubber) is disposed in the openings.

Claims

1. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue, and

a hollow inner member having rigid proximal and distal ends disposed within said outer member for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue that is exposed to said implement through said opening,

a region of said inner member disposed between said proximal and distal ends being relieved so that, when straight, said region includes a plurality of openings disposed in walls thereof to render said region relatively flexible, said walls of said region having a thickness that is substantially the same as a thickness of walls of at least a portion of said proximal end disposed adjacent to said region, said region having sufficient stiffness to transmit said applied force to said cutting implement an cause it to cut said tissue.

2. The instrument of claim 1 wherein said outer member includes a curved region disposed proximally of said distal region, said flexible region of said inner member being disposed within at least a portion of said curved region of said outer member.

3. The instrument of claim 2 wherein said curved region is bounded on at least one side by a straight region of said outer member, a portion of said flexible region being disposed within at least a portion of said straight region.

4. The instrument of claim 3 wherein said curved region is bounded on two sides by straight regions, said flexible region being sufficiently long to span said curved region and be disposed in at least a portion of each said straight region.

5. The instrument of claim 1 or 2 wherein said openings are disposed in a symmetrical pattern.

6. The instrument of claim 1 or 2 wherein said openings comprise a plurality of slots each of which extends over a section of the circumference of said inner member, said slots being disposed along at least a portion of the length of said flexible region.

7. The instrument of claim 6 wherein said slots are circumferentially offset with respect to one another.

8. The instrument of claim 6 wherein said slots are disposed in a succession of planes perpendicular to a longitudinal axis of said inner member and a set of said slots are disposed in each said plane, the slots in adjacent planes being offset circumferentially with respect to one another.

9. The instrument of claim 8 wherein said sets of

10. The instrument of claim 1 or 2 wherein said openings comprise generally round holes.

11. The instrument of claim 10 wherein said holes are arranged in a plurality of rows disposed along at least a portion of the length of said flexible region.

12. The instrument of claim 11 wherein said holes in adjacent rows are offset from each other along said length.

13. The instrument of claim 1 wherein said force is applied to rotate said inner member.

14. The instrument of claim 13 wherein said force is applied by a motor that applies a torque to said inner member, said flexible region being configured to transmit said applied torque to said cutting implement.

15. The instrument of claim 1 wherein said hollow inner member is adapted receive suction at its proximal end and to transport tissue fragments cut by said cutting implement away from a surgical site while the instrument remains in situ for further cutting.

16. The instrument of claim 1 wherein said cutting implement comprises a blade.

17. The instrument of claim 1 wherein a region of said outer member within which said flexible region is disposed is arranged generally along an axis and said force is applied to rotate said inner member, said flexible region being adapted to accommodate itself to deviations in said region of said outer member from said axis.

18. The instrument of claim 17 wherein said outer member includes a curved region, said flexible region of said inner member being disposed within at least a portion of said curved region.

46. The instrument of claim 1, 19, 26, 34, 43, or 44 wherein said body cavity is a joint space.

19. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue, and

a hollow inner member having rigid proximal and distal ends disposed within said outer member for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue that is exposed to said implement through said opening,

a region of said inner member disposed between said proximal and distal ends being configured to be relatively flexible, said region and at least a portion of said proximal end that is disposed adjacent to said region comprising a single member.

20. The instrument of claim 19 wherein said outer member includes a curved region disposed proximally of said distal region, said flexible region of said inner member being disposed within at least a portion of said curved region of said outer member.

21. The instrument of claim 20 wherein said inner member is relieved to render it flexible in said region.

22. The instrument of claim 19 or 20 wherein said inner member is relieved to render it flexible in said integral region.

23. The instrument of claim 22 wherein said flexible region is relieved with a plurality of openings disposed in walls of said inner member.

24. The instrument of claim 23 wherein said holes comprise a plurality of circumferentially extending slots disposed in a succession of planes along at least a portion of a longitudinal axis of said inner member, a set of said slots being disposed in each said plane, the slots in adjacent planes being circumferentially offset with respect to one another.

25. The instrument of claim 23 wherein said openings comprise holes arranged in a plurality of rows disposed along at least a portion of the length of said flexible region, holes in adjacent rows being offset from each other along said length.

26. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

an outer member having an opening in a distal region thereof for admitting said tissue,

a movable cutting implement adapted to cut said tissue that is exposed to said implement through said opening, and

a hollow inner member disposed within said outer member for transmitting force applied to a proximal end of said inner member to move said cutting implement, a region of said inner member including a plurality of discrete openings disposed in walls thereof, said openings having a size selected to weaken said inner member with respect to the remainder of said inner member to cause said region to break if the force applied to said inner member exceeds a predetermined threshold, said region and at least a portion of said rigid proximal end disposed adjacent to said region comprising a unitary structure.

27. The instrument of claim 26 wherein said threshold is selected to be less than a maximum desired force to be applied to said cutting implement.

28. The instrument of claim 26 wherein said force is rotational force and said threshold is a torque threshold.

29. The instrument of claim 26 wherein said weakened region is disposed a predetermined distance proximally of said opening so that, if said region breaks, the portion of said inner member disposed distally of the break is captured within said outer member.

30. The instrument of claim 26 wherein said relieved, weakened region is integral with said proximal end of said inner member.

31. The instrument of claim 30 wherein said openings comprise circumferentially extending slots.

32. The instrument of claim 26 wherein said outer member includes a curved region, said weakened region of said inner member being disposed within at least a portion of said curved region.

33. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

an outer member having an opening in a distal region thereof for admitting said tissue,

a movable cutting implement adapted to cut said tissue that is exposed to said implement through said opening, and

a hollow inner member disposed within said outer member for transmitting force applied to a proximal end of said inner member to move said cutting implement,

a region of said inner member including a plurality of discrete openings disposed in walls thereof, said openings comprising generally round holes having a size selected to weaken said inner member with respect to the remainder of said inner member to cause said region to break if the force applied to said inner member exceeds a predetermined threshold, said region and at least a portion of said rigid proximal end disposed adjacent to said region comprising an integral, unitary structure.

34. A surgical instrument that is constructed for insertion into a joint space of a body for cutting tissue therein, comprising

a hollow member having rigid proximal and distal ends for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue to which it is exposed,

a region of said member disposed between said proximal and distal ends having a plurality of openings disposed in walls thereof to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said walls of said region having a thickness that is substantially the same as a thickness of walls of at least a portion of said proximal end disposed adjacent to said region, and

pliable material disposed in said openings.

35. The instrument of claim 34 further comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue,

said hollow member being disposed along an axis within said outer member so that said applied force causes said hollow member to move with respect to said outer member so that said cutting implement moves past said opening to cut said tissue exposed to said implement though said opening, said pliable material reducing axial compression of said hollow member during movement thereof.

36. The instrument of claim 35 wherein said outer member includes a curved region disposed proximally of said distal region, said flexible region of said hollow member being disposed within at least a portion of said curved region.

37. The instrument of claim 35 wherein said force is applied by a motor that applies a torque to said hollow member, said flexible region being configured to transmit said applied torque to said cutting implement.

38. The instrument of claim 34 wherein said pliable material comprises a polymeric material.

39. The instrument of claim 38 wherein said pliable material comprises silicone rubber.

40. A surgical instrument that is constructed for insertion into a joint space of a body for cutting tissue therein, comprising

a hollow member having rigid proximal and distal ends for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue to which it is exposed,

a region of said member disposed between said proximal and distal ends having a plurality of openings disposed in walls thereof to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said walls of said region having a thickness that is substantially the same as a thickness of walls of at least a portion of said proximal end disposed adjacent to said region, and

pliable material disposed in said openings,

wherein said openings define edges on an interior surface of said hollow member, said pliable material being disposed to be substantially coextensive with said interior surface at said edges.

41. The instrument of claim 40 wherein said hollow member is adapted to receive suction at its proximal end and to transport tissue fragments cut by said cutting implement away from a surgical site while the instrument remains in situ for further cutting, said pliable material being disposed to provide a substantially smooth surface for passage of said tissue fragments through said flexible region to reduce the tendency of said tissue fragments to become caught on said edges.

42. A surgical instrument that is constructed for insertion into a joint space of a body for cutting tissue therein, comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue,

a hollow member disposed along an axis within said outer member, said hollow member having rigid proximal and distal ends and being responsive to a force applied to said proximal end by moving with respect to said outer member to transmit said force to move a cutting implement disposed at said distal end past said opening, said cutting implement being constructed to cut said tissue to which it is exposed through said opening,

a region of said hollow member disposed between said proximal and distal ends having a plurality of openings disposed in walls thereof to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said walls of said region having a thickness that is substantially the same as a thickness of walls of at least a portion of said proximal end disposed adjacent to said region, and

pliable material disposed in said openings, said pliable material reducing axial compression of said hollow member during movement thereof, said openings defining edges on an exterior surface of said hollow member, said pliable material being disposed to be substantially coextensive with said exterior surface at said edges.

43. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue, said outer member including a curved region disposed proximally of said distal region,

a hollow inner member having rigid proximal and distal ends disposed within said outer member for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue that is exposed to said implement through said opening,

a region of said inner member disposed between said proximal and distal ends having a plurality of openings disposed in walls thereof to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said flexible region being disposed within at least a portion of said curved region, said region having an inner diameter that is substantially the same as an inner diameter of at least a portion of said hollow inner member disposed adjacent to said member, and

pliable material disposed in said openings.

44. A surgical instrument that is constructed for insertion into a body cavity for cutting tissue therein, comprising

a rigid outer member having an opening in a distal region thereof for admitting said tissue, and

a hollow inner member having rigid proximal and distal ends disposed within said outer member for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue that is exposed to said implement through said opening,

a region of said inner member disposed between said proximal and distal ends being relieved with a plurality of axially and circumferentially spaced, discrete openings to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said region having an inner diameter that is substantially the same as an inner diameter of at least a portion of said hollow inner member disposed adjacent to said member.

45. The instrument of claim 44 further comprising pliable material disposed in said openings.

47. A surgical instrument that is constructed for insertion into a joint space of a body for cutting tissue therein, comprising

a hollow member having rigid proximal and distal ends for transmitting force applied to said proximal end to move a cutting implement disposed at said distal end, said cutting implement being constructed to cut said tissue to which it is exposed,

a region of said member disposed between said proximal and distal ends having a plurality of openings disposed in walls thereof to render said region relatively flexible while providing said region with sufficient stiffness to transmit said applied force to said cutting implement and cause it to cut said tissue, said walls of said region having a thickness that is substantially the same as a thickness of walls of at least a portion of said proximal end disposed adjacent to said region, and

pliable material disposed on said inner member to cover at least one of said openings. slots are uniformly spaced along said axis.