Surgical instrument

• US 5,443,475 A
• Filed: 08/03/1992
• Issued: 08/22/1995
• Est. Priority Date: 11/09/1990
• Status: Expired due to Term

• Current Assignee: Biomet Manufacturing, LLC (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Arthrotek Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Shutt, George V., Auerbach, Burt J.
• Primary Examiner(s): Thaler, Michael H.
• Application Number:
  US07/925,225
• Time in Patent Office: 1,114 Days
• Field of Search: 604/22, 606/205-208, 606/170, 606/167, 606/174, 606/83, 606/79, 606/184, 128/751
• US Class Current: 606/170
• CPC Class Codes: A61B 17/1608 the two jaw elements being linked to two elongated shaft elements moving longitudinally relative to each other
• CPC Class Codes: A61B 17/1675 for the knee
• CPC Class Codes: A61B 17/1684 for the shoulder
• CPC Class Codes: A61B 17/29 Forceps for use in minimally invasive surgery

Abstract

A surgical instrument has an elongate support shaft, a tip assembly permanently attached to the shaft, a cutting jaw which opens in a backward facing direction and which is laterally offset from the longitudinal axis of the support shaft, and a rod extending coaxially with the elongate support shaft for applying closing and opening forces to the cutting jaw. The tip assembly comprises a stationary portion and a movable portion having respective tissue cutting edges which define the cutting jaw. The stationary portion of the tip assembly is permanently attached to the distal end of the support shaft, and the movable portion of the tip assembly is pivotally attached to a distal end of the stationary portion. The stationary portion of the tip assembly has a plurality of cutting edges which define an opening which extends axially adjacent the longitudinal axis of the support shaft. The movable portion has corresponding cutting edges which cooperate with the cutting edges of the stationary portion to define the cutting jaw. The cutting jaw has a fully open position in which the movable element extends outwardly from the longitudinal axis and toward a proximal end of the elongate shaft at an angle of approximately 60°. The cutting jaw has a fully closed position in which the cutting element is disposed within the opening in the stationary portion of the tip assembly. The tip assembly has an overall height dimension, when the cutting element is in the fully closed position, which is substantially equal to a corresponding cross-sectional dimension of the elongate support shaft.

Claims

1. A surgical instrument for cutting body tissue, comprising:

an elongate support shaft;

a tip assembly attached to a distal end of the support shaft, said tip assembly comprising a stationary portion and a movable portion, a distal end of said movable portion being pivotally connected to a distal end of the stationary portion so as to form a cutting jaw; and

means extending coaxially with the support shaft for applying closing and opening forces to the movable portion of the cutting jaw;

wherein said stationary portion comprises a first cutting edge extending substantially parallel to and laterally adjacent a central longitudinal axis of the support shaft, and a second cutting edge extending substantially orthogonally from the first cutting edge and outwardly from the longitudinal axis of the support shaft; and

wherein said movable portion comprises first and second cutting edges which cooperate, respectively, with the first and second cutting edges of the stationary portion to define first and second substantially orthogonally disposed cutting planes; and

wherein said stationary portion further comprises a third cutting edge extending substantially orthogonally from the second cutting edge and substantially parallel to the first cutting edge such that said first, second and third cutting edges of the stationary portion define three sides of a generally rectangular opening in the stationary portion, and wherein said movable portion further comprises a third cutting edge which cooperates with the third cutting edge of the stationary portion to form a third cutting plane substantially orthogonally disposed to said second cutting plane.

2. A surgical instrument according to claim 1, wherein said stationary portion further comprises first and second sidewalls, extending laterally adjacent and substantially parallel to the longitudinal axis of the support shaft, and wherein said sidewalls have openings formed therein for receiving respective ends of a pivot pin which extends through, and forms a pivot axis of, said movable portion of the tip assembly.

3. A surgical instrument according to claim 2, wherein said first second and third cutting edges lie between substantially parallel planes extending, respectively, substantially transversely through the respective ends of the pivot pin.

4. A surgical instrument according to claim 2, wherein said stationary portion further comprises a third sidewall extending substantially orthogonally from a distal end of the first sidewall to a distal end of the second sidewall.

5. A surgical instrument according to claim 2, wherein said means extending coaxially with the support shaft comprises a wire rod having a flattened distal end which is pivotally connected to the movable portion of the tip assembly.

6. A surgical instrument according to claim 5, wherein said movable portion of the tip assembly is provided with a slot which receives the distal end of the wire rod, and wherein the distal end of the wire rod is pivotally attached to opposing sidewalls of the slot.

7. A surgical instrument according to claim 6, wherein the pivotable connection between the wire rod and the movable portion of the tip assembly, and the three sides of the generally rectangular opening defined by the first, second and third cutting edges, lie between substantially parallel planes extending, respectively, substantially transversely through the respective ends of the pivot pin.

8. A surgical instrument according to claim 1, wherein a surface of said movable portion partially defined by said first, second and third cutting edges is scalloped to facilitate the positioning of tissue to be cut by the instrument.

9. A surgical instrument according to claim 8, wherein said scalloped surface comprises a plurality of ridges which extend substantially parallel to said second cutting edge.

10. A surgical instrument according to claim 4, wherein the cutting jaw has a fully open position in which the movable portion extends outwardly from the longitudinal axis and toward a proximal end of the elongate shaft at an angle of approximately 60°

.

11. A surgical instrument according to claim 4, wherein the cutting jaw has a fully open position in which the movable portion extends outwardly from the longitudinal axis and toward a proximal end of the elongate shaft at an angle which is controlled by interaction of a surface on said movable portion and a surface of the stationary portion.

12. A surgical instrument for cutting body tissue, comprising:

a support shaft having a longitudinal axis;

a tip assembly attached to a distal end of the support shaft, said tip assembly comprising a stationary portion and a movable portion, said stationary portion having a pair of opposing sidewalls;

means for pivotally connecting a distal end of the movable portion between distal ends of the opposing sidewalls of the stationary portion so as to form a cutting jaw;

means extending coaxially with the support shaft for applying closing and opening forces to the movable portion of the cutting jaw, said means comprising an elongate, substantially straight member pivotally connected to the movable portion of the tip assembly; and

wherein said stationary and movable portions comprise a plurality of cooperating cutting edges which define a plurality of cutting planes, said cutting edges being disposed between substantially parallel planes which extend substantially transversely through the pivotable connections at the distal ends of the opposing sidewalls.

13. A surgical instrument according to claim 12, wherein said substantially straight member comprises a wire rod having a flattened distal end which is pivotally connected to the movable portion of the tip assembly.

14. A surgical instrument according to claim 13, wherein said movable portion of the tip assembly is provided with a slot which receives the distal end of the wire rod, and wherein the distal end of the wire rod is pivotally attached to opposing sidewalls of the slot.

15. A surgical instrument according to claim 14, wherein the pivotable connection between the wire rod and the movable portion of the tip assembly is disposed between the parallel planes which extend through the pivotable connections of the movable portion.

16. A surgical instrument according to claim 12, wherein said stationary portion comprises a first cutting edge extending substantially parallel to and laterally adjacent the longitudinal axis of the support shaft, and a second cutting edge extending substantially orthogonally from the first cutting edge and outwardly from the longitudinal axis of the support shaft, and wherein said movable portion comprises first and second cutting edges which cooperate, respectively, with the first and second cutting edges of the stationary portion to define first and second substantially orthogonally disposed cutting planes.

17. A surgical instrument according to claim 16, wherein said stationary portion further comprises a third cutting edge extending substantially orthogonally from the second cutting edge and substantially parallel to the first cutting edge such that said first, second and third cutting edges of the stationary portion define three sides of a generally rectangular opening in the stationary portion, and wherein said movable portion further comprises a third cutting edge which cooperates with the third cutting edge of the stationary portion to form a third cutting plane substantially orthogonally disposed to said second cutting plane.

18. A surgical instrument according to claim 17, wherein said opposing sidewalls comprise first and second sidewalls, extending laterally adjacent and substantially parallel to the longitudinal axis of the support shaft, and wherein said sidewalls have openings formed therein for receiving respective ends of a pivot pin which extends through, and forms a pivot axis of, said movable portion of the tip assembly.

19. A surgical instrument according to claim 18, wherein said stationary portion further comprises a third sidewall extending substantially orthogonally from a distal end of the first sidewall to a distal end of the second sidewall.