Torque limiting device and methods

• US 20070256527A1
• Filed: 03/30/2007
• Published: 11/08/2007
• Est. Priority Date: 07/11/2005
• Status: Active Grant

• Current Assignee: Kyphon SARL (Medtronic Plc)
• Original Assignee: Kyphon SARL (Medtronic Plc)
• Inventors: Phan, Christopher
• Granted Patent: US 8,317,791 B2
• Time in Patent Office: Days
• US Class Current: 81/475
• CPC Class Codes: A61B 17/8875 Screwdrivers, spanners or wrenches
• CPC Class Codes: A61B 2090/031 torque limiting
• CPC Class Codes: A61C 1/186 with torque adjusting or limiting means
• CPC Class Codes: B25B 23/1427 by mechanical means

Abstract

A surgical device can include a torque limiting device or system. The surgical device can include a rod attached on one end to a rotatable handle and attached on the opposite end to a surgical implement. A first torque limiting element can be connected to the handle, and a second torque limiting element can be operably connected to the rod and surgical implement and releasably engageable with the first torque limiting element. When the first and second torque limiting elements are engaged, rotation of the handle can cause rotation of the rod and surgical implement. When a rotational force that exceeds a predetermined torque limit is applied to the handle, the first torque limiting element can disengage from the second torque limiting element, so that the handle is rotatable without rotation of the rod and surgical implement. The first and second torque limiting elements can be re-engageable so that further rotation of the handle can cause rotation of the rod and surgical implement.

Claims

1. A surgical device comprising:

a rod attached on one end to a rotatable handle and attached on the opposite end to a surgical implement;

a first torque limiting element connected to the handle; and

a second torque limiting element operably connected to the rod and surgical implement and releasably engageable with the first torque limiting element,

wherein rotation of the handle causes rotation of the rod and surgical implement, and

wherein when a rotational force applied to the handle exceeds a predetermined torque limit, the first torque limiting element disengages from the second torque limiting element, so that the handle is rotatable without rotation of the rod and surgical implement.

2. The surgical device of claim 1, wherein after becoming disengaged, the first torque limiting element is re-engageable with the second torque limiting element so that further rotation of the handle causes rotation of the rod and surgical implement.

3. The surgical device of claim 1,

wherein the first torque limiting element further comprises (a) a ball plunger comprising a ball and housed in a cylinder attached to the handle, and (b) a biasing mechanism positioned in the cylinder and configured to urge the ball plunger ball into engagement with the second torque limiting element, and

wherein the second torque limiting element further comprises a ball engaging receptacle attached to the rod for releasably engaging the ball plunger ball.

4. The surgical device of claim 3, wherein after becoming disengaged, the ball plunger ball is re-engageable with the ball engaging receptacle so that further rotation of the handle causes rotation of the rod and surgical implement.

5. The surgical device of claim 3, wherein the ball plunger is positioned substantially perpendicular to the rod.

6. The surgical device of claim 3, wherein the biasing mechanism further comprises a spring.

7. The surgical device of claim 3, wherein the second torque limiting element is attached to a hollow shaft through which the rod is slidingly movable, and wherein the first and second torque limiting elements are embedded in a cavity in the handle.

8. The surgical device of claim 3, further comprising a ball bearing positioned on opposite sides of the ball engaging receptacle and fixedly attached in a cavity in the handle.

9. The surgical device of claim 1, the rod further comprising a ball joint attached to the end of the rod attached to the handle, and the handle further comprising a lever pivotably attached to the handle and having a ball joint receptacle rotatably positioned about the ball joint,

wherein when the lever pivots in the handle, the surgical implement is moved to an angle relative to the rod, and

wherein when the torque limiting elements are disengaged, the handle is rotatable about the rod without rotation of the surgical implement.

10. The surgical device of claim 1, further comprising a first surface attached to the handle and in biased contact with a second surface attached to the rod,

the first torque limiting element further comprising a projection from the first surface and the second torque limiting element further comprising a notch in the second surface for releasably engaging the projection.

11. The surgical device of claim 10, wherein after becoming disengaged, the projection is re-engageable with the notch so that further rotation of the handle causes rotation of the rod and surgical implement.

12. A surgical device comprising:

a rod having a first end and a second end;

a handle positioned near the first end of the rod;

a surgical implement attached to the second end of the rod;

a first surface attached to the handle; and

a second surface attached to the rod, the second surface in releasably engageable contact with the first surface such that rotation of the handle causes rotation of the rod and surgical implement,

wherein when a rotational force applied to the handle exceeds a predetermined torque limit, the first surface disengages from the second surface, so that the handle is rotatable without rotation of the rod and surgical implement.

13. The surgical device of claim 12, further comprising a housing attached to the handle and defining a cavity within which the first and second surfaces are positioned.

14. The surgical device of claim 13, the first surface comprising a first plate having a projection and the second surface comprising a second plate having a notch, wherein the projection is engageable with the notch.

15. The surgical device of claim 14, wherein the projection and the notch are substantially the same size and shape.

16. The surgical device of claim 14, further comprising a spring disposed between the housing and the first surface, the spring capable of exerting a force on the first surface to engage the projection with the notch.

17. The surgical device of claim 14, the housing further comprising a support that prevents movement of the second surface toward the second end of the rod.

18. The surgical device of claim 13, the first surface comprising a ball plunger having a ball attached at one end and the second surface comprising a disk having a depression, wherein the ball is releasably engageable with the depression.

19. The surgical device of claim 18, wherein the ball and the depression are substantially the same size and shape.

20. A surgical device comprising:

a rod comprising a first section and a second section, the first section rotatably connected to the second section;

a handle attached to the first section of the rod;

an implement attached to the second section of the rod;

a first plate attached to the first section of the rod, the first plate having a raised portion;

a second plate attached to the second section of the rod, the second plate having a depression of substantially the same size and shape as the raised portion of the first plate;

a housing that defines a cavity, the first plate and second plate fitting inside the cavity and the second plate restrained within the housing by a ledge; and

a compression spring disposed between a cap of the housing and a surface of the first plate such that the spring pushes the first plate longitudinally toward the second plate,

wherein the raised portion of the first plate is engageable with the depression of the second plate, so that rotation of the first section of the rod causes rotation of the second section of the rod and the implement, and

wherein when a rotational force applied to the handle and the first section of the rod exceeds a predetermined torque limit, the spring compresses and the raised portion of the first plate disengages from the depression of the second plate, so that the first section is rotatable without rotation of the second section and the implement.

21. The surgical device of claim 20, the rod further comprising a cylindrical tube in which an actuator is disposed, the actuator being operable to activate the implement.

22. The surgical device of claim 20, further comprising a trigger positioned on the handle operable to control the actuator.

23. A surgical device comprising:

a rod having a first end and a second end;

a handle positioned near the first end of the rod;

a surgical implement attached to the second end of the rod;

a ball plunger comprising a ball and housed in a cylinder attached to the handle;

a spring positioned in the cylinder and configured to push the ball plunger in a longitudinal direction within the cylinder; and

a disk attached to the rod and having a depression of substantially the same size and shape as the ball of the ball plunger,

wherein the ball plunger ball is engageable with the depression of the disk so that rotation of the handle causes rotation of the rod and surgical implement, and

wherein when a rotational force applied to the handle exceeds a predetermined torque limit, the spring compresses and the ball plunger ball disengages from the depression, so that the handle is rotatable without rotation of the rod and surgical implement.

24. The surgical device of claim 23, further comprising a housing attached to the handle and defining a cavity having a substantially cylindrical shape and a diameter and in which the disk and ball plunger are positioned.

25. The surgical device of claim 24, the disk and the housing cavity each have a diameter, wherein the cavity diameter is between 0 and 10 millimeters larger than the disk diameter.

26. The surgical device of claim 23, the handle having a cavity for receiving the first end of the rod.

27. The surgical device of claim 23, the housing comprising a mechanism for limiting longitudinal movement of the rod.

28. A surgical device comprising:

a handle;

an elongated member extending from the handle and configured such that a distal end of the elongated member can be percutaneously placed into a tissue in a patient'"'"'s body; and

a torque limiting mechanism coupling a proximal portion of the elongated member to the handle.

29. The surgical device of claim 28, wherein the elongated member is capable of axial rotation about the longitudinal axis of the elongated member, and wherein the torque limiting mechanism disallows axial rotation of the elongated member when a torque on the elongated member is greater than a predetermined amount.

30. The surgical device of claim 29, wherein the tissue comprises a bone, and the distal end of the elongated member is configured to displace a cancellous bone within the bone.

31. The surgical device of claim 30, wherein the bone comprises a vertebral body.

32. The surgical device of claim 29, wherein the tissue comprises an intervertebral disc.

33. The surgical device of claim 29, wherein the elongated member comprises a rigid shaft and a moveable distal tip portion, and wherein the handle comprises an actuating member coupled to and configured to move the moveable distal tip portion.

34. The surgical device of claim 33, wherein the actuating member comprises a lever adapted to be displaced relative to the handle, such that displacement of the lever can move the distal tip portion of the elongated member.

35. The surgical device of claim 34, wherein the distal tip portion of the elongated member comprises a configuration for scraping bone.

36. The surgical device of claim 34, wherein the distal tip portion of the elongated member is adapted to rotate axially relative to the rigid shaft.

37. The surgical device of claim 28, further comprising an axial load limiting mechanism coupled to the handle and to the elongated member.

38. The surgical device of claim 28, wherein the torque limiting mechanism further comprises a ball bearing biased into engagement with the elongated member and capable of disengagement from the elongated member when a torque on the elongated member is greater than a predetermined amount.

39. The surgical device of claim 38, wherein after becoming disengaged, the ball bearing is re-engageable with the elongated member.

40. The surgical device of claim 38, wherein the ball bearing is configured to be engaged with and disengaged from the elongated member in a direction substantially perpendicular to a longitudinal axis of the elongated member.

41. A method of using a surgical tool, comprising:

providing the surgical tool having a rod rotatingly engageable on one end with a handle and attached on the opposite end to a surgical implement, and a first torque limiting element connected to the handle and engageable with a second torque limiting element operably connected to the surgical implement;

inserting the surgical implement and a portion of the rod into an interior body region;

applying a first rotational force to the handle to rotate the surgical implement; and

applying a second rotational force to the handle that exceeds a predetermined torque limit, thereby disengaging the first element from the second element such that the handle rotates without rotation of the surgical implement.

42. The method of claim 41, further comprising rotating the handle to re-engage the first element with the second element so that further rotation of the handle causes rotation of the surgical implement.

43. The method of claim 42,

the surgical tool further comprising a first surface attached to the handle and in biased contact with a second surface attached to the rod,

the first torque limiting element further comprising a projection from the first surface and the second torque limiting element further comprising a notch in the second surface,

wherein the rotating the handle to re-engage the first element with the second element further comprises realigning the projection from the first surface with the notch in the second surface.

44. The method of claim 42,

the first torque limiting element further comprising a ball plunger having an attached ball and the second torque limiting element further comprising a ball engaging receptacle, the ball in biased contact with the ball engaging receptacle,

wherein the rotating the handle to re-engage the first element with the second element further comprises realigning the ball plunger ball with the ball engaging receptacle.

45. The method of claim 41, wherein the ball plunger is positioned substantially perpendicular to the rod.

46. A method comprising:

inserting percutaneously an elongated member having a shaft into a patient'"'"'s body;

placing at least a distal portion of the elongated member into a bone in the patient'"'"'s body;

moving the distal portion of the elongated member relative to the shaft;

applying a first torque force on a handle coupled to the elongated member so as to rotate the shaft of the elongated member axially about a longitudinal axis of the shaft; and

applying a second torque force on the handle that exceeds a predetermined amount of torque to disengage the handle from the shaft and rotate the handle without rotating the shaft of the elongated member.

47. The method of claim 46, further comprising:

rotating the handle to re-engage the handle with the shaft; and

applying the first torque force on the handle to rotate the shaft.

48. The method of claim 46, further comprising actuating a lever coupled to the distal portion of the elongated member to move the distal portion of the elongated member.

49. The method of claim 46, wherein the moving the distal portion of the elongated member further comprises rotating the distal portion axially relative to the shaft.

50. The method of claim 46, wherein the moving the distal portion of the elongated body further comprises displacing a cancellous bone within the bone.

51. The method of claim 46, wherein the moving the distal portion of the elongated member further comprises scraping bone.

52. The method of claim 46, wherein the placing at least a distal portion of the elongated member into a bone further comprises placing at least a distal portion of the elongated member into a vertebral body.

53. The method of claim 46, further comprising limiting an axial load placed on the distal portion of the elongated member.