External fixation system and method of use

• US 20070049930A1
• Filed: 08/25/2005
• Published: 03/01/2007
• Est. Priority Date: 08/25/2005
• Status: Active Grant

• Current Assignee: Synthes USA LLC (Johnson & Johnson)
• Original Assignee: Synthes USA LLC (Johnson & Johnson)
• Inventors: Hearn, Jim, Wahl, Michael, Horan, Timothy, Maughan, Thomas
• Granted Patent: US 8,029,505 B2
• Time in Patent Office: Days
• US Class Current: 606/56
• CPC Class Codes: A61B 17/62 Ring frames, i.e. devices extending around the bones to be positioned A61B17/6433 , A61B17/66 take precedence
• CPC Class Codes: A61B 17/66 Alignment, compression or distraction mechanisms

Abstract

An external fixation system for connecting one or more bone segments together to facilitate healing of bone. The system may include one or more rings and/or ring segments. One or more linear distractors and/or angular distractors may connect the rings to each other so as to allow for distraction and/or reduction/compression of a bone. Linear distractors may enable an operator to move the rings towards and away from each other, while angular distractors may enable an operator to angle the rings relative to each other. In an embodiment using angular distractors, one or more angular separation assemblies may be positioned between the rings. These separation assemblies may have joints which may two portions which may be angled relative to each other and connected directly or indirectly to the rings. Various fasteners (e.g., nuts) and/or tightening members may configured for quick movement along and selective tightening to various components. Moreover, clamps may be attached to the rings and may engage pins, wire, rods, which may be inserted into bone to hold bone segments to each other. The components of the external fixation system may be provided in sets or kits so that the a surgeon may select various combinations of components to create an external fixation system which is configured specifically for the particular needs of a patient and the bone fracture/deformity.

Claims

1. An external fixation system, comprising:

a first ring member and a second ring member;

at least one distractor disposed between said first and second ring members, the distractor being configured to move the first and second ring members relative to each other; and

at least one clamp operably connected to at least one ring member comprising;

a base having an engagement portion;

a first vise plate and a second vise plate, the vise plates being sized and configured to receive a bone connection element therebetween, wherein the second vise plate has an engagement portion for engaging the engagement portion on the base;

a fastener positioned through the first and second vise plates, wherein the fastener engages the base;

a first biasing member positioned between the fastener and the first vise plate; and

a second biasing member positioned between the second vise plate and the base for separating the engagement portions of the second vise plate and the base, the second biasing member being compressible to allow the engagement portions to engage each other upon tightening of the fastener to the base.

2. The system of claim 1, wherein at least one of the first and second ring members comprises multiple ring segments.

3. The system of claim 1, wherein at least one of the first and second ring members is a ring assembly which comprises at least two ring segments.

4. The system of claim 1, wherein the bone connection element is selected from the group consisting of a pin, a wire and a screw.

5. The system of claim 1, wherein the distractor comprises:

a body portion having a proximal end, a distal end and an opening therein, wherein the proximal end of the body portion is operable connected to one of the first and second ring members;

a threaded member having a proximal end and a distal end, the threaded member being positioned within the opening of the body portion and being operably attached to the other of the first and second ring members; and

a knob having a bore therethrough for receiving the threaded member, the knob rotatably coupled to the distal end of the body portion, wherein rotation of the knob causes the rod to move axially within the knob and the opening of the body portion so that the first and second ring members move relative to each other.

6. The system of claim 5, wherein said body portion further comprises a gauge for determining changes in position of the threaded member relative to the body portion.

7. The system of claim 6, wherein the body portion further comprises a window for viewing the position of the proximal end of said threaded member within the body portion.

8. The system of claim 5, wherein the distractor comprises a detent assembly operably associated with the knob, the body portion comprises one or more indentations positioned at predetermined intervals around an outer surface of the body portion, and the knob comprises at least one protrusion engageable with one or more indentations as the knob is rotated about the body portion such that an operator is provided with at least one of tactile and audible feedback.

9. The system of claim 8, wherein the knob further comprises a plurality of markings, each marking designating a discreet increment of movement between indentations.

10. The system of claim 5, wherein rotation of the knob in a first direction moves the first and second ring members together, and rotation of the knob in a second direction moves the first and second ring member apart.

11. The system of claim 1, wherein the second biasing member is a radial spring.

12. The system of claim 1 wherein one of the first and second vise plates of the at least one clamp comprises at least one protrusion and the other of the first and second vise plate having at least one recess for receiving the at least one protrusion such that the first and second vise plates can move axially, but has limited rotational movement relative to each other.

13. The system of claim 1, further comprising a nut having a first end, a second end, a central axis and a bore extending from the first to the second end, the bore having an axis which is oblique relative to the axis of the nut.

14. The system of claim 13, wherein the bore comprises a first threaded portion proximate the first end, a second threaded portion proximate the second end and an unthreaded portion between the first and second ends.

15. The system of claim 1 further comprising a tightening member comprising:

a body portion having an opening therethrough and a passageway oriented substantially perpendicular to the opening for receiving a threaded member having an axis, the passageway having a wall;

an inner member positioned within the body portion, the inner member having a bore therethrough, the bore having a threaded portion and an unthreaded portion and being sized and configured to selectively engage the threaded member, wherein the inner member is moveable between a first position, where the threaded portion of the inner member engages the threaded member and the threaded member is held between the threaded portion and the wall of the passageway, and a second position where the threaded portion is disengaged from the threaded member so that the tightening member is freely moveable along the axis of the threaded member.

16. The system of claim 1 wherein the at least one distractor comprises:

a first connector and a second connector, the first and second connector being sized and configured to engage one of the first ring member and the second ring member;

a rod having a proximal end and a distal end, the second connector rotatably connects the rod to one of the first and second ring members; and

a knob having a bore therethrough, the knob being operably connected to the first connector and to the rod such that rotation of the knob causes the rod to move axially through the bore of the knob, wherein the first connector rotatably connects the knob to the other of the first and second ring members and wherein the knob moves rotationally, but not axially, with respect to the first connector.

17. The system of claim 16, wherein the first connector comprises a barrel nut having a detent mechanism and the knob has at least one indentation, the detent mechanism selectively engaging the at least one indentation.

18. The system of claim 17 further comprising a coupling positioned between a groove in the knob and a groove in the barrel nut, the coupling preventing axial movement of the knob relative to the barrel nut.

19. An external fixation system, comprising:

a first ring member and a second ring member;

at least one clamp operably connected to at least one ring member; and

at least one distractor disposed between said first and second ring members, the distractor being configured to move the first and second ring members relative to each other, wherein the at least one distractor comprises;

a first connector and a second connector, the first and second connector being sized and configured to engage one of the first ring member and the second ring member;

a rod having a proximal end and a distal end, the second connector rotatably connecting the rod to one of the first and second ring members; and

a knob having a bore therethrough, the knob being operably connected to the first connector and to the rod such that rotation of the knob causes the rod to move axially through the bore of the knob, wherein the first connector rotatably connects the knob to the other of the first and second ring members and wherein the knob moves rotationally, but not axially, with respect to the first connector.

20. The system of claim 19, wherein the first connector comprises a barrel nut having a detent mechanism and the knob has at least one indentation, the detent mechanism selectively engaging the at least one indentation.

21. The system of claim 20 further comprising a coupling positioned between a groove in the knob and a groove in the barrel nut, the coupling preventing axial movement of the knob relative to the barrel nut.

22. The system of claim 19 wherein the at least one clamp comprises:

a base having an engagement portion;

a first vise plate and a second vise plate, the vise plates being sized and configured to receive a bone connection element therebetween, wherein the second vise plate has an engagement portion for engaging the engagement portion on the base;

a fastener positioned through the first and second vise plates, wherein the fastener engages the base;

a first biasing member positioned between the fastener and the first vise plate; and

a second biasing member positioned between the second vise plate and the base for separating the engagement portions of the second vise plate and the base, the second biasing member being compressible to allow the engagement portions to engage each other upon tightening of the fastener to the base.

23. The system of claim 22, wherein one of the first and second vise plates of the at least one clamp comprises at least one protrusion and the other of the first and second vise plate having at least one receiving portion for receiving the at least one protrusion such that the first and second vise plates can move axially, but are limited rotationally relative to each other.

24. The system of claim 19, wherein the first and second connectors each have a barrel nut, the barrel nut of the first connector having a passage therethrough for receiving a portion of the knob, the barrel nut of the second connector having a passage therethrough for receiving a portion of the rod.

25. The system of claim 24, wherein the rod has external threads and the barrel nut of the second connector has internal threads, the external threads engaging the internal threads.

26. The system of claim 19, further comprising at least one angular separation assembly being sized and configured to be operably connected to the first and second ring members.

27. The system of claim 26, wherein the at least one angular separation assembly comprises a first body portion and a second body portion, the first and second body portions operably connected to each other such that the body portions are rotatable relative to each other.

28. The system of claim 27, wherein the first body portion is operably connected to one of the first and second ring members and the second body portion is operably connected to the other of the first and second ring members.

29. The system of claim 27, wherein the at least one angular separation assembly further comprises a first rod operably connected to one of the first and second body portions for connecting one of the first and second body portions to one of the first and second ring members.

30. The system of claim 29, wherein the at least one angular separation assembly further comprises a second rod operably connected to the other of the first and second body portions for connecting the other of the first and second body portions to the other of the first and second ring members.

31. The system of claim 28, wherein one of the first and second body portions comprises a ball and the other of the first and second body portions comprises a socket for receiving the ball such that the first and second body portions are polyaxially moveable relative to each other.

32. The system of claim 19 further comprising a washer assembly, wherein the washer assembly comprises a male washer having a bore therethrough and a convex surface and a female washer having a bore therethrough and a concave surface, wherein the convex surface of the male washer moves within the concave surface of the female washer.

33. A kit for constructing an external fixation system, comprising:

at least two ring members;

at least one distractor disposed between at least two ring members, the distractor being configured to move the at least two ring members relative to each other; and

at least one clamp operably connected to at least one ring member comprising;

a base having an engagement portion;

a first vise plate and a second vise plate, the vise plates being sized and configured to receive a bone connection element therebetween, wherein the second vise plate has an engagement portion for engaging the engagement portion on the base;

a fastener positioned through the first and second vise plates, wherein the fastener engages the base;

a first biasing member positioned between the fastener and the first vise plate; and

a second biasing member positioned between the second vise plate and the base for separating the engagement portions of the second vise plate and the base, the second biasing member being compressible to allow the engagement portions to engage each other upon tightening of the fastener to the base.

34. The kit of claim 33 further comprising a plurality of bone connection elements.

35. The kit of claim 33 wherein the at least one distractor comprises:

a body portion having a proximal end, a distal end and an opening therein, wherein the proximal end of the body portion is operable connected to one of the at least two ring members;

a threaded member having a proximal end and a distal end, the threaded member being moveable within the opening of the body portion and being operably attached to the other of the at least two ring members; and

a knob having an opening therethrough for receiving the threaded member, the knob rotatably coupled to the distal end of the body portion, wherein rotation of the knob causes the rod to move axially within the knob and the opening of the body portion so that the at least two ring members move relative to each other.

36. The kit of claim 35 wherein one of the at least one distractor is an angular distractor.

37. The kit of claim 36 wherein the angular distractor comprises:

a first connector and a second connector, the first and second connector being configured to engage one of the at least two ring members;

a rod having a proximal end and a distal end, the second connector rotatably connects the rod to one of the at least two ring members; and

a knob having a bore therethrough, the knob being operably connected to the first connector and to the rod such that rotation of the knob causes the rod to move axially through the bore of the knob, wherein the first connector rotatably connects the knob to the other of the at least two ring members and wherein the knob moves rotationally, but not axially, with respect to the first connector.

38. The kit of claim 37, wherein the first connector comprises a barrel nut having a detent mechanism and the knob has at least one indentation, the detent mechanism selectively engaging the at least one indentation.

39. The kit of claim 38 further comprising a coupling positioned between a groove in the knob and a groove in the barrel nut, the coupling preventing axial movement of the knob relative to the barrel nut.

40. The kit of claim 37 further comprising a nut having a first end, a second end, a central axis and a bore extending from the first to the second end, the bore having an axis which is oblique relative to the axis of the nut.

41. The kit of claim 37 further comprising a tightening member comprising:

a body portion having an opening therethrough and a passageway oriented substantially perpendicular to the opening for receiving a threaded member having an axis, the passageway having a wall;

an inner member positioned within the body portion, the inner member having a bore therethrough, the bore having a threaded portion and an unthreaded portion and being sized and configured to selectively engage the threaded member, wherein the inner member is moveable between a first position, where the threaded portion of the inner member engages the threaded member and the threaded member is held between the threaded portion and the wall of the passageway, and a second position where the threaded portion is disengaged from the threaded member so that the tightening member is freely moveable along the axis of the threaded member.

42. A kit for constructing an external fixation system, comprising:

at least two ring members;

at least one clamp operably connected to at least one ring member; and

at least one distractor disposed between said at least two ring members, the distractor being configured to move at least two ring members relative to each other, wherein the at least one distractor comprises;

a first connector and a second connector, the first and second connector being configured to engage one of the at least two ring members;

a rod having a proximal end and a distal end, the second connector rotatably connecting the rod to one of the at least two ring members; and

a knob having a bore therethrough, the knob being operably connected to the first connector and to the rod such that rotation of the knob causes the rod to move axially through the bore of the knob, wherein the first connector rotatably connects the knob to the other of the at least two ring members and wherein the knob moves rotationally, but not axially, with respect to the first connector.

43. The kit of claim 42 further comprising a plurality of bone connection elements.

44. The kit of claim 43 wherein the at least one distractor comprises:

a body portion having a proximal end, a distal end and an opening therein, wherein the proximal end of the body portion is operable connected to one of the at least two ring members;

a threaded member having a proximal end and a distal end, the proximal end of the threaded member being positioned within the opening of the body portion, the distal end of the threaded member being operably attached to the other of the at least two ring members; and

a knob having an opening therethrough for receiving the threaded member, the knob rotatably coupled to the distal end of the body portion, wherein rotation of the knob causes the rod to move axially within the knob and the opening of the body portion so that the at least two ring members move relative to each other.

45. The kit of claim 44 further comprising a nut have an axis, a first end, a second end and a bore extending from the first to the second end, the bore having an axis which is oblique to the axis of the nut.

46. The kit of claim 44 further comprising a tightening member comprising:

a body portion having an opening therethrough and a passageway oriented substantially perpendicular to the opening for receiving a threaded member having an axis, the passageway having a wall;

an inner member positioned within the body portion, the inner member having a bore therethrough, the bore having a threaded portion and an unthreaded portion and being sized and configured to selectively engage the threaded member, wherein the inner member is moveable between a first position, where the threaded portion of the inner member engages the threaded member and the threaded member is held between the threaded portion and the wall of the passageway, and a second position where the threaded portion is disengaged from the threaded member so that the tightening member is freely moveable along the axis of the threaded member.

47. The kit of claim 42 further comprising a washer assembly, wherein the washer assembly comprises a male washer having a bore therethrough and a convex surface and a female washer having a bore therethrough and a concave surface, wherein the convex surface of the male washer moves within the concave surface of the female washer.