Bone fixation device, tools and methods

• US 9,155,574 B2
• Filed: 09/28/2009
• Issued: 10/13/2015
• Est. Priority Date: 05/17/2006
• Status: Active Grant

• Current Assignee: Arthrex Incorporated
• Original Assignee: Sonoma Orthopedic Products Incorporated (Arthrex Incorporated)
• Inventors: Saravia, Heber, McDaniel, Stephen R., Pham, Trung Ho, Nelson, Charles L., Gunther, Stephen
• Primary Examiner(s): Merene, Jan Christopher
• Assistant Examiner(s): COTRONEO, STEVEN J
• Application Number:
  US13/203,713
• Publication Number:
  US 20120239038A1
• Time in Patent Office: 2,206 Days
• Field of Search: 606 62- 68, 623/23.23
• US Class Current: 1/1
• CPC Class Codes: A61B 17/1725 for applying transverse screws or pins through intramedullary nails or pins
• CPC Class Codes: A61B 17/7208 Flexible pins, e.g. ENDER pins
• CPC Class Codes: A61B 17/7225 for bone compression
• CPC Class Codes: A61B 17/7241 the nail having separate elements through which screws pass
• CPC Class Codes: A61B 17/7266 with fingers moving radially outwardly
• CPC Class Codes: A61B 17/8872 Instruments for putting said fixation devices against or away from the bone A61B17/7074, A61B17/808 take precedence
• CPC Class Codes: A61B 2017/00004 (bio)absorbable, (bio)resorbable or resorptive

Abstract

A bone fixation device is provided with an elongate body having a longitudinal axis and having a first state in which at least a portion of the body is flexible and a second state in which the body is generally rigid, an actuateable gripper disposed at one or more locations on the elongated body, a hub located on a proximal end of the elongated body, and an actuator operably connected to the gripper(s) to deploy the gripper(s) from a retracted configuration to an expanded configuration. Methods of repairing a fracture of a bone are also disclosed. One such method comprises inserting a bone fixation device into an intramedullary space of the bone to place at least a portion of an elongate body of the fixation device in a flexible state on one side of the fracture and at least a portion of a hub on another side of the fracture, and operating an actuator to deploy at least one gripper of the fixation device to engage an inner surface of the intramedullary space to anchor the fixation device to the bone. Alternative gripper designs are disclosed that may be used in various combinations.

Claims

1. A bone fixation device comprising:

an elongate body having a longitudinal axis and a flexible-to-rigid portion having a first state in which at least a portion of the body is flexible and a second state in which the body is generally rigid;

a first actuatable bone engaging gripper disposed on the elongate body;

a second actuatable bone engaging gripper disposed on the elongate body distal from the first gripper;

a hub coupled to a proximal end of the elongate body; and

an actuator operably connected to at least one of the first and the second grippers to actuate the gripper from a disengaged configuration to an engaged configuration, the first and the second grippers each having at least one bendable member, the member pivoting away from the longitudinal axis of the elongate body when the gripper is actuated, the actuator also being operably connected to the elongate body to change the elongate body from its flexible state to its rigid state,

wherein the actuator comprises an actuator head comprising a ramped surface, wherein the actuator head is slideably disposed on an interior of the at least one of the first and the second grippers, the actuator head configured to outwardly actuate the at least one of the first and the second grippers away from the longitudinal axis;

a second actuator, thereby allowing each of the two grippers to be independently actuated.

2. The bone fixation device of claim 1, wherein the flexible-to-rigid portion of the elongate body is disposed at a location on the elongate body distal to the first gripper and proximal to the second gripper.

3. The bone fixation device of claim 2 wherein the hub is straight.

4. The bone fixation device of claim 2 wherein the hub is curved.

5. The bone fixation device of claim 2 wherein the actuator and the second actuator are connected to actuate both grippers from a disengaged configuration to an engaged configuration.

6. A surgical kit comprising:

the bone fixation device of claim 1; and

an alignment tool configured to couple to the hub, the tool further configured to align with a portion of the device to form at least one screw hole into the portion of the device.

7. The surgical kit of claim 6 wherein the alignment tool is configured to align with at least the hub of the device to form a screw hole in the hub.

8. The surgical kit of claim 6 wherein the alignment tool is configured to align with at least the flexible-to-rigid portion of the device to form a screw hole in that portion.

9. The bone fixation device of claim 1, wherein the flexible-to-rigid portion of the elongate body is disposed at a location on the elongate body distal to both the first and the second grippers.

10. The bone fixation device of claim 9 wherein the hub is straight.

11. The bone fixation device of claim 9 wherein the hub is curved.

12. A surgical kit comprising:

the bone fixation device of claim 9; and

an alignment tool configured to couple to the hub, the tool further configured to align with a portion of the device to form at least one screw hole into the portion of the device.

13. The surgical kit of claim 12 wherein the alignment tool is configured to align with at least the hub of the device to form a screw hole in the hub.

14. The surgical kit of claim 12 wherein the alignment tool is configured to align with at least the flexible-to-rigid portion of the device to form a screw hole in that portion.

15. A bone fixation device comprising:

a generally tubular body having a circumferential surface, an inner lumen, and a wall extending therebetween, and an actuatable bone engaging gripper disposed on the wall, the body being sized to fit within an intramedullary space within a bone, the body having a longitudinal axis;

the gripper having at least one bendable member, the member pivoting away from the longitudinal axis of the tubular body when the gripper is actuated,

an actuator operably connected to the gripper to actuate the gripper from a disengaged configuration to an engaged configuration,

wherein the actuator comprises an actuator head comprising a ramped surface, wherein the actuator head is slideably disposed in the inner lumen, the actuator head configured to outwardly actuate the gripper away from the longitudinal axis,

a helical slit through the body wall extending around the circumferential surface and axially along at least a portion of the body; and

a compression mechanism configured to apply an axial compression to the body to move the slit towards a closed position, thereby transforming the body from a generally flexible state to a generally rigid state,

wherein the helical slit forms multiple pairs of mating features, each pair having a proximally projecting member and a distally projecting member, the proximally projecting member having a ramped surface on its proximally facing end of sufficient angle to cause the proximally projecting member to move in a first generally transverse direction when under axial compression, the distally projecting member having a ramped surface on its distally facing end of sufficient angle to cause the distally projecting member to move in a second generally transverse direction generally opposite the first direction when under axial compression such that the projecting members of a pair move toward each other when under axial compression.

16. The bone fixation device of claim 15 wherein at least one of the projecting members of a pair comprises a laterally projecting keying feature that interengage with a keying feature of the opposite member of the pair when the members of the pair move toward each other.

17. The bone fixation device of claim 15 wherein at least one of the projecting members of a pair comprises a plurality of laterally projecting keying features that interengage with keying features of the opposite member of the pair when the members of the pair move toward each other.

18. The bone fixation device of claim 15 wherein each of the projecting members of a pair has a plurality of laterally projecting keying features that interengage with the keying features of the opposite member of the pair when the members of the pair move toward each other.

19. The bone fixation device of claim 17 wherein at least one of the plurality of laterally projecting keying features is nested on another of the laterally projecting keying features.

20. The bone fixation device of claim 15 further comprising at least two pairs of mating features located within one revolution of the helical slit.

21. The bone fixation device of claim 15 further comprising at least five pairs of mating features located within one revolution of the helical slit.