Fixation device and method of using the same

Patent metadata

Field	Value
Publication number	US-11517361-B2
Application number	US-201816499013-A
Country	US
Kind code	B2
Filing date	Mar 30, 2018
Priority date	Mar 30, 2017
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A fixation device includes a tapered cannula defining a bore therethrough, a shaft, and a post. The shaft includes a proximal portion disposed within the bore, and central and distal portions extending distally from the tapered cannula. The proximal portion includes a threaded inner surface defined therein. The shaft includes blades disposed within the central portion, the blades movable between a closed position in which the blades are disposed within the shaft and an open position in which the blades extend laterally through the shaft. The post includes a threaded outer surface threadingly engaged with the threaded inner surface of the shaft. The post is movable longitudinally within the shaft to transition the blades between the closed and open positions.

First claim

What is claimed is:

1. A fixation device comprising:
a tapered cannula defining a bore therethrough;
a shaft including a proximal portion disposed within the bore of the tapered cannula, and central and distal portions extending distally from the tapered cannula, the distal portion being entirely unthreaded, the proximal portion including a threaded inner surface defined therein, the shaft including blades disposed within the central portion and distal of the tapered cannula, the blades movable between a closed position in which the blades are disposed within the shaft and an open position in which the blades extend laterally through the shaft; and
a post including a threaded outer surface threadingly engaged with the threaded inner surface of the shaft, the post movable longitudinally within the shaft to transition the blades between the closed and open positions.

2. The fixation device according to claim 1 , further comprising a snap ring disposed within an annular groove defined in the bore of the tapered cannula and an annular groove defined in an outer surface of the shaft.

3. The fixation device according to claim 1 , wherein the central portion of the shaft defines blade openings therein and, when the blades are disposed in the open position, each of the blades extends through one of the blade openings.

4. The fixation device according to claim 3 , wherein the central portion of the shaft includes spines disposed in opposed relation relative to each other and extending longitudinally between the proximal and distal portions of the shaft.

5. The fixation device according to claim 4 , wherein the central portion of the shaft includes ledges that laterally interconnect the spines.

6. The fixation device according to claim 5 , wherein, when the blades are disposed in the closed position, a portion of each of the blades rests against the respective ledge disposed distal of the blade.

7. The fixation device according to claim 3 , wherein each blade includes a body portion defining an opening therethrough and a wing portion extending from the body portion.

8. The fixation device according to claim 7 , wherein each blade includes a notch extending from the body portion, the notch configured to inhibit rotation of the blade when the blade reaches the open position.

9. The fixation device according to claim 7 , further comprising pins extending through the openings defined in the body portions of the blades, the blades rotatable around the pins.

10. The fixation device according to claim 9 , further comprising aligners wherein each aligner includes a head disposed within the proximal portion of the shaft, an elongate tail extending into the central portion of the shaft, and a groove extending longitudinally therein, wherein end portions of each of the pins are disposed within the grooves of the aligners.

11. The fixation device according to claim 10 , wherein the heads of the aligners are disposed adjacent to and distal of the post, and longitudinal movement of the post causes longitudinal movement of the aligners, the pins, and the blades.

12. The fixation device according to claim 11 , wherein each blade rotates about the respective pin when the wing portion of the blade contacts a portion of the shaft defining the blade opening in which the respective blade is disposed.

13. The fixation device according to claim 10 , further comprising a cap disposed within the distal portion of the shaft, the cap including bosses extending from opposed sides of a body, the bosses disposed within the grooves of the aligners.

14. The fixation device according to claim 13 , further comprising a spring disposed within a slot of the cap, the spring being compressed by the cap when the blades are in the open position and the spring applying a proximal force on the cap when the blades are in the closed position.

15. A method of securing a fixation device to osseous tissue, comprising:
inserting a distal portion of a shaft and a tapered cannula of a fixation device into an insertion hole in osseous tissue, the shaft including a proximal portion disposed within a bore of the tapered cannula, the fixation device disposed in a closed position in which blades are disposed within a central portion of the shaft distal of the tapered cannula, the distal portion being entirely unthreaded; and
applying a force to a post of the fixation device to move the post distally, the post engaged with and longitudinally movable relative to the shaft such that distal movement of the post relative to the shaft causes the fixation device to transition from the closed position to an open position in which the blades extend laterally through the shaft and engage the osseous tissue.

16. The method according to claim 15 , wherein applying the force to the post includes rotating the post relative to the shaft, the post and the shaft threadingly engaged with each other.

17. The method according to claim 15 , wherein applying the force to the post includes inserting an engagement tip of a driving instrument into an opening defined in a head of the post.

18. The method according to claim 15 , further comprising applying a force to the post to move the post proximally relative to the shaft to cause the fixation device to transition from the open position back to the closed position.

19. The method according to claim 15 , further comprising applying a rotational force to the tapered cannula to engage helical threads disposed on an outer surface of the tapered cannula with the osseous tissue.

20. The method according to claim 19 , wherein applying the rotational force to the tapered cannula includes inserting tabs of an insertion instrument into cut-outs defined in a proximal end of the tapered cannula.

Assignees

• K2M Inc

Inventors

• Major Eric
• Errico Thomas J
• Newton Peter
• Shufflebarger Harry
• Mcclintock Larry E

Classifications

• A61B17/7082

  for driving, i.e. rotating, screws or screw parts specially adapted for spinal fixation, e.g. for driving polyaxial or tulip-headed screws · CPC title

• A61B2017/8655

  with special features for locking in the bone · CPC title

• A61B17/8875

  Screwdrivers, spanners or wrenches · CPC title

• A61B17/8625

  Shanks, i.e. parts contacting bone tissue · CPC title

• A61B17/864 Primary

  hollow, e.g. with socket or cannulated · CPC title