Method and apparatus for spondylolysis repair

Patent metadata

Field	Value
Publication number	US-10413334-B2
Application number	US-201514723377-A
Country	US
Kind code	B2
Filing date	May 27, 2015
Priority date	May 27, 2014
Publication date	Sep 17, 2019
Grant date	Sep 17, 2019

Abstract

Disclosed are fixation devices for repairing spondylolysis. The fixation device can include a first anchor, a second anchor, and a bridge that couples the first and second anchors together. In use, the first anchor can be implanted on one side of a pars fracture, the second anchor can be implanted on the other side of the pars fracture, and the bridge can span across the pars fracture. In some embodiments, the fixation device can be compressible to promote healing of the fracture.

First claim

We claim:

1. A method for repairing spondylolysis comprising the steps of:
advancing a fixation device having a first anchor, a second anchor, and a bridge that extends between the first and second anchors towards a target site, wherein the first anchor includes a first portion and a second portion detachably coupled to the first portion;
positioning the first anchor of the fixation device against a bone on one side of a pars fracture;
positioning the second anchor of the fixation device against the bone on the other side of the pars fracture;
applying a rotational force to a rotatable coupling of the second portion of the first anchor, thereby advancing a distal anchor of the first portion of the first anchor into the bone;
axially shortening the first anchor by reducing a distance between the distal anchor and a proximal anchor of the first anchor, such that a locking element on the proximal anchor engages at least one retention structure on a body of the first anchor that prevents movement of the proximal anchor away from the distal anchor; and
detaching and removing the second portion from the first portion after the axially shortening step.

2. The method of claim 1 , wherein the first anchor comprises a compression screw.

3. The method of claim 2 , wherein the body includes the distal anchor, the proximal anchor, and an inner member disposed within the body.

4. The method of claim 2 , comprising the step of slidably moving the second anchor with respect to the first anchor.

5. The method of claim 1 , further comprising the step of pulling the first and second anchors toward one another after being advanced into bone.

6. The method of claim 1 , wherein the advancing step comprises advancing the first and second anchors into bone substantially simultaneously.

7. The method of claim 1 , further comprising disposing bone graft material, bone growth promoters, and/or bone cement into the pars fracture.

8. The method of claim 1 , wherein the advancing step further comprises the step of seating a flange against an outer surface of the bone so as to compress a fracture between the proximal and distal anchors.

9. The method of claim 8 , wherein the flange is coupled to or integral with the bridge.

10. The method of claim 8 , wherein the first anchor includes the flange.

11. A method for repairing spondylolysis comprising the steps of:
creating an access path from a position above, posterolaterally or lateral to a pars fracture;
inserting a fixation device through the access path, the fixation device including a first anchor, a second anchor, and a bridge that extends between the first and second anchors, wherein the fixation device further includes a flange;
advancing a distal anchor of the first anchor into bone, and axially shortening the first anchor by reducing a distance between the distal anchor and a proximal anchor of the first anchor, such that the flange seats against an outer surface of the bone so as to compress-against the bone; and
securing the pars fracture.

12. The method of claim 11 , wherein the step of creating an access path from a position above a pars fracture to the pars fracture comprises placing a guide member from a position above the fracture site into a fracture site and then advancing a dilator over the guide member to form the access path.

13. The method of claim 12 , wherein the guide member comprises a k-wire or guide wire.

14. The method of claim 12 , wherein the dilator comprises a series of sequential dilators.

15. The method of claim 11 wherein the fixation device is made at least partially from a bioabsorbable metallic material or metallic alloy.

16. The method of claim 15 , wherein bioabsorbable metallic material or metallic alloy comprises magnesium, a magnesium alloy, zinc and/or a zinc alloy.

17. The method of claim 11 , wherein the flange is coupled to or integral with the bridge.

18. The method of claim 11 , wherein the first anchor includes the flange.

19. The method of claim 11 , wherein the securing step comprises urging the first and second anchors toward each other.

Assignees

• Depuy Synthes Products Inc

Inventors

• Warren Christopher R
• Flower Robert

Classifications

• A61B17/8695

  Washers (surrounding screw head in plate hole A61B17/8047, between bone plate and bone A61B17/8028) · CPC title

• A61B17/869

  characterised by an open form, e.g. wire helix · CPC title

• A61B17/7047

  Clamps comprising opposed elements which grasp one vertebra between them · CPC title

• A61B17/1671

  for the spine · CPC title

• A61B17/0642 Primary

  for bones, e.g. for osteosynthesis or connecting tendon to bone · CPC title