Facet fixation prosthesis

Patent metadata

Field	Value
Publication number	US-2016346014-A1
Application number	US-201615235163-A
Country	US
Kind code	A1
Filing date	Aug 12, 2016
Priority date	Jan 24, 2008
Publication date	Dec 1, 2016
Grant date	—

Abstract

A facet screw system for surgical implantation into bone tissue having a shaft, a compression member and a washer. The shaft includes a shaft having a bone engaging portion and a compression member engaging portion. The compression member includes a spherical head portion having a recess for engaging with a driving instrument, and an elongated coupling portion having internal threads for coupling with the compression member engaging portion of the shaft and a washer coupled to the spherical head portion of the compression member and having a plurality of bone engaging protrusions. The washer is adapted to be polyaxially rotatable with respect to the compression member.

First claim

What is claimed is:

1 . A facet screw system for surgical implantation into bone tissue, comprising:
a shaft, the shaft having a bone engaging portion, a graft window, and a compression member engaging portion; a compression member, the compression member comprising:
a spherical head portion having a recess for engaging with a driving instrument, and
a coupling portion for coupling with the compression member engaging portion of the shaft; and
a washer coupled to the spherical head portion of the compression member, wherein a diameter of the spherical head portion of the compression member is greater than a diameter of a bottom portion of the washer.

2 . The facet screw system of claim 1 , wherein the facet screw system is cannulated for receiving a guide wire.

3 . The facet screw system of claim 1 , wherein a flute is provided at a distal end of the shaft.

4 . The facet screw system of claim 1 , wherein the washer comprises a plurality of slits extending from a bottom portion of the washer through the top portion of the washer.

5 . The facet screw system of claim 1 , wherein the spherical head of the compression member is configured to receive the driving instrument.

6 . The facet screw system of claim 1 , wherein the shaft portion comprises a recess for receiving the driving instrument.

7 . The bone screw of claim 1 , wherein the shaft portion is configured with one type of thread and the compression member engaging portion is configured with another type of thread.

8 . The bone screw of claim 1 , wherein the screw is made from stainless steel alloys, titanium, titanium based alloys, or polymeric materials.

9 . A facet screw system for surgical implantation into bone tissue, comprising:
a shaft, the shaft having a bone engaging portion, a graft window, and a compression member engaging portion; a compression member having a proximal end and a distal end, the compression member comprising:
a spherical head portion located at the proximal end and having a recess for engaging with a driving instrument; and
an elongated coupling portion having internal threads for coupling with the compression member engaging portion of the shaft; and
a washer having a ridge positioned on a top portion of the washer and plurality of bone engaging protrusions on a bottom portion, wherein the washer is polyaxially rotatable with respect to the compression member.

10 . The facet screw system of claim 9 , wherein the facet screw system is cannulated for receiving a guide wire.

11 . The facet screw system of claim 9 , wherein a flute is provided at a distal end of the shaft.

12 . The facet screw system of claim 9 , wherein the spherical head of the compression member is configured to receive the driving instrument.

13 . The facet screw system of claim 9 , wherein the shaft portion comprises a recess for receiving the driving instrument.

14 . The bone screw of claim 9 , wherein the shaft portion is configured with one type of thread and the compression member engaging portion is configured with another type of thread.

15 . The bone screw of claim 9 , wherein the screw is made from stainless steel alloys, titanium, titanium based alloys, or polymeric materials.

16 . A facet screw system for surgical implantation into bone tissue, comprising:
a shaft, the shaft having a bone engaging portion, a graft window, and a compression member engaging portion; a compression member having a proximal end and a distal end, the compression member comprising:
a spherical head portion located at the proximal end and having a recess for engaging with a driving instrument; and
an elongated coupling portion having internal threads for coupling with the compression member engaging portion of the shaft; and
a washer having a plurality of bone engaging protrusions on a bottom portion, the washer being coupled to the spherical head portion of the compression member, wherein the washer comprises a plurality of slits extending along a top portion of the washer, wherein the slits extend to an edge of the top portion of the washer and enable engagement with the compression member.

17 . The bone screw of claim 16 , wherein the slits do not extend through the bottom portion.

18 . The bone screw of claim 16 , wherein an outer diameter of the elongated coupling portion of the compression member is substantially the same as an outer diameter of the bone engaging portion of the shaft.

19 . The bone screw of claim 16 , wherein the washer includes an opening extending through the top portion and the bone engaging portion, and a diameter of the opening being greater in the bone engaging portion relative to the top portion.

20 . The bone screw of claim 16 , wherein the washer extends around an entire periphery of the compression member.

Assignees

• Globus Medical Inc

Inventors

• Cianfrani Jason
• Laskowitz Daniel
• Karpowicz Edward

Classifications

• A61B17/8695

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

• A61B17/8685

  comprising multiple separate parts · CPC title

• A61B17/7064 Primary

  Devices acting on, attached to, or simulating the effect of, vertebral facets; Tools therefor · CPC title

• A61B17/686

  Plugs, i.e. elements forming interface between bone hole and implant or fastener, e.g. screw · CPC title

• A61B17/685

  Elements to be fitted on the end of screws or wires, e.g. protective caps · CPC title