Spinal plate assembly having locking mechanism

Patent metadata

Field	Value
Publication number	US-10456181-B2
Application number	US-201614993369-A
Country	US
Kind code	B2
Filing date	Jan 12, 2016
Priority date	Jan 12, 2016
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

A spinal plate assembly comprising a base plate defining an opening adjacent at least one aperture for receiving a bone screw which attaches to a spinal vertebrae. The aperture includes a seat and an annular groove having an end wall. The assembly comprises a locking mechanism having a split ring partially recessed within the annular groove and moveable between a locked condition partially blocking the aperture for retaining the screw in the seat and an unlocked condition radially deformable into the annular groove for permitting screw removal. The split ring has a proximal end and a distal end. The distal end is configured to engage the end wall of the annular groove. The locking mechanism comprises a rotating member retained within the opening of the base plate and having a notch configured to engage the proximal end of the ring to drive the ring toward the unlocked condition.

First claim

What is claimed is:

1. A spinal plate assembly comprising:
a base plate defining at least one aperture for receiving a screw, the at least one aperture including a seat and an annular groove terminating at an end wall;
a flexible element having a distal end and a proximal end, the flexible element partially retained within the annular groove and moveable between a locked condition partially blocking the at least one aperture for retaining the screw in the seat and an unlocked condition radially deformable in the annular groove for permitting the screw to be removed from the at least one aperture;
a moveable member for biasing the flexible element toward the unlocked condition, wherein the proximal end of the flexible element is configured to contact the moveable member and the distal end of the flexible element is configured to contact the end wall, and
wherein in the locked condition the flexible element rests adjacent a top of the screw and substantially surrounds a head of the screw.

2. The spinal plate assembly of claim 1 , wherein the flexible element is a resiliently deformable split ring.

3. The spinal plate assembly of claim 1 , further comprising a bone screw sized to be inserted through the at least one aperture such that the bone screw sits within the seat of the at least one aperture for engaging a spinal vertebra, wherein the bone screw further comprises a top, wherein the flexible element blocks the at least one aperture in the locked condition by engaging the top of the bone screw.

4. The spinal plate assembly of claim 3 , wherein the top of the bone screw further comprises a circumferential recess for engaging the flexible element in the locked condition.

5. The spinal plate assembly of claim 4 , wherein the annular groove is dimensioned to receive at least part of the flexible element, and wherein the end wall engages the distal end of the flexible element when the flexible element is in the unlocked condition.

6. The spinal plate assembly of claim 5 , wherein the moveable member further comprises a notch configured to engage the proximal end of the flexible element such that rotation of the moveable member radially deforms the flexible element within the annular groove.

7. The spinal plate assembly of claim 1 , wherein the base plate further comprises:
an opening adjacent the at least one aperture for retaining the moveable member, the opening configured to substantially correspond to a shape of the moveable member; and
a seat within the opening having a bore extending axially therethrough.

8. The spinal plate assembly of claim 7 , wherein the moveable member further comprises:
a head having an engaging portion with a recess for receiving a driver; and
a pin extending from the head portion configured to be disposed within and retained by the bore of the seat.

9. The spinal plate assembly of claim 8 , wherein the recess has a cross-section selected from the group consisting of: slotted, square, triangular, rectangular, pentagonal, hexagonal, octagonal, n-lobular, hexalobular, stardrive, and trilobular.

10. The spinal plate assembly of claim 7 , wherein the opening is configured to retain the moveable member between a pair of apertures to simultaneously bias more than one flexible element toward the unlocked condition.

11. The spinal plate assembly of claim 1 , wherein the base plate includes an upper surface such that the moveable member is configured to be positioned flush with or beneath the upper surface of the base plate.

12. A spinal plate assembly comprising:
a base plate defining an opening adjacent at least one aperture for receiving a bone screw which attaches to a spinal vertebra, the opening including a seat having a bore extending axially therethrough, the at least one aperture including an annular groove terminating at an end wall; and
a locking mechanism having a flexible element having a distal end and a proximal end, the flexible element partially retained within the annular groove and moveable between a locked condition and an unlocked condition, and a rotating member positioned within the opening of the base plate for rotating the flexible element toward the unlocked condition, wherein the rotating member includes a head having an engaging portion for receiving a driver, a pin extending from the head configured to be inserted within the bore of the seat, and wherein the proximal end of the flexible element is configured to contact the rotating member and the distal end of the flexible element configured to contact the end wall,
wherein the flexible element partially blocks the at least one aperture preventing the screw from backing out of the at least one aperture in the locked condition,
wherein the rotating member forces the flexible element to radially deform within the annular groove permitting the screw to be removed from the at least one aperture in the unlocked condition, and
wherein in the locked condition the flexible element rests adjacent a top of the screw and substantially surrounds a head of the screw.

13. The spinal plate assembly of claim 12 , wherein the flexible element is a resiliently deformable split ring.

14. The spinal plate assembly of claim 13 , wherein the annular groove is dimensioned to receive at least part of the flexible element, and wherein the end wall engages the distal end of the flexible element when the flexible element is in the unlocked condition.

15. The spinal plate assembly of claim 14 , wherein the rotating member further comprises a notch configured to engage the proximal end of the flexible element such that rotation of the rotating member radially deforms the flexible element within the annular groove.

16. The spinal plate assembly of claim 15 , wherein the engaging portion is a recess having a cross-section shaped to receive a driving tool having a corresponding drive shaft.

17. The spinal plate assembly of claim 16 , wherein the cross-section of the recess is selected from the group consisting of: slotted, square, triangular, rectangular, pentagonal, hexagonal, octagonal, n-lobular, hexalobular, stardrive, and tribolular.

18. The spinal plate assembly of claim 12 , wherein the opening is configured to retain the rotating member between a pair of apertures to simultaneously rotate more than one flexible element toward the unlocked condition.

19. The spinal plate assembly of claim 12 , wherein the base plate includes an upper surface such that the rotating member is configured to be positioned flush with or beneath the upper surface of the base plate.

20. A spinal plate assembly comprising:
a base plate having a first aperture, a second aperture, and an opening defined between the first and second apertures for coupling adjacent spinal vertebrae, the opening including a first seat having a bore extending axially therethrough, the first and second apertures each including a second seat and annular groove having an end wall;
a bone screw sized to be inserted through each aperture such that the bone screw sits within the seat of the respective aperture for engaging the spinal vertebrae; and
a locking mechanism having:
a first split ring at least partially disposed within the annular groove of the first aperture, a second split ring at least partially disposed within the annular groove of the second aperture, the first and second split rings each having a proximal end and a distal end,
wherein the split rings are moveable between the locked condition partially blocking the apertures for retaining the bone screws in the respective a

Assignees

• Globus Medical Inc

Inventors

• Cianfrani Jason
• Morris Ross

Classifications

• A61B17/8605 Primary

  Heads, i.e. proximal ends projecting from bone · CPC title

• A61B17/8042

  the additional component being a cover over the screw head · CPC title

• A61B17/7059

  Cortical plates (A61B17/7007, A61B17/7058 take precedence) · CPC title