Granted Patent B2

US 8,333,792 · App. 12/566,491 · Granted Dec 18, 2012

Assignee: Spartek Medical, Inc.

Abstract

Claims (145)

1. A dynamic pedicle screw comprising:

a bone screw having a longitudinal axis, a proximal end and a distal end;

the distal end of the bone screw having surface texture and adapted to engage a vertebra;

a housing at the proximal end of the bone screw;

a bore in the housing aligned with the longitudinal axis of the bone screw, the bore having an open end and a closed end and the closed end of the bore terminating in a hemispherical pocket;

an elongated deflectable post;

a ball-shaped retainer at a first end of the deflectable post,

wherein the deflectable post is received in the bore such that the ball-shaped retainer is positioned within the hemispherical pocket and a second end of the deflectable post extends through the open end of the bore;

a fastener which secures the ball-shaped retainer in the hemispherical pocket such that the ball may pivot and rotate within the hemispherical pocket; and

a compliant sleeve positioned within the bore between the deflectable post and the housing such that the deflectable post is flexibly aligned with the longitudinal axis of the bone screw such that deflection of the deflectable post away from alignment with the longitudinal axis of the bone screw causes compression of the compliant sleeve such that the compliant sleeve applies a force upon the deflectable post pushing the deflectable post towards a position in which the deflectable post is aligned with the longitudinal axis of the bone screw; and

said housing associated with a surface positioned to contact the deflectable post after a predetermined amount of deflection of the deflectable post away from alignment with the longitudinal axis of the bone screw; and

wherein further deflection of said deflectable post beyond said predetermined amount requires a larger load per unit of deflection than deflection of said deflectable post up to said predetermined amount.

2. The dynamic pedicle screw of claim 1 , wherein:

said deflectable post and ball-shaped retainer are made in one piece; and

said housing and bone screw are made in one piece.

3. The dynamic pedicle screw of claim 1 , wherein said sleeve is a polymer.

4. The dynamic pedicle screw of claim 1 , wherein said sleeve is a hydrophilic polymer.

5. The dynamic pedicle screw of claim 1 , wherein said sleeve has an isotropic deflection profile.

6. The dynamic pedicle screw of claim 1 , wherein the housing has an exterior surface adapted to mount a connector.

7. The dynamic pedicle screw of claim 1 , wherein the housing has an exterior surface and wherein said exterior surface is fluted to be adapted to engage the exterior surface by one of a connector and a driver.

8. A dynamic pedicle screw comprising:

a bone screw having a longitudinal axis, a proximal end and a distal end;

the distal end of the bone screw having surface texture and adapted to engage a vertebra;

a housing at the proximal end of the bone screw;

a bore in the housing aligned with the longitudinal axis of the bone screw, the bore having an open end and a closed end and the closed end of the bore terminating in a hemispherical pocket;

an elongated deflectable post;

a ball-shaped retainer at a first end of the deflectable post,

wherein the deflectable post is received in the bore such that the ball-shaped retainer is positioned within the hemispherical pocket and a second end of the deflectable post extends through the open end of the bore;

a fastener which secures the ball-shaped retainer in the hemispherical pocket such that the ball may pivot and rotate within the hemispherical pocket; and

a compliant sleeve positioned within the bore between the deflectable post and the housing such that the deflectable post is flexibly aligned with the longitudinal axis of the bone screw such that deflection of the deflectable post away from alignment with the longitudinal axis of the bone screw causes compression of the compliant sleeve such that the compliant sleeve applies a force upon the deflectable post pushing the deflectable post towards a position in which the deflectable post is aligned with the longitudinal axis of the bone screw; and

said housing associated with a surface positioned to contact the deflectable post after a predetermined amount of deflection of the deflectable post away from alignment with the longitudinal axis of the bone screw; and

wherein further deflection of said deflectable post beyond said predetermined amount requires at least double the load per unit of deflection than deflection of said post up to said first amount.

9. A dynamic pedicle screw comprising:

a bone screw having a longitudinal axis, a proximal end and a distal end;

the distal end of the bone screw having surface texture and adapted to engage a vertebra;

a housing at the proximal end of the bone screw;

a bore in the housing aligned with the longitudinal axis of the bone screw, the bore having an open end and a closed end and the closed end of the bore terminating in a hemispherical pocket;

an elongated deflectable post;

a ball-shaped retainer at a first end of the deflectable post,

wherein the deflectable post is received in the bore such that the ball-shaped retainer is positioned within the hemispherical pocket and a second end of the deflectable post extends through the open end of the bore;

a fastener which secures the ball-shaped retainer in the hemispherical pocket such that the ball may pivot and rotate within the hemispherical pocket; and

a compliant sleeve positioned within the bore between the deflectable post and the housing such that the deflectable post is flexibly aligned with the longitudinal axis of the bone screw such that deflection of the deflectable post away from alignment with the longitudinal axis of the bone screw causes compression of the compliant sleeve such that the compliant sleeve applies a force upon the deflectable post pushing the deflectable post towards a position in which the deflectable post is aligned with the longitudinal axis of the bone screw; and

said sleeve has an anisotropic deflection profile.

10. A spine stabilization device comprising:

a bone screw having a distal end adapted to engage a bone;

a housing at a proximal end of said bone screw;

a longitudinal bore in said housing;

said bore being aligned with the bone screw and having an open end and a closed end;

a hemispherical pocket at the closed end of said bore;

a deflectable post having a proximal end, an elongated body and a distal end;

the proximal end of said deflectable post extending from the open end of said longitudinal bore;

a spherical retainer at the distal end of the deflectable post;

the spherical retainer being received in the hemispherical pocket of the bore;

a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and

a compliant member positioned within the bore between the deflectable post and the housing such the compliant member flexibly resists pivoting of the deflectable post towards the housing and

a limit surface associated with the housing and positioned to contact the deflectable post after a first angle of pivoting of the deflectable post away from alignment with the bone screw; and

wherein deflection of the proximal end of the deflectable post after contact between the deflectable post and the limit surface requires at least double the load per unit of deflection than deflection of said post prior to contact between the deflectable post and the limit surface.

11. The spine stabilization device of claim 10 , wherein:

said deflectable post and spherical retainer are made in one piece; and

said housing and bone screw are made in one piece.

12. The spine stabilization device of claim 10 , wherein said compliant member is a polymer.

13. The spine stabilization device of claim 10 , wherein said compliant member is a hydrophilic polymer.

14. The spine stabilization device of claim 10 , wherein said compliant member has an isotropic deflection profile.

15. The spine stabilization device of claim 10 , wherein the housing has an exterior surface adapted to mount a connector.

16. The spine stabilization device of claim 10 , wherein the housing has an exterior surface and wherein said exterior surface is fluted to be adapted to engage the surface by one of a connector and a driver.

17. A spine stabilization device comprising:

a bone screw having a distal end adapted to engage a bone;

a housing at a proximal end of said bone screw;

a longitudinal bore in said housing;

said bore being aligned with the bone screw and having an open end and a closed end;

a hemispherical pocket at the closed end of said bore;

a deflectable post having a proximal end, an elongated body and a distal end;

the proximal end of said deflectable post extending from the open end of said longitudinal bore;

a spherical retainer at the distal end of the deflectable post;

the spherical retainer being received in the hemispherical pocket of the bore;

a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and

a compliant member positioned within the bore between the deflectable post and the housing such the compliant member flexibly resists pivoting of the deflectable post towards the housing and

a limit surface associated with the housing and positioned to contact the deflectable post after a first angle of pivoting of the deflectable post away from alignment with the bone screw; and

wherein said compliant member has an anisotropic deflection profile.

18. An implantable spine stabilization device comprising:

an elongated bone anchor having a distal end and a proximal end;

a post having a distal end and a proximal end;

a joint which secures the distal end of the post to the proximal end of the bone anchor such that the post may pivot relative to the bone anchor;

a tubular extension of the bone anchor which extends over a distal portion of the post; and

a compliant member disposed between the distal portion of the post and the tubular extension of the bone anchor whereby the compliant member biases the post into alignment with the bone anchor; and

wherein said compliant member is a polymer disc having an outer diameter sized to fit with the tubular extension and a central aperture sized to receive the post.

19. The spine stabilization device of claim 18 , further comprising:

a limit surface associated with the tubular extension housing and positioned to contact the post when the post pivots through a first angle from alignment with the bone anchor; and

wherein the limit surface resists pivoting of said post beyond said first angle.

20. The spine stabilization device of claim 18 , wherein:

the post is aligned with a longitudinal axis of the bone anchor when unloaded; and

wherein application of a load on the proximal end of the post causes the post to pivot away from alignment with a longitudinal axis of the bone anchor thereby compressing the compliant member between the post and the tubular extension.

21. The spine stabilization device of claim 18 , wherein:

said bone anchor and tubular extension are made in one piece.

22. A spine stabilization device comprising:

a bone screw having a distal end adapted to engage a bone;

a housing at a proximal end of said bone screw;

a longitudinal bore in said housing;

said bore being aligned with the bone screw and having an open end and a closed end;

a hemispherical pocket at the closed end of said bore;

a deflectable post having a proximal end, an elongated body and a distal end;

the proximal end of said deflectable post extending from the open end of said longitudinal bore;

a spherical retainer at the distal end of the deflectable post;

the spherical retainer being received in the hemispherical pocket of the bore;

a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and

a compliant member positioned within the bore between the deflectable post and the housing such the compliant member flexibly resists pivoting of the deflectable post towards the housing; and

said housing associated with a surface positioned to contact the deflectable post after a predetermined amount of deflection of the deflectable post away from alignment with the longitudinal axis of the elongated member; and

wherein further deflection of said deflectable post beyond said predetermined amount requires a larger load per unit of deflection than deflection of said deflectable post up to said predetermined amount.

23. A dynamic pedicle screw comprising:

a bone screw having a longitudinal axis, a proximal end and a distal end;

the distal end of the bone screw having surface texture and adapted to engage a vertebra;

a housing at the proximal end of the bone screw;

a bore in the housing aligned with the longitudinal axis of the bone screw, the bore having an open end and a closed end and the closed end of the bore terminating in a hemispherical pocket;

an elongated deflectable post;

a ball-shaped retainer at a first end of the deflectable post,

wherein the deflectable post is received in the bore such that the ball-shaped retainer is positioned within the hemispherical pocket and a second end of the deflectable post extends through the open end of the bore;

a fastener which secures the ball-shaped retainer in the hemispherical pocket such that the ball may pivot and rotate within the hemispherical pocket; and

said housing associated with a surface positioned to contact the deflectable post after a predetermined amount of deflection of the deflectable post away from alignment with the longitudinal axis of the elongated member; and

wherein further deflection of said deflectable post beyond said predetermined amount requires a larger load per unit of deflection than deflection of said deflectable post up to said predetermined amount.

24. A spine stabilization device comprising:

a bone screw having a distal end adapted to engage a bone;

a housing at a proximal end of said bone screw;

a longitudinal bore in said housing;

said bore being aligned with the bone screw and having an open end and a closed end;

a hemispherical pocket at the closed end of said bore;

a deflectable post having a proximal end, an elongated body and a distal end;

the proximal end of said deflectable post extending from the open end of said longitudinal bore;

a spherical retainer at the distal end of the deflectable post;

the spherical retainer being received in the hemispherical pocket of the bore;

a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and

a limit surface associated with the housing and positioned to contact the deflectable post after a first angle of pivoting of the deflectable post away from alignment with the bone screw; and

wherein deflection of the proximal end of the deflectable post after contact between the deflectable post and the limit surface requires at least double the load per unit of deflection than deflection of said post prior to contact between the deflectable post and the limit surface.

25. A spine stabilization device comprising:

a bone screw having a distal end adapted to engage a bone;

a housing at a proximal end of said bone screw;

a longitudinal bore in said housing;

said bore being aligned with the bone screw and having an open end and a closed end;

a hemispherical pocket at the closed end of said bore;

a deflectable post having a proximal end, an elongated body and a distal end;

the proximal end of said deflectable post extending from the open end of said longitudinal bore;

a spherical retainer at the distal end of the deflectable post;

the spherical retainer being received in the hemispherical pocket of the bore;

a fastener which secures the spherical retainer in the hemispherical pocket and allows the deflectable post to pivot and rotate relative to the bone screw; and

said housing associated with a surface positioned to contact the deflectable post after a predetermined amount of deflection of the deflectable post away from alignment with the longitudinal axis of the elongated member; and

wherein further deflection of said deflectable post beyond said predetermined amount requires a larger load per unit of deflection than deflection of said deflection post up to said predetermined amount.

Assignments (1)

Continuity (13)