Pedicle screws with integrated anchor for retaining artificial ligament tape used for posterior ligament reconstruction

Abstract

A pedicle screw of the type used in spinal fixation surgery has integral structure for anchoring artificial ligament tape. A tape-receiving passageway is formed through the tulip assembly of the pedicle screw. The passageway has open ends and is configured to receive an artificial ligament tape threaded through the passageway. An opening is formed in the tulip assembly, transversely intersecting the passageway and opening to the exterior of the tulip assembly. A clamping member is movable along the opening into clamping engagement against a segment of the artificial ligament tape that is threaded through the passageway.

The invention claimed is: 
     
       1. An improved pedicle screw including a threaded screw shank mounted to a tulip assembly, the tulip assembly including a tulip head having cylindrically contoured peripheral sides and including a U-shaped slot forming a saddle for receipt of a spinal support rod and the tulip assembly also including a primary set screw that engages an interior wall of the saddle or a primary nut that engages an exterior wall of the tulip assembly, the primary set screw or nut moving axially when rotated for clamping the rod against a bottom surface of the U-shaped slot of the saddle, wherein the tulip head additionally comprises:
 (a) a ligament tape-receiving passageway formed through the tulip head, spaced on a side from the slot, extending parallel to the slot between opposite peripheral sides of the tulip head and terminating at opposite open ends located at an outer peripheral surface of the tulip head no further outward than the cylindrically contoured peripheral sides of the tulip head, the passageway not intersecting the slot and configured to receive an artificial ligament tape threaded through the passageway parallel to the support rod; 
 (b) an opening in the tulip head, transversely intersecting the passageway, not intersecting the slot and opening to the exterior of the tulip head at a cylindrically contoured peripheral side of the tulip head; and 
 (c) a clamping member that is movable within the tulip head along the opening into clamping engagement against a segment of the artificial ligament tape threaded through and enclosed by the passageway. 
 
     
     
       2. A pedicle screw in accordance with  claim 1  wherein the tulip head has a longitudinal axis and the passageway is aligned across the tulip head transversely with respect to the longitudinal axis. 
     
     
       3. A pedicle screw in accordance with  claim 2  wherein the passageway is a hole through the tulip head, the opening is a threaded hole and the clamping member is a secondary set screw threadedly engaged in the opening and configured to advance along the opening and against the artificial ligament tape by rotation of the secondary set screw. 
     
     
       4. A pedicle screw in accordance with  claim 3  wherein the passageway has a rectangular cross section. 
     
     
       5. A pedicle screw in accordance with  claim 4  wherein the passageway is aligned at a right angle to the longitudinal axis. 
     
     
       6. A pedicle screw in accordance with  claim 4  wherein the rectangular cross-section has a major axis and a minor axis, and the major and minor axes are inclined at an acute angle to the longitudinal axis. 
     
     
       7. A pedicle screw in accordance with  claim 1 , wherein the pedicle screw is a polyaxial pedicle screw.  
     
     
       8. A pedicle screw in accordance with  claim 1 , wherein the pedicle screw is a monoaxial pedicle screw.  
     
     
       9. A spinal support system, comprising:
 a pedicle screw;   a tulip head connector having cylindrically contoured peripheral sides and extending in a longitudinal direction from an upper surface to a lower surface and extending in a lateral direction perpendicular to the longitudinal direction, the tulip head connector comprising a U-shaped slot for retaining a spinal support rod therein, the U-shaped slot including cylindrically contoured interior surfaces having threads and peripheral side surfaces, the cylindrically contoured interior surfaces define a longitudinal axis extending in the longitudinal direction;   a first set screw having a thread pattern on a side surface thereof for engaging the cylindrically contoured interior surfaces of the U-shaped slot;   at least one passageway extending through the tulip head connector, the at least one passageway being configured to receive at least one ligature for passing therethrough and enclose the at least one ligature within the passageway, the passageway spaced on a side from the slot, extending parallel to the slot between opposite peripheral sides of the tulip head and terminating at opposite ends located at an outer peripheral surface of the tulip head no further outward than the cylindrically contoured peripheral sides of the tulip head;   at least one opening extending through the tulip head connector, from a cylindrically contoured peripheral side of the tulip head, and intersecting with the at least one passageway, the at least one opening having interior surfaces having threads thereon; and   a second set screw, the second set screw having a thread pattern on a side surface thereof for engaging the interior surfaces of the at least one opening.    
     
     
       10. The spinal support system of  claim 9 , wherein the first set screw is configured to:
 move axially when disposed in the U-shaped slot and rotated; and   secure the rod within the U-shaped slot when moved axially towards a bottom surface of the U-shaped slot.    
     
     
       11. The spinal support system of  claim 9 , wherein the at least one passageway is:
 formed in the tulip head.    
     
     
       12. The spinal support system of  claim 9 , wherein the at least one passageway does not intersect with the U-shaped slot and is configured to receive the at least one ligature such that the at least one ligature extends through the at least one passageway in a lateral direction that is parallel to an extension direction of the spinal support rod.  
     
     
       13. The spinal support system of  claim 9 , further comprising:
 the spinal support rod and the at least one ligature,   wherein the U-shaped slot comprises a bottom surface shaped like a saddle and the first set screw is configured to move axially along the longitudinal axis when rotated, the first set screw being configured for clamping the spinal support rod against the bottom surface of the U-shaped slot when moved axially forward along the longitudinal axis toward the bottom surface.    
     
     
       14. The spinal support system of  claim 9 , wherein the at least one passageway extends through a first peripheral side and a second peripheral side of the peripheral sides of the tulip head connector in a direction that is substantially parallel to the U-shaped slot.  
     
     
       15. The spinal support system of  claim 9 , wherein the at least one passageway extends in a direction that is substantially perpendicular to the longitudinal axis of the tulip head connector.  
     
     
       16. The spinal support system of  claim 9 , wherein the pedicle screw is a polyaxial pedicle screw or a monoaxial pedicle screw.  
     
     
       17. A spinal implant system, comprising:
 a polyaxial pedicle screw;   a tulip head connector coupled to the polyaxial pedicle screw, the tulip head connector having cylindrically contoured peripheral sides and extending in a longitudinal direction from an uppermost surface to a lowermost surface and extending in a lateral direction perpendicular to the longitudinal direction, the tulip head connector comprising a U-shaped slot with a bottom surface shaped like a saddle for retaining a spinal support rod therein, the U-shaped slot including at least one cylindrically contoured interior surface having a thread pattern thereon, the tulip head connector including a plurality of outside peripheral side surfaces,   a first set screw having a thread pattern on a side surface thereof for engaging the at least one cylindrically contoured interior surface of the U-shaped slot;   at least one passageway extending through the tulip head connector and configured to receive and enclose a ligature within the passageway, the passageway spaced on a side from the slot, extending parallel to the slot between opposite peripheral sides of the tulip head and terminating at opposite ends located at an outer peripheral surface of the tulip head no further outward than the cylindrically contoured peripheral sides of the tulip head;   at least one ligature for passing through the at least one passageway;   at least one opening extending through the tulip head connector, from a cylindrically contoured peripheral side of the tulip head, and intersecting with the at least one passageway, the at least one opening including interior surfaces having threads thereon; and   a second set screw, the second set screw having a thread pattern on a side surface thereof for engaging the interior surfaces of the at least one opening.    
     
     
       18. The spinal support system of  claim 17 , wherein
 the at least one opening is inclined at an acute angle to the longitudinal direction; and   the second set screw comprises threads configured to engage with the at least one opening.    
     
     
       19. The improved pedicle screw of  claim 2 , wherein
 the opening in the tulip head is inclined at an acute angle to the longitudinal axis; and   the clamping member comprises a secondary set screw having threads configured to engage with the opening.    
     
     
       20. The spinal support system of  claim 9 , wherein
 the at least one opening is inclined at an acute angle to the longitudinal direction; and   the second set screw comprises threads configured to engage with the at least one opening.