Universal coupler for spinal fixation

Abstract

A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient which includes a tubular coupler member, an eyebolt, an insert and a set screw. The coupler member has a longitudinal bore, a central axis, and an end portion that is open ended and internally threaded and a second end portion that is closed. A plurality of openings in the tubular coupler member that includes a first pair of openings intersecting the central axis of the bore at generally right angles and a second pair of openings intersecting the central axis of the bore at generally right angles. The first and second pairs of openings being perpendicular to each other. The first pair of openings are sized and shaped to receive a spinal rod. The eyebolt has a shank portion and an eye portion, with the shank portion being insertable through the second pair of openings of the coupler body. The eye portion has an opening sized and shaped to mate with a selected bone bolt or bone screw. The insert fits within the bore and has opposed, arc-shaped end portions with recesses for engaging the spinal rod and eyebolt member. The set screw threadably engages the internally threaded end portion of the bore and tightens the assembly of the rod, insert, and eyebolt within the coupler member.

1. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
 a) a tubular coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;  
 b) a plurality of openings through the wall of the tubular coupler member, each of the openings communicating with the bore;  
 c) the plurality of openings including a first pair of openings aligning along a first line that intersects the central axis of the bore at generally right angles, and a second pair of openings aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first pair of openings is spaced longitudinally from the periphery of the second pair of openings;  
 d) the first pair of openings sized and shaped for receiving a spinal rod having a longitudinal axis, which can be aligned with the first line of the first pair of openings of the coupler body;  
 e) an eyebolt having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second pair of openings of the coupler body, aligning the central axis of the shank with the second line of the second pair of openings, the eye portion having an opening sized and shaped to mate with a selected fastener;  
 f) an insert that fits within the bore, the insert having an outer surface that generally conforms to the shape of the bore, the insert having opposed, arc-shaped end portions with recesses for engaging the spinal rod the eyebolt shank portion;  
 g) a set screw that threadably engages the internally threaded end portion of the bore so that the set screw tightens the assembly of the rod, insert, and eyebolt within the coupler member;  
 h) whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.  
 
     
     
       2. The coupler assembly of  claim 1 , wherein the eye portion of the eyebolt has an upper and a lower surface with the eye portion opening having a spherically shaped surface on the upper and lower surface of the eye portion. 
     
     
       3. The coupler assembly of  claim 1 , wherein the shank portion of the eyebolt has an outer surface with knurling on a portion of the outer surface. 
     
     
       4. The coupler assembly of  claim 1 , wherein the shank portion of the eyebolt includes a shank end with a recess so as to allow slight flanging of the shank end after the shank portion is inserted through the second pair of openings in the coupler body. 
     
     
       5. The coupler assembly of  claim 1 , wherein the tubular coupler member includes an upper portion and a lower portion with the first pair of openings positioned in the upper portion and the second pair of openings positioned in the lower portion. 
     
     
       6. The coupler assembly of  claim 5 , wherein the upper portion of the tubular coupler member has a larger diameter in relation to the lower portion of the tubular coupler member. 
     
     
       7. The coupler assembly of  claim 1 , wherein the set screw has an upper surface and a lower surface, the lower surface being generally conical in shape and the upper surface being generally flat with a tool receptive socket for receiving a tool designed to thread the set screw into the threaded portion of the bore. 
     
     
       8. A spinal prosthesis providing four degrees of freedom, comprising:
 a) an elongated spinal rod having a central longitudinal axis;  
 b) a tubular coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;  
 c) a plurality of openings through the wall of the tubular coupler member, each of the openings communicating with the bore;  
 d) the plurality of openings including a first pair of openings aligning along a first line that intersects the central axis of the bore at generally right angles, and a second pair of openings aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first pair of openings is spaced longitudinally from the periphery of the second pair of openings;  
 e) the first pair of openings sized and shaped to receive a spinal rod having a longitudinal axis with the rod being insertable through the first pair of openings, aligning the rod's longitudinal axis with the first line of the first pair of openings of the coupler body;  
 f) an eyebolt having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second pair of openings of the coupler body, aligning the central axis of the shank with the second line of the second pair of openings, the eye portion having an opening sized and shaped to mate with a selected fastener;  
 g) an insert that fits within the bore, the insert having an outer surface that generally conforms to the shape of the bore, the insert having opposed, shaped end portions with recesses for engaging the spinal rod and the eyebolt shank portion;  
 h) a set screw that threadably engages the internally threaded end portion of the bore so that the set screw tightens the assembly of the rod, insert, and eyebolt within the coupler member;  
 i) the bone fastener for anchoring the coupler assembly to a patient's vertebrae, the bone bolt having a first threaded portion configured to be surgically implantable into a patient's bone tissue and a second portion having surfaces for engaging the eyebolt opening;  
 j) whereby the assembled spinal prosthesis provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when implanted in a patient.  
 
     
     
       9. The coupler assembly of  claim 8 , wherein the eyebolt has an upper and a lower surface with the eyebolt opening having a spherically shaped surface on the upper and lower surface of the eyebolt that cooperates with the surface of the bone fastener. 
     
     
       10. The coupler assembly of  claim 8 , wherein the shank portion of the eyebolt has an outer surface with knurling on a portion of the outer surface. 
     
     
       11. The coupler assembly of  claim 8 , wherein the shank portion of the eyebolt includes a shank end with a recess so as to allow slight flanging of the shank end after the shank portion is inserted through the second pair of openings in the coupler body. 
     
     
       12. The coupler assembly of  claim 8 , wherein the tubular coupler member includes an upper portion and a lower portion with the first pair of openings positioned in the upper portion and the second pair of openings positioned in the lower portion. 
     
     
       13. The coupler assembly of  claim 12 , wherein the upper portion of the tubular coupler member has a larger diameter in relation to the lower portion of the tubular coupler member. 
     
     
       14. The coupler assembly of  claim 8 , wherein the set screw has an upper surface and a lower surface, the lower surface being generally conical in shape and the upper surface being generally flat with a tool receptive socket for receiving a tool designed to thread the set screw into the threaded portion of the bore. 
     
     
       15. The coupler assembly of  claim 8 , wherein the bone fastener further includes a central non-threaded portion having a load transfer surface and an second threaded portion for threadably receiving a nut, the second threaded portion sized to be insertable through the eyebolt opening and able to be locked into place with the nut. 
     
     
       16. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
 a) a coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;  
 b) a plurality of openings in the coupler member, each of the openings communicating with the bore;  
 c) the plurality of openings including a first through opening aligning along a first line that intersects the central axis of the bore at generally right angles, and a second through opening aligning along a second line that intersects the central axis of the bore at generally right angles, the first and second lines being generally perpendicular to each other and spaced apart so that the periphery of the first opening is spaced longitudinally from the periphery of the second opening;  
 d) the first opening being sized and shaped to receive a spinal rod having a longitudinal axis, the rod's longitudinal axis aligning with the first line of the first opening of the coupler body;  
 e) an eyebolt member having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second opening of the coupler body, aligning the central axis of the shank with the second line of the second opening, the eye portion having an opening sized and shaped to mate with a selected bone fastener;  
 f) means for tightening the assembly of the rod and eyebolt in a selected position within the coupler member;  
 g) whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along and a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.  
 
     
     
       17. A spinal rod coupler assembly comprising:
   a coupler member having first, second, and third openings, the first opening dimensioned to slidably receive a spinal rod and fully surround a portion thereof and the second opening dimensioned to receive a locking fastener to retain the spinal rod within a coupler member; and        a fastener receiving member having an opening to receive a bone fastener, the fastener receiving member rotatably and slidably mounted with respect to the coupler member to adjust the position of the fastener, the fastener receiving member being mountable in the third opening of the coupler member.     
     
     
       18. The coupler assembly of  claim 17 , wherein a longitudinal axis extending through the first opening is transverse to a longitudinal axis extending though the second opening. 
     
     
       19. The coupler assembly of  claim 17 , wherein a longitudinal axis extending through the third opening is transverse to the longitudinal axis of the first opening. 
     
     
       20. The coupler assembly of  claim 17 , wherein the longitudinal axis of the third opening is transverse to the longitudinal axis of the second opening. 
     
     
       21. The coupler assembly of  17 , wherein the periphery of the second and third openings are spaced apart. 
     
     
       22. The coupler assembly of  17 , wherein the opening in the fastener receiving member is circular in configuration. 
     
     
       23. The coupler assembly of  17 , wherein the bone fastener is a bolt. 
     
     
       24. The coupler assembly of  17 , wherein the bone fastener is a screw. 
     
     
       25. The coupler assembly of  17 , wherein a potion of the second opening of the coupler member is internally threaded. 
     
     
       26. The coupler assembly of  25 , further comprising an insert member mountable within the second opening, the insert member having a first recess which conforms to the shape of the spinal rod. 
     
     
       27. The coupler assembly of  26 , wherein the fastener receiving member has an elongated shank portion extending into the third opening of the coupler member and the insert has a second recess which conforms to the shape of the shank portion. 
     
     
       28. The coupler assembly of  17 , wherein the locking fastener is a set screw engagable with an internal thread formed adjacent the second opening of the coupler member. 
     
     
       29. The coupler assembly of  17 , wherein the fastener receiving member has an elongated shank portion extending into the third opening of the coupler member. 
     
     
       30. The coupler assembly of  29 , wherein at least a portion of the shank portion has a knurled surface. 
     
     
       31. The coupler assembly of  29 , wherein the shank portion is substantially cylindrical in configuration. 
     
     
       32. The coupler assembly of  31 , wherein the shank portion has an end portion with a recess formed therein. 
     
     
       33. The coupler assembly of  17 , wherein a portion of the coupler opposite the second opening is closed. 
     
     
       34. A spinal rod coupler assembly comprising:
   a coupler member having first, second, and third openings, the first opening dimensioned to slidably receive a spinal rod, and the second opening dimensioned to receive a locking fastener to retain the spinal rod within the coupler member, a portion of the coupler opposite the second opening being closed;        a fastener receiving member having an opening to receive a bone fastener, the fastener receiving member rotatably and slidably mounted with respect to the coupler member to adjust the position of the fastener, the fastener receiving member being mountable in the third opening of the coupler member,        and an insert interposed between the spinal rod and the fastener receiving member.     
     
     
       35. The coupler assembly of  34 , further comprising a nut engagable with a threaded portion of the bone fastener. 
     
     
       36. A spinal rod coupler comprising:
   a first opening dimensioned to slidably receive and fully surround a portion of a spinal rod and having a first longitudinal axis extending therethrough;        a second opening dimensioned to receive a locking fastener and having a second longitudinal axis extending therethrough transverse to the first longitudinal axis; and        a third opening dimensioned to slidably and rotatably receive an elongated connector to mount a bone fastener, the third opening having a third longitudinal axis extending therethrough transverse to the first longitudinal axis and the second longitudinal axis.     
     
     
       37. The spinal rod coupler of  claim 36 , wherein at least portion of the second opening is threaded. 
     
     
       38. The spinal rod coupler of  claim 36 , wherein the periphery of the first and third openings are longitudinally spaced. 
     
     
       39. The spinal rod coupler of  claim 37 , wherein the coupler is substantially cylindrical in configuration. 
     
     
       40. A spinal rod coupler assembly comprising:
   a coupler having a first opening to receive a spinal rod and fully surround a portion thereof;        a connecting member having a longitudinal axis, the connecting member extending from the coupler and rotatable with respect to the coupler;        a bone fastener positioned within the connecting member, wherein movement of the connecting member with respect to the coupler adjusts the position of the bone fastener; and        a locking member for securing the spinal rod the locking member extending at an angle to the longitudinal axis of the connecting member.     
     
     
       41. The spinal rod coupler assembly  claim 40 , wherein the connecting member is slidably movable within a first bore formed in the coupler. 
     
     
       42. The spinal rod coupler assembly of  claim 41 , wherein the connecting member is rotatably mounted with the first bore. 
     
     
       43. The spinal rod coupler assembly of  claim 40 , wherein the coupler is slidably mounted with respect to the spinal rod. 
     
     
       44. The spinal rod coupler assembly of  claim 40 , wherein the coupler is rotatably mounted with respect to the spinal rod. 
     
     
       45. The spinal rod coupler assembly of  claim 40 , wherein the bone fastener is received in a circular opening in the connecting member. 
     
     
       46. A spinal rod coupler assembly comprising:
   a coupler having a first opening to receive a spinal rod;        a connecting member extending from the coupler;        a bone fastener positioned within the connecting member, wherein movement of the connecting member with respect to the coupler adjusts the position of the bone fastener; and        an insert mounted within the coupler and interposed between the spinal rod and connecting member.     
     
     
       47. A spinal rod coupler assembly providing four degrees of freedom for connecting a spinal rod to a vertebrae of a patient, comprising:
   a )  a coupler member having a longitudinal bore surrounded by a wall, the bore having a central axis and first and second end portions, the first end portion being open ended and internally threaded, the second end portion being closed;        b )  a plurality of openings in the coupler member, each of the openings communicating with the bore;        c )  the plurality of openings including a first through opening aligning along a first line that intersects the central axis of the bore at generally right angles, and a second through opening aligning along a second line that intersects the central axis of the bore at generally right angles;        d )  the first opening being sized and shaped to receive a spinal rod having a longitudinal axis, the rod's longitudinal axis aligning with the first line of the first opening of the coupler body;        e )  an eyebolt member having a shank portion with a central axis and an eye portion, the shank portion being insertable through the second opening of the coupler body, aligning the central axis of the shank with the second line of the second opening, the eye portion having an opening sized and shaped to mate with a selected bone fastener;        f )  whereby the coupler assembly provides for movement along four degrees of freedom which include a movement along and a rotation about the longitudinal axis of the spinal rod, and a movement along a rotation about the central axis of the eyebolt shank when the assembly is being implanted in a patient.