Systems and methods for delivering bone cement to a bone anchor

Abstract

A method of stabilizing a first vertebra and a second vertebra includes implanting a first bone anchor into the first vertebra, implanting a second bone anchor into the second vertebra, connecting a first anchor connection instrument to the first anchor, connecting a second anchor connection instrument the second anchor, positioning a cement delivery tube into a passage provided through the first anchor, delivering bone cement from a bone cement delivery system coupled to the bone cement delivery tube through the passage in the first anchor to the first vertebra, removing the cement delivery tube from the first anchor connection instrument and the first anchor, connecting the cement delivery tube to second anchor connecting instrument connected to the second anchor, delivering bone cement through a passage in the second anchor to the second vertebra, connecting a spinal connection element to the first anchor and the second anchor.

The invention claimed is: 
     
       1. A method of delivering cement to a spinal anchor anchored in a vertebra of a patient, the method comprising:
 advancing a distal end of an a single-piece anchor connection instrument through an opening in a proximal portion of a spinal anchor, the proximal portion of the spinal anchor having a slot for receiving a spinal rod and a thread for receiving a closure mechanism for securing the rod in the proximal portion, the distal end of the anchor connecting connection instrument including a first connection feature spaced apart from a second connection feature, the first connection feature comprising an external thread, the second connection feature comprising a drive tip located at a distal tip of the distal end of the anchor connection instrument, 
 advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the spinal anchor, the passage communicating with the opening in the proximal portion of the spinal anchor, 
 rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the spinal anchor, the first connection feature being positioned between the proximal end and the distal end of the anchor connection instrument a distance from the drive tip, the distance selected to allow the drive tip to be advanced into the drive feature of the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor, the anchor connection instrument holding the proximal portion of the spinal anchor relative to the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor and the second connection feature is advanced into the drive feature of the distal bone engaging portion of the spinal anchor, 
 positioning a bone cement delivery tube through the anchor connection instrument, 
 advancing a distal end of the bone cement delivery tube into the passage of the distal bone engaging portion of the spinal anchor, 
 connecting a proximal end of the bone cement delivery tube to a bone cement delivery system, and 
 injecting cement into the passage of distal bone engaging portion of the spinal anchor through the bone cement delivery tube. 
 
     
     
       2. The method of  claim 1 , wherein at least a portion the bone cement delivery system is positioned outside of a fluoroscopic imaging field about the patient. 
     
     
       3. The method of  claim 1 , further comprising
 removing the anchor connection instrument and the bone cement delivery tube from the spinal anchor, 
 advancing a distal end of the anchor connection instrument through an opening in a proximal portion of a second spinal anchor, 
 advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the second spinal anchor, the passage communicating with the opening in the proximal portion of the second spinal anchor, 
 rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the second spinal anchor, 
 positioning the bone cement delivery tube through the anchor connection instrument, 
 advancing the distal end of the bone cement delivery tube into the passage of the distal bone engaging portion of the second spinal anchor, and 
 injecting cement into the passage of distal bone engaging portion of second the spinal anchor through the bone cement delivery tube. 
 
     
     
       4. The method of  claim 1 , wherein the thread of the first connection feature is interrupted at two spaced apart, opposed unthreaded sections and further comprising
 inserting the first connection feature into the proximal portion of the bone anchor with the unthread sections facing the thread, and 
 rotating the first connection feature to engage the thread on the first connection feature with the thread on the proximal portion of the bone anchor. 
 
     
     
       5. The method of  claim 1 , further comprising connecting a spinal rod to the proximal portion of the bone anchor after injecting cement into spinal anchor. 
     
     
       6. The method of  claim 5 , further comprising connecting a connection mechanism to the proximal end of the bone anchor to capture to the spinal rod to the spinal anchor. 
     
     
       7. The method of claim 1, further comprising placing a tubular member having a proximal end, a distal end, and a central passage extending therethrough, such that fingers extending from the distal end of the tubular member abut the proximal portion of the bone anchor to provide a counter torque. 
     
     
       8. A method of delivering cement to a spinal anchor anchored in a vertebra of a patient, the method comprising:
 advancing a distal end of an anchor connection instrument through an opening in a proximal portion of a spinal anchor, the proximal portion of the spinal anchor having a slot for receiving a spinal rod and a thread for receiving a closure mechanism for securing the rod in the proximal portion, the distal end of the anchor connection instrument including a first connection feature spaced apart from a second connection feature, the first connection feature comprising an external thread, the second connection feature comprising a drive tip located at a distal tip of the distal end of the anchor connection instrument,   advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the spinal anchor, the passage communicating with the opening in the proximal portion of the spinal anchor,   rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the spinal anchor, the first connection feature being positioned between the proximal end and the distal end of the anchor connection instrument a distance from the drive tip, the distance selected to allow the drive tip to be advanced into the drive feature of the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor, the anchor connection instrument holding the proximal portion of the spinal anchor relative to the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor and the second connection feature is advanced into the drive feature of the distal bone engaging portion of the spinal anchor   positioning a bone cement delivery tube through the anchor connection instrument,   advancing a distal end of the bone cement delivery tube into the passage of the distal bone engaging portion of the spinal anchor, and   injecting cement into the passage of the distal bone engaging portion of the spinal anchor through the bone cement delivery tube,   wherein the first connection feature and the second connection feature are advanced simultaneously.   
     
     
       9. The method of claim 8, wherein the bone cement delivery tube is connected to a bone cement delivery system, at least a portion of which is positioned outside of a fluoroscopic imaging field about the patient. 
     
     
       10. The method of claim 8, further comprising
 removing the anchor connection instrument and the bone cement delivery tube from the spinal anchor,   advancing the distal end of the anchor connection instrument through an opening in a proximal portion of a second spinal anchor,   advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the second spinal anchor, the passage communicating with the opening in the proximal portion of the second spinal anchor,   rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the second spinal anchor,   positioning the bone cement delivery tube through the anchor connection instrument, advancing the distal end of the bone cement delivery tube into the passage of the distal bone engaging portion of the second spinal anchor, and   injecting cement into the passage of the distal bone engaging portion of the second spinal anchor through the bone cement delivery tube.   
     
     
       11. The method of claim 8, wherein the external thread of the first connection feature is interrupted at two spaced apart, opposed unthreaded sections and further comprising
 inserting the first connection feature into the proximal portion of the spinal anchor with the unthreaded sections facing the thread of the proximal portion of the spinal anchor, and   rotating the first connection feature to engage the external thread of the first connection feature with the thread of the proximal portion of the spinal anchor.   
     
     
       12. The method of claim 8, further comprising connecting a spinal rod to the proximal portion of the spinal anchor after injecting cement into the spinal anchor. 
     
     
       13. The method of claim 12, further comprising connecting a closure mechanism to the proximal end of the spinal anchor to capture the spinal rod to the spinal anchor. 
     
     
       14. The method of claim 8, wherein the anchor connection instrument is inserted through a tubular screw extension attached to the spinal anchor. 
     
     
       15. The method of claim 8, wherein the anchor connection instrument comprises a tubular instrument body having a protruding annular portion at a proximal end thereof. 
     
     
       16. The method of claim 8, wherein the anchor connection instrument includes a connecting feature comprising an annular groove at the proximal end of the anchor connection instrument. 
     
     
       17. The method of claim 8, wherein the bone cement delivery tube includes a proximal connector for connecting the bone cement delivery tube to a cement delivery system. 
     
     
       18. The method of claim 8, wherein the bone cement delivery tube includes a handle comprising two wings extending laterally-outward from a proximal end of the bone cement delivery tube. 
     
     
       19. The method of claim 18, wherein the bone cement delivery tube includes a connector disposed between the two wings of the handle for connecting the bone cement delivery tube to a reservoir of bone cement. 
     
     
       20. The method of claim 8, further comprising connecting the bone cement delivery tube to a reservoir of bone cement and applying pressure to bone cement in the reservoir to move the bone cement into the bone cement delivery tube. 
     
     
       21. The method of claim 20, wherein the reservoir includes a valve for controlling cement delivery to the cement delivery tube. 
     
     
       22. The method of claim 8, further comprising placing a tubular member having a proximal end, a distal end, and a central passage extending therethrough, such that fingers extending from the distal end of the tubular member abut the proximal portion of the bone anchor to provide a counter torque. 
     
     
       23. The method of claim 8, further comprising injecting the cement through openings in a sidewall of the distal bone engaging portion of the spinal anchor and into surrounding bone. 
     
     
       24. A method of delivering cement to a spinal anchor anchored in a vertebra of a patient, the method comprising:
 advancing a distal end of an anchor connection instrument through an opening in a proximal portion of a spinal anchor, the proximal portion of the spinal anchor having a slot for receiving a spinal rod and a thread for receiving a closure mechanism for securing the rod in the proximal portion, the distal end of the anchor connection instrument including a first connection feature spaced apart from a second connection feature, the first connection feature comprising an external thread, the second connection feature comprising a drive tip located at a distal tip of the distal end of the anchor connection instrument,   advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the spinal anchor, the passage communicating with the opening in the proximal portion of the spinal anchor,   rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the spinal anchor, the first connection feature being positioned between the proximal end and the distal end of the anchor connection instrument a distance from the drive tip, the distance selected to allow the drive tip to be advanced into the drive feature of the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor, the anchor connection instrument holding the proximal portion of the spinal anchor relative to the distal bone engaging portion of the spinal anchor when the first connection feature engages the proximal portion of the spinal anchor and the second connection feature is advanced into the drive feature of the distal bone engaging portion of the spinal anchor   positioning a bone cement delivery tube through the anchor connection instrument,   placing a distal end of the bone cement delivery tube into fluid communication with the passage of the distal bone engaging portion of the spinal anchor, and   injecting cement into the passage of the distal bone engaging portion of the spinal anchor through the bone cement delivery tube,   wherein rotating the first connection feature simultaneously rotates the second connection feature.   
     
     
       25. The method of claim 24, wherein the bone cement delivery tube is connected to a bone cement delivery system, at least a portion of which is positioned outside of a fluoroscopic imaging field about the patient. 
     
     
       26. The method of claim 24, further comprising
 removing the anchor connection instrument and the bone cement delivery tube from the spinal anchor,   advancing the distal end of the anchor connection instrument through an opening in a proximal portion of a second spinal anchor,   advancing the drive tip of the anchor connection instrument into a drive feature at a proximal opening in a passage formed in a distal bone engaging portion of the second spinal anchor, the passage communicating with the opening in the proximal portion of the second spinal anchor,   rotating the first connection feature to engage the external thread of the first connection feature with the thread on the proximal portion of the second spinal anchor,   positioning the bone cement delivery tube through the anchor connection instrument, placing the distal end of the bone cement delivery tube into fluid communication with the passage of the distal bone engaging portion of the second spinal anchor, and   injecting cement into the passage of the distal bone engaging portion of the second spinal anchor through the bone cement delivery tube.   
     
     
       27. The method of claim 24, wherein the external thread of the first connection feature is interrupted at two spaced apart, opposed unthreaded sections and further comprising
 inserting the first connection feature into the proximal portion of the spinal anchor with the unthreaded sections facing the thread of the proximal portion of the spinal anchor, and   rotating the first connection feature to engage the external thread of the first connection feature with the thread of the proximal portion of the spinal anchor.   
     
     
       28. The method of claim 24, further comprising connecting a spinal rod to the proximal portion of the spinal anchor after injecting cement into the spinal anchor. 
     
     
       29. The method of claim 28, further comprising connecting a closure mechanism to the proximal end of the spinal anchor to capture the spinal rod to the spinal anchor. 
     
     
       30. The method of claim 24, wherein the anchor connection instrument is inserted through a tubular screw extension attached to the spinal anchor. 
     
     
       31. The method of claim 24, wherein the anchor connection instrument comprises a tubular instrument body having a protruding annular portion at a proximal end thereof. 
     
     
       32. The method of claim 24, wherein the anchor connection instrument includes a connecting feature comprising an annular groove at the proximal end of the anchor connection instrument. 
     
     
       33. The method of claim 24, wherein the bone cement delivery tube includes a proximal connector for connecting the bone cement delivery tube to a cement delivery system. 
     
     
       34. The method of claim 24, wherein the bone cement delivery tube includes a handle comprising two wings extending laterally-outward from a proximal end of the bone cement delivery tube. 
     
     
       35. The method of claim 34, wherein the bone cement delivery tube includes a connector disposed between the two wings of the handle for connecting the bone cement delivery tube to a reservoir of bone cement. 
     
     
       36. The method of claim 24, further comprising connecting the bone cement delivery tube to a reservoir of bone cement and applying pressure to bone cement in the reservoir to move the bone cement into the bone cement delivery tube. 
     
     
       37. The method of claim 36, wherein the reservoir includes a valve for controlling cement delivery to the cement delivery tube. 
     
     
       38. The method of claim 24, further comprising injecting the cement through openings in a sidewall of the distal bone engaging portion of the spinal anchor and into surrounding bone. 
     
     
       39. The method of claim 24, further comprising placing a tubular member having a proximal end, a distal end, and a central passage extending therethrough, such that fingers extending from the distal end of the tubular member abut the proximal portion of the bone anchor to provide a counter torque. 
     
     
       40. A bone anchor kit, comprising:
 a bone anchor, including:
 a proximal portion having a slot for receiving a spinal rod and a thread for receiving a closure mechanism to secure the spinal rod to the proximal portion, 
 a distal bone engaging portion, 
 a passage extending into the distal bone engaging portion from a drive interface at a proximal end of the distal bone engaging portion, and 
 an opening in a sidewall of the distal bone engaging portion, the opening communicating with the passage; 
   a volume of bone cement;   a reservoir for receiving the volume of bone cement, the reservoir including a valve for controlling flow of the bone cement out of the reservoir;   a single piece anchor connection instrument having a proximal end, a distal end, and a central passage extending therethrough, the distal end of the anchor connection instrument including a first connection feature spaced apart from a second connection feature, the first connection feature comprising an external thread, the second connection feature comprising a drive tip located at a distal tip of the distal end of the anchor connection instrument, wherein advancing the drive tip of the anchor connection instrument into the drive feature of the bone anchor and threading the external thread of the first connection feature into the thread of the bone anchor holds the proximal portion of the bone anchor relative to the distal bone engaging portion of the bone anchor; and   a cement delivery tube connectable to the reservoir, the cement delivery tube being positionable within the central passage of the anchor connection instrument and being configured such that, when placed through the anchor connection instrument while the anchor connection instrument is attached to the bone anchor, the cement delivery tube is in fluid communication with the passage of the bone anchor to deliver cement through the passage and through the opening in the sidewall of the bone anchor,   wherein the first connection feature and the second connection feature are formed as part of the single piece anchor connection instrument.   
     
     
       41. The kit of claim 40, wherein the anchor connection instrument comprises a tubular instrument body having a proximal portion with an enlarged outside diameter. 
     
     
       42. The kit of claim 40, wherein the cement delivery tube includes a handle comprising two wings extending laterally-outward from a proximal end of the cement delivery tube. 
     
     
       43. The kit of claim 40, wherein the anchor connection instrument includes a connecting feature comprising an annular groove at the proximal end of the anchor connection instrument. 
     
     
       44. The kit of claim 40, wherein the cement delivery tube includes a connector disposed between the two wings of the handle for connecting the cement delivery tube to the reservoir. 
     
     
       45. The kit of claim 40, wherein the external thread of the first connection feature is interrupted at two spaced apart, opposed unthreaded sections. 
     
     
       46. The kit of claim 40, further comprising a tubular member having a proximal end, a distal end, and a central passage extending therethrough, wherein the distal end of the tubular member has fingers extending therefrom, the fingers configured to abut against the proximal portion of the bone anchor to provide a counter torque.