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 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 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. 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 into 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 distal tip of the distal end of the anchor connection instrument,   advancing the distal tip of the anchor connection instrument into a proximal opening in a passage formed in a distal bone engaging portion of the spinal anchor, the passage communicating with 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 distal tip, the distance selected to allow the distal tip to be advanced into the proximal opening 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 proximal opening of the distal bone engaging portion of the spinal anchor   positioning a bone cement delivery tube through the anchor connection instrument while the anchor connection instrument is engaged with 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.    
     
     
       8. The method of claim 7, further comprising removing the anchor connection instrument after injecting cement into the passage of the distal bone engaging portion of the spinal anchor.  
     
     
       9. The method of claim 7, wherein removing the anchor connection instrument includes rotating the first connection feature to disengage the external thread of the first connection feature from the thread of the proximal portion of the bone anchor.  
     
     
       10. The method of claim 9, wherein the tubular extension is connected to the bone anchor.  
     
     
       11. The method of claim 10, further comprising connecting a closure mechanism to the proximal end of the spinal anchor to capture the spinal rod to the spinal anchor.  
     
     
       12. The method of claim 7, further comprising positioning the anchor connection instrument through a tubular extension.  
     
     
       13. The method of claim 7, further comprising connecting a spinal rod to the proximal portion of the spinal anchor after injecting cement into the spinal anchor.  
     
     
       14. The method of claim 7, wherein the anchor connection instrument comprises a tubular instrument body having a protruding annular portion at a proximal end thereof.  
     
     
       15. The method of claim 14, 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.  
     
     
       16. The method of claim 7, 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. 
     
     
       17. The method of claim 7, 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.  
     
     
       18. The method of claim 7, further comprising injecting the cement through openings in a sidewall of the distal bone engaging portion of the spinal anchor and into surrounding bone.  
     
     
       19. 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 into 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 distal tip of the distal end of the anchor connection instrument,   advancing the distal tip of the anchor connection instrument into a proximal opening in a passage formed in a distal bone engaging portion of the spinal anchor, the passage communicating with the proximal portion of the spinal anchor,   rotating the anchor connection instrument 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 distal tip, the distance selected to allow the distal tip to be advanced into the proximal opening of the distal bone engaging portion of the spinal anchor as the anchor connection instrument is rotated, 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 proximal opening 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 while the anchor connection instrument is engaged with the spinal anchor,   wherein rotating the first connection feature simultaneously rotates the second connection feature.    
     
     
       20. The method of claim 19 further comprising removing the anchor connection instrument after injecting cement into the passage of the distal bone engaging portion of the spinal anchor.  
     
     
       21. The method of claim 19, wherein removing the anchor connection instrument includes rotating the anchor connection instrument to disengage the external thread of the first connection feature from the thread of the proximal portion of the bone anchor.  
     
     
       22. The method of claim 21, wherein the tubular extension is connected to the bone anchor.  
     
     
       23. The method of claim 22, further comprising connecting a closure mechanism to the proximal end of the spinal anchor to capture the spinal rod to the spinal anchor.  
     
     
       24. The method of claim 19, further comprising positioning the anchor connection instrument through a tubular extension.  
     
     
       25. The method of claim 19, further comprising connecting a spinal rod to the proximal portion of the spinal anchor after injecting cement into the spinal anchor.  
     
     
       26. The method of claim 19, wherein the anchor connection instrument comprises a tubular instrument body having a protruding annular portion at a proximal end thereof.  
     
     
       27. The method of claim 19, wherein the bone cement delivery tube includes a proximal connector for connecting the bone cement delivery tube to a cement delivery system.  
     
     
       28. The method of claim 27, 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.  
     
     
       29. The method of claim 19, 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.  
     
     
       30. The method of claim 19, 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.  
     
     
       31. The method of claim 19, further comprising injecting the cement through openings in a sidewall of the distal bone engaging portion of the spinal anchor and into surrounding bone.