Intervertebral implant for transforaminal posterior lumbar interbody fusion procedure

Abstract

An intervertebral implant for fusing vertebrae is disclosed. The implant may have a body with curved, posterior and anterior faces separated by two narrow implant ends, superior and inferior faces having a plurality of undulating surfaces for contacting vertebral endplates, and at least one depression in the anterior or posterior face for engagement by an insertion tool. The implant may also have one or more vertical through-channels extending through the implant from the superior face to the inferior face, a chamfer on the superior and inferior surfaces at one of the narrow implant ends, and/or a beveled edge along a perimeter of the superior and inferior faces. The implant configuration facilitates transforaminal insertion of the implant into a symmetric position about the midline of the spine so that a single implant provides balanced support to the spinal column. The implant may be formed of a plurality of interconnecting bodies assembled to form a single unit. An implantation kit and method are also disclosed.

What is claimed is: 
     
       1. An intervertebral implant comprising:
 a three-dimensional substantially kidney bean-shaped body comprising a concave arcuate posterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body and a convex arcuate anterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body, wherein the distance between the posterior face and the anterior face defines a width of the body;   a superior face and an inferior face for contacting at least a portion of a first and a second vertebrae, wherein the distance between the superior face and the inferior face defines a thickness of the body and, at least one of the superior and inferior faces includes a plurality of undulating surfaces to resist migration of the implant when the implant is implanted between two vertebrae; and   a curved first end portion and a curved second end portion connecting the posterior and anterior faces,   wherein the distance between the first and second end portions defines a length of the body that is greater than the width of the body, the thickness of the body is greatest at the mid-section and tapers toward each end portion and, at least one of the first end portion and the second end portion comprises a chamfered edge on at least one of the superior face and the inferior face.   
     
     
       2. The intervertebral implant of  claim 1 , wherein the plurality of undulating surfaces comprises teeth or ridges. 
     
     
       3. The intervertebral implant of  claim 2 , wherein the teeth comprise a saw-tooth or pyramidal configuration. 
     
     
       4. The intervertebral implant of  claim 1 , wherein the implant comprises cortical bone. 
     
     
       5. The intervertebral implant of  claim 1 , wherein the implant comprises a plurality of interconnecting bone pieces assembled to form a single unit. 
     
     
       6. The intervertebral implant of  claim 1 , wherein the chamfered edge has a smooth surface without any undulating surfaces on at least one of the superior and inferior faces. 
     
     
       7. The intervertebral implant of  claim 1 , wherein both of the superior and inferior faces are arcuate shaped. 
     
     
       8. The intervertebral implant of  claim 1 , wherein the implant body comprises allogenic bone. 
     
     
       9. The intervertebral implant of  claim 1 , wherein the implant includes a vertical channel extending through the implant from the superior face to the inferior face. 
     
     
       10. The intervertebral implant of  claim 1 , wherein the implant further includes at least one horizontal channel extending into at least one of the anterior face and the posterior face. 
     
     
       11. The intervertebral implant of  claim 10 , wherein the at least one horizontal channel extends through the implant from the anterior face to the posterior face. 
     
     
       12. The intervertebral implant of  claim 1 , wherein the implant comprises a non-threaded recessed portion disposed along a portion of the anterior face. 
     
     
       13. The intervertebral implant of  claim 1 , wherein the implant comprises a polymeric material. 
     
     
       14. An intervertebral implant for insertion between two vertebrae comprising:
 a three-dimensional substantially kidney bean-shaped body formed at least partially of cortical bone and comprising a concave arcuate posterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body and a convex arcuate anterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body, wherein the distance between the posterior and anterior faces defines a width of the body;   a superior face and an inferior face for contacting at least a portion of a first and a second vertebrae, wherein the distance between the superior face and the inferior face defines a thickness of the body and, at least one of the superior and inferior faces includes a plurality of undulating surfaces to resist migration of the implant when the implant is implanted between two vertebrae; and   a curved first end portion and a curved second end portion connecting the posterior and anterior faces,   wherein the distance between the first and second end portions defines a length of the body that is greater than the width of the body, the thickness of the body is greatest at the mid-section and tapers toward each end portion and, at least one of the first end portion and the second end portion comprises a chamfered edge substantially smooth and free of undulating surfaces on at least one of the superior face and the inferior face.   
     
     
       15. The intervertebral implant of  claim 14 , wherein the implant is formed entirely of bone. 
     
     
       16. The intervertebral implant of  claim 14 , wherein the plurality of undulating surfaces comprise teeth or ridges. 
     
     
       17. The intervertebral implant of  claim 16 , wherein both of the superior and inferior faces are arcuate shaped. 
     
     
       18. The intervertebral implant of  claim 16 , wherein the teeth comprise a saw-tooth or pyramidal configuration. 
     
     
       19. The intervertebral implant of  claim 14 , wherein the first curved end portion and the second curved end portion each are curved for substantially their entire length. 
     
     
       20. The intervertebral implant of  claim 14 , wherein the implant includes a vertical channel extending through the implant from the superior face to the inferior face. 
     
     
       21. The intervertebral implant of  claim 14 , wherein the implant comprises a non-threaded recessed portion disposed along a portion of the anterior face. 
     
     
       22. An intervertebral implant comprising:
 a three-dimensional body having a substantially kidney bean shape, and comprising a concave arcuate posterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body and a convex arcuate anterior face comprising a curve extending substantially the length of the longitudinal axis of the implant body, wherein the distance between the posterior and anterior faces defines a width of the body;   a superior face and an inferior face for contacting at least a portion of a first and a second vertebrae, wherein the distance between the superior face and the inferior face defines a thickness of the body and, at least one of the superior and inferior faces includes a plurality of teeth or ridges to resist migration of the implant when the implant is implanted between two vertebrae; and   a curved first end portion and a curved second end portion connecting the posterior and anterior faces,   wherein the distance between the first and second end portions defines a length of the body, at least one of the first end portion and the second end portion comprises a chamfered edge substantially smooth and free of teeth or ridges on at least one of the superior face and the inferior face and, the thickness of the implant is greatest at the midsection and tapers toward each end portion.   
     
     
       23. The intervertebral implant of  claim 22 , wherein the implant includes a vertical channel extending through the implant from the superior face to the inferior face. 
     
     
       24. The intervertebral implant of  claim 22 , wherein the implant comprises a non-threaded recessed portion disposed along a portion of the anterior face. 
     
     
       25. The intervertebral implant of  claim 22 , wherein the teeth comprise a saw-tooth or pyramidal configuration. 
     
     
       26. The intervertebral implant of  claim 22 , wherein the implant comprises a polymeric material. 
     
     
       27. The intervertebral implant of  claim 22 , wherein the implant comprises cortical bone. 
     
     
       28. An intervertebral implant, comprising:
 a body constructed of a radiolucent material and having a first end and a second end, a superior face and an inferior face each with a plurality of teeth to resist migration of the body when the body is implanted between two vertebrae, an anterior face and a posterior face extending from the first end to the second end and between the superior face and the inferior face, wherein a thickness of the body between the superior face and the inferior face is greatest at a middle portion of the body and tapers toward each end, and two vertical through-channels extending through the body from the superior face to the inferior face, the vertical through-channels being spaced from one another in a way to define a wall extending between the vertical through-channels from the superior face to the inferior face; and   at least three radiopaque markers extending substantially through the body from the superior face to the inferior face and disposed in the body so as to be enclosed in the radiolucent material of the body from the superior face to the inferior face to indicate implant location and size in postoperative spinal scans, a first of the three radiopaque markers disposed in the body adjacent the first end of the body, a second of the three radiopaque markers disposed in the body adjacent the second end of the body, and a third of the three radiopaque markers disposed in the body adjacent the wall between the vertical through-channels.    
     
     
       29. The intervertebral implant of claim 28, wherein the anterior face is convex shaped.  
     
     
       30. The intervertebral implant of claim 29, wherein the posterior face is concave shaped.  
     
     
       31. The intervertebral implant of claim 30, wherein the anterior and posterior faces are each curved and substantially parallel to each other.  
     
     
       32. The intervertebral implant of claim 28, wherein a length of the body is greater than each of a maximum width and a maximum thickness of the body.  
     
     
       33. The intervertebral implant of claim 32, wherein the length of the body is at least two times the maximum width of the body between the posterior face and the anterior face.  
     
     
       34. The intervertebral implant of claim 33, wherein the maximum thickness of the body is greater than the maximum width of the body.  
     
     
       35. The intervertebral implant of claim 28, wherein at least one of the radiopaque markers is proximate the anterior face.  
     
     
       36. The intervertebral implant of claim 28, wherein the anterior face is a convex arcuate anterior face, and at least one of the radiopaque markers is proximate the convex arcuate anterior face.  
     
     
       37. The intervertebral implant of claim 28, wherein the body comprises a non-threaded recessed portion disposed along a portion of the anterior face.  
     
     
       38. The intervertebral implant of claim 28, wherein the body comprises a non-threaded recessed portion disposed along a portion of the posterior face.  
     
     
       39. The intervertebral implant of claim 28, wherein at least one of the first end and the second end of the body comprises a chamfered edge on at least one of the superior face and the inferior face.