Polyaryletherketone artificial intervertebral disc

Abstract

Various implementations include intervertebral discs and associated methods of use and imaging. One implementation includes an intervertebral disc capable of imaging under MRI, the disc including: an upper plate including a polyaryletherketone (PAEK) portion having a lower bearing surface and an upper vertebra contacting surface, the upper surface formed at least in part from a metal for improved bone attachment; a lower plate including a PAEK portion having an upper bearing surface and a lower vertebra contacting surface, the lower surface formed at least in part from a metal for improved bone attachment; and a ceramic core to mate and articulate with respect to the bearing surfaces of the upper and lower plates, wherein upon imaging under X-ray the PAEK portion of the upper and lower plates are substantially completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are substantially completely visible.

We claim: 
     
         1 . An intervertebral disc capable of imaging under MRI, the intervertebral disc comprising:
 an upper plate including a polyaryletherketone (PAEK) portion having a lower bearing surface and an upper vertebra contacting surface, the upper vertebra contacting surface formed at least in part from a metal for improved bone attachment;   a lower plate including a polyaryletherketone (PAEK) portion having an upper bearing surface and a lower vertebra contacting surface, the lower vertebra contacting surface formed at least in part from a metal for improved bone attachment; and   a ceramic core configured to mate with and articulate with respect to both the bearing surfaces of the upper and lower plates,   wherein upon imaging under X-ray the PAEK portion of the upper and lower plates are substantially completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are substantially completely visible.   
     
     
         2 . The intervertebral disc of  claim 1 , wherein the lower bearing surface of the upper plate is a PAEK lower bearing surface,
 wherein the upper bearing surface of the lower plate is a PAEK upper bearing surface; and   wherein the ceramic core includes an upper ceramic bearing surface and a lower ceramic bearing surface, and when implanted, the PAEK lower bearing surface of the upper plate contacts and articulates relative to the upper ceramic bearing surface of the ceramic core and the PAEK upper bearing surface of the lower plate contacts and articulates relative to the lower ceramic bearing surface of the ceramic core.   
     
     
         3 . The intervertebral disc of  claim 1 , wherein the upper plate further comprises an upper anchoring element extending from an opposing side of the PAEK portion relative to the lower bearing surface  2 , wherein the lower plate further comprises a lower anchoring element extending from an opposing side of the PAEK portion relative to the upper bearing surface. 
     
     
         4 . The intervertebral disc of  claim 1 , wherein the ceramic core comprises upper and lower bearing surfaces, and when implanted, the ceramic core is positioned between the upper and lower plates such that the upper and lower bearing surfaces of the ceramic core are configured to articulate with respect to both the bearing surfaces of the upper and lower plates. 
     
     
         5 . The intervertebral disc of  claim 1 , wherein the upper plate further comprises an upper anchoring element and an upper vertebra contacting surface, wherein the upper vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounds the upper anchoring element, wherein the lower plate further comprises a lower anchoring element and a lower insert having a lower vertebra contacting surface, wherein the lower vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounding the lower anchoring element. 
     
     
         6 . The intervertebral disc of  claim 1 , wherein the PAEK portions comprises neat poly(aryl-ether-ether-ketone) (PEEK), and
 wherein upon the imaging under X-ray the PAEK portion of the upper and lower plates are completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are completely visible.   
     
     
         7 . The intervertebral disc of  claim 6 , wherein the PAEK portions consist approximately entirely of PEEK. 
     
     
         8 . The intervertebral disc of  claim 1 , wherein the upper plate includes an upper insert and wherein the lower plate includes a lower insert, wherein the lower insert is a separate component from the PAEK portion of the lower plate and when implanted, rests on the opposing side of the PAEK portion relative to the upper bearing surface, and wherein the lower insert comprises an opening through which the lower anchoring element extends when implanted, the opening serving to locate the lower insert on the opposing side of the PAEK portion. 
     
     
         9 . The intervertebral disc of  claim 8 , wherein the upper insert is a separate component from the PAEK portion of the upper plate and when implanted, rests on the opposing side of the PAEK portion, and wherein the upper insert comprises an opening through which the upper anchoring element extends when implanted, the opening serving to locate the insert on the opposing side of the PAEK portion. 
     
     
         10 . The intervertebral disc of  claim 1 , wherein the ceramic core is the only member interfacing between the bearing surfaces of the upper and lower plates. 
     
     
         11 . A method for relieving back pain with an intervertebral disc capable of imaging under MRI, the method comprising:
 implanting an upper plate including a polyaryletherketone (PAEK) portion having a lower bearing surface and an upper vertebra contacting surface, the upper vertebra contacting surface formed at least in part from a metal for improved bone attachment;   implanting a lower plate including a polyaryletherketone (PAEK) portion having an upper bearing surface and a lower vertebra contacting surface, the lower vertebra contacting surface formed at least in part from a metal for improved bone attachment; and   positioning a ceramic core configured to mate with and articulate with respect to both the bearing surfaces of the upper and lower plates,   wherein upon imaging under X-ray the PAEK portion of the upper and lower plates are substantially completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are substantially completely visible.   
     
     
         12 . The method of  claim 11 , wherein the lower bearing surface of the upper plate is a PAEK lower bearing surface,
 wherein the upper bearing surface of the lower plate is a PAEK upper bearing surface; and   wherein the ceramic core includes an upper ceramic bearing surface and a lower ceramic bearing surface, and when implanted, the PAEK lower bearing surface of the upper plate contacts and articulates relative to the upper ceramic bearing surface of the ceramic core and the PAEK upper bearing surface of the lower plate contacts and articulates relative to the lower ceramic bearing surface of the ceramic core.   
     
     
         13 . The method of  claim 11 , wherein the upper plate further comprises an upper anchoring element extending from an opposing side of the PAEK portion relative to the lower bearing surface, wherein the lower plate further comprises a lower anchoring element extending from an opposing side of the PAEK portion relative to the upper bearing surface, wherein the ceramic core comprises upper and lower bearing surfaces, and when implanted, the ceramic core is positioned between the upper and lower plates such that the upper and lower bearing surfaces of the ceramic core are configured to articulate with respect to both the bearing surfaces of the upper and lower plates. 
     
     
         14 . The method of  claim 13 , wherein the upper vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounds the upper anchoring element, wherein the lower vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounding the lower anchoring element. 
     
     
         15 . The method  claim 11 , wherein the PAEK portions comprises neat poly(aryl-ether-ether-ketone) (PEEK), and
 wherein upon the imaging under X-ray the PAEK portion of the upper and lower plates are completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are completely visible, wherein the PAEK portions consist approximately entirely of PEEK.   
     
     
         16 . The method of  claim 11 , wherein the upper plate comprises an upper anchoring element and the lower plate comprises a lower anchoring element, wherein the lower insert is a separate component from the PAEK portion of the lower plate and when implanted, rests on the opposing side of the PAEK portion relative to the upper bearing surface, and wherein the lower insert comprises an opening through which the lower anchoring element extends when implanted, the opening serving to locate the lower insert on the opposing side of the PAEK portion, wherein the upper insert is a separate component from the PAEK portion of the upper plate and when implanted, rests on the opposing side of the PAEK portion, and wherein the upper insert comprises an opening through which the upper anchoring element extends when implanted, the opening serving to locate the insert on the opposing side of the PAEK portion, and
 wherein the ceramic core is the only member interfacing between the bearing surfaces of the upper and lower plates.   
     
     
         17 . The method of  claim 11 , further comprising:
 removing at least one of the PAEK portion of the upper plate or the PAEK portion of the lower plate after the implanting processes without removing a corresponding one of the upper insert or the lower insert; and   replacing the removed at least one of the PAEK portion of the upper plate or the PAEK portion of the lower plate after removal without removing the corresponding one of the upper insert or the lower insert.   
     
     
         18 . A method of imaging a patient's spine with an artificial intervertebral disc, the method comprising:
 implanting an upper plate including a polyaryletherketone (PAEK) portion having a lower bearing surface and an upper vertebra contacting surface, the upper vertebra contacting surface formed at least in part from a metal for improved bone attachment;   implanting a lower plate including a polyaryletherketone (PAEK) portion having an upper bearing surface and a lower vertebra contacting surface, the lower vertebra contacting surface formed at least in part from a metal for improved bone attachment;   positioning a ceramic core configured to mate with and articulate with respect to both the bearing surfaces of the upper and lower plates;   imaging the implanted artificial disc with MRI, wherein the MM image of the implanted upper and lower plates and ceramic core clearly show the vertebrae and surrounding tissues with very minimal distortion caused by the intervertebral disc; and   imaging the implanted artificial disc with X-ray, wherein the X-ray image shows the PAEK portion of the upper and lower plates are substantially completely invisible and the metal upper and lower vertebral contacting surfaces of the upper and lower plates are substantially completely visible.   
     
     
         19 . The method of  claim 18 , wherein the lower bearing surface of the upper plate is a PAEK lower bearing surface, wherein the upper bearing surface of the lower plate is a PAEK upper bearing surface, and
 wherein the ceramic core includes an upper ceramic bearing surface and a lower ceramic bearing surface, and when implanted, the PAEK lower bearing surface of the upper plate contacts and articulates relative to the upper ceramic bearing surface of the ceramic core and the PAEK upper bearing surface of the lower plate contacts and articulates relative to the lower ceramic bearing surface of the ceramic core.   
     
     
         20 . The method of  claim 18 , wherein the upper plate comprises an upper anchoring element and the lower plate comprises a lower anchoring element, wherein the upper vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounds the upper anchoring element, wherein the lower vertebra contacting surface is positioned adjacent the PAEK portion and substantially surrounding the lower anchoring element, wherein the PAEK portions comprises neat poly(aryl-ether-ether-ketone) (PEEK), and
 wherein upon the imaging under X-ray the PAEK portion of the upper and lower plates are completely invisible and the upper and lower vertebral contacting surfaces of the upper and lower plates are completely visible.