Methods and systems for enhancing radiographic images of radiolucent implants

Abstract

A radiolucent intervertebral prosthesis is implanted in an environment that has been prepared in a manner which enhances radiopacity of the prosthesis and/or the environment. A liquid, powder, or other fluid radiopaque (RO) material, such as iohexol, is introduced into an implantation site, either by directly introducing the material into the site and/or by applying the material to a surface of the implant. The presence of the RO material in the implantation site provides contrast with the material of radiolucent prosthesis while the implantation site is being radiographically imaged, e.g. during fluoroscopic visualization while the prosthesis is being implanted. During implantation, the RO material helps the physician view and manipulate the implant, and after the implantation is complete, the RO material will be resorbed or otherwise lost from the implantation site so that the area returns to a radiolucent condition to facilitate subsequent radiographic imaging when needed.

What is claimed is: 
     
         1 . A prosthetic disc for insertion between adjacent vertebrae, the prosthetic disc comprising:
 upper and lower plates having outer surfaces locatable against the respective vertebrae and inner surfaces, wherein said inner surfaces are configured to allow relative articulation of the plates when the disc is implanted between adjacent vertebrae;   wherein at least one of said upper and lower plates is at least partially formed from a radiolucent polymer; and   wherein said at least one of said upper and lower plates has one or more collection features formed on a surface of the radiolucent polymer, said collection feature being configured to collect and retain fluoroscopic contrast medium to enhance radiographic imaging of the plate when being implanted in a patient in the presence of a fluid radiographic imaging medium.   
     
     
         2 . A prosthetic disc as in  claim 1 , wherein the radiolucent polymer is polyaryletherketone (PAEK). 
     
     
         3 . A prosthetic disc as in  claim 2 , wherein the PAEK comprises polyetheretherketone (PEEK). 
     
     
         4 . A prosthetic disc as in  claim 1 , wherein the collection feature comprise comprises at least one of a hole, a trough or a capillary. 
     
     
         5 . A prosthetic disc as in  claim 1 , wherein the collection feature is formed on at least an outer surface of one of the endplates. 
     
     
         6 . A prosthetic disc as in  claim 1 , wherein the collection feature is formed on at least an inner surface of one of the endplates. 
     
     
         7 . A prosthetic disc as in  claim 1 , wherein the collection feature is formed on at least a peripheral surface of one of the endplates. 
     
     
         8 . A prosthetic disc as in  claim 1 , further comprising a mobile core disposed between inner surfaces of the upper and lower plates, the core arranged to slide and translate with respect to both the upper and lower plates when the prosthetic disc is implanted. 
     
     
         9 . A prosthetic disc as in  claim 8 , further comprising a restraining structure on at least one of the plates configured to hold an outermost periphery of the core captive between the plates during sliding movement of the plates over the core when the prosthetic disc is implanted. 
     
     
         10 . A prosthetic disc as in  claim 8 , wherein the core is formed of a ceramic. 
     
     
         11 . A prosthetic disc as in  claim 1 , wherein the collection features are arranged in a pattern which is visible during implantation to facilitate observing the orientation of the implant as it is being implanted. 
     
     
         12 . A prosthetic disc as in  claim 1 , wherein the radiolucent implant is coated with a fluoroscopic contrast medium. 
     
     
         13 . A prosthetic disc as in  claim 1 , wherein the radiolucent implant is packaged with the liquid contrast medium.