Patent Publication Number: US-2007112427-A1

Title: Intervertebral Spacer

Description:
PRIORITY  
      The application claims priority from the disclosure of U.S. Provisional Patent Application Ser. No. 60/737,436, entitled “Intervertebral Spacer,” filed Nov. 16, 2005, which is herein incorporated by reference in its entirety. 
    
    
     BACKGROUND  
      Versions of the present invention relate to retaining spinal mobility following discectomies and other spinal procedures and, more particularly, to retaining spinal mobility following discectomies by providing a replacement disc allowing at least partial spinal movement. A variety of medical devices have been created and used, but no one prior to the inventor(s) has created or used the invention described in the appended claims.  
      Versions of the present invention relate to retaining spinal mobility following discectomies and other spinal procedures and, more particularly, to retaining spinal mobility following discectomies by providing a replacement disc allowing at least partial spinal movement. A variety of medical devices have been created and used, but no one prior to the inventor(s) has created or used the invention described in the appended claims. 
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
      In accordance with versions herein, it is believed the present invention will be better understood from the following description taken in conjunction with the accompanying drawings. The drawings and detailed description that follow are intended to be merely illustrative and are not intended to limit the scope of the invention.  
       FIG. 1  presents a side view of a spacer positioned between two vertebra having one surface adapted to fuse with a vertebra;  
       FIG. 2  presents a side view of an alternate version of a spacer positioned between two vertebra having one surface adapted to fuse with a vertebra. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      In versions contained herein, the device is an intervertebral implant  10  that is intended to maintain limited mobility between adjacent vertebrae  12 ,  14  or take the place of a vertebra. In one version, pins  16  and  20  are inserted into the vertebrae of a patient surrounding a disc that is to be removed with, for example, a pedicle screw system having dynamic stabilization. Pin  18  is inserted into the spacer  22 . Once inserted, the vertebrae  12 ,  14  may be held apart while a spacer  22  is placed therebetween. The spacer  22  may be, for example, configured to match the natural shape of the patient&#39;s disc.  
      The spacer  22  includes a first surface  24  adapted to fuse with a first vertebra  12 . The first surface  24  may be constructed from any suitable material with which bone may fuse and may be provided with a rough, porous, and/or textured surface to facilitate fusion. The spacer  22  further includes a second surface  26  adapted to lie adjacent to the second vertebra  14 . In one version, the second surface  26  is configured such that it is resistant to the fusion of the spacer  22  to the second vertebra  14  where, for example, the second  26  surface may be substantially smooth and/or constructed from a material resistant to bone fusion. The intervertebral implant  10  may be provided with a spring or flexible element  28 , an elastic portion, a memory retention portion, a motion dampening portion, and/or a flexible portion operably configured to allow the vertebrae to move relative to one another. The couplings between the pins and/or the spacer may be rigidly fixed, an elastic portion, a spring portion, a memory retention portion, a motion dampening portion, and/or a flexible portion, and combinations thereof.  
      It will be appreciated that the spacer  22 , the first surface  24 , and the second surface  26  may be configured from any suitable biomaterial, artificial material, or combinations thereof. It will be appreciated that the first surface and the second surface  26  are disclosed by way of example only, where any arrangement or configuration of surfaces is contemplated. It is further contemplated that the spacer  22  be configured from a cushioning material and/or shock absorbing material to substantially mimic the natural function of a vertebral disc.  
      With reference to  FIG. 2 , the surface intended to resist vertebral fusion may be oriented to either the superior surface or the inferior surface of the vertebra, as illustrated. The second surface may be either convex or concave in shape to match and articulate with the mating vertebra.  
      Providing a first surface and a second surface as disclosed herein may provide the benefits of at least partial spinal motion, or dynamic stabilization, with the benefits of spinal fusion. By fusing the first surface to a vertebra, the spacer may be secured thereto in a permanent fashion. It is further contemplated, however, that the spacer may be retained within the first and second vertebrae with an artificial ligament system.  
      With the first surface secured, either by fusion to the bone, an artificial ligament system, or the like, the second surface is operably configured to articulate with the movement of the spine. Unlike traditional spinal fusion procedures, where two vertebrae are fused permanently together, versions herein may maintain at least partial mobility between a vertebra and the spacer. This mobility may increase a patient&#39;s range of motion and comfort level such that, following such a procedure, the results may feel more natural than traditional spinal fusion.