Intervertebral disk prosthesis

Abstract

An intervertebral disk prosthesis includes a first part, and the first part has a top, a bottom having an opening, an outer surface, an inner surface and a socket extending into an interior of the first part from the opening and defined by the inner surface. The disk prosthesis further includes a second part including a top, a bottom, and an outer surface. The outer surface of the second part proximate the top of the second part cooperatively engages the inner surface of the first part thereby allowing at least two-degrees of freedom of movement. At least one of the upper part and the lower part further comprises at least one arch spanning the outer surface proximate the top and the outer surface proximate the bottom, respectively.

1 . An intervertebral disk prosthesis having a convexly tapered distal end, a convexly tapered proximal end, an anterior side and a posterior side, the intervertebral disk prosthesis comprising: 
 an upper part including a convexly-shaped and rounded top, a bottom having an opening, an outer surface, an inner surface and a socket extending into an interior of the upper part from the opening, the outer surface proximate the top being configured to contact a concave portion of a first vertebra; and    a lower part including a top, a convexly-shaped and rounded bottom, and an outer surface, the outer surface proximate the bottom being configured to contact a concave portion of a second vertebra that is adjacent to the first vertebra, and the outer surface of the lower part proximate the top of the lower part being cooperatively and movably overlapped by the inner surface of the upper part thereby allowing at least two-degrees of freedom of movement,    at least one of the upper part and the lower part further comprising at least one arch spanning the outer surface proximate the top and the outer surface proximate the bottom, respectively.    
   
   
       2 . The intervertebral disk prosthesis of  claim 1 , wherein the top of the upper part has an ingrowth opening to encourage vertebral ingrowth and is configured to align the intervertebral disk prosthesis within an intervertebral space.  
   
   
       3 . The intervertebral disk prosthesis of  claim 2 , further comprising a generally continuous sheet of biocompatible porous material at least partially spanning the ingrowth opening.  
   
   
       4  The intervertebral disk prosthesis of  claim 3 , wherein the porous material is hydroxyapatite-coated metal.  
   
   
       5 . The intervertebral disk prosthesis of  claim 2 , further comprising a mesh structure at least partially spanning the ingrowth surface.  
   
   
       6 . The intervertebral disk prosthesis of  claim 2 , wherein the upper part further comprises at least one arch spanning the ingrowth opening.  
   
   
       7 . The intervertebral disk prosthesis of  claim 1 , wherein the bottom of the lower part has an ingrowth opening to encourage vertebral ingrowth and is configured to align the intervertebral disk prosthesis within an intervertebral space.  
   
   
       8 . The intervertebral disk prosthesis of  claim 7 , further comprising a generally continuous sheet of biocompatible porous material at least partially spanning the ingrowth surface.  
   
   
       9 . The intervertebral disk prosthesis of  claim 8 , wherein the porous material is hydroxyapatite-coated metal.  
   
   
       10 . The intervertebral disk prosthesis of  claim 7 , further comprising a mesh structure at least partially spanning the ingrowth surface.  
   
   
       11 . The intervertebral disk prosthesis of  claim 7 , wherein the lower part further comprises at least one arch spanning the ingrowth opening.  
   
   
       12 . The intervertebral disk prosthesis of  claim 1  in combination with an insertion tool, the insertion tool have a first finger configured to engage an ingrowth opening in the top of the upper part, a second finger configured to engage an ingrowth opening in the bottom of the lower part and a driving member disposed between the first and second fingers.  
   
   
       13 . The combination according to  claim 12 , wherein the driving member is configured to engage the intervertebral prosthesis.  
   
   
       14 . The combination according to  claim 12 , wherein the first and second fingers are retractable relative to the driving member.  
   
   
       15 . The combination according to  claim 12 , wherein when the first and second fingers are engaged with the ingrowth openings, all exposed surfaces of the combination are generally round.  
   
   
       16 . The combination according to  claim 12  further comprising third and fourth fingers configured to retractably move between the space between the upper part and the lower part of the intervertebral prosthesis.  
   
   
       17 . The intervertebral disk prosthesis of  claim 1 , further comprising a connector configured to temporarily and removably couple with an insertion tool.  
   
   
       18 . The intervertebral disk prosthesis of  claim 17 , wherein the connector is one of a threaded shaft, a socket, a detent, a hole and a slot.  
   
   
       19 . The intervertebral disk prosthesis of  claim 1 , wherein a distal end of the intervertebral prosthesis is generally bluntly rounded.  
   
   
       20 . The intervertebral disk prosthesis of  claim 1 , wherein a proximal end of the intervertebral prosthesis is generally bluntly rounded.  
   
   
       21 . The intervertebral disk prosthesis of  claim 1 , wherein an exterior surface of the intervertebral prosthesis is generally rounded.  
   
   
       22 . The intervertebral disk prosthesis of  claim 1 , wherein the intervertebral prosthesis is formed at least partially of a biocompatible material selected from the group consisting of stainless steel, titanium, cobalt-chrome alloy, nickel plated metal, a biocompatible alloy, a biocompatible ceramic, and a biocompatible polymeric material.  
   
   
       23 . The intervertebral disk prosthesis of  claim 1 , further comprising a pliable, biocompatible slip-cover that covers at least a portion of the upper part and a portion of the lower part, the slip-cover being configured to flexibly retain the movably coupled upper and lower parts.  
   
   
       24 . The intervertebral disk prosthesis of  claim 1 , wherein the length of the intervertebral prosthesis as measured from the distal end to the proximal end is between about 10 mm and about 30 mm.  
   
   
       25 . The intervertebral disk prosthesis of  claim 1 , wherein the width of the intervertebral prosthesis as measured between the anterior side and the posterior side is between about 10 mm and about 25 mm.  
   
   
       26 . The intervertebral disk prosthesis of  claim 1 , wherein the height of the intervertebral prosthesis as measured between the top of the upper part and the bottom of the lower part is between about 5 mm and about 25 mm.  
   
   
       27 . The intervertebral disk prosthesis of  claim 1 , wherein the freedom of movement is limited to between about 2-15 degrees tilt in any direction.  
   
   
       28 . The intervertebral disk prosthesis of  claim 1 , wherein the disk prosthesis minimizes translational movement.  
   
   
       29 . An intervertebral disk prosthesis having a convexly tapered distal end, a convexly tapered proximal end, an anterior side and a posterior side, the intervertebral disk prosthesis comprising: 
 an upper part including a convexly-shaped and rounded top, a bottom having an opening, an outer surface, an inner surface and a socket extending into an interior of the upper part from the opening, the outer surface proximate the top being configured to contact a concave portion of a first vertebra; and    a lower part including a top, a convexly-shaped and rounded bottom, and an outer surface, the outer surface proximate the bottom being configured to contact a concave portion of a second vertebra that is adjacent to the first vertebra, and the outer surface of the lower part proximate the top of the lower part being cooperatively and movably overlapped by the inner surface of the upper part thereby allowing at least two-degrees of freedom of movement,    at least one of the upper part and the lower part further comprising at least one sharpened cone disposed thereon being configured to subside into vertebral bone.    
   
   
       30 . An intervertebral disk prosthesis having a convexly tapered distal end, a convexly tapered proximal end, an anterior side and a posterior side, the intervertebral disk prosthesis comprising: 
 an upper part including a convexly-shaped and rounded top, a bottom having an opening, an outer surface, an inner surface and a socket extending into an interior of the upper part from the opening, the outer surface proximate the top being configured to contact a concave portion of a first vertebra; and    a lower part including a top, a convexly-shaped and rounded bottom, and an outer surface, the outer surface proximate the bottom being configured to contact a concave portion of a second vertebra that is adjacent to the first vertebra, and the outer surface of the lower part proximate the top of the lower part being cooperatively and movably overlapped by the inner surface of the upper part thereby allowing at least two-degrees of freedom of movement,    at least one of the upper part and the lower part further comprising at least one arch having a partially sharpened edge spanning the outer surface proximate the top and the outer surface proximate the bottom, respectively.