Intervertebral cage for arthrodesis

Abstract

Disclosed is an intervertebral cage for arthrodesis, where at least part of an upper and/or lower contact zone is made of a porous titanium material with a thickness of at least 1 mm and with a porosity of between 50% and 90%, where the diameter of the pores (DP) is between 200 μm and 1 mm, and where the pores have an aperiodic distribution.

1 . An intervertebral cage ( 1 ,  2 ) for arthrodesis, composed of:
 an upper face ( 10 ) and a lower face ( 20 ) comprising, respectively, an upper contact zone ( 11 ) and a lower contact zone which are intended to contact, respectively, a first vertebra and a second vertebra consecutive to the first vertebra, each of these faces comprising an orifice ( 15 );   a part ( 30 ) connecting the upper face ( 10 ) and the lower face ( 20 ), with continuity of material, and configured to form a cavity ( 35 ) intended to receive a bone graft, where said cavity opens out at the orifices of each of the upper and lower faces;   wherein at least part of the upper and/or lower contact zone is made of a porous titanium material with a thickness of at least 1 mm and with a porosity of between 50% and 90%, where the diameter of the pores (DP) is between 200 μm and 1 mm, and where the pores have an aperiodic distribution.   
     
     
         2 . The intervertebral cage as claimed in  claim 1 , wherein the porous titanium material is composed of at least 95% by weight of metallic titanium, for example at least 99% by weight of metallic titanium. 
     
     
         3 . The intervertebral cage as claimed in  claim 1 , wherein the porosity of the porous titanium material is between 60% and 80%. 
     
     
         4 . The intervertebral cage as claimed in  claim 1 , wherein the diameter of the pores of the porous titanium material is between 500 μm and 900 μm, for example between 700 μm and 800 μm. 
     
     
         5 . The intervertebral cage as claimed in  claim 1 , wherein the part of the upper and/or lower contact zone made of a porous titanium material occupies a surface area of greater than or equal to 30% of the surface area of the upper and/or lower contact zone, respectively. 
     
     
         6 . The intervertebral cage as claimed in  claim 1 , wherein the porous titanium material is composed of a plurality of filaments of dense titanium material which are interlaced and in part join each other, where the pores are formed by the space between these filaments ( 100 ), and where the filaments are of a substantially circular cross section with a diameter DF of between 50 and 500 μm, for example between 100 and 300 μm. 
     
     
         7 . The intervertebral cage as claimed in  claim 1 , wherein the part connecting with upper face to the lower face, with continuity of material, comprises an opening ( 36 ,  37 ) suitable for receiving a device for gripping said intervertebral cage. 
     
     
         8 . The intervertebral cage as claimed in  claim 1 , wherein the intervertebral cage is elongate, and wherein that the length of the upper face and of the lower face is equal to or greater than twice their width, for example with a length of between 15 mm and 40 mm and a width of between 5 mm and 15 mm. 
     
     
         9 . The intervertebral cage as claimed in  claim 8 , wherein the orifice of the upper face and the orifice of the lower face are elongate, and in that the length of each of the orifices is equal to or greater than twice their width, for example with a length of between 10 mm and 25 mm and a width of between 3 mm and 8 mm. 
     
     
         10 . The intervertebral cage as claimed in  claim 1 , wherein the porous titanium material, with a porosity of between 50% and 90%, where the diameter of the pores is between 200 μm and 1 mm and where the pores have an aperiodic distribution, is produced by additive manufacturing. 
     
     
         11 . The intervertebral cage as claimed in  claim 1 , wherein the intervertebral cage is made of a titanium material of substantially constant chemical composition, and wherein the density of the titanium material differs between at least two parts of the cage. 
     
     
         12 . The intervertebral cage as claimed in  claim 1 , wherein the intervertebral cage is made of one or more biocompatible materials and of the porous titanium material, and where the chemical composition of said one or more biocompatible materials differs from that of the porous titanium material. 
     
     
         13 . The intervertebral cage as claimed in  claim 2 , wherein the porosity of the porous titanium material is between 60% and 80%. 
     
     
         14 . The intervertebral cage as claimed in  claim 2 , wherein the diameter of the pores of the porous titanium material is between 500 μm and 900 μm, for example between 700 μm and 800 μm. 
     
     
         15 . The intervertebral cage as claimed in  claim 3 , wherein the diameter of the pores of the porous titanium material is between 500 μm and 900 μm, for example between 700 μm and 800 μm. 
     
     
         16 . The intervertebral cage as claimed in  claim 2 , wherein the part of the upper and/or lower contact zone made of a porous titanium material occupies a surface area of greater than or equal to 30% of the surface area of the upper and/or lower contact zone, respectively. 
     
     
         17 . The intervertebral cage as claimed in  claim 3 , wherein the part of the upper and/or lower contact zone made of a porous titanium material occupies a surface area of greater than or equal to 30% of the surface area of the upper and/or lower contact zone, respectively. 
     
     
         18 . The intervertebral cage as claimed in  claim 4 , wherein the part of the upper and/or lower contact zone made of a porous titanium material occupies a surface area of greater than or equal to 30% of the surface area of the upper and/or lower contact zone, respectively. 
     
     
         19 . The intervertebral cage as claimed in  claim 2 , wherein the porous titanium material is composed of a plurality of filaments of dense titanium material which are interlaced and in part join each other, where the pores are formed by the space between these filaments ( 100 ), and where the filaments are of a substantially circular cross section with a diameter DF of between 50 and 500 μm, for example between 100 and 300 μm. 
     
     
         20 . The intervertebral cage as claimed in  claim 3 , wherein the porous titanium material is composed of a plurality of filaments of dense titanium material which are interlaced and in part join each other, where the pores are formed by the space between these filaments ( 100 ), and where the filaments are of a substantially circular cross section with a diameter DF of between 50 and 500 μm, for example between 100 and 300 μm.