Augment element for prosthesis, in particular for knee prosthesis

Abstract

An augment element for tibial applications in a knee prosthesis. The augment element comprises a metal body of a substantially truncated conical shape configured to be inserted into a bone extremity and having an outer surface comprising a metal trabecular surface The the metal body is hollow with an axial through-cavity defining a plurality of substantially annular transversal sections. The metal body is inclined in a direction of inclination, so as to define at least one eccentricity between a first transversal section at a first end of the axial through-cavity and a second transversal section at a second end of the axial through-cavity The first transversal section at the first end is larger in size than the second transversal section at the second end. The metal body comprises lateral walls having respective curved and concave shapes with respect to the outside of the metal body, to replicate a medial/side and rear bone anatomy.

1 . An augment element for tibial applications in a knee prosthesis, said augment element comprising a metal body of a substantially truncated conical shape configured to be inserted into a bone extremity and having an outer surface comprising a metal trabecular surface, said metal body being hollow with an axial through-cavity defining a plurality of substantially annular transversal sections, wherein said metal body is inclined in a direction of inclination, so as to define at least one eccentricity between a first transversal section at a first end of said axial through-cavity and a second transversal section at a second end of said axial through-cavity, wherein said first transversal section at said first end is larger in size than said second transversal section at said second end, and wherein said metal body comprises lateral walls having respective curved and concave shapes with respect to the outside of said metal body, to replicate a medial/side and rear bone anatomy. 
     
     
         2 . The augment element according to  claim 1 , wherein said axial cavity has a longitudinal axis inclined in said direction of inclination with respect to a vertical axis of said metal body, said vertical axis being perpendicular to one of said first or second transversal section. 
     
     
         3 . The augment element according to  claim 2 , wherein said metal body comprises a frontal wall extended towards said direction of inclination and further comprises a rear wall opposite said frontal wall and extended away from said direction of inclination, wherein said frontal wall has an inclination with respect to said vertical axis that is less than an inclination of said rear wall. 
     
     
         4 . The augment element according to  claim 3 , wherein an inclination of said frontal wall with respect to said vertical axis is comprised between 0° and 5°. 
     
     
         5 . (canceled) 
     
     
         6 . The augment element according to  claim 4 , wherein for tibial applications an inclination of said rear wall with respect to said vertical axis is comprised between 15° and 20°. 
     
     
         7 . The augment element according to  claim 6 , wherein said rear wall further has a curved and concave shape with respect to the outside of said metal body, to replicate a tibial bone rear anatomy. 
     
     
         8 . The augment element according to  claim 1 , further comprising a plurality of through-slits in said metal body, open from said first end up to an intermediate portion on said metal body, wherein said plurality of through-slits is configured for a radial compression of said metal body, locally reducing a circumference of said substantially annular transversal sections during insertion of said augment element, and increasing a press-fit towards a bone portion. 
     
     
         9 . (canceled) 
     
     
         10 . The augment element according to  claim 8 , wherein for tibial applications said first transversal section is larger in size with respect to said second transversal section, so as to facilitate an insertion of said metal body into said tibial bone extremity. 
     
     
         11 . The augment element according to  claim 8 , wherein each of said plurality of through-slits ends in a respective enlarged circular hole beside to said intermediate portion, said enlarged circular hole being configured to improve a localized mechanical resistance of said metal body . 
     
     
         12 - 15 . (canceled) 
     
     
         16 . The augment element according to  claim 1 , further comprising a pair of cutouts arranged at said lateral walls and open from said first end up to an intermediate portion on said metal body. 
     
     
         17 . The augment element according to  claim 1 , wherein said first transversal section is bilobed annular and said second transversal section is circular annular, said outer surface of said metal body being tapered between said first transversal section and said second transversal section. 
     
     
         18 . The augment element according to  claim 1 , wherein said metal body comprises a smooth edge on said outer surface surrounding said metal trabecular surface. 
     
     
         19 . The augment element according to  claim 1 , wherein said metal trabecular surface is made in one piece and seamlessly with said metal body. 
     
     
         20 . The ]augment element according to  claim 1 , wherein said metal body comprises walls having a substantially constant thickness.