ORTHOPEDIC IMPLANTS AND METHODS
A prosthesis for replacing a natural articular surface on a bone may have a joint facing side with an articular surface, a bone anchoring side with a bone engagement surface, and a bone engagement pad secured to at least part of the bone engagement surface. The bone engagement pad may have a transverse portion extending transverse to a length of the bone, and one or more protruding portions extending generally perpendicular to the transverse portion. The transverse portion may have a pad bone-facing surface with a first porosity level, and a pad joint-facing surface on an opposite side of the transverse portion from the pad bone-facing surface, with a second, lower porosity level. The bone engagement surface may be formed via a first manufacturing process selected from the group consisting of forging, milling, and casting. The bone engagement pad may be formed via an additive manufacturing process.
1 . A knee implant for replacing a natural articular surface on bone, the knee implant comprising:
a joint facing side comprising an articular surface shaped to replace the natural articular surface, wherein the natural articular surface is one of a natural tibial articular surface and a natural femoral articular surface;
a bone anchoring side comprising a bone engagement surface; and
a bone engagement pad secured to at least part of the bone engagement surface, the bone engagement pad comprising:
a transverse portion extending transverse to a length of the bone, the transverse portion comprising:
a pad bone-facing surface comprising a first porosity level; and
a pad joint-facing surface on an opposite side of the transverse portion from the pad bone-facing surface, the pad joint-facing surface comprising a second porosity level lower than the first porosity level; and
one or more protruding portions extending generally perpendicular to the transverse portion;
wherein:
the bone engagement surface is formed via a first manufacturing process selected from the group consisting of forging, milling, and casting;
the bone engagement pad is formed via a second manufacturing process different from the first manufacturing process; and
the second manufacturing process is an additive manufacturing process.
2 . The knee implant of claim 1 , wherein:
the bone engagement pad extends generally transverse to a length of the bone, and has a thickness, parallel to the length, that is substantially uniform; and
the thickness is within the range of 0.5 mm to 1.5 mm.
3 . The knee implant of claim 1 , wherein:
the bone engagement surface comprises a bone engagement feature extending through an aperture formed in the transverse portion; and
the one or more protruding portions extend from one or more edges of the aperture, alongside one or more surfaces of the bone engagement feature.
4 . A prosthesis for replacing a natural articular surface on bone, the prosthesis comprising:
a joint facing side comprising an articular surface;
a bone anchoring side comprising a bone engagement surface; and
a bone engagement pad secured to at least part of the bone engagement surface, the bone engagement pad comprising:
a pad bone-facing surface comprising a first porosity level; and
a pad joint-facing surface comprising a second porosity level lower than the first porosity level.
5 . The prosthesis of claim 4 , wherein:
the bone engagement surface is formed via a first manufacturing process; and
the bone engagement pad is formed via a second manufacturing process different from the first manufacturing process.
6 . The prosthesis of claim 5 , wherein:
the first manufacturing process is selected from the group consisting of forging, milling, and casting; and
the second manufacturing process is an additive manufacturing process.
7 . The prosthesis of claim 4 , wherein the bone engagement pad has a thickness within the range of 0.5 mm to 1.5 mm.
8 . The prosthesis of claim 4 , wherein:
the bone engagement pad comprises a transverse portion that extends generally transverse to a length of the bone;
the pad bone-facing surface and the pad joint-facing surface are on opposite sides of the bone engagement pad; and
the transverse portion has a thickness, parallel to the length, that is substantially uniform.
9 . The prosthesis of claim 4 , wherein the bone engagement pad comprises:
a transverse portion extending transverse to a length of the bone, wherein the pad bone-facing surface and the pad joint-facing surface are on opposite sides of the transverse portion; and
one or more protruding portions extending generally perpendicular to the transverse portion.
10 . The prosthesis of claim 9 , wherein:
the bone engagement surface comprises a bone engagement feature extending through an aperture formed in the transverse portion; and
the one or more protruding portions extend from one or more edges of the aperture, alongside one or more surfaces of the bone engagement feature.
11 . The prosthesis of claim 4 , wherein:
the bone engagement pad comprises a transverse portion that extends generally transverse to a length of the bone;
the pad bone-facing surface and the pad joint-facing surface are on opposite sides of the bone engagement pad; and
the transverse portion comprises a porosity gradient by which porosity of the transverse portion gradually increases toward the pad bone-facing surface.
12 . The prosthesis of claim 4 , wherein:
the bone engagement pad comprises a transverse portion that extends generally transverse to a length of the bone;
the pad bone-facing surface and the pad joint-facing surface are on opposite sides of the bone engagement pad; and
the transverse portion comprises a low-porosity layer proximate the pad joint-facing surface, by which a porosity of the transverse portion abruptly increases toward the pad bone-facing surface.
13 . The prosthesis of claim 4 , wherein:
the prosthesis comprises a knee implant;
the articular surface is shaped to replace the natural articular surface; and
the natural articular surface is one of a natural tibial surface and a natural femoral articular surface.
14 . A prosthesis for replacing a natural articular surface on bone, the prosthesis comprising:
a joint facing side comprising the articular surface;
a bone anchoring side comprising a bone engagement surface; and
a bone engagement pad secured to at least part of the bone engagement surface, the bone engagement pad comprising:
a transverse portion extending transverse to a length of the bone; and
one or more protruding portions extending generally perpendicular to the transverse portion.
15 . The prosthesis of claim 14 , wherein:
the bone engagement surface is formed via a first manufacturing process; and
the bone engagement pad is formed via a second manufacturing process different from the first manufacturing process.
16 . The prosthesis of claim 15 , wherein:
the first manufacturing process is selected from the group consisting of forging, milling, and casting; and
the second manufacturing process is an additive manufacturing process.
17 . The prosthesis of claim 14 , wherein the bone engagement pad has a thickness within the range of 0.5 mm to 1.5 mm.
18 . The prosthesis of claim 14 , wherein the transverse portion extends generally transverse to a length of the bone, and has a thickness, parallel to the length, that is substantially uniform.
19 . The prosthesis of claim 14 , wherein:
the bone engagement surface comprises a bone engagement feature extending through an aperture formed in the transverse portion; and
the one or more protruding portions extend from one or more edges of the aperture, alongside one or more surfaces of the bone engagement feature.
20 . The prosthesis of claim 14 , wherein:
the prosthesis comprises a knee implant;
the articular surface is shaped to replace the natural articular surface; and
the natural articular surface is one of a natural tibial surface and a natural femoral articular surface.