Polymer interlock support structure and method of manufacture thereof

An orthopedic implant comprising:

• a polymeric structure;
• a metallic support structure;
• an intermediate layer;
• and
• a porous bone ingrowth layer having a different porosity than the intermediate layer, the intermediate layer being located between and inseparable from the bone ingrowth layer and the support structure,
• wherein the polymeric structure extends through the support structure,
• wherein the intermediate layer has a lesser porosity than the support structure and thereby prevents interdigitation of the polymeric structure across the intermediate layer and into the bone ingrowth layer, and
• wherein the support structure adjoins the bone ingrowth layer.

An orthopedic implant, comprising:

• a porous insert having a first insert portion having a first insert thickness and a second insert portion having a second insert thickness, the porous insert having a porous first layer, an intermediate layer attached to the first layer and having a different porosity than the first layer, and a porous second layer attached to the intermediate layer on a side of the intermediate layer opposite the first layer;
• and
• a non-metallic structure having a first non-metallic portion having a first non-metallic thickness and a second non-metallic portion having a second non-metallic thickness, the first non-metallic portion being attached to the first insert portion and the second non-metallic portion being attached to the second insert portion,
• wherein either one or both of (i) the second insert thickness is different from the first insert thickness and (ii) the second non-metallic thickness is different from the first non-metallic thickness,
• wherein the second layer includes a base and a porous projection, the base having a base thickness and a porous projection, the base having a base thickness and the porous projection extending from the base into the non-metallic structure and having a projection thickness greater than the base thickness,
• wherein the first insert thickness, the second insert thickness, the first non-metallic thickness, the second non-metallic thickness, the base thickness, and the projection thickness are all defined in a same direction,
• wherein the base and the porous projection each include pores into which the nonmetallic structure enters such that the base and the porous projection each interlock with the nonmetallic structure,
• wherein the intermediate layer has a greater density than the second layer and thereby prevents interdigitation of the non-metallic portion from the second layer to the first layer via the intermediate layer, and
• wherein a plane extending through the porous insert intersects the first layer and the second layer and is spaced from the intermediate layer of the porous insert.