The Zimmer NexGen Trabecular
Metal Material Primary Patella—a porous patella. A biomaterial
structurally similar to cancellous bone, Trabecular Metal
Material has up to 80% porosity and physical and mechanical properties
very similar to bone. No competitive product on the market today
offers a material that compares to it in these respects.
The Zimmer NexGen Trabecular Metal Material
Primary Patella mimics the shape of the NexGen Patellar
Groove in mid-to-deep flexion. This optimizes the patello-femoral
contact area, where stresses on the patella are the highest. In
addition, the NexGen Primary Porous Patella possesses a metal
backing with low stiffness, which may further minimize stresses.
The Monoblock Trabecular Metal Patella is a one-piece
construct. It retains the articular geometry of the current
NexGen All-Poly Component and therefore is compatible with
all NexGen Femoral Components. The base is manufactured from
Trabecular Metal Material and then polyethylene is directly
compression molded from powder into the pores of the Trabecular
Metal, resulting in a 1-piece monoblock construct.
The direct compression molding of the poly into the pores of the
Trabecular Metal Material base minimizes the potential for
the poly disassociating from the Trabecular Metal Material
base. The weakest link of this construct is the actual shear strength
of the poly itself.
Trabecular Metal Material simulates bone like no other
prosthetic material. That's because it is designed to replicate the
shape, the cellular structure, the elasticity, and the weight-bearing
characteristics of bone. It's a unique, highly porous,
three-dimensional biomaterial, not a coating. Trabecular Metal
Material unites strength with excellent biocompatibility. It has
up to 80% porosity, but retains physical and mechanical properties
that resemble bone more closely than other porous materials. Thus, it
allows significant bone and soft tissue ingrowth.