e+ Blended to move orthopedic technology forward
An appropriately cross- linked polyethylene material, e-plus, a knees- specific formula, is blended with vitamin E and formulated to reduce long-term wear.
Re-Melting Not Required
In the case of most highly cross-linked polyethylene, an anneal or re-melt step occurs following cross-linking to link free radicals (created by the irradiation). Annealing or polyethylene can reduce mechanical strength properties.
Vitamin E neutralizes the negative effects of free radicals, an anneal or re-melt step is rendered unnecessary.
In a material yield strength test, compression molded samples and e-plus performed statistically the same, while a highly cross linked re-melted sample exhibited a 12% drop in yield strength.
Vitamin E is blended right into the resin, assuring complete homogeneous distribution. Scatter electron microscope (SEM) and polarized light microscopy from freeze fracture specimen show that e- plus has equivalent consolidation as conventional compression molded . Also Vitamin E, a non-irritant is the most effective naturally occurring anti-oxidant in the human body.
The impact of oxygen exposure to e-plus sample was evaluated in accelerated aging tests. Un-aged and aged e-plus samples yielded the same results during yield strength testing.
Impact testing for the aged e-plus sample actually revealed slightly better results than the un-aged sample, indicating that oxygen has no negative impact on e-plus