Could it be as simple as FDA is worried that without some amount of bone, there will be subsistence or breakage longterm? Essentially believing that insufficient amount of bone adheres to the implant.
SiNi encourages bone to grow onto it meaning bone should completely encase the implant as well as grow through CsC pores. Why then is a small chunk of bone needed in the middle? What structural benefit is achieved that can't be achieved with multiple bone shoots growing through and on CsC?
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