|
The
very poor results obtained with screwed rings without any
coating, and the excellent results achieved after 15 years
with impacted acetabular cups with a coating, allowing
secondary osteo-integration, confirm the absolute need for
bony adhesion to achieve durable stability.
Sophisticated
coatings such as titanium fibermesh allow bone ongrowth,
i.e. the bone penetrates in the implant, providing durable
stability. The disadvantage is they result in major bone
damage when removed. Titanium sanding provides bone ongrowth
type adhesion, provided the sand blasting is adequate, with
an RA at least equal to 4 µ. The bony
adhesion is slow (a few months) and partial.
The
efficiency of bioactive substances such as hydroxyapatite,
which has been used for 15 years now, in periprosthesis
osteogenesis stimulation has been proved through lab, animal
and human experimentation. The hydroxyapatite provides close
and full bone adhesion in a few weeks, without any fibrous
tissue interference, as shown by the work of
Söballe 21.
The close osteo-integration prevents the migration of
micro-particles usually associated with peri-prosthesis
macrophagous reactions resulting in loosening. This
certainly contributes to the quality of our 15 years +
results with Atlas®.
|
