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There
were 7 cases of explant within the first 3 years after the
operation, 10 between 4 and 6 years, 8 between 7 and 9 years
and 5 after 10 years or more. All
explants were studied under the microscope, first of all
over the whole convexity, for friction signs, then in the
unpolished-looking tightening area.
  Microscope
study
The
convexity shows the marks left by the machining tool.
 
Enlarged machining marks
(LNE)
The
tightening area shows grooves in the impaction axis, small
enlargement in our labs, strong enlargement at the
Laboratoire National d'Essai, LNE.
These
grooves were made when the cup was impacted, with the rough
internal surface allows for rotation stabilisation.
Tightening grooves : enlarged 25
times
Tightening grooves found by the LNE :
enlarged 300 times
The slot is clearly visible after 11
years and 9 months
Conclusion
Nowhere
on any explant did we observe that the marks disappears,
which rules out friction on the insert convexity.
Observing the area opposite the slot shows that without
clamping at that place, the machining marks are still there,
even after 10 years. The clear outline in strong enlargement
images points to the absence of micromobility.
No
micromobility
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