or equal to 3 mm but greater than 2 mm to guarantee sufficient mechanical strength it is seen more particularly in fig4 and 8 that the insertion shell 1 includes a peripheral receiving structure 8 that projects beyond the receiving face 6 of the fixed final joint insert 4 inserted into the insertion shell 1 the peripheral receiving structure 8 constitutes a short annular extension of the wall of the insertion shell 1 with in this embodiment an interior annular receiving face 10 shown in dashed line in fig4 and 8 extending from and continuous with the concave receiving face 3 of the insertion shell 1 in the embodiments of fig1 to 9 to enable the fixing of an impacter a placement and orientation insert 11 is provided removably fixed to the peripheral receiving structure 8 of the insertion shell 1 the placement and orientation insert 11 can thus be fastened to the insertion shell 1 in the presence of the ceramic fixed final joint insert 4 engaged in the insertion shell 1 fig4 5 6 7 and 9 and can be separated from the insertion shell 1 as shown better in fig8 after impaction of the cotyle into the cotyle cavity of the patient the placement and.