The invention relates to an expandable acetabular cup (46) which is
designed to eliminate the difficulties associated with positioning in the
acetabulum of the patient. The inventive device comprises a hemispherical
acetabular cup (46) which is partially slotted at six points to
facilitate the expansion of a core with conical fitting. The expandable
acetabular cup (46) is designed such that it can be introduced freely, or
with slight pressure, into a preformed bone cavity. The conical core (16)
is designed to be fixed to a guide/impacteur graduated in degrees to
maximize the desired position. The implantation is performed gradually.
The inclination and anteversion can be checked at all times during the
implantation. The retaining mechanism of the guide/impacteur can be used
to remove the conical core (16) to re-position the acetabular cup (46) if
necessary. The expandable acetabular cup (46) can receive a conical
auto-blocking core (85A, 85C) or, according to the patient' condition, a
conical core (16) and a supporting auto-blocking ring (26), preferably
pre-assembled to facilitate the chirgien's task. The device is secured in
final position thereof using the thongs (86A, 96C) of the conical core
(85A, 85C), which are disposed in the ribs (20) of a compressed
expandable acetabular cup (46) in the acetabulum of the patient. It is
recommended to use a femoral head (36) whose diameter is a function of
the exterior diameter of the expandable acetabular cup, to therefore
obtain the optimal thickness of the conical core (16) and to conserve the
required thickness of the acetabular cup (46).
