Acetabular cup positioning device

An acetabular cup trialing system comprising:

• a trial acetabular cup having a body comprising an outer surface, a part-spherical inner surface and a rim extending between the inner and outer surface, the rim comprising a plurality of spaced resiliently deflectable rim members each connected at a first end to the body outer surface, the part-spherical inner surface comprising a plurality of spaced resiliently deflectable bearing members each having an arcuate inner surface forming part of the body part-spherical inner surface, the deflectable bearing members having a first end deflectable towards the body outer surface;
• upon deflection, one of the plurality of deflectable rim members is capable of contacting the first end of a corresponding one of the plurality of deflectable bearing members and moving the bearing member towards the body outer surface;
• and
• an electrical contact sensing device connected to a power source mounted on the body intermediate the outer surface thereof and the deflectable bearing member, the deflectable bearing members are configured to contact the electric contact sensing device upon deflection towards the body outer surface, the contact sensing device having a variable output depending on which of the bearing members contact the electrical contact sensing device.

A acetabular trialing system comprising:

• a hip femoral component;
• a trial acetabular cup having a body comprising an outer surface, a part-spherical inner defining cavity and a rim extending between the inner and outer surface, the rim comprising a plurality of spaced resiliently deflectable rim members having a first end connected to the body and a second free end, the part-spherical inner surface comprising a plurality of spaced resiliently deflectable bearing members, the resiliently deflectable bearing members spaced by slots extending from a base portion of the cavity and having free ends adjacent the second end of the rim members, each bearing member having an arcuate inner surface forming part of the body part-spherical inner surface, the plurality of deflectable rim members are deflectable towards the body inner cavity by contact with the femoral component, upon deflection rim members are capable of contacting one of the plurality of deflectable bearing members and moving the bearing member towards the body outer surface;
• and
• an electrical contact sensing element connected to a power source mounted on the body intermediate the outer surface thereof and the deflectable bearing member, deflection of the resiliently deflected bearing member towards the body outer surface by the femoral component contact with the deflectable rim-member is configured to cause a surface of the bearing member to contacts the electrical contact sensing element.