Femoral head centre of rotation locating device

A kit for use in comparing the position of a femoral head centre of rotation of a native femoral head and a trial femoral head component, the kit comprising:

• (a) a femoral head centre of rotation locating device comprising:
• an adjustable frame having a frame axis, the frame comprising:
• a central frame portion;
• a first jaw that is linearly moveable relative to the central frame portion along the frame axis and having a first femoral head contacting surface;
• a second jaw that is linearly moveable relative to the central frame portion along the frame axis and having a second femoral head contacting surface, and a gearwheel mounted on the central frame portion, the gear wheel having a centric aperture located substantially equidistant from the first and second femoral head contacting surfaces, the gear wheel being operably connected to each of the first and second moveable jaws by gear teeth provided on a surface of each of the first and second moveable jaws,
• wherein linear movement of the first jaw in a first direction rotates the gear wheel to cause reciprocal linear movement of the second jaw to maintain the centric aperture at a position equidistant from the first and second femoral head contacting surfaces to align the centric aperture with the native head centre of the femur as the first and second femoral head contacting surfaces come into contact with opposite surfaces of the femoral head wherein each of the first and second jaw includes an end wall and a pair of arms extending therefrom, such that the end wall and pair of arms create a U-shape, with the pair of arms being parallel to one another;
• (b) a trochanter marking device comprising:
• a connection element configured for connecting the trochanter marking device to (i) the femoral head centre of rotation of the native femoral head and (ii) a femoral head centre of centre of rotation of a trial femoral head component, such that the trochanter marking device can pivot about each femoral head centre of rotation, and
• a marking aperture dimensioned for receiving a marking tool for marking the position of the marking aperture on the trochanter.