A system for registering an orthopedic implant in a computer assisted navigation
system. The system includes a plurality of differently sized implants which may
be the femoral component or hip stem of a prosthetic hip joint. A registration
device is engageable with each of the implants in a predefined relative position.
The registration device also includes at least one reference element registerable
in the computer assisted navigation system. A second reference structure also having
at least one reference element registerable in the computer assisted navigation
system is detachably secured to the implant. The relative positions of the reference
elements located on the registration device and second reference structure differs
for each of the plurality of implants and thereby allows the navigation system
to determine the nominal size of the implant. The relative position and orientation
of the implant relative to the second structure can also be calibrated using the
registration device.
