An apparatus for reaming a patella includes a clamp for securing the patella and a reamer. The orientation piece comprises a housing with standard optical interfaces to allow it to be inserted between the telescope focusing mechanism and the eyepiece. Patient impedance measurement system comprising patient signal generator and patient signal receiver. One or more layers of donated skin are attached to the patient’s skin covering the bare region. The output terminal is also coupled to an input terminal of a socket which is structured to hold the IC-chip.