How close does an uncemented hip stem match the final rasp position?

During total hip arthroplasty the final clinical position of the cementless CLS stem (Centerpulse) is not always identical to the position of the final rasp with which a successful trial reduction was performed. Therefore, the rasp-stem correspondence of CLS system (Centerpulse) was investigated in a laboratory study and compared to the CBC-T system (Mathys). Both systems showed an average rasp-stem mismatch below 2 mm in three orthogonal directions. It was found that this mismatch related to geometric differences at the corners between rasp and stem. The measured mismatch is not expected to have adverse clinical consequences.