Methods of surgically preparing a patients tibia are disclosed. Some methods include positioning a guide tower on a surgically-prepared proximal surface above an opening of a medullary canal of the patients tibia, attaching a stem trial to a lower end of an offset tool that is sized to be received in the guide tower, and advancing the stem trial through the guide tower and the surgically-prepared proximal surface into the medullary canal. The method may include moving the guide tower to a desired offset orientation on the surgically-prepared proximal surface and advancing a reamer through the guide tower into the medullary canal. The method may also include positioning a tibial base trial on the surgically-prepared proximal surface based on the desired offset orientation.
