Navigation systems aid in achieving precision and accuracy of surgical steps. Conventional techniques fail to achieve optimal correction in more than 20% of patients undergoing high tibial osteotomy, which is sensitive to the accuracy of limb axis correction. A computer navigation system with dedicated software has been developed to allow the leg axis to be navigated intraoperatively, and the desired correction can be obtained with a corrective device of the appropriate height. Unicompartmental knee replacement also is sensitive to the accuracy of component placement. Standard navigation software has been modified to allow better accuracy when using a minimally invasive surgical approach. Revision total knee replacement is a challenging procedure because most of the standard bony and ligamentous landmarks are lost during the initial implantation. Using the standard navigation technique allows easier restoration of the joint line, adequate limb axis correction, and improved ligamentous stability than can be achieved using a conventional technique. However, standard software does not allow navigation of the stem extensions, which can lead to significant malpositioning of the prosthetic components. Specific software is currently being developed to address this issue.