High Tibial Osteotomy With a Kinematic Navigation System

Abstract

Summary In the recent past, joint saving operations were thrust into the background, compared with joint arthroplasty, including the high tibial osteotomy which, more and more has been displaced by unicondylar knee prostheses. This seems unjustified, when looking to two long-term studies of 200 patients each after high tibial osteotomy performed by our hospital. In 96%/75% an implantation of a knee endoprosthesis could be avoided until 10 years postoperative. The complication rate all in all was low, but wrong sawing directions, incomplete osteotomies, and over- or under-corrections could be detected. With the help of the navigation-system OrthoPilot (Aesculap, Tuttlingen) we have further developed the traditional operative technique. With this technical support we hope to improve the intraoperative realization of the preoperative planning, and to standardize the quality of the operation. When using a navigation system, the data from the conventionally done preoperative planning were put into the computer. An intraoperative reference marker (also called rigid body) was fixed into the tibia with a screw. This rigid body is measured optoelectronically as well as further reference points at the bone. In doing this, the navigation system was able to detect the exact position of the leg. After preparation of the bone a cutting jig and the saw itself could be positioned exactly with the help of the navigation system so that the first horizontal osteotomy and the second osteotomy could be performed. During the sawing procedure, the surgeon was informed about the sawing angle and the distance between the tip of the saw and the medial cortical bone on the monitor. The technology could be used for closing wedge and opening wedge operations. We now use this system for 1 year and have very positive experiences. Postoperative x-rays showed that we always got the exact correction angle compared with the preoperative planning. We could not detect any complications.