Accurate placement of bone tunnels in reconstruction of the anterior cruciate ligament -: a contribution of computer-assisted navigation

Rupture of the anterior cruciate ligament (ACL) is one of the most frequent injuries to the knee joint in the young. ACL repair is a major orthopedic procedure most often performed in the younger adult population. Early stabilization of the knee joint by ACL reconstruction also decreases the risk of injury to other important structures. At ACL reconstruction, the biggest problem is usually the exact placement of drilled tunnels. This significantly affects the outcome of surgery, i.e., range of motion, knee joint stability, reaction of the synovium in the knee, pain, impingement and potential graft failure with lesion development. However, 70 % of ACL reconstructions are carried out by orthopedic surgeons whose experience is limited to less than 20 ACL repair procedures in a year! Arthroscopy does not allow the surgeon to gain a complete 3D view of important anatomical structures, particularly in the anteroposterior direction. Computer-assisted navigation systems should aid in minimizing these problems. First reports on the use of computer-assisted navigation in ACL reconstruction, which have already been published in the international literature, have provided clear evidence that more exact bone tunnel placement can be achieved with navigation than with the use of conventional techniques. In addition, kinematic navigation enables us to measure anteroposterior and rotational knee stability, isometry, impingement and the angles of bone tunnel placement. It permits a choice from various types of graft. Last but not least, kinematic navigation provides a tool for recording surgery outcomes without a necessity to use further examination methods. Its drawbacks, namely, the learning curve, additional fixation of navigation probes to the femur and tibia and slightly longer operative time, should be considered in the context of presumed long-term benefits for the patient.