Preliminary report for navigated MIS TKA with OrthoPilot

摘要

Introduction: The success of TKA depends on several factors, including correct surgical technique and effective operative care. A computer-assisted navigation system could improve the quality of implantation in comparison with the conventional techniques. The author has performed TKA with an infrared navigation system (OrthoPilot, Aesculap, Germany) from October 2004. The surgeon decides, without any limitation, the optimal orientations of the bony resections according to the intra-operatively displayed information, and can at any time switch back to the classical instruments if necessary. The system completely works with intra-operative analysis of the lower limb kinematics, without any additional imaging and preoperative examination. The OrthoPilot could show the value of ligament balance and also allows dependent cut technique. Navigated dependent cut technique could simply improve the issue of ligament balance and stability. Especially, ligament balance and stability are essential to the immediate and long-term clinical success; the use of OrthoPilot could increase the accuracy and reproducibility of these critical components of the operation. MIS instruments have been available from Aesculap Germany in phases. Tibial cutting guide and femoral distal cutting guide were introduced prior to the other instruments. The author has started MIS TKA with navigation from September 2005. Currently, 8 or 9 cm of skin is incised without MIS femoral 4-in-l cutting guide or a femoral component holder. When MIS instruments become completely available, it will allow smaller incisions. The author uses sub-vastus approach to protect the extensor mechanism. Additionally, supra-pattelar pouch is reconstructed at the final closing of the capsule. The aim of this procedure is to acquire smooth patellar tracking throughout the range of motion. In the near future, a complete set of MIS instruments will become available, which allows us to achieve a better MIS than now.