2010 年 12 巻 4 号 p. 511-518
In these days, external fixation is widely used for femoral fractures because of less-invasiveness of surgical exposure. It requires surgical staff their X-ray exposure by fluoroscopy for aligning bone fragments and fixing the bones by a multi-joint external fixator. A surgical navigation system is often employed to reduce the amount of X-ray exposure by indicating intuitive information for surgical tool guidance. Additionally, it can lead high accuracy and time saving for surgeries. Nakajima et a1.4) have been proposed a laser navigation method for guiding surgical tool position and orientation. Two laser-beam planes are directly emitted into the surgical field, and the entry point is appeared as the cross-sectional point of two laser-beam lines on the patient's skin and the orientation is shown as two parallel laser-beam lines on the side face of the surgical tool. The accuracy was 1 mm for translation and 1 degree for rotation. The feasibility to apply it to percutaneous surgeries has been predicted in his paper, however it have not been evaluated. Therefore, we evaluate the accuracy of the laser guidance method for percutaneous surgeries in our preliminary experiments and validate the feasibility to apply it to the percutaneous insertion of a surgical pin which uses for external fixation of fractured bones in our phantom tests. We also validate the feasibility of the template surgeries by using a joint-less external fixator for bones. The results show the tool guiding accuracy of 1.39 mm and 1.03 degrees in the condition of percutaneous surgeries and the accuracy of 2.74 mm and 3.28 degrees for bone alignment in the template fracture reduction surgeries.
