Fig. 1From: Posterior atlantoaxial internal fixation using Harms technique assisted by 3D-based navigation robot for treatment of atlantoaxial instabilityGuiding pin placement. The guiding cannula was placed onto the end of the robotic arm. Once the accuracy of guidance was less than 0.5 mm and became steady, a K-wire was drilled into the vertebrae along the guiding cannula to an optimal depthBack to article page