Purpose: The aim of this work was the evaluation of a navigated and power controlled milling system for spine surgery (navigated control spine). The navigation is based on a set of intraoperatively taken fluoroscopic images from different angles. A manually planned workspace limits the power of the mill and assures a higher automatisation degree than any other established navigation system for spine surgery.
Methods: Both a technical study in workspace planning from fluoroscopic images and a milling study on a spine phantom were performed with participants with different level of knowledge of spinal surgery.
Results: In the region of interest the workspace planning could be performed with a maximum excess of 1.40 mm for surgeons. In the study performing the milling of a standardised workspace the remnant bone after milling had a mean difference from the planned workspace margin of 1.96-2.12 mm in the region of most interest. Accurate handling of the mill still required a certain level of medical knowledge and experience. In both studies the time needed for application of the system proved acceptable for clinical purposes.
Discussion: This concept of navigated and power controlled spinal surgery has proven feasible in an experimental study. This navigation system seems therefore promising for clinical application.