Abstract:

BACKGROUND: Pedicle screw fixation, as a commonly used technique, can provide super bio-mechanical effect. Various guiding methods have been employed including computer aided surgery navigation system (CASNS). However, none of them can ensure absolute accuracy, and malpositioning may result in disastrous consequence.
OBJECTIVE: To perform pedicle guide-wire placement with pedicle standard axis view (PSAV) using Frameless Spinal Navigation Surgery Robot (FSNSR) so as to explore a high accurate and easily tackled transpedicular placement technique.
METHODS: A total of 6 human lumbar spines vertebras (L1 to L5) were used. All specimens underwent pre-intervention CT scanning, and the angle (α) between pedicle centre axis and vertebra body sagittal plane (m plane) and the angle (β) between the axis and superior surface of vertebra body (s plane) were measured, respectively. During the operation, a standard posterior-anterior fluoroscopic image of target vertebra was obtained; the PSAV was acquired via C-arm rotation according to α and β; the guide-wire was inserted into the centre of approximate circular projection of pedicle by teleoperating FSNSR. After surgery, each vertebra underwent vertebra body axial and lateral radiographs as well as CT scans to assess guide-wire trajectory and excursion between post/preoperative α and β.
RESULTS AND CONCLUSION: A total of 60 guide-wires were successfully inserted. All guide-wires were confirmed in the core of the pedicle by axial and lateral X-ray, as well as CT scanning. None of the guide-wire trajectory was found to contract or perforate the pedicle wall. FSNSR guide-wire placement with PSAV is a novel, safe and accurate transpedicular placement technique, which can reduce or prevent radiation exposure.