Percutaneous access to the vertebral bodies: a video and fluoroscopic overview of access techniques for trans-, extra-, and infrapedicular approaches.

OBJECTIVE: With increasing popularity of percutaneous spinal access for minimally invasive spinal neurosurgery, the treatment paradigm has shifted from open approaches to vertebroplasty or kyphoplasty for degenerative spinal disease and vertebral compression fractures. Addressing the challenges of this shift, we integrate the fluoroscopic studies of these percutaneous approaches with the three-dimensional surgical anatomy. Step-by-step techniques are illustrated in video demonstrations that highlight the nuances of effective percutaneous access during spinal surgeries for vertebral compression fractures and pedicle screw fixation.
METHODS: Imaging guidelines, approach planning, surgical techniques, and relevant anatomical features are noted for the transpedicular, lumbar extrapedicular, and thoracic extra- and infrapedicular approaches. Video clips and accompanying fluoroscopic images highlight the critical steps. Subtle refinements unique to each percutaneous access are presented related to skin incision, needle trajectory, and cement deposition.
RESULTS: With the transpedicular approach (popular technique for vertebroplasty and pedicle screw placement), safe access requires accurate interpretation of the fluoroscopic anatomy, specifically identification of the target vertebral body in true anterior-posterior and lateral planes. The transpedicular trajectory uses the slight inferior and medial orientation of the pedicle followed anteriorly. The lumbar extrapedicular approach uses an oblique trajectory anterior to the transverse process at the level of the pedicles. A thoracic approach uses the potential space between the rib head, transverse process, and pedicle. The infrapedicular approach, which allows greater flexibility in its medial angulation but at the expense of the bony confines of the thoracic extrapedicular approach, takes advantage of the narrow-waisted thoracic laminae.
CONCLUSIONS: With an appreciation for the standard anatomical landmarks, fluoroscopic views, and avenues of approach, percutaneous access techniques can be safely and effectively applied to many spinal procedures.