Sliding on cortical shell: Biomechanical characterization of the vertebral cannulation for pedicle screw insertion.

Background: Pedicular screws pull-out has been well studied unlike their insertion. A need for characterizing cannulation before pedicle screw implantation is highlighted in literature and offers promising prospects for future intra-operation instrumentation. A reliable cannulation protocol for ex-vivo testing in swine and cadaver vertebrae is presented in this work to predict extra pedicular perforation.

Change of vertebral orientation, between the supine position and the prone position.

Purpose: Our aim was to assess the change of vertebral orientation, expressed in the sagittal plane, in the transversal plane and in the frontal plane, at each level from T1 to S1 between the supine position (like in in a CT scan) and the prone position lying on bolsters like in an OR.

Methods: Thirty-six patients were selected and included for a total number of one hundred and forty-eight vertebral levels. There were 30 females and 6 males.