Use starting point of screw as per common technique. Fluoroscopic confirmation of sagittal angle is recommended. Once the starting point is opened using burr or awl, the trajectory of the instrument on the sagittal is recorded, and the axial trajectory from the preoperative templating is combined with the sagittal trajectory to advance the initial pedicle probe.
Technique tip: RJB is internally oriented to gravity only. It is critical that the flat portion of the RJB module remain parallel to the craniocaudal axis of the patient to maintain consistent measurements. If there is coronal scoliosis/angulation, the flat portion of the RJB module should be facing the opposite pedicle. It is recommended that the probe be advanced, stopped, orientation checked then sagittal and axial angles obtained, then the process repeated until the depth desired is reached.
Technique Tip: Locate and burr a starting hole on both sides while using the fluoroscopy. This will enable the surgeon to immediately place both screws at that level, rather than place one screw and bring in the fluoroscopy machine for the starting point of the other side.
Straight or curved Lenke probes are usable. Confirm the trajectory of the pedicle screw insertion screwdriver matches that of the Lenke probe's trajectory as the screw is being advanced.
The contralateral side can immediately be done with maintaining the same sagittal and axial angle.
Determine the new sagittal angle at each new level to be instrumented.