LAUSR

During minimally-invasive long-construct posterior instrumentation, it may be challenging to contour and place the rod as the screw heads are not visualized. To overcome this, we utilized the image data merging (IDM) facility of our spinal navigation system to visualize a coherent whole image of the construct throughout the procedure. Here, we describe this technique that was used for a patient in whom L1–L5 posterior instrumentation was performed. Using an IDM facility, screws are color coded and after placement, the final image is saved. Saved images of all previous screws are displayed and observed while placing the subsequent screws. Therefore, the entry point, depth, and mediolateral alignment of subsequent screws can be adjusted to fall in line with previous screws such that the rod can be placed without hassle. Moreover, final adjustments to the construct are kept to a minimum. The possibility of screw pullout due to force engaging the rod on poorly aligned screws is thus avoided.