SlicerIGT pathexplorer

There is a pedicle screw planning extension for Slicer:

It is not listed in the extension manager but you have to download it from here and unzip all files to a folder on your computer. Then start Slicer and in Application settings / Modules, add to “Additional module paths” the directory that contains PedicleScrewSimulator.py.

See also this discussion: How to install pedicle screws simulator extension?.