Hypothesis #1 The PediGuardTM will be more accurate for pedicle screw placement as compared to other standard manual techniques of similar size of pedicle screw insertion. At least 90% of screws placed with the PediGuardTM will be positioned correctly in the pedicle (defined as less than 2 mm breach by CT scan). In contrast, only 80% of screws using manual placement will be positioned correctly in the pedicle.