The pedicle screw extension system may include a removable cannulated extension provided to a pedicle screw tulip head. The cannulated extension may permit percutaneous implantation of pedicle screws followed by rod placement that may be guided by slots running along the length of the extension. The cannulation may allow for passage and attachment of secondary instruments, such as for example: a screw driving device, a rod measuring device, and a set screw driving device. The screw extension may also include secondary device attachment features allowing the rod to be pushed down in a screw tulip head and for extension removal as needed.