In Brief:
Monoaxial, uniaxial, polyaxial, and multiple-degrees-of-freedom postloading (6DOF) pedicle screws were compared through instrumentation simulations. Deformity corrections were close. In terms of lowering adverse bone-screw forces and accommodating screw malalignment, 6DOF pedicle screws had the best performance followed by polyaxial, uniaxial, and then the monoaxial pedicle screws.