Abstract: A universal pair of pedicle screw-mounted retractor blades and locking shims configured for mounting over and locking onto the tower or extended top threaded post of a pair of adjacent pedicle screws pre-positioned in adjacent vertebrae. Each cylindrical retractor blade body has a proximal flange with an inverted post extending distally, configured for attachment to a handle or arm of a ratcheting retractor. The L-shaped locking shim is removably positioned along a grooved slot within the retractor blade body and temporarily locked into place within the tulip portion of the pedicle screw using a set screw.