A clamping body for a pedicle screw assembly has an axial passage extending axially between first and second end portions thereof. The spine rod-receiving channel extends through the first end portion in a traverse direction with respect to the axial passage thereby forming upstanding leg portions of the clamping body and closed end portion of the spine rod-receiving channel. A material thickness reducing relief is provided in an outer surface of each one of the upstanding leg portions at a location between the closed end portion of the spine rod receiving channel and the first end portion of the clamping body whereby the a partial segment of the upstanding leg portions are frangibly detachable. A bridge member is frangibly connected between the upstanding leg portions at the first end portion of the clamping body. The bridge member spans across the spine rod-receiving channel.