Surgical instrument

An assembly may include a medical device, an introducer sheath connected to the medical device, and a surgical instrument. The medical device may include a cage, a screw, a bone screw, a pedicle screw, and/or an implant. The introducer sheath may be connected to the medical device at a pre-determined breaking point. The introducer sheath may be hollow. The surgical instrument may comprise an extension. The extension may be configured to be inserted into the introducer sheath. The surgical instrument may comprise a pin. The surgical instrument may comprise a separator. The separator may be configured for breaking off the introducer sheath from the medical device at the pre-determined breaking point by rotating the extension about a longitudinal axis of the extension. A part of the medical device may be configured serve as a counter bearing to the rotation by accommodating the pin during rotation.