The disclosed subject matter relates a medical instrument (100) having a rotational drive mechanism that can be integrated into a variety of medical devices, including a tool used as an external retaining ring removal tool or as a non-marring bushing inserter, or in a spinal interbody device (1500). The tool can include a knob portion (110) at a proximal end and a drive mechanism at the distal end. The drive mechansim can include a plurality of drive pins (150) that can be actuated to extend outward by rotating the knob portion. The spinal interbody device can include a drive mechanism configured to translate rotational motion into a linear driving motion to cause locking projections (1602) to move into engagement with vertebrae.
