Abstract: This disclosure relates generally to surgical instruments used to deliver locking or set screws to secure a rod or spinal fixation element relative to an implanted bone anchor or other spinal fixation construct during spine surgery. In one embodiment, the inserter instrument can include an inner driver shaft, a ratcheted outer sleeve, and a handle configured to receive the shafts therein. The inner driver shaft can receive a plurality of set screws on a distal end thereof. A side latch, pawl, or button can engage with the ratcheted outer sleeve to facilitate step-wise advancement of the sleeve relative to the driver shaft for set screw delivery. Step-wise advancement can be controlled using another button that causes movement of the side latch.

Abstract: An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.

Abstract: An example apparatus includes a gear comprising a gear hub; a swing-arm rotationally engaged with the gear hub; and a spring circumferentially engaged with the gear hub and the swing-arm to apply a radial clamping force between the swing-arm and the gear hub. Torque is frictionally coupled from the gear hub to the swing-arm to lock a capped print head assembly (PHA) in a non-printing location.