A surgical instrument and/or method of using a surgical instrument during spinal surgery. The surgical instrument may find particular applicability to spinal implants for the intervertebral disc space that require relative rotation between parts in order to change the height of the implant. The instrument includes a knob that rotatable and selectively longitudinally moveable relative to a handle section. In a forward position, turning the knob turns a drive shaft that is coupled to the rotatable actuator of the implant, and causes the implant to expand or retract depending on the direction of rotation. In the rearward position, the drive shaft is retracted, and turning the knob turns a coupling shaft, distinct from the drive shaft, for decoupling the implant from the instrument.