A medical screwdriver configured to avoid disengaging from a screw during implantation of the screw at a surgical site, the screwdriver including an outer shaft having a housing in which is located a piston and a spring, an inner shaft, and a collar. When the collar is rotated in a first direction the collar is positioned at a first position and the inner shaft is rotationally coupled to the outer shaft. When the collar is rotated in a second direction opposite the first direction, the collar moves to a second position and the inner shaft is unlocked from the outer shaft.
