Multi-mode torque drivers employing anti-backdrive units for managing pedicle screw attachments with vertebrae, and related systems and methods

A method for managing an attachment of a pedicle screw with a vertebra, comprising:

• transmitting, with an output element of an anti-backdrive unit disposed within an inner space of a handle body of a torque driver, a system torque from the output element to a pedicle screw, wherein the system torque comprises one of a manual torque and a motorized torque, and the handle body extending along an output rotational axis from a first end to a second end, the handle body including an inner surface forming the inner space connecting at least one motor control port to an output opening at the second end;
• generating, with a motor assembly disposed within the inner space, the motorized torque at an output interface of the motor assembly, wherein the motor assembly is coupled to the anti-backdrive unit, wherein the anti-backdrive unit includes the output element disposed through the output opening, at least one locking element, and a housing portion statically coupled to the second end of the handle body;
• upon receiving the motorized torque with the output element of the anti-backdrive unit from the output interface of the motor assembly as the system torque, the output element rotates and the output interface of the motor assembly abuts against the at least one locking element to move the at least one locking element along an inner circumferential surface of the housing portion, wherein the at least one locking element, the output element, and the output interface commonly rotate about the output rotational axis;
• and
• upon applying the manual torque to the first end of the handle body with a single hand of a user while the output element is coupled to the pedicle screw and the output element is free from the motorized torque, then the manual torque moves the handle body relative to the output element until the at least one locking element abuts against both the inner circumferential surface of the housing portion and a non-concentric external surface of the output element to create a mechanical interference which automatically locks the output element relative to the handle body and transmits the manual torque from the handle body to the output element as the system torque.