Bone anchor driver and methods

A method for operating a bone anchor driver, comprising:

• rotating a driver to simultaneously rotate a torque limiter and an outer shaft coupled to the driver to thereby drive a first closure mechanism onto a bone anchor, wherein the driver decouples from the outer shaft when a torque being applied to the driver exceeds a first predetermined threshold torque;
• continuing to rotate the driver while the driver is decoupled from the outer shaft to cause the torque limiter to rotate relative to the outer shaft and engage an inner shaft on the driver to thereby couple the driver to the inner shaft;
• and
• continuing to rotate the driver while the driver is coupled to the inner shaft to simultaneously rotate the torque limiter and the inner shaft relative to the outer shaft to thereby drive a second closure mechanism into the bone anchor, wherein the driver decouples from the inner shaft when the torque being applied to the driver exceeds a second predetermined threshold torque.

A method for operating a bone anchor driver, comprising:

• providing a bone anchor driver, the bone anchor driver including
• a rotatable actuator,
• a torque limiting mechanism coupled to the actuator such that rotation of the actuator causes corresponding rotation of the torque limiting mechanism,
• an outer shaft having the torque limiting mechanism fully disposed therein, the outer shaft being configured to engage an outer closure mechanism coupled to a bone anchor assembly, and
• an inner shaft disposed within the torque limiting mechanism, the inner shaft being configured to engage an inner closure mechanism coupled to a bone anchor assembly;
• applying a first torque to the actuator to rotate the actuator and the torque limiting mechanism to thereby cause the torque limiting mechanism to engage and rotate the outer shaft relative to the inner shaft;
• and
• applying a second torque to the actuator to cause the torque limiting mechanism to automatically slide axially within the outer shaft and around the inner shaft to disengage from the outer shaft and engage the inner shaft to thereby cause rotation of the inner shaft relative to the outer shaft, wherein the second torque exceeds the first torque.