Self-retaining driver for a bone screw

A method of installing a bone anchor into a bony structure, comprising:

• screwing a threaded bone screw of a bone anchor into a bony structure a first amount with a first driver instrument, the bone anchor including a housing pivotably coupled to a head of the threaded bone screw;
• disengaging the first driver instrument from a driver socket of the head of the bone screw once the bone screw has been screwed into the bony structure the first amount;
• advancing a second driver instrument toward the bone screw screwed into the bony structure after disengaging the first driver instrument from the driver socket of the bone screw, the second driver instrument including an elongate shaft extending distally from a handle, a tapered distal tip at a distal end of the elongate shaft, and a driver engagement feature located proximally of the tapered distal tip;
• advancing the tapered distal tip of the second driver instrument into the driver socket of the bone screw screwed into the bony structure the first amount;
• engaging the driver engagement feature of the second driver instrument with the driver socket of the bone screw as the tapered distal tip of the second driver instrument is further advanced into the driver socket of the bone screw;
• wherein a longitudinal rotational axis of the second driver instrument moves into co-axial alignment with a longitudinal rotational axis of the bone screw as the driver engagement feature of the second driver instrument is engaged with the driver socket of the bone screw;
• and
• further screwing the threaded bone screw of the bone anchor into the bony structure a second amount with the second driver instrument.

A method of engaging a driver instrument with a bone anchor already screwed into a bony structure, comprising:

• advancing a driver instrument through an incision toward a bone anchor already screwed into the bony structure from a location exterior of the incision, wherein the driver instrument is advanced through the incision while disengaged from the bone anchor, the driver instrument including an elongate shaft extending distally from a handle, a tapered distal tip at a distal end of the elongate shaft, and a driver engagement feature located proximally of the tapered distal tip;
• advancing the tapered distal tip of the driver instrument into a driver socket of the bone anchor after advancing the driver instrument through the incision;
• engaging the driver engagement feature of the driver instrument with the driver socket of the bone anchor as the tapered distal tip of the driver instrument is further advanced into the driver socket of the bone anchor;
• and
• rotating the bone anchor relative to the bony structure with the driver instrument.