Guides and instruments for improving accuracy of glenoid implant placement

1. A method of aligning a rotationally asymmetric glenoid component to a glenoid of a specific patient, comprising:

exposing the glenoid;

applying a glenoid guide to the glenoid, the glenoid guide comprising a rotation control feature forming member, the rotation control feature forming member including a channel configured to define an elongated visual indicator in a predetermined position, and wherein a point at a bottom of an arc of the channel is on an axis extending from a center of a hub of the glenoid guide and through a center of a cylindrical body of a peripheral member of the glenoid guide;

forming a rotation control feature with reference to the rotation control feature forming member in or on the scapula at or adjacent to the glenoid;

advancing the rotationally asymmetric glenoid component onto the glenoid with reference to the rotation control feature to align the rotationally asymmetric glenoid component to the glenoid in a prescribed rotational orientation for the specific patient; and

securing the rotationally asymmetric glenoid component to the glenoid in the prescribed rotational orientation for the specific patient.

2. The method of claim 1 , wherein advancing the instrument or the rotationally asymmetric glenoid component onto the glenoid with reference to the rotation control feature comprises:

coupling a patient specific rigid body with the instrument or the rotationally asymmetric glenoid component and with an aperture formed on or in the glenoid; and

advancing the instrument and/or the rigid body and/or the rotationally asymmetric glenoid component relative to the rotation control feature in a controlled manner.

3. The method of claim 2 , wherein coupling the patient specific rigid body with the rotation control feature comprises advancing a peg through the aperture formed in the scapula at or adjacent to the glenoid.

4. The method of claim 3 , wherein advancing the rotationally asymmetric glenoid component onto the glenoid comprises engaging a bone interface portion of the patient specific rigid body with the peg to provide rotation control.

5. The method of claim 4 , wherein the bone interface portion of the patient specific rigid body comprises a cylindrical member and advancing the rotationally asymmetric glenoid component onto the glenoid comprises advancing the cylindrical member over a proximal portion of the peg such that a rotational position of an inserter coupled with the rotationally asymmetric glenoid component and with the patient specific rigid body is controlled.

6. The method of claim 1 , wherein the rotation control feature comprises an aperture formed in the glenoid and a pin disposed therein and wherein advancing the instrument or the rotationally asymmetric glenoid component onto the glenoid with reference to the rotation control feature comprises advancing a lumen of a patient specific rigid body over the pin such that a rotational position of a reamer or an inserter coupled with the rotationally asymmetric glenoid component and with the patient specific rigid body is controlled.

7. The method of claim 1 , wherein the rotation control feature comprises a bovie mark and wherein forming the rotation control feature comprises directing a pen into contact with the surface of the glenoid along a channel formed in a periphery of the glenoid guide.

8. The method of claim 7 , further comprising advancing a driver toward the glenoid and rotationally orienting the driver relative to the bovie mark.

9. The method of claim 8 , wherein the driver comprises a pointer, and rotationally orienting comprises aligning the pointer with the bovie mark.