Patent ID: 7905884

Claim:
A method for forming an opening in bone, the method comprising: providing a cannula having a distal end, a proximal end, a passage therethrough, and a mid-longitudinal axis, the distal end having an outer perimeter converging at an angle toward the mid-longitudinal axis of the cannula; providing a stylet having a distal end, a proximal end, and a tapered transition portion proximate the distal end, the tapered transition portion having an angle approximating the converging angle of the outer perimeter of the distal end of the cannula, the stylet being sized and configured to be inserted into the passage of the cannula; prior to insertion into the bone, placing the stylet into the cannula with at least a portion of the tapered transition portion and the distal end of the stylet extending beyond the distal end of the cannula, the cannula and the stylet forming a smooth transition between the angled portion of the stylet and the converging part of the cannula to facilitate introduction into bone; inserting, with the stylet placed within the cannula, the distal end of stylet into the bone; advancing simultaneously into the bone the stylet and cannula with the tapered transition portion of the stylet contacting the bone prior to the converging part of the cannula to form an opening into the bone, the opening having a reduced transverse dimension proximate the stylet and a larger transverse dimension proximate the cannula; and removing the stylet from the cannula with the cannula remaining in the bone.