Cutting burr shank configuration

A cutting burr, comprising:

• a cylindrically shaped shank;
• a cutting bit formed at distal end of the cutting burr;
• and
• an attachment portion formed at a proximal end of the cutting burr, the attachment portion defining a first diamond-shaped portion at a proximal end thereof, and a second diamond-shaped portion at an axially spaced intermediate position that is a predetermined distance from the first diamond-shaped portion,
• wherein the first diamond-shaped portion and the second diamond-shaped portion have axially aligned apexes and respective facets disposed within parallel planes,
• wherein the first diamond-shaped portion is adapted to receive clockwise or counter-clockwise rotation forces applied by a surgical drill having a complementary keyed slot to receive the first diamond-shaped portion, and
• wherein the second diamond-shaped portion is adapted to be axially locked within the surgical drill.

A cutting burr comprising:

• a shank with an engagement feature at a proximal end of the shank sized and configured to receive rotational forces from a surgical drilling instrument and a cutting bit formed on a distal end of the shank,
• the engagement feature including four planar surfaces, where a first pair of the planar surfaces includes a first surface and a second surface that meet at a first apex, where a second pair of the planar surfaces includes a third surface and a fourth surface that meet at a second apex, where the first and the third surfaces are opposite and parallel each other and the second and the fourth surfaces are opposite and parallel each other,
• an insert including a slot defined by substantially parallel opposing side walls, where the engagement feature is received within the slot and the width of the slot measured between the opposing side walls corresponds to a width between the first surface and the third surface of the engagement feature such that shank cannot rotate within the slot when the shank is coupled to the insert, the insert further defining a pointed-shaped inlet end, where the inlet end facilitates an alignment and insertion of the cutting burr as it is advanced toward and into the slot,
• wherein, during coupling, contact between the proximal end of the shank and the pointed-shaped inlet end of the insert causes the shank to rotate thereby bringing the engagement feature into alignment with the slot.