Orthopaedic cutting instrument and method

A method of cutting tissue at a surgical site comprising:

• introducing a cutter into a surgical site having relatively hard tissues and relatively soft tissues, the cutter including a blade having a blade tip rotatable about a rotational axis, the blade tip spaced from the rotational axis by a radius;
• driving the blade tip of the cutter through a rotational amplitude, such that a lineal displacement of the blade tip is equal to twice the product of the radius and the rotational amplitude, the lineal displacement less than a displacement that the relatively soft tissues can tolerate without being cut but more than the relatively hard tissues can tolerate without being cut, whereby the cutter is adapted to cut the relatively hard tissues without cutting the relatively soft tissues;
• and
• manipulating the cutter within the surgical site to morselize relatively hard tissues.