Cutter blades made of shape memory materials. Rotation of a cutter blade as part of a cutter assembly within an intervertebral disc space cuts the material present there for removal from the intervertebral disc space. Cutter blades with different attributes (such as throw length, cutter blade angle, type and location of blade edges) are adapted to achieve different objectives within the intervertebral disc space. The use of a hollow ground to enhance the cutting action of a blade edge is described in connection with the creation of cutter blades. A variety of thin cutter blades are described which may be used in the interior of a thin intervertebral disc (having a reduced distance between the endplates of the adjacent vertebral bodies).