Milling tool for surgical purposes

A surgical milling tool for milling a member of a joint having a substantially spherical shape, said tool being adapted to be connected to a hand-operated milling machine and comprising a cup member having a milling surface, at least a portion of said milling surface being hemispherical, said hemispherical portion being defined by a radius and an equatorial plane, said cup member being rotatable about an axis perpendicular to the equatorial plane, said hemispherical portion having a plurality of openings therethrough, each of said openings having a trailing edge portion on the perimeter thereof, each trailing edge portion defining a cutting edge movable along a cutting trajectory when said cup member is rotated about said axis, at least some of said cutting edges being spaced from said axis of rotation by a distance less than said radius of said hemispherical portion, each cutting edge having a length, the entire length of at least some of said cutting edges being substantially equi-spaced a radial distance from a hemispherical surface of said cup member, said openings being distributed over said hemispherical portion in relation to one another such that the cutting trajectories of said at least some cutting edges define a hemisphere.