Patent ID: 8784422

Claim:
A tool for cutting a hemispherical cavity in bone, comprising: a) a hemispherical, hollow dome comprising: i) a proximal hemispherical wall portion extending along a rotational axis from an apex to an equatorial rim of the dome, wherein the rotational axis intersects the hemispherical wall portion at the apex, and wherein the equatorial rim is spaced from the rotational axis and resides on an imaginary equatorial plane aligned substantially perpendicular to the rotational axis, ii) at least one lobe extending distally from the proximal hemispherical wall portion to a lobe rim, wherein the lobe rim is distal both the equatorial rim and the imaginary equatorial plane away from the apex, and iii) wherein the hemispherical wall portion and the at least one lobe have the same outer radii with respect to a focal point residing where the rotational axis intersects with the imaginary equatorial plane; b) a plurality of first dome cutting teeth arrayed along the proximal hemispherical wall portion of the hollow dome; c) at least one second lobe cutting tooth positioned at least partially within the at least one lobe, the at least one second lobe cutting tooth comprising: i) a lobe cutting tooth edge facing a lobe cutting tooth opening, ii) wherein the lobe cutting tooth edge comprises a plurality of lobe cutting tooth outer radii that are of a greater length with respect to the focal point than the outer radii of the hemispherical wall portion and of the at least one lobe, and iii) wherein the lobe cutting tooth opening is completely enclosed by the lobe or by the lobe and the hemispherical wall portion; and d) at least one mounting bar extending perpendicular to the rotational axis and comprising spaced apart mounting bar ends secured to opposed locations of the hemispherical hollow dome.