Patent ID: 7871412

Claim:
An orthopaedic cutting tool, comprising: a partially hemispherical shell having a shell radius, and a circumferential base including a first circumferential base segment, a second circumferential base segment, a third circumferential base segment, and a fourth circumferential base segment, said circumferential base not forming a circle, said first and second circumferential base segments opposing one another and each being curved and coupled with said third and fourth circumferential base segments, said third and fourth circumferential base segments opposing one another and each being straight and coupled with said first and second circumferential base segments, said first, second, third, and fourth circumferential base segments being coplanar relative to one another, said shell including a first part on one side of said first circumferential base segment and said second circumferential base segment, and a second part on another side of said first circumferential base segment and said second circumferential base segment, said third circumferential base segment forming a portion of said first part, said fourth circumferential base segment forming a portion of said second part; a first non-planar surface connected to said first part, said first non-planar surface having a first curvature not equal to said shell radius, said first curvature being parabolic shaped along a cross-sectional plane taken perpendicular to said third and fourth circumferential base segments and through a top dead center of said shell; and a second non-planar surface connected to said second part, said second non-planar surface having a second curvature not equal to said shell radius.