Cartilage implant devices having oval articular ends are provided. The
articular ends have a convex upper face and a concave lower face. The
convex upper face has a first circular pitch radius and a first circular
roll radius. The concave lower face has a first surface comprising a
second circular pitch radius and a second circular roll radius, and at
least two second surfaces each second surface having a third circular
pitch radius and a third circular roll radius. The convex upper face
blends into a rim, wherein at least a first and second portion of the rim
extends at least a first distance along the vertical axis and a third and
fourth portion of the rim tapers inward along the vertical axis, the rim
blends into the concave lower face. The implant devices further have a
stem extending from the concave lower face away from the convex upper
face.