A prosthetic device for a knee joint includes a body portion and a first
keel. The body portion attaches to a bone of a knee joint. The body
portion can have a bearing surface configured to replace at least a
portion of the bone and an implantation surface configured to face the
bone upon implantation. The first keel can be configured to be inserted
into a corresponding first keel void formed in the bone. The first feel
can be configured to project outwardly from the implantation surface by
an amount sufficient to inhibit movement of the body portion relative to
the bone in both medial and lateral directions upon insertion into the
first keel void. The first keel can extend along a longitudinal direction
of the body portion and is offset from a longitudinal centerline of the
body portion. Methods of implanting and removing the prosthetic device
are also provided.