A prosthesis for implanting into a bone having a cavity is disclosed. The
prosthesis comprises a body and a stem. A first coating including a bone
ingrowth promoting material that promotes ingrowth of bone onto the stem
and a bioabsorbable material that delays the ingrowth of bone onto the
stem is disposed on a proximal portion of the stem outer surface. A second
coating including the bone ingrowth promoting material and the
bioabsorbable material is disposed on a distal portion of the stem outer
surface. The ratio of bone ingrowth promoting material to bioabsorbable
material in the first coating is greater than the ratio of bone ingrowth
promoting material to bioabsorbable material in the second coating whereby
the affixation of the bone to the proximal zone of the stem is faster and
stronger over time than the affixation of the bone to the distal zone of
the stem.
