A medical device can include a metal member including a porous first portion with pores extending from a surface of the metal member into the first portion and non-porous second portion. The first portion can have a porosity that varies with distance from the surface of the metal member....http://www.google.com.au/patents/US20080145400?utm_source=gb-gplus-sharePatent US20080145400 - Ion Bombardment of Medical Devices
