Powder metal-made orthopedic implants with porous surface for fixation by tissue ingrowth.

Powder metal-made orthopedic implants with a porous coating provide an effective means for implant fixation by tissue ingrowth. Additionally, the use of metal alloy powders for forming porous surfaces offers the advantage of uniform coatings on complex part shapes. With proper processing, implants with strong, porous surface layers and good substrate mechanical properties can be formed. The in vivo tests have demonstrated the need for initial implant stability to achieve bony ingrowth. Animal studies indicate an optimum pore size range of 50-400 mu, and human hip prostheses with pores in this range appear to function well. A porous surface integrated with a compatible implant design avoids undesirable bone remodeling with these types of implants.