A method of treating pain in a warm-blooded animal comprising administering to anwarm-blooded animal in need thereof an amount of a compound of the formula wherein the substituents are defined in accordance with the disclosure. The invention also provides a metallic orthopaedic implant comprising a metallic body and metallic elements adhered to a portion of the surface of the metallic body to define a three-dimensional porous surface geometry, wherein at least some of the metallic elements have a micron or nanometer-scale surface roughness. When the fixed contacts and the movable contacts are in contact, the fixed contacts are electrically connected to each other via the conductive plate.