Forms and material specifications are detailed in a number of international and domestic specifications, including ASTM and BS7252/ ISO 5832 examples below: Table 1. Titanium alloys suitable for medical applications. ASTM BS/ISO Alloy(s) Designation(s) F67 Part 2 Unalloyed titanium – CP grades 1-4 (ASTM F1341 specifies wire) F136 Part 3 Ti6Al4V ELI wrought (ASTM F620 specifies ELI forgings) F1472 Part 3 Ti6Al4V standard grade (SG) wrought (F1108 specifies SG castings) F1295 Part 11 Ti6Al7Nb wrought - Part 10 Ti5Al2.5Fe wrought F1580 - CP and Ti6Al4V SG powders for coating implants F1713 - Ti13Nb13Zr wrought F1813 - Ti12Mo6Zr2Fe wrought Bone and Joint Replacement About one million patients worldwide are treated annually for total replacement of arthritic hips and knee joints. The prostheses come in many shapes and sizes. Hip joints normally have a metallic femoral stem and head which locates into an ultrahigh molecular weight low friction polyethylene socket, both secured in position with polymethyl methacrylate bone cement. Some designs, including cementless joints, use roughened bioactive surfaces (including hydroxyapatite) to stimulate osseointegration, limit resorption and thus increase the implant lifetime for younger recipients. Internal and external bone-fracture fixation provides a further major application for titanium as spinal fusion devices, pins, bone-plates, screws, intramedullary nails, and external fixators.
