In medical transplantation, artificial joints and artificial bone replacement materials should have the following basic characteristics: lightweight and high strength, biocompatibility, corrosion resistance, no deterioration of materials caused by tissue reactions of implants in the body, fatigue and less damage caused by repeated stress, etc.The most important properties of metal implants are formability, machine additivity, and polishing. They must maintain their function over the expected life span and not deteriorate when subjected to fatigue, abrasion, corrosion, and impact loads.Titanium and titanium alloy materials meet all the above requirements.
The first use of denture powder, polypropylene, plexiglass and other artificial joint materials of low strength, easy folding, poor biocompatibility, and later converted to stainless steel.But stainless steel not only in the body by humoral action will appear corrosion and fracture, and a larger proportion, about 2 times the proportion of human skeleton.Co-Cr alloy is also an excellent artificial joint material, but unfortunately, cobalt, chromium elements are toxic to the human body.However, titanium and titanium alloy have small specific gravity (similar to that of human bone), high strength, good mechanical processing and excellent corrosion resistance, so it has become a new and ideal artificial joint material irreplaceable.
The titanium materials specified for surgical transplantation are mainly pure titanium and ti-6al-4veli alloy.In recent years, ti-13nb1-13zr and ti-6al-7nb transplantation materials with good human affinity have also obtained ASTM standard recognition.Titanium artificial bones and joints on which cells can regenerate without affecting bone growth and have good affinity with human bones, epithelium and building tissues.
At present, titanium ASTM F67 and titanium alloys Ti6Al4V ASTM F136 have been widely used in artificial bones, artificial bone joints, joint baseboards, broken bone fixers, bone marrow nails, artificial heart valves, cranium and so on.According to incomplete statistics, the annual demand for titanium alloy artificial joints in China exceeds 5,000 sets, and good results have been achieved in clinical application.