With the development of orthopedic market, the implant material research is also increasingly attracting people’s attention. According to Yao Zhixiu’s introduction, current implant metal materials usually include stainless steel, titanium and titanium alloy, cobalt base alloy and these materials will exist for a long time. For Titanium and titanium alloy, local instrument factory generally use pure titanium and Ti6Al4V alloy (TC4), while US has 12 kinds of titanium alloy materials for implants and the most commonly ones in Europe and US are Ti6Al4VELI and Ti6Al7Nb.
Wu Xiaolei, Asia-Pacific Sales Manager of Sandvik Medical Technology said, stainless steel material is widely used in Europe and US, and Chinese market is relatively complex: different products are suitable for various markets but in general they favor titanium and titanium alloy. “From the point of joint applications, different materials are selected by different purposes, for example, holding force parts shall choose high nitrogen stainless steel material which has higher strength; when wear resistant materials are required, we can choose Cobalt chromium molybdenum alloy."
At present, the surface modification is one of the key developments of orthopedic implant materials. “The surface of implanted devices directly contacts with the human body and through the surface modification, it can improve biological compatibility and reduce wear and tear, and thereby it may reduce implant loosening and ensure a long-term performance.” Wu Xiaolei said, for example, Sandvik Bioline 316LVM is used for human implantation and Bioline 1RK91 for manufacturing medical apparatus. The former is a vacuum re melt molybdenum austenitic stainless steel with good micro purity and corrosion resistance, and it can be used for joint handles, femoral heads, bone plates, bone nails, bone positioning needles, intramedullary nails, acetabular cups; the latter is a kind of precipitation hardening stainless steel, which is commonly used in surgical instruments such as bone drills and bone needles, and it shows better strength, toughness and corrosion resistance. Both have a wider application in China market.
"We can also learn experience from other fields, for example, applying the tool material development to the joint implant material development and using ceramic coating to achieve surface modifications.”