Why are all prostheses used in hospitals titanium?

Have you ever noticed that many medical devices in hospitals, such as many prosthetic limbs, hip joints, shoulder joints and bone fixation devices, are made of titanium alloy? I'm sure many attentive partners have noticed this, and some partners with a good knowledge base will tell me that titanium is very compatible with the human body.

Yes, titanium alloys have many excellent properties such as high strength, good thermal strength, good corrosion resistance and good low temperature properties. Titanium alloy has been widely used in many fields such as automotive industry, aviation industry, medical equipment and so on. Nowadays, titanium alloy is also widely used in civilian applications, for example, many people wear glass that may be made of titanium alloy, which is generally a good choice for high strength, light weight and comfortable to wear.

So, back to our original question, why are titanium alloys so compatible with the human body? Why can't other metals, such as stainless steel, do the same?

Titanium is very compatible with the human body. Titanium is a pure metal, and because of its "pure" nature, there is no chemical reaction when titanium comes into contact with it. In other words, because titanium has high corrosion resistance and stability, it does not affect its nature after long-term contact with humans, so it does not cause human allergies, only it has no effect on the human autonomic nerves and taste of the metal.

Specifically, titanium has a very low density, which can greatly reduce the load on the human body after implantation. Titanium also has excellent corrosion resistance. Under specific environment, titanium surface can form a stable corrosion-resistant oxide film, which is an excellent bio-inertial metal material. Titanium is non-toxic and has a low modulus of elasticity. The elastic modulus of titanium alloy is quite close to that of natural bone and has good biocompatibility. Based on these advantages, titanium alloys are widely used in medical materials such as bone trauma products, artificial joints, cardiovascular stents, and dental implants. The research of titanium alloy material is also one of the research hotspots of biomedical materials.

In the area of bone injury, fixed with titanium sheet and titanium screw, the bone will grow on the titanium sheet and the thread of the screw after a few months. The new muscle is wrapped around the titanium piece, and this "titanium bone" resembles a real bone, and it is even possible to use titanium artificial bone instead of human bone to treat fractures.

When titanium is used as an artificial organ, it dissolves with human tissue, which means that there is no major rejection, which makes the body feel not very different from the original tissue, but not really dissolve with each other, but actually similar.

Considering this, I am sure that everyone will be surprised by the fact that titanium can be used as a biological metal.

Translated with www.DeepL.com/Translator (free version)