"The titanium limbs, which were implanted into Dymka’s leg bones, were coated with calcium phosphate to help doctors mount them and reduce the risk of infection. According to a paper in the Journal of Biomedical Materials Research, the titanium is used “as biomaterial” in prosthetics because of its compatibility “with living tissue.” In addition to its antibacterial properties, the calcium phosphate also helps "
https://www.popularmechanics.com/science/animals/a31022925/cat-prosthetic-limbs/
https://www.popularmechanics.com/science/animals/a31022925/cat-prosthetic-limbs/