Does tantalum exhibit any intrinsic antimicrobial or antibiofilm properties?

Tantalum (Ta) trabecular metal components are increasingly used to reconstruct major bone defects in revision arthroplasty surgery. It is known that some metals such as silver have antibacterial properties. Recent reports have raised the question regarding whether Ta components are protective against infection in revision surgery. This laboratory study aimed to establish whether Ta has intrinsic antibacterial properties against planktonic bacteria, or the ability to inhibit biofilm formation. Equal-sized pieces of Ta and titanium (Ti) acetabular components were sterilised and incubated with a low dose inoculum of either Staphylococcus (S.) aureus or S. epidermidis for 24 hours. After serial dilution, colony forming units (cfu) were quantified on Mueller-Hinton agar plates. In order to establish whether biofilms formed to a greater extent on one material than the other, these Ta and Ti pieces were then washed twice, sonicated and washed again to remove loosely adhered planktonic bacteria. They were then re-incubated for 24 hours prior to quantifying the number of cfu. All experiments were performed in triplicate. More than 1x10(8) cfu/ml were observed in both the Ta and Ti experiments. After washing and sonication, more than 2x10(7) cfu/ml were observed for both Ta and Ti groups. The results were the same for both S. aureus and S. epidermidis. Compared with Ti controls, Ta did not demonstrate any intrinsic antibacterial activity or ability to inhibit biofilm formation. Hence, intrinsic antimicrobial properties of Ta do not account for the previously observed reduction in the frequency of subsequent infections when Ta was used in revision procedures. Cite this article: Bone Joint J 2017;99-B:1153-6. [Abstract copyright: ©2017 The British Editorial Society of Bone & Joint Surgery.]