The Standardization and Comparability Gap in Evaluating Antibacterial Surfaces for Load-Bearing Orthopedic Implants: A Critical Review

Periprosthetic joint infection is among the most serious complications of joint replacement, and the implant surface, where infection begins, is a rational prevention target. Antibacterial titanium surfaces act by releasing an agent, by contact killing, or by resisting adhesion. Yet the field cannot readily tell which method performs best, because efficacy is evaluated with methods that differ at every level and are rarely comparable: the same surface can read as highly effective under one assay and inactive under another, so the test rather than the material decides the verdict. This review asks where comparability is lost and what would restore it, for permanent load-bearing arthroplasty implants. We dissect the gap across in vitro assays, durability testing, surface characterization, in vivo models, clinical infection definitions, and regulatory expectations and ask whether the antibacterial–osseointegration trade-off is assessed coherently. We then propose a ten-item, stage-stratified minimum-reporting checklist and test it retrospectively on thirteen open-access studies. No study reported every item required at its stage; none related antibacterial dose to a stated cytotoxicity threshold; and studies fell short at different tiers, so their reported efficacies are not commensurable. The checklist is offered as a testable starting point for multi-stakeholder consensus, not a finished standard.