Evaluating the effectiveness of completely metal-free ceramic total knee replacement compared to traditional metal-based implants: a systematic review.

Abstract

Total knee replacement (TKR) is the standard treatment for advanced knee arthritis. Concerns related to metal hypersensitivity, ion release, and wear debris have led to the development of completely metal-free ceramic implants. This systematic review evaluates the available clinical evidence regarding ceramic TKR and examines its reported clinical outcomes and contextualizes these findings alongside conventional metal-based systems. This review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD420251091190). PubMed, Web of Science, Ovid MEDLINE, Cochrane Library, and Google Scholar were searched from inception to April 2025. Outcomes included clinical scores (Oxford Knee Score, Knee Score, Functional Score, EQ-5D VAS), survivorship, radiological findings, and complications. Study quality was assessed using the Newcastle-Ottawa Scale. Of 1951 records, six prospective studies (2002-2024) involving 402 patients were included. Mean age was 62.9 years, with 12-102 months of follow-up. Postoperative improvements in clinical scores were observed across studies, consistent with expected outcomes following primary TKR. Mid-term survivorship ranged from 95% to 99% at 5-10 years, comparable to reported outcomes of conventional implants. Radiological findings varied; some cohorts demonstrated stable fixation, while others reported high rates of radiolucent lines without observed mid-term clinical failure. Overall study quality was moderate, though most evidence derived from small, non-comparative cohorts. Current evidence suggests that completely metal-free ceramic TKR is feasible and demonstrates encouraging short- to mid-term outcomes in selected populations. However, available data are limited, largely observational, and insufficient to support definitive comparative conclusions. Further independent, adequately powered, long-term studies are required.