Revision in Ceramic-on-Ceramic and Ceramic-on- Polyethylene Bearing in Primary Total Hip Arthroplasty with Press-fit Cups: A Systematic Review and Metaanalysis of Different Methodological Study Designs

Background: The influence of bearing on revision, especially in press-fit modular cup total hip arthroplasty (THA),remains underexposed.Methods: A systematic literature review was conducted in PubMed, Embase, Cochrane Library, and ClinicalTrials.gov in line with the PRISMA guidelines. The primary outcome was an overall revision between ceramic-on-ceramic(CoC) and all sorts of ceramic-on-polyethylene (CoPE) bearings. As secondary outcomes complications and reasons forrevision were compared between bearings. Outcomes were presented in subgroups based on study design (randomizedcontrolled trials (RCT), non-randomized comparative, and registry studies). The quality of evidence was assessed usingthe GRADE. The risk of bias was assessed using the Cochrane collaboration’s tool and the MINORS criteria.Results: This meta-analysis included twelve RCTs, three nonrandomized comparative studies and two registry studies,including 38,772 THAs (10,909 CoPE and 27,863 CoC). Overall revision showed a lower risk in CoPE compared to CoCin the two registry studies (HR 0.71 (95%CI 0.53; 0.99)) (very low-quality GRADE evidence). In RCTs and nonrandomizedcomparative studies, no difference was observed (low-quality GRADE evidence). Loosening, dislocation, infection, andpostoperative periprosthetic fracture showed no significant differences in risk ratio for all designs.Conclusion: The lower risk of overall revision in registry studies of primary THA with a press-fit modular cup usingCoPE bearing compared to CoC should be considered preliminary since this outcome was just slightly significant,based on very low-quality GRADE evidence and based on only two studies with several limitations. Since nodifference was observed in the other methodological designs and the separate reasons for revision showed nosignificant difference in all designs either, no preference for CoC or CoPE can be expressed, and therefore bothseem a suitable options based on the available literature. More comparative long-term studies are needed toconfirm the potential advantages of wear-reduction of both bearings since the currently available literature is limited.Level of evidence