Work

Advanced preclinical testing of a design-optimized ceramic bearing for a cervical total disc replacement

Year: 2026

Type: article

Abstract: OBJECTIVE: Arthroplasty in the cervical spine is performed using Total Disc Replacement (TDR) implants. This study investigates the safety and tribology of a design-optimized ceramic TDR bearing. METHODS: Samples of an optimized bearing geometry were manufactured from the bioceramic BIOLOX®delta (CeramTec GmbH, Germany) and tested in a six degree of freedom universal joint simulator in diluted calf serum at body temperature. The investigated load and motion profiles simulated movements of daily living; three pure rotations under static load and three rotations coupled under sinusoidal load as well as adverse events (three subluxation test conditions). RESULTS: Dynamic coefficients of friction during flexion/extension and lateral bending were µ = 0.16 ± 0.011 and µ = 0.16 ± 0.070, respectively. Friction factors during flexion/extension and lateral bending were f = 0.14 ± 0.0092 and f = 0.13 ± 0.063, whereas the friction factor in axial rotation was f = 0.033 ± 0.0028 and for three coupled rotations under sinusoidal load, it was f = 0.13 ± 0.028. The design demonstrated a sufficient resistance against subluxation, with subluxation forces more than 3.5-fold the 20N that are typically required as acceptance criteria in FDA safety and effectiveness data. CONCLUSION: Friction values were found to be comparable to or higher than those typically reported for ceramic-on-ceramic hip replacements. Furthermore, the results indicated that the optimized bearing design is sufficiently resistant to subluxation. Significance: Test protocols to investigate safety and tribology of cervical TDRs are proposed and their results are reported for a design-optimized ceramic TDR bearing.

Source: PLoS ONE

DOI: 10.1371/journal.pone.0339851