Lumbar and cervical viscoelastic disc replacement:Concepts and current experience

摘要

The ideal lumbar and cervical discs should provide six degrees of freedom andtri-planar (three-dimensional) motion. Although all artificial discs are intended toachieve the same goals, there is considerable heterogeneity in the design oflumbar and cervical implants. The “second generation total disc replacements”are non-articulating viscoelastic implants aiming at the reconstruction ofphysiologic levels of shock absorption and flexural stiffness. This review aims togive an overview of the available implants detailing the concepts and thefunctional results experimentally and clinically. These monobloc prostheses raisenew challenges concerning the choice of materials for the constitution of theviscoelastic cushion, the connection between the components of the internalstructure and the metal endplates and even the bone anchoring mode. Newobjectives concerning the quality of movement and mobility control must bedefined.