Explant analysis of two rhine cervical discs

These observations highlight deformation of the viscoelastic core in Rhine cervical discs. Whether this finding relates to surgical factors such as implant sizing and positioning, or to implant design itself, improper sizing and malpositioning may contribute to excessive shear forces, core deformation, and poor clinical outcomes. These factors are all important in implant survival and should be carefully considered. The deformation observed in the cores of the explants is consistent with viscoelastic polymer limitations reported in the literature for other viscoelastic cervical discs.