A prosthetic spinal disc system is provided. The prosthetic disc system has a nucleus component having an upper surface configured to engage a superior vertebra and a lower surface configured to engage an inferior vertebra, an anchor configured to affix to an anterior surface of at least one of the superior vertebra or the inferior vertebra, and a tether tying the nucleus component to the anchor. In such embodiments, the nucleus component further has a perimeter situated substantially between the upper surface and the lower surface of the nucleus component and the tether is at least partially situated on the perimeter of the nucleus component. In certain embodiments, the upper surface and the lower surface of the nucleus component are configured to allow for implantation of the disc system such that after a discectomy, no preparation of at least one of the superior and inferior vertebrae is necessary.
