Artificial disc replacement (ADR) systems with intradiscal components feature non anterior-posterior (A-P) or oblique-oriented keels such that the great vessels do not require as much retraction during insertion. The system may further include guides for aligning the ADR prior to insertion, and for cutting an oblique slot into a vertebral endplate to receive the keel. A screw adapted to penetrate a vertebral body may be used in conjunction with the keel. The screw and keel may converge, diverge or intersect. The screw may further include a mechanism providing a locking relationship with the keel. The system may further including a guide to direct drill bits and screws through holes in the keel. ADRs according to the invention may additionally, independently include a non-symmetrical endplate shaped so as to decrease the risk of injuring the great vessels. By virtue of the invention, a second ADR may be installed at a second level having a keel oriented differently from that of the ADR having an orientation other than anterior-to-posterior.