Abstract: A computer-assisted surgical system and method are described herein. The computer-assisted surgical system comprises a computer including three-dimensional models of anatomical structures and a user interface including a position sensing system to register in real-time the relative positions of the anatomical structures of interest and of a surgical tool. Interactions between the tool and the anatomical structure are displayed on a monitor using the three-dimensional models. Multi-view display, transparency display and use of cutting planes allow the surgeon to visualize the interaction between the tool and the anatomical structures any time during the surgical procedure. The system can also predict the constraint on anatomical structures before surgery.