Abstract: A device for positively clamping to the patella for use in knee surgical procedures such as total or partial knee arthroplasty to aid in determining the position of the center of the patellar implant and the amount of resection of the posterior patella for to achieve optimal tracking of the patello-femoral joint with the least amount of soft tissue releases. In one embodiment, the device includes a docking mechanism for attaching a posterior patella guide and one or more navigation devices, sensors and/or fiduciaries to monitor the position of the patella in the full range of motion and to aid in selecting the optimal position of the patella and patellar implant.

Abstract: A system and method for detecting and measuring changes in angular position with respect to a reference plane is useful in surgical procedures for orienting various instruments, prosthesis, and implants with respect to anatomical landmarks. One embodiment of the device uses dual orientation devices of a type capable of measuring angular position changes from a reference position. One such device provides information as to changes in position of an anatomical landmark relative to a reference position. The second device provides information as to changes in position of a surgical instrument and/or prosthesis relative to the reference position.

Abstract: A device for detecting and measuring a change in angular position with respect to a reference plane is useful in surgical procedures for orienting various instruments, prosthesis, and implants with respect to anatomical landmarks. One embodiment of the device uses three orthogonal rate sensors, along with integrators and averagers, to determine angular position changes using rate of change information. A display provides position changes from a reference position. Various alignment guides are useful with surgical instruments to obtain a reference plane.