Patent ID: 8109942

Claim:
A method for performing shoulder arthroplasty or hemiarthroplasty surgical operations on portions of a shoulder joint, the method comprising: generating navigational reference information relating to position and orientation of a body part forming at least a portion of the shoulder joint, wherein the body part is a humerus; storing at least some of the navigational reference information in a computer; attaching at least one first navigational reference capable of being tracked by the navigational sensor to the body part; attaching at least one second navigational reference capable of being tracked by a navigational sensor to a surgical instrument; receiving information from the navigational sensor regarding the position and orientation of the surgical instrument with respect to the body part, wherein the information received from the navigational sensor comprises the epicondylar axis of the humerus and the information received is used to determine the retroversion reference axis; navigating the surgical instrument relative to the body part according to the position and orientation information; tracking a trial component using the navigational sensor; receiving information from the navigational sensor regarding the position and orientation of the trial component with respect to the body part; generating and displaying on the monitor associated with the computer a visual image of the trial component properly positioned and oriented relative to the body part; navigating the trial component relative to the body part and attaching the trial component to the body part according to the image; performing soft tissue balancing tests while the navigation sensor continues to track the first and second navigational references; using data generated by the computer to assess alignment and stability of the joint with the trial component attached; and releasing soft tissue to adjust alignment and stability.