Patent ID: 7885705

Claim:
A system for performing hip surgery on a patient having a leg, a pelvis and a femur, the system comprising: a tracking unit configured to detect a femoral position tracking frame removably secured to the patient's femur; a navigation engine coupled to the tracking unit, the navigation unit configured to establish a pelvic coordinate system at the patient's pelvis and to derive a first, pre-reconstruction location of the femoral position tracking frame relative to the pelvic coordinate system and a pre-reconstruction orientation of the femoral position tracking frame relative to the pelvic coordinate system while the leg is in a predetermined orientation; an image generator coupled to the tracking unit and the navigation engine; and a display screen coupled to the image generator, wherein the navigation engine is configured to utilize the previously derived pre-reconstruction orientation of the femoral position tracking frame to compute a plurality of orientation change values following a trial reduction as the patient's leg is moved, and to provide the computed orientation change values to the image generator, the image generator is configured to display on the display screen one or more images including the computed orientation change values to assist in returning the patient's leg to the predetermined orientation following a trial reduction, the navigation engine is further configured, with the patient's leg returned to the predetermined orientation, to derive a second, post-reconstruction location of the femoral position tracking frame, and to compute one or more of a leg length change value, an offset change value and an anterior-posterior (AP) change value, based on the first, pre-reconstruction location, the image generator displays the one or more computed leg length change value, the offset change value, and the AP change value, and the system is free from establishing a coordinate system on the patient's femur.