Assessment of Soft Tissue Tension In Hip Procedures

A method of evaluating soft tissue tension in a hip joint of a patient using navigation and software, the method comprising:

• retrieving first head center coordinates of a center of a head of a femoral implant or a trial when the femoral implant or trial is reduced in an acetabulum of the patient;
• capturing a real-time location of the head when the head is distracted from its reduced position during performance of an intraoperative test, the distraction of the head during the intraoperative test causing tension in soft tissue in the hip joint to increase relative to tension before distraction;
• determining second head center coordinates of the center of the head while the head is distracted;
• comparing the second head center coordinates to a peripheral tension-limit boundary of the center of the head, the peripheral tension-limit boundary being based on moving the femur through a range of motion while distracted and defined by an outer limit of movement of the center of the head;
• and
• using a distraction vector defined by a difference between the first head center coordinates and the second head center coordinates to evaluate soft tissue tension when the distraction vector is aligned on an axis passing internal to the peripheral tension-limit boundary.

A method of evaluating soft tissue tension surrounding a hip of a patient during an implant replacement procedure, the method using navigation and software to track positions of a femur and an acetabulum of the patient in real time, the method comprising:

• dislocating the femur relative to the acetabulum;
• retrieving first coordinates of a center of the acetabulum;
• performing an intra-operative test to bring soft tissue of the patient into tension comprising holding and pulling the femur to distract the femur relative to the acetabulum;
• retrieving second coordinates of a femoral head center of a femoral implant based on a position of the femoral implant when the femoral implant is disposed in the femur while the femur is distracted relative to the acetabulum;
• and
• determining a distraction vector based on a difference between the first coordinates and the second coordinates in a coronal plane.