Knee jig positioning apparatus and method

1. A surgical method for a human knee joint which includes a femur bone, a tibia bone, and ligaments, wherein the ligaments are under anatomical tension to connect the femur and tibia together, creating a load-bearing articulating joint, the method comprising:

inserting into the knee joint a tensioner-balancer having a femoral interface surface;

coupling a first tracking marker to the femur and a second tracking marker to the tibia;

providing an electronic receiving device;

using the tensioner-balancer to distract the knee joint;

moving the knee joint through at least a portion of its range of motion;

while moving the knee joint, using the electronic receiving device to collect data from the tracking markers;

processing the collected data to produce a digital geometric model of the knee joint;

attaching a jig positioning apparatus to one of the bones, the apparatus having a moveable mounting head with a jig coupled thereto;

adjusting the mounting head such that a reference feature of the jig is in a predefined alignment with a toolpath defined in the digital geometric model; and

machining the bone using a cutting tool guided by the reference feature of the jig.

2. The method of claim 1 , further comprising:

using a position feedback means to determine a real-time position of the reference feature of the jig;

using a digital display to display the position of the real-time position of the reference feature combined with a view of the joint.

3. The method of claim 2 , wherein the position feedback means includes a tracking marker disposed in the mounting block.

4. The method of claim 2 , further comprising:

computing a difference between the real-time position of the reference feature and a desired position of the reference feature;

using the digital display to display a graphical feedback based on the computed difference.

5. The method of claim 2 , wherein a specific graphical feedback is provided in response to the computed difference being less than a predetermined amount.

6. The method of claim 1 , wherein:

the jig positioning apparatus is affixed to the femur;

the jig is a cutting block; and

the toolpath is a cutting plane for a distal femoral cut in the femur.

7. The method of claim 6 , further comprising:

replacing the cutting block with a drilling guide; and

using the drilling guide to drill mounting holes in the femur.

8. The method of claim 7 , further comprising:

removing the drilling guide;

attaching a 4-in-1 block to the femur using the mounting holes; and

using the 4-in-1 block to guide a cutting tool to make one or more cuts in the femur.

9. The method of claim 1 , wherein:

the jig positioning apparatus is affixed to the tibia; and

the toolpath is a cutting plane for a tibial plateau cut in the tibia.

10. The method of claim 1 , wherein a body-worn virtual reality display is used to portray the joint.

11. The method of claim 1 , wherein the collected data used to produce the digital geometric model includes:

a medial spline representing a locus of points of contact of a medial condyle of the femur with the femoral interface surface, over a range of knee flexion angles; and

a lateral spline representing the locus of points of contact of the femur with the femoral interface surface over a range of knee flexion angles.