Instruments for knee surgery and method uf use

A femoral positioning guide for establishing a position reference on a femur to guide the cutting of the distal femur, the femur having a proximal end, a distal end, an anatomic axis from the proximal end to the distal end, an intramedullary canal along the anatomic axis, a medial epicondyle, a lateral epicondyle, an anterior surface and a posterior surface, the femoral positioning guide comprising:

• a body having a closed end and an opposite open end with opposing sides able to straddle the distal end of the femur;
• a pair of probes mounted on the opposing sides in coaxial alignment, the pair of probes being simultaneously alignable with the medial and lateral epicondyles;
• an intramedullary rod mounted on the body, the intramedullary rod being engageable with the intramedullary canal;
• and
• means for establishing a position reference on the femur that records a desired position and orientation in a way that permits positive engagement by a bone cutting guide to produce a bone cut relative to the position and orientation information.

A method comprising the steps of:

• positioning a femoral position guide adjacent a distal end of a femur, the femoral position guide having a position reference guide able to be positioned at a desired varus-valgus angle and at a desired external rotation angle;
• determining a desired varus-valgus angle and a desired external rotation angle;
• creating a position reference on the femur that permits positive engagement by a cut guide to orient the cut guide at the desired varus-valgus and external rotation angles;
• engaging a cut guide with the position reference;
• and
• guiding a cutter with the cut guide to cut the femur.