A device and method for resecting a distal portion of a femur comprises a distal cutting guide [98], a valgus guide [102], and a variable collet [10]. The distal cutting guide [98] is configured to overlie an anterior portion of the femur and comprises a slot for guiding a cutting tool across a distal portion of the femur. The valgus guide [102] is configured to connect to the distal cutting guide [98]. The valgus guide [102] is configured to align the slot of the distal cutting guide [98] at the proper varus/valgus angle. The variable collet [10] is configured to attach to an intramedullary rod and the valgus guide [102]. The variable collet [10] comprises a port [30] for receiving the intramedullary rod. The port [30] is angularly adjustable with respect to the valgus guide [102] such that adjusting the port [30] adjusts the varus/valgus angle of the distal cutting guide [98].