A system of precision instruments for utilization in knee surgery, particularly for component replacement includes a series of alignment and cutting guides which function to align various necessary cuts of bone structure with respect to the ankle. The system in its preferred arrangement includes a cutting guide head mounted on an elongated, extensible support frame member having a laterally adjustable ankle guide for adjustably aligning the cutting heads for a proper angle of cut with respect to the weight bearing axis through the ankle and the hip joint. A tibial resection guide head with a cutting guide slot is fixed to the upper end of the elongated extensible support frame member and including a traction grip extending outward from the extendable support frame member for application of traction or tension to the collateral ligaments. An anterior femoral condyle resector/posterior spacer guide is applied to the anterior femoral cortex superior to the anterior condyles, and is used to accurately remove the anterior femoral condyles and predetermine the size of the optimal tibial prosthesis. A distal femoral condyle resector guide is detachably mountable on the frame and includes a cutting guide head for guiding a cut of the distal femur that is aligned with the tibial plateau. A posterior femoral condyle resector/chamfer guide is a template, the actual size of the prosthesis, that provides the surgeon with a visual guide to properly fit the prosthesis on the distal femur, and not only allows for precision cuts on the distal femur but allows the surgeon to make rotational and spacing adjustments at this final stage. A weight bearing axis alignment guide for alignment of the support frame member includes a bracket with an indicator for positioning above the hip joint and a flexible line for extending to the ankle bracket for alignment over the center of the femoral head. A system of tamps and broaches, in conjunction with a drill guide, is used to make precision cuts on the resected tibial and femoral surface, and provides the optimal amount of space around the various stems of the prosthesis, for bone cement.