An assembly for guiding resection of a femur and tibia of a knee joint in preparation for installing a femoral and tibial knee components. For example, the assembly can include tibial and femoral IM rods to which are connected through a tensioning bolt that allows controlled adjustment of the distraction of the tibia and femur during cut positioning in a range of flexion angles. Also, the assembly is usable with relatively small, noninvasive approaches to the knee joint by way of relatively narrow, low profile components that attach to tibial and femoral IM rods. Further, the assembly includes several quick-release components to allow fast assembly and disassembly in a surgical setting. Each of these aspects, along with the ability of the assembly to accurately guide initial reference cuts to the tibia and femur, promotes an improved outcome for the patient.