The milling instrumentation of this invention provides a milling guide connected to the femur for accommodating a milling device. The milling instrumentation includes an alignment guide which is used by the surgeon to set a femoral bracket or base on the medial and lateral sides of the exposed femur adjacent its distal end. Once the brackets are set, the alignment guide is removed and a milling guide is connected to the bases. The milling guide establishes a series of reference planes each including a slot. A powered milling device having a burr connected thereto is guided by the slots along the reference planes to accurately mill away a portion of the bone. The milling device includes a bobbin-shaped tip which positively engages the slots to ensure that the milling device is held substantially perpendicular to the reference planes of the milling guide. If necessary, other instrumentation may be connected to the femoral bases which would form a common connection point for the additional instruments thereby ensuring alignment between the various instruments. Optionally, a one piece cutting guide may be connected to the bases to allow resection of the bone by a standard oscillating saw blade. The cutting guide includes a plurality of slots such that all the cuts required for the femur can be made with one cutting guide without reorienting the guide.