A modular knee implant system allows a surgeon to select between several different styles of distal femoral implant components and several different styles of stem extensions while also allowing for use of a metaphyseal component. The metaphyseal component can be a universal one that is usable with all of the styles of distal femoral implant components through use of an adapter. A second adapter allows for use of stem extensions with different types of connectors with the metaphyseal component. A separate metaphyseal component could also be provided with a distal Morse taper post to mate with a distal femoral component having a proximal Morse taper bore. The metaphyseal component may have an outer surface that is configured to maximize contact area with the patient's bone, and may have a surface finish over a substantial part of its overall length that is conducive to bone ingrowth.