A method of forming a bone void for receipt of a prosthesis, comprising the steps of: inserting a stem of a reaming guide assembly into an intramedullary canal of a bone, the reaming guide assembly having first and second reamer guides disposed adjacent to each other, the first and second reamer guides being connected to an end of the stem； reaming the bone through the aperture of the first reamer guide to form a first bone void； inserting the lobe trial into the first bone void； and reaming the bone through the aperture of the second reamer guide to form a second bone void.
