A system for cooperating with an elongated IM member during preparation of a bone for receiving a prosthesis can include a scaffold, skeleton or frame. An alignment assembly can be selectively coupled to the frame. The alignment assembly can cooperate with the IM member to position the frame relative to the bone. A cutting block can be selectively coupled to the frame. According to other features, a posterior stabilized (PS) box guide assembly can have a PS box guide attachment portion that selectively couples with the first attachment portion of the frame. A posterior foot can selectively couple with a second attachment portion on the frame. The posterior foot can be positioned to occupy space of a joint line in an installed position.