Abstract: A trialing assembly for use during knee replacement procedures to determine size and position of a tibial plate implant as well as the size and thickness of the articular surface prior to implantation of the implant. The trialing assembly includes a broaching plate having a tibia engaging bottom surface adapted for placement atop a tibia and an opposite top surface, the bottom and top surfaces extending between an anterior edge and a posterior edge of the broaching plate. The broaching plate includes an anterior rail and a posterior rail protruding superiorly from the top surface and extending along the anterior and posterior edges, respectively. A trialing plate is configured to removably fit atop the broaching plate between the anterior and posterior rails. The trialing plate includes an engagement member extending from a superior surface of the trialing plate and adapted to engage with an articular surface provisional.