According to the invention, there is provided a trial implant comprising a modular bracket defining a structure having an internal surface adapted to be seated on the distal aspect of a resected femur bone and an external surface with a shape resembling the normal distal condyle of the femur. The bracket has an elongated central opening appointed to expose the resected bone of the femur, including a pair of tracks for guiding a tool along a predetermined path for controlled shaping of a patellar groove in the bone exposed through the opening. An end mill guide cooperates with the bracket to receive another tool to form a deep recess for accommodating a posterior-stabilizing housing. After the recess is formed, the guide is replaced with an insert having a posterior-stabilizing housing which covers the opening of the bracket and articulates with a proximal aspect of the tibia during interoperative trial reduction of the knee joint. Removal of the bracket from the resected bone is unnecessary following the shaping steps prior to performing the trial reduction.