An instrument set and related method for preparing a proximal tibia during a bi-cruciate retaining procedure are disclosed. The instrument set can include a tibial resection block (54), a cut guide (72), and a locking arm (72b). The tibial resection block can be configured to be fixed to an anterior portion of the proximal tibia. The tibial resection block can define a slot (71) that extends in a medial - lateral direction when the tibial resection block is fixed to the proximal tibia. The cut guide can have a body (75b), a medial arm (75c), and a lateral arm (77c). A medial cut slot (75a) can be defined between the body and the medial arm. A lateral cut slot (77a) can be defined between the body and the lateral arm. The cut guide can further comprise a tongue (72a) extending therefrom. The tongue can be configured to be received by and slidably translate along the slot of the tibial resection block.
