A customized patient-specific tibial cutting block has a body with a bone-facing surface having a customized patient-specific negative contour configured to receive a portion of an anterior side of a patient's tibia that has a corresponding positive contour and a portion of a medial side of the patient's tibia that has a corresponding positive contour such that an angle greater than zero is defined between a vertically-extending, bisecting plane of the body and a bisecting saggital plane of the patient's tibia when the portions of the patient's tibia are received in the customized patient-specific negative contour of the body. At least one tab extends posteriorly from the body, and has a bone-facing surface with a customized patient-specific negative contour configured to receive a portion of the proximal side of the patient's tibia that has a corresponding positive contour.
