A knee implant system, including a femoral knee implant and a patient specific tibial knee implant created for a patient, wherein said tibial knee implant comprises: (a) a tray component for placement on the patient's resected lateral tibial plateau having a perimeter shape that substantially matches the perimeter of the resected surface of the patient's lateral tibial plateau; (b) a tray component for placement on the patient's resected medial tibial plateau having a perimeter shape that substantially matches the perimeter of the resected surface of the patient's medial tibial plateau; (c) an insert component for insertion into the tray component for placement on the patient's resected lateral tibial plateau having a joint facing surface for mating with a lateral condyle surface of the femoral implant, wherein the joint facing surface of the insert component substantially negatively matches the curvature of the lateral condyle of the femoral implant; and (d) an insert component for insertion into the tray component for placement on the patient's resected medial tibial plateau having a joint facing surface for mating with a medial condyle surface of the femoral implant, wherein the joint facing surface of the insert component substantially negatively matches the curvature of the medial condyle of the femoral implant, wherein the lateral condyle or the medial condyle or both have a patient specific sagittal curvature, and wherein the joint facing surface of the insert component of said tibial knee implant for insertion into the tray component for placement on the patient's resected lateral tibial plateau substantially negatively matches the sagittal curvature, or both the coronal curvature and the sagittal curvature of the lateral condyle surface of a femoral implant, wherein the joint facing surface of the insert component of said tibial knee implant for insertion into the tray component for placement on the patient's resected medial tibial plateau substantially negatively matches the sagittal curvature, or both the coronal curvature and the sagittal curvature of the medial condyle surface of a femoral implant. (a) a tray component for placement on the patient's resected lateral tibial plateau having a perimeter shape that substantially matches the perimeter of the resected surface of the patient's lateral tibial plateau; (b) a tray component for placement on the patient's resected medial tibial plateau having a perimeter shape that substantially matches the perimeter of the resected surface of the patient's medial tibial plateau; (c) an insert component for insertion into the tray component for placement on the patient's resected lateral tibial plateau having a joint facing surface for mating with a lateral condyle surface of the femoral implant, wherein the joint facing surface of the insert component substantially negatively matches the curvature of the lateral condyle of the femoral implant; and (d) an insert component for insertion into the tray component for placement on the patient's resected medial tibial plateau having a joint facing surface for mating with a medial condyle surface of the femoral implant, wherein the joint facing surface of the insert component substantially negatively matches the curvature of the medial condyle of the femoral implant, wherein the lateral condyle or the medial condyle or both have a patient specific sagittal curvature, and