Methods and devices are provided for knee joint replacement with anterior cruciate ligament (ACL) substitution. Generally, the methods and devices can allow a knee joint to be partially or totally replaced in conjunction with substitution of the knee joint's ACL. In one embodiment, a knee replacement prosthesis can include a medial or lateral femoral implant, a femoral intercondylar notch structure, a medial or lateral tibial insert, and an ACL-substitution member. The ACL-substitution member can be configured to engage with the femoral intercondylar notch structure during a full range of knee motion and/or during only early knee flexion.