Fig. 4

a–d Stress distribution of the interface at the tibial surface of the two prosthesis types. a Stress distribution of the interface at the tibial surface of the MBT prosthesis when loading 1600 N. b Stress distribution of the interface at the tibial surface of the APT prosthesis when loading 1600 N. c Stress distribution of the interface at the tibial surface of the MBT prosthesis with 15° of knee joint flexion and loading of 2200 N. d Stress distribution of the interface at the tibial surface of the APT prosthesis with 15° of knee joint flexion and loading of 2200 N