Fig. 4

Establishment of the coordinate system and measurement of PCA in the 3D femoral model. Figure A: Reconstructed 3D femoral model. Figure B: Positioning of the hip joint center (O) and the knee joint center (O'). Figure C-D: Determination of the X, Y, and Z axes and the X–Y plane. Figure F: Localization of anatomical landmarks of the distal femur, with a ~ d indicating the most prominent point on the lateral epicondyle, the lowest points on the lateral and medial posterior condyles, and the medial epicondyle sulcus, respectively. Figure G: Localization of sTEA and PCL in the 3D model. Figure H-I: Measurement of PCA in the X–Y plane