Objective:To evaluate the biomechanical performance of our self-designed anatomical plate for posterolateral tibial plateau in comparison with conventional plates for treatment of posterolateral tibial plateau fractures.Methods:A novel anatomic plate for posterolateral tibial plateau was designed according to the data measured in the superior fibular capitulum and 3D CT segmentation. Twenty-four knee joints were obtained from 12 freshly frozen adult cadavers to make models of posterolateral tibial plateau fracture. The models were divided into 3 groups( n=8). In group A, fixation was simulated via the supra-fibular-head approach after autogenous iliac bone-graft by our self-designed anatomic plate for posterolateral tibial plateau; in group B, fixation was simulated via the posterior tibial approach after autogenous iliac bone-graft by a small T-plate; in group C, fixation was simulated via the supra-fibular-head approach after autogenous iliac bone-graft by a normal L-plate. Biomechanical tests were carried out in the 3 groups to measure the vertical displacements of split bone fragment under the vertical compression loads of 500 N, 1,000 N and 1,500 N and the maximum compression upon failure of internal fixation (compressed displacemen t=3 mm). Results:At the vertical compression loads of 500 N, 1,000 N and 1,500 N, the vertical displacements of split bone fragment showed significant differences among the 3 groups ( P<0.05); there was a significant difference between group C and groups A and B, respectively ( P<0.05), but an insignificant difference between group A and group B ( P>0.05) though group A performed slightly better. In terms of the maximum compression upon failure of internal fixation, significant differences existed among the 3 groups ( P<0.05); there was a significant difference between group C and groups A and B, respectively ( P< 0.05), but an insignificant difference between group A and group B ( P>0.05). Conclusions:Our self-designed anatomic plate for posterolateral tibial plateau can firmly fixate the fracture fragments of posterolateral condyle.