Objective To design anatomical plates for internal fixation of acetabular posterior column fracture on the basis of digital morphological characterization of the acetabular posterior column.Methods From January.2008 to March 2012,three-dimensional (3D) reconstruction models of the pelvis were developed from CT scan data of 111 adult patients (72 men and 39 women,45.4 ± 15.7 years of age).Diameters (D) of the femoral head,radius of curvature (R1,R2 and R3) of the 3 approximate arcs along the acetabular posterior column plate,and the angle α reflecting the relative positions of the 3 arcs were measured,respectively.Independent sample t-test and Pearson correlation analysis were used to analvze the differences between genders and the correlation of the above morphological parameters.Anatomical plates of the acetabular posterior column were designed according to the analyses.Results On average,D was 47.43±3.74 mm,R1 47.96±7.80 mm,R267.71±13.35 mm,R3 9.76±0.43 mm and α51.38°± 6.83°.There was a significant difference between male and female regarding α and D (P ＜ 0.05),but no significant difference regarding R1,R2 and R3 (P ＞ 0.05).R1,R2 and R3 had no correlation with D.R2 had a positive correlation with R1 while α had a negative correlation with R1 and R2.R3 was relatively independent.Taking R1 as the basic reference,the data were divided into 3 groups to determine 3 curvature forms of the bone surface of the acetabular posterior column.Three types of anatomical plates were subsequently designed.Conclusions The anatomical structure of the acetabular posterior column varies greatly from individual to individual.This study has designed 3 anatomical plates for acetabular posterior column fracture which are more reasonable than conventional ones because they take into consideration both the reduction quality and clinically acceptable errors.