Comparative biomechanical testing of customized three-dimensional printing acetabular-wing plates for complex acetabular fractures

Background.Three-dimensional (3D) printing of an acetabular wing-plate is a new minimally invasive surgical technique for complex acetabular fractures. Objectives.To investigate the biomechanical stability of 3D printing acetabular wing-plates.The results were compared with 2 conventional fixation systems. Material and methods.Eighteen fresh frozen cadaveric pelvises with both column fractures were randomly divided to 3 groups: A -iliosciatic plates fixation system; B -3D printing plates; C -2 parallel reconstruction plates fixation system.These constructions were loaded onto a biomechanical testing machine.Longitudinal displacement and stiffness values of the constructs were measured to estimate their stability.Results.When the load force reached 700 N, Group A was superior to Group B in the longitudinal displacement of point 1 (p > 0.05).The longitudinal displacement of point 2 showed no significant differences among Groups A, B and C, and the displacement of the fracture line over point 3 showed no significant differences between Groups A and B (p > 0.05).The axial stiffness of Groups A, B and C were 122.4800 ±8.8480 N/mm, 168.4830 ±14.8091N/mm and 83.1300 ±3.8091 N/mm, respectively.Group B was significantly stiffer than A and C (p < 0.05).Loads at failure of internal fixation were 1378.83±34.383N, 1516.83 ±30.896N and 1351.00 ±26.046N for Groups A, B and C, respectively.Group B was significantly superior to Groups A and C (p > 0.05).Conclusions.Customized 3D printing acetabular-wing plates provide stability for acetabular fractures compared to intraspecific buttressing fixation.