Fractures of the quadrilateral plate treated with a reconstruction plate and trans-plate quadrilateral screws: An experimental study on cadaveric specimens and finite element analysis.

Quadrilateral plate fracture is one of the most complex and challenging pelvic lesions. Operative reduction and internal fixation are the gold standard management for displaced quadrilateral plate fractures. Traditional methods include various kinds of operative reduction and internal fixation through either anterior or posterior approaches using various combinations of plates and lag screws or acute total hip arthroplasty. Here we introduced a new fixation technique named reconstruction plate combined with trans-plate quadrilateral screws. We performed a cadaveric study to determine the biomechanical properties of this system comparing with conventional titanium plate combined with 1/3 tube titanium plate in a both-column acetabular fracture model in standing position. Besides, a finite element model of both-column acetabular fractures fixed by this system was developed and the mechanical properties of implants and acetabular fractures were analyzed. The biomechanical test showed the superiority of reconstruction plate combined with trans-plate quadrilateral screws over conventional titanium plate combined with 1/3 tube titanium plate in treating both-column quadrilateral plate fractures in standing position. Later finite element analysis confirmed the stabilities of the fractures under 1-legged stance. Thus, reconstruction plate combined with trans-plate quadrilateral screws provides an alternative method in treating quadrilateral plate fractures.