Abstract:[Objective] To investigate the clinical consequence of 3D printing design for reconstruction plate combined with posteriorcolumn lag screw in the treatment of acetabular quadrilateral plate fractures. [Methods] A retrospective study was done on 25 patients whohad acetabular quadrangular plate fractures fixed with reconstruction plate combined with posterior column lag screw based on 3D printingdesign in our hospital from January 2019 to January 2022. The documents regarding to clinical and imaging conditions were evaluated. [Re-sults] All the 25 patients had operation performed smoothly with the average operation time of (156.8±26.3) min and the average intraopera-tive blood loss of (791.1±163.4) ml, were followed up for an average of (21.1±6.9) months. As time went from the point 1 month after opera-tion, 3 months postoperatively to the last follow-up, the Merled Aubign-Postel score [(10.6±1.9), (13.1±1.9), (17.0±1.6), P＜0.001], hip flex-ion-extension range of motion (ROM) [(84.8±13.1)°, (105.5±13.5)°, (127.0±12.1)°, P＜0.001], hip internal-external rotation ROM [(23.6±2.9)°, (39.6±3.1)°, (51.9±2.7)°, P＜0.001] were significantly increased. As for imaging, there was no significant change in Matta grade at thelast follow-up compared with that immediately after operation (P＞0.05). All patients had fractures healed, with healing time of (13.7±1.4)weeks on an average. [Conclusion] The 3D printed reconstruction plate combined with posterior column lag screw does achieve satisfactoryclinical outcomes for acetabular quadrilateral plate fractures.