Preoperative 3D printing-assisted plate precontouring for complex acetabular fractures: a case series

Abstract Background Acetabular fractures remain a major surgical challenge due to their complex three-dimensional anatomy and the technical difficulty of achieving stable fixation. Fracture patterns involving the quadrilateral plate require demanding implant contouring to restore pelvic anatomy and provide adequate medial support. Three-dimensional (3D) printing has emerged as a surgical planning adjunct; however, its direct technical role in patient-specific plate precontouring remains underreported. This study aimed to describe the clinical application and feasibility of patient-specific 3D-printed pelvic models for preoperative anatomical plate precontouring in complex acetabular fractures. Methods A retrospective case series of nine adult patients with unilateral acetabular fractures treated surgically between January 2024 and April 2025 was performed. High-resolution CT scans were used to generate patient-specific, 1:1 scale 3D-printed pelvic models using fused deposition modeling. These models were used for fracture analysis, surgical planning, and anatomical precontouring of fixation plates prior to surgery. The primary outcome was technical feasibility, defined as successful intraoperative use of precontoured plates without major recontouring. Secondary variables included precontouring time, operative time, reduction quality, and complications. Results Patient-specific 3D models were successfully generated and anatomical plate precontouring was completed preoperatively in all nine cases. Precontoured plates were applied as definitive implants in all patients without major additional intraoperative recontouring. The most frequent fracture pattern was anterior column with posterior hemitransverse. Postoperative reduction quality, assessed by the Matta grading system, was anatomical (≤ 1 mm residual displacement) in 6/9 patients and poor (> 3 mm) in 3/9. Postoperative complications occurred in three patients; no intraoperative events related to implant mismatch were observed. Conclusions Patient-specific 3D-printed pelvic models enable reliable preoperative plate precontouring in complex acetabular fractures, reducing intraoperative adjustments and simplifying the definitive fixation phase. Prospective comparative studies are needed to quantify the impact on operative time, fixation stability, and clinical outcomes.