Clinical efficacy and biomechanical analysis of 3D-printed guide plate-assisted cannulated screw fixation compared with conventional fixation in complex acetabular fractures.

BACKGROUND

Optimal fixation for pelvic and acetabular fractures remains challenging due to competing demands for stability and minimally invasive surgery. This study combined finite element (FE) modeling and a retrospective clinical analysis to compare three fixation strategies.

METHODS

A three-dimensional FE model of a representative both-column acetabular fracture was constructed to compare cannulated screw-only, plate-only, and combined cannulated screw-plate fixation under simulated standing and sitting conditions. Clinically, patients with acetabular fractures treated between November 2021 and May 2023 were retrospectively grouped into 3D-printed guide plate-assisted cannulated screw plus plate (n = 8), conventional cannulated screw plus plate (n = 14), and plate-only fixation (n = 12). Perioperative outcomes, postoperative complications, and 3-month hip function were analyzed with multivariable adjustment.

RESULTS

FE analysis showed higher stress and displacement under sitting than standing across all constructs, with combined cannulated screw-plate fixation providing better fracture-line displacement control than screw-only fixation, particularly under sitting conditions. Clinically, after multivariable adjustment, the 3D-printed guide group had significantly shorter operative time than the plate-only group and the conventional screw plus plate group (-56.15 min, P = 0.048; -68.46 min, P = 0.031, respectively), lower intraoperative blood loss than the plate-only group (-575.48 mL, P = 0.001), and shorter incision length than the plate-only group (-7.94 cm, P = 0.004). Both the 3D-printed guide group and the conventional screw plus plate group showed significantly lower total hospitalization costs than the plate-only group (-39,944.29 RMB, P = 0.040; -32,527.55 RMB, P = 0.048, respectively). No significant adjusted differences were observed in complication risk, 3-month hip function, or hospital length of stay.

CONCLUSIONS

Combined cannulated screw-plate fixation provides superior biomechanical stability for complex acetabular fractures, while patient-specific 3D-printed guide plate significantly improve perioperative efficiency without compromising short-term safety or functional recovery.