Abstract: Objective To evaluate the efficacy of combining 3D printing with T-shaped steel plate elastic fixation in the treatment of complex acetabular fractures involving the posterior column.Methods A total of 84 patients with complex acetabular fractures involving the posterior column,admitted to the hospital from January 2020 to January 2023,were randomly divided into an observation group (42 cases) and a control group (42 cases) using a random number table.The control group underwent T-shaped steel plate elastic fixation,while the observation group received 3D printing in addition to the conventional treatment.The surgical outcomes,fracture healing time,and reduction quality were compared between the two groups.Additionally,serum bone morphogenetic protein-2 (BMP-2),transforming growth factor-β1 (TGF-β1),bone callus density,and postoperative complications were compared between the two groups.Results The operation time and fracture healing time of the observation group were (227.58±25.96) minutes and (42.54±3.68) days, which were lower than (285.47±35.85) minutes and (56.98±6.74) days of the conventional group, and the differences were statistically significant (P < 0.05). The intraoperative blood loss of the observation group was (458.25±48.14) ml, which was less than the conventional group[(526.35±58.52) ml] , and the difference was statistically significant (P < 0.05).On the 30th day after surgery,BMP-2 of the observation group and the conventional group was(86.98±10.36) ng/L and (82.39±9.20) ng/L,respectively,TGF-β1was (63.85±8.17) ng/ml and (55.85±7.12) ng/ml,respectively.The levels of BMP-2 and TGF-β1 in the observation group and the conventional group were higher than those before operation (P＜0.05),and the levels of BMP-2 and TGF-β1 in the observation group were higher than those in the conventional group (P＜0.05).The excellent and good rate of fracture reduction in observation group (95.24%) was higher than that in conventional group (80.95%) (P<0.05).The bone callus density [(0.44±0.07) g/cm² and (0.59±0.10) g/cm²] in the observation group were higher than those in the conventional group [(0.32±0.04) g/cm² and (0.42±0.09) g/cm²] at 30 d and 3 months after surgery (P<0.05),and there were 2 cases of traumatic arthritis in the conventional group.One case of ectopic ossification,the total complication rate was 7.14%;In the observation group,there were 2 cases of traumatic arthritis and 2 cases of ectopic ossification.The total complication rate was 9.52%.There was no significant difference in the total complication rate between the two groups (P＞0.05).Conclusion The combination of 3D printing and T-shaped steel plate elastic fixation in the treatment of complex acetabular fractures involving the posterior column can achieve satisfactory surgical reduction,promote fracture healing,improve bone callus density,and is safe and reliable.

Key words: 3D printing, acetabular fracture, T-shaped plate effect