Effect of three-dimensional printing-assisted minimally invasive plate osteosynthesis on anti-malrotation for different types of tibial fractures

Abstract

To compare the postoperative tibial malrotation between traditional minimally invasive plate osteosynthesis (MIPO) and three-dimensional printing-assisted MIPO (3D-MIPO) for different types of tibial fractures, and explore the change of these differences. A prospective randomized controlled trial was conducted. The 120 patients with unilateral tibial fracture who met the selection criteria between January 2016 and October 2018 (40 patients in each of AO types A, B, and C) into the trial group (20 patients, 3D-MIPO) and the control group (20 patients, traditional MIPO) at ratio of 1∶1. There was no significant difference between the two groups (P>0.05) in gender, age, fracture site, and other general information. The bilateral tibial rotation angles were measured on the CT images within 1 week after operation, and the difference of tibial rotation angle between affected and unaffected sides was calculated. The tibial malrotation was defined when the difference exceeded 10°. The degree of tibial rotation and the incidence of malrotation between the two groups in different types of tibial fractures were compared. Postoperative infection occurred in 1 case, and improved after the dressing change and anti-inflammatory treatment. No complications such as loosening and displacement of internal fixation occurred. There was no significant difference in the difference of bilateral tibial rotation angles between the two groups in type A fractures after operation (t=0.559, P=0.580); while in types B and C fractures, the differences of bilateral tibial rotation angles in control group were significantly higher than those in trial group (P<0.05). There was no significant difference in distribution of internal or external rotation between the two groups in types A, B, and C fractures (P>0.05). No malrotation occurred in type A fractures, and there was no significant difference in the incidence of malrotation between the two groups in type B fractures (P=1.000). The incidence of malrotation in control group was significantly higher than that in trial group in type C fractures (P=0.044). 3D-MIPO has the same anti-malrotation effect as traditional MIPO for type A tibial fracture, but for types B and C tibial fractures, the anti-malrotation effect of 3D-MIPO is significantly better than that of traditional MIPO. The more complex the fracture type is, the more significant this advantage is.