Open wedge high tibial osteotomy using three-dimensional printed models: Experimental analysis using porcine bone

Background The purpose of this study was to evaluate the usefulness of three-dimensional (3D) printed models for open wedge high tibial osteotomy (HTO) in porcine bone. Methods Computed tomography (CT) images were obtained from 10 porcine knees and 3D imaging was planned using the 3D-Slicer program. The osteotomy line was drawn from the three centimeters below the medial tibial plateau to the proximal end of the fibular head. Then the osteotomy gap was opened until the mechanical axis line was 62.5% from the medial border along the width of the tibial plateau, maintaining the posterior tibial slope angle. The wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The open wedge HTO surgery was reproduced in porcine bone using the 3D-printed model and the osteotomy site was fixed with a plate. Accuracy of osteotomy and posterior tibial slope was evaluated after the osteotomy. Results The mean mechanical axis line on the tibial plateau was 61.8 ± 1.5% from the medial tibia. There was no statistically significant difference (P = 0.160). The planned and post-osteotomy correction wedge angles were 11.5 ± 3.2° and 11.4 ± 3.3°, and the posterior tibial slope angle was 11.2 ± 2.2° pre-osteotomy and 11.4 ± 2.5° post-osteotomy. There were no significant differences (P = 0.854 and P = 0.429, respectively). Conclusion This study showed that good results could be obtained in high tibial osteotomy by using 3D printed models of porcine legs.