Abstract
Purpose
The purpose was to compare the accuracy of the method using 3D printing model with the method using picture archiving and communication system (PACS) images in high tibial osteotomy (HTO).
Materials and methods
This study analyzed 40 patients with varus deformity and medial osteoarthritis. From 2012 to 2016, patients underwent HTO using either 3D printing model (20 knees) or method based on a PACS image (20 knees). After obtaining the correction angle for the target point (62.5% point of the mediolateral tibial plateau width), in the 3D printing method, the wedge-shaped 3D-printed model was designed with the measured angle and osteotomy section and was produced by the 3D printer. The PACS method used preoperative radiographs to shift the weight bearing axis. The accuracy of the HTO and the proportion of acceptable range (62.5 ± 5%) at each method was compared using the full-length lower limb radiographs at the sixth postoperative week. The pre and postoperative posterior tibial slope angle was also compared at each method.
Results
The weight bearing line on the tibial plateau was corrected from a preoperative 21.1 ± 11.8% to a postoperative 61.6 ± 3.4% in the 3D group and from 19.5 ± 12.3% to 61.4 ± 8.0% in the PACS group. The patients in an acceptable range were more in 3D printing group (80%) than in PACS group (60%) (p=0.028). The mean of absolute difference with the target point was less in 3D printing groups (2.4 ± 2.5) than PACS group (6.2 ± 5.1) (p=0.006). The posterior tibial slope was not significantly different in 3D printing group (8.6° to 8.9°, p=0.073), whereas different in PACS group (9.9° to 10.5°, p=0.042).
Conclusions
In HTO, correction based on the 3D printing method was more accurate than correction using the PACS method.
