Abstract
The purpose of this study was to evaluate the usefulness of a three-dimensional (3D)
printed model for open-wedge high tibial osteotomy (HTO). This study retrospectively
evaluated 20 patients with medial knee osteoarthritis and varus deformity. Between
October 2015 and July 2016, the patients underwent open-wedge HTO using a 3D printed
model. The mean age of patients was 55.2 years (range, 51–60 years). The mean preoperative
mechanical femorotibial angle (mFTA) was varus 7.8 degrees (range, varus 4.7–11.6
degrees). After measuring the target angle using full-length lower limb weight-bearing
radiography, the osteotomy was simulated using 3D images obtained from computed tomography
(CT) with the 3D Slicer program. On the basis of the simulated osteotomy section and
the target angle, the model was then designed and printed. Open-wedge HTO was then
performed by applying the 3D printed model to the opening gap. The accuracy of osteotomy
and the change in posterior tibial slope (PTS) angle were evaluated. The weight-bearing
line on the tibial plateau was corrected from a preoperative mean of 19.5 ± 9.8% to
a postoperative mean of 63.1 ± 6.1% (p < 0.001). The postoperative values were not statistically significantly different
from the preoperative target points (p = 0.688). The mFTA was corrected to a postoperative mean of valgus 3.8 ± 1.4 degrees.
The PTS angle showed no significant change (p = 0.256). A 3D printed model using CT may be useful for preoperative planning of
open-wedge HTO. Satisfactory correction can be obtained without a change in the PTS.
Keywords
high tibial osteotomy - 3D printing - accuracy
