Pfeffer Glenn B, Michalski Max P, Basak Tina, Giaconi Joseph C
1 Department of Orthopaedic Surgery, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
2 Department of Radiology, Cedars-Sinai Medical Center, Los Angeles, CA, USA.
Foot Ankle Int. 2018 May;39(5):591-597. doi: 10.1177/1071100717753622. Epub 2018 Jan 24.
Cavovarus deformity of the hindfoot is typically caused by neurologic disorders. Multiple osteotomies have been described for the correction of varus deformity but without clinical comparison. In this study, we used 18 identical 3-dimensional (3D) prints of a patient with heel varus to compare the operative correction obtained with Dwyer, oblique, and Z osteotomies.
A computed tomography (CT) scan of a patient with heel varus was used to create 18 identical 3D prints of the talus, calcaneus, and cuboid. Coordinate frames were added to the talus and calcaneus to evaluate rotation. The prints were then divided into 3 groups of 6 models each. A custom jig precisely and accurately replicated each osteotomy. Following the simulated operations, cut models were CT scanned and compared with 6 uncut models. Measurements were calculated using multiplanar reconstruction image processing. An analysis of variance (ANOVA) was performed on the initial data to determine significant differences among the measured variables. A Tukey Studentized range test was run to compare variables that showed statistically significant differences using the ANOVA.
The coronal angle of the Dwyer and oblique osteotomies was significantly less than that of the Z osteotomy ( P < .05). The axial angle, lateral displacement, and calcaneal shortening of the uncut model and Z osteotomy were significantly less than the Dwyer and oblique osteotomies.
Dwyer, oblique, and Z osteotomies did not create either lateral translation or coronal rotation without the addition of a lateralizing slide or rotation of the posterior tuberosity.
Dwyer and oblique osteotomies would be best suited for mild deformity, yet the amount of calcaneal shortening must be acknowledged. A Z osteotomy is a complex procedure that has the capability of correcting moderate-severe coronal plane rotation but fails to provide lateralization of the pull of the Achilles insertion.
后足内翻畸形通常由神经疾病引起。已有多种截骨术用于矫正内翻畸形，但尚无临床比较。在本研究中，我们使用一名足跟内翻患者的18个相同的三维（3D）打印模型，比较Dwyer截骨术、斜行截骨术和Z形截骨术的手术矫正效果。
对一名足跟内翻患者进行计算机断层扫描（CT），以制作18个相同的距骨、跟骨和骰骨3D打印模型。在距骨和跟骨上添加坐标框架以评估旋转。然后将打印模型分为3组，每组6个模型。使用定制夹具精确复制每种截骨术。模拟手术后，对切割后的模型进行CT扫描，并与6个未切割的模型进行比较。使用多平面重建图像处理计算测量值。对初始数据进行方差分析（ANOVA），以确定测量变量之间的显著差异。使用Tukey Studentized范围检验比较ANOVA显示有统计学显著差异的变量。
Dwyer截骨术和斜行截骨术的冠状角明显小于Z形截骨术（P <.05）。未切割模型和Z形截骨术的轴角、外侧移位和跟骨缩短明显小于Dwyer截骨术和斜行截骨术。
在不增加外侧移位或后结节旋转的情况下，Dwyer截骨术、斜行截骨术和Z形截骨术均不会产生外侧平移或冠状面旋转。
Dwyer截骨术和斜行截骨术最适合轻度畸形，但必须认识到跟骨缩短的程度。Z形截骨术是一种复杂的手术，能够矫正中度至重度冠状面旋转，但不能使跟腱止点的拉力向外移位。
