Department of Orthopaedic Surgery, Ghent University Hospital, De Pintelaan 185, 9000, Ghent, Belgium.
AZ Monica, Florent Pauwelslei 21, 2100, Deurne, Belgium.
Int J Comput Assist Radiol Surg. 2018 Dec;13(12):1999-2008. doi: 10.1007/s11548-018-1727-5. Epub 2018 Mar 9.
The exact radiographic assessment of the hindfoot alignment remains challenging. This is reflected in the different measurement methods available. Weightbearing CT (WBCT) has been demonstrated to be more accurate in hindfoot measurements. However, current measurements are still performed in 2D. This study wants to assess the use of computed methods to convert the former uniplanar hindfoot measurements obtained after WBCT towards a 3D setting.
Forty-eight patients, mean age of 39.6 ± 13.2 years, with absence of hindfoot pathology were included. A WBCT was obtained, and images were subsequently segmented and analyzed using computer-aided design operations. In addition to the hindfoot angle (HA), other ankle and hindfoot parameters such as the anatomical tibia axis, talocalcaneal axis (TCA), talocrural angle, tibial inclination (TI), talar tilt, and subtalar vertical angle were determined in 2D and 3D.
The mean [Formula: see text] was [Formula: see text] of valgus ± 3.2 and the [Formula: see text] was [Formula: see text] of valgus ± 6.5. These angles differed significantly from each other with a [Formula: see text]. The correlation between both showed to be good by [Formula: see text] Pearson correlation coefficient (r) of 0.72 ([Formula: see text]). The [Formula: see text] showed to be excellent when compared to the [Formula: see text], which was good. Similar findings were obtained in other angles. The highest correlation was seen between the [Formula: see text] and [Formula: see text] (r = 0.83, [Formula: see text]) and an almost perfect agreement in the [Formula: see text] ([Formula: see text]).
This study shows a good and reliable correlation between the [Formula: see text] and [Formula: see text]. However, the [Formula: see text] overcomes the shortcomings of inaccuracy and provides valuable spatial data that could be incorporated during computer-assisted surgery to assess the multiplanar correction of a hindfoot deformity.
后足对线的精确放射学评估仍然具有挑战性。这反映在现有的不同测量方法上。负重 CT（WBCT）已被证明在后足测量中更准确。然而，目前的测量仍在 2D 中进行。本研究旨在评估使用计算方法将以前在 WBCT 后获得的单平面后足测量值转换为 3D 设置。
共纳入 48 例患者，平均年龄 39.6±13.2 岁，无后足病变。进行了 WBCT 检查，随后使用计算机辅助设计操作对图像进行分割和分析。除了后足角（HA）外，还在 2D 和 3D 中确定了其他踝关节和后足参数，如解剖胫骨轴、距跟骨轴（TCA）、距骨下关节角、胫骨倾斜度（TI）、距骨倾斜度和距下垂直角。
平均[Formula: see text]为[Formula: see text]，平均[Formula: see text]为[Formula: see text]。这些角度彼此差异显著，具有统计学意义[Formula: see text]。通过 Pearson 相关系数（r）为 0.72（[Formula: see text]）的相关性良好。与[Formula: see text]相比，[Formula: see text]显示出极好的相关性，而与[Formula: see text]相比则显示出良好的相关性。其他角度也得到了类似的发现。[Formula: see text]与[Formula: see text]之间的相关性最高（r = 0.83，[Formula: see text]），而[Formula: see text]之间几乎存在完美的一致性（[Formula: see text]）。
本研究表明[Formula: see text]和[Formula: see text]之间存在良好且可靠的相关性。然而，[Formula: see text]克服了不准确性的缺点，并提供了有价值的空间数据，可以在计算机辅助手术中用于评估后足畸形的多平面矫正。
