Wukelic Corey P, Roush Grant C, Whittaker Eric C, Meeker James, Apostle Kelly, Sangeorzan Bruce J, Ledoux William R
RR&D Center for Limb Loss and MoBility (CLiMB), VA Puget Sound, Seattle, WA, USA.
Department of Mechanical Engineering, University of Washington, Seattle, WA, USA.
Foot Ankle Int. 2025 May;46(5):484-494. doi: 10.1177/10711007241310235. Epub 2025 Apr 22.
Progressive collapsing flatfoot deformity (PCFD) describes the pathologic form of a flatfoot (pes planus). Pes planus is often treated with lateral column-lengthening (LCL) procedures such as the Evans LCL. The Z-osteotomy has been explored as an alternative to the Evans LCL. We aim to compare bone position using radiographs and dynamic movement using a robotic gait simulator (RGS).
Flatfoot was produced in cadaveric specimens by attenuating medial arch supporting ligaments and cyclically loading through the tibia. Clinical diagnostic measures from radiographs were used to assess foot shape. Each flatfoot underwent testing on the RGS with ground reaction forces scaled to 25% of the donor's body weight and the stance phase simulated 6 times slower than physiologic gait (4.09 seconds). After flatfoot data collection, one foot in each pair received either the Evans LCL or Z-osteotomy. Postoperative radiographs were taken, and the feet were again tested on the RGS. Kinematic and kinetic data were collected and compared for both flatfoot and postsurgical trials.
All radiographic parameters were significantly ( < .05) different after the flattening procedure, indicating arch collapse, forefoot abduction, and hindfoot eversion. The calcaneal pitch angle decreased, although not to the level seen in physiologic flatfoot. Changes toward arch restoration were seen in the radiographic parameters after surgeries, but there were no radiographic differences between surgery type for the number of specimens we tested (7 pairs). Peak pressure under the lateral forefoot significantly ( < .05) increased after both surgeries but did not differ between procedures. Kinematic data only showed a few differences between the Evans and the Z-osteotomy.
Radiographic evidence demonstrated that our model produced a mild flatfoot from neutrally aligned cadaveric specimens, and postsurgical feet showed significant improvement ( < .05). Few differences between the surgical techniques were seen in the kinematic and kinetic data.
This cadaveric simulation study found that the Evans and Z-osteotomies are similar in their ability to biomechanically address mild flatfoot.
进行性塌陷性平足畸形（PCFD）描述了平足（扁平足）的病理形态。扁平足通常采用外侧柱延长（LCL）手术治疗，如伊文斯LCL手术。Z形截骨术已被探索作为伊文斯LCL手术的替代方法。我们旨在使用X线片比较骨位置，并使用机器人步态模拟器（RGS）比较动态运动。
通过减弱内侧足弓支撑韧带并通过胫骨进行周期性加载，在尸体标本中制造扁平足。使用X线片的临床诊断测量方法评估足形。每个扁平足在RGS上进行测试，地面反作用力按供体体重的25%进行缩放，站立期模拟为比生理步态慢6倍（4.09秒）。在收集扁平足数据后，每对中的一只脚接受伊文斯LCL手术或Z形截骨术。术后拍摄X线片，并再次在RGS上对脚进行测试。收集并比较扁平足和手术后试验的运动学和动力学数据。
在扁平足手术操作后，所有X线片参数均有显著差异（P <.05），表明足弓塌陷、前足外展和后足外翻。跟骨倾斜角减小，尽管未达到生理性扁平足所见的水平。手术后X线片参数显示出向足弓恢复的变化，但对于我们测试的标本数量（7对），手术类型之间在X线片上没有差异。两次手术后前足外侧下方的峰值压力均显著增加（P <.05），但不同手术之间没有差异。运动学数据仅显示伊文斯手术和Z形截骨术之间存在一些差异。
X线片证据表明，我们的模型从解剖位置正常的尸体标本中制造出了轻度扁平足，手术后的脚显示出显著改善（P <.05）。在运动学和动力学数据中，手术技术之间的差异很少。
这项尸体模拟研究发现，伊文斯手术和Z形截骨术在生物力学治疗轻度扁平足的能力方面相似。
