Department of Orthopedics and Trauma Surgery, Medical University of Vienna, Waehringer Guertel 18-20, 1090, Vienna, Austria.
Center of Anatomy and Cell Biology, Medical University of Vienna, Waehringer Strasse 13, 1090, Vienna, Austria.
Int Orthop. 2022 Oct;46(10):2257-2264. doi: 10.1007/s00264-022-05514-x. Epub 2022 Jul 18.
The proximal chevron osteotomy and the modified Lapidus arthrodesis are both procedures utilized for deformity correction in patients with severe symptomatic hallux valgus. The aim of the current study was to compare their biomechanical stability when using locking plate fixation.
Twelve matched pairs of human anatomical lower leg specimens underwent on one side a proximal chevron osteotomy with a medial locking plate and on the other side a modified Lapidus arthrodesis with a plantar locking plate utilizing an interfragmentary compression screw. All specimens underwent bone mineral density (BMD) assessment and were tested in a servohydraulic load frame which applied a load on the centre of the metatarsal head over 1000 loading cycles with subsequently ultimate load testing. Displacement of the proximal and distal bone segment, ultimate load, and bending stiffness were analyzed.
Mean displacement of both procedures showed no statistically significant difference throughout all the loading cycles (0.213 ≤ p ≤ 0.834). The mean ultimate load of the proximal chevron osteotomy was 227.9 N (± 232.4) and of the modified Lapidus arthrodesis 162.9 N (± 74.6) (p = 0.754). The proximal chevron osteotomy (38.2 N/mm (± 24.9)) had a significantly higher bending stiffness compared to the modified Lapidus arthrodesis (17.3 N/mm (± 9.9)) (p = 0.009). There was no correlation between BMD and displacement in all loading cycles, ultimate load, and bending stiffness of either procedure (p > 0.05).
Although the bending stiffness of the chevron osteotomy was higher, there was no statistically significant difference between the surgical techniques in mean displacement and ultimate load. The BMD did not influence the overall stability of either reconstruction. Locking plate fixation increases the clinical value of the modified Lapidus arthrodesis by outweighing most of the biomechanical disadvantages in comparison to the proximal chevron osteotomy.
近侧楔形截骨术和改良 Lapidus 融合术都是用于矫正严重症状性拇外翻畸形的手术方法。本研究的目的是比较两者在使用锁定板固定时的生物力学稳定性。
12 对配对的人体解剖小腿标本，一侧行近侧楔形截骨术并使用内侧锁定板固定，另一侧行改良 Lapidus 融合术并使用足底锁定板和骨间加压螺钉固定。所有标本均进行骨密度（BMD）评估，并在伺服液压加载框架中进行测试，该框架在跖骨头中心施加 1000 次加载循环的载荷，随后进行极限载荷测试。分析近端和远端骨段的位移、极限载荷和弯曲刚度。
两种手术方法的平均位移在所有加载循环中均无统计学显著差异（0.213≤p≤0.834）。近侧楔形截骨术的平均极限载荷为 227.9N（±232.4），改良 Lapidus 融合术的平均极限载荷为 162.9N（±74.6）（p=0.754）。近侧楔形截骨术（38.2N/mm（±24.9））的弯曲刚度明显高于改良 Lapidus 融合术（17.3N/mm（±9.9））（p=0.009）。两种手术方法在所有加载循环、极限载荷和弯曲刚度中，BMD 与位移之间均无相关性（p>0.05）。
虽然楔形截骨术的弯曲刚度较高，但两种手术技术在平均位移和极限载荷方面没有统计学显著差异。BMD 不影响任何一种重建的整体稳定性。与近侧楔形截骨术相比，锁定板固定增加了改良 Lapidus 融合术的临床价值，克服了其大部分生物力学劣势。
