摘要
目的分析拇外翻第1跖骨颈部不同截骨角度与截骨端稳定的关系,探讨维持截骨端稳定的最佳截骨角度。方法建立拇外翻有限元截骨模型,模拟截骨线与第1跖骨轴线在矢状面上成30°、45°、60°、75°、90°、105°、120°共7个截骨角度,7种工况。截骨近端设为固定端,远端设为自由端,断端间设为肉芽组织填充。体质量为62kg拇外翻患者单足约承受310N的体重载荷。截骨后拇趾跖屈站立时,仅考虑屈拇长肌和屈拇短肌对截骨端的影响,设肌力与第1跖骨长轴平行,并以载荷表示。截骨端摩擦系数设为0.6。计算在上述约束与加载条件下,7种工况截骨端边缘节点的VonMises应力和总位移,并进行比较。结果截骨端总位移从截骨角度为30°时逐渐变小,至60°达到最小值,后逐渐增大,超过90°后位移有明显加大的趋势。截骨端VonMises应力从截骨角度为30°时逐渐增加,至75°达到第一个峰值,后应力走平并有逐渐减小趋势,至105°应力迅速增大。结论第1跖骨矢状面截骨线方向需从远端背侧到近端跖侧截骨端才能维持稳定;截骨角度在60°左右时截骨端最稳定;最佳截骨角度要根据患者的不同情况适当调整。
Objective To analyze the relationship between the osteotomy stability and the different osteotomy angles on the first metatarsal neck of hallux valgus, and to explore the best osteotomy angle to maintain osteotomy stability. Methods Finite element osteotomy models of hallux valgus were established. Seven kinds of working conditions were simulated, which of the osteotomy line and the first metatarsal axis were angulated in 30°, 45°, 60°, 75°, 90°, 105°, 1200 on the sagittal plane. The proximal osteotomy segment was set as fixed segment, the distal as the free segment. Between the two sides granulation tissue was set to fill with. A hallux valgus patient＇ s single foot with 62 kg body weight was bear about 310 N loads. The effects of flexor pollicis longus and flexor pollicis brevis muscle were considered to the osteotomy segment only when standing with hallux plantar flexion after osteotomy. Muscle strength was set parallel to the longaxis of the first metatarsal and expressed load. The friction coefficient between the osteotomy segments was set to 0.6. We calculated the maximum Von Mises stress and the total displacement V value of osteotomy segment edge node of 7 kinds of working conditions on the above constraints and loading conditions, and compared the calculations. Results The total displacement V value of osteotomy segment diminished gradually from 30°, reached to the minimum at 60°, and then increased significantly as osteotomy angle exceeded 90°. The Von Mises stress of osteotomy segment increased gradually from 30°, reached the first peak at 75°, and then flattened and reduced gradually. The stress increased rapidly at 105°. Conclusions Only keep the osteotomy direction of the first metatarsal on the sagittal plane from the distal dorsal to proximal plantar side, can the osteotomy segment maintain stability. It is at 60° or so that the osteotomy segment was the most stable. The best osteotomy angle needs adjustment according to different patients.
出处
《中华损伤与修复杂志（电子版）》
CAS
2012年第5期22-25,共4页
Chinese Journal of Injury Repair and Wound Healing(Electronic Edition)
基金
国家自然基金资助项目(30772815)
关键词
拇外翻
截骨术
有限元分析
生物力学
Hallux valgus
Osteotomy
Finite element analysis
Biomechanics
