摘要
[目的]建立母外翻术后转移性跖骨痛足的有限元模型,探索足第1跖楔关节在矢状位的角度变化对前足跖骨头下的应力影响。[方法]对母外翻术后转移性跖骨痛患足进行CT扫描,利用VTK、Geomagic Studio 8.0、ANSYS 13.0软件在计算机内构建右足三维有限元模型,静态直立加载人体重力,矢状位模拟第1跖楔关节角度分别在9°、12°、15°时,综合观察前足第15跖骨头下应力数值变化特点。[结果]通过有限元方法对应力分析,第2、3、5跖骨头下Von Mises应力呈增大趋势,内侧籽骨应力逐渐减小,外侧籽骨应力先减小后增大,第4跖骨头下应力先增大后减小。[结论]利用有限元分析方法研究第1跖楔关节对前足的应力影响,随着第1跖楔关节角度增加,前足外侧应力负荷有增大趋势。第1跖楔关节失稳可能是引起转移性跖骨痛发生的一个相关因素。临床医生对第1跖楔关节失稳应予以充分的重视,对于术前检查存在第1跖楔关节失稳,X线片有阳性表现的患者应向其交待术后出现转移性跖痛症的风险,并建议患者行跖楔关节融合术,以减少术后出现跖痛症的发生概率。
[ Objective ] To establish a finite element model of foot with transfer metatarsalgia after hallux valgus correction surgery, and discover the pressure distribution under the metatarsal heads with the change of the first tarsometatarsal joint angle in the sagittal plane. [ Methods ] The foot with transfer metatarsalgia after hallux valgus surgery was scanned with CT. With VTK, Raindrop Geomagic 8. 0, ANSYS 13.0, a three - dimensional finite element model of right foot was constructed in the computer. When the finite element model was loaded by the gravity of human body to simulate status of foot in static stance phase, the first tarsometatarsal joint angle in sagittal plane were simulated as 9°, 12°, 15°, and the change of these stress fig- ures under forefoot from the 1 st to the 5th metatarsal head were recorded and compared. [ Results] The stress data were acquired by a finite element software ： the Von Mises stress under the 2nd , 3rd, 5th metatarsal head was increasing, but the stress of medial sesamoid was decreasing gradually; the stress under the lateral sesamoid was decreasing firstly and then increasing, and the stress of under the 4th metatarsal head was increasing firstly and then decreasing. [ Conclusion] A trendency exsited in the dis- tribution of stress under metatarsal heads with the change of the first tarsometatarsal joint angle by use of the way of the finite ele- ment analysis. The larger the first tarsometatarsal joint angle became, the more stress was loaded to the later side. The first tar- sometatarsal joint instability can lead to load trsafer from the medial side to the later side under forefoot which may be one of po- tential factors to cause transfer metatarsalgia. The clinicians should pay more attention to the first tarsometatarsal joint instability. Especially before surgery, a patient with the first tarsometatarsal joint instability confirmed by X - ray and physical examination should be acknowledged the risk of transfer metatarslagia postoperatively and the first tarsometatarsal joint arthrodesis might be a good solution of it.
出处
《中国矫形外科杂志》
CAS
CSCD
北大核心
2013年第9期908-913,共6页
Orthopedic Journal of China
基金
北京市自然科学基金资助项目(项目编号:7102167)
关键词
母外翻
转移性跖骨痛
有限元
第1跖楔关节
应力
hallux valgus, transfer metatarsalgia, the finite element, first tarsometatarsal joint, pressure
