Brilakis Emmanuel, Kaselouris Evaggelos, Xypnitos Frank, Provatidis Christopher G, Efstathopoulos Nicolas
Second Department of Trauma and Orthopaedics, National and Kapodistrian University of Athens, Konstantopoulion General Hospital of Nea Ionia, Athens, Greece.
J Foot Ankle Surg. 2012 Nov-Dec;51(6):720-8. doi: 10.1053/j.jfas.2012.08.006. Epub 2012 Sep 13.
The goal of this study was to evaluate the effects of maintaining different foot postures during healing of proximal fifth metatarsal fractures for each of 3 common fracture types. A 3-dimensional (3D) finite element model of a human foot was developed and 3 loading situations were evaluated, including the following: (1) normal weightbearing, (2) standing with the affected foot in dorsiflexion at the ankle, and (3) standing with the affected foot in eversion. Three different stages of the fracture-healing process were studied, including: stage 1, wherein the material interposed between the fractured edges was the initial connective tissue; stage 2, wherein connective tissue had been replaced by soft callus; and stage 3, wherein soft callus was replaced by mature bone. Thus, 30 3D finite element models were analyzed that took into account fracture type, foot posture, and healing stage. Different foot postures did not statistically significantly affect the peak-developed strains on the fracture site. When the fractured foot was everted or dorsiflexed, it developed a slightly higher strain within the fracture than when it was in the normal weightbearing position. In Jones fractures, eversion of the foot caused further torsional strain and we believe that this position should be avoided during foot immobilization during the treatment of fifth metatarsal base fractures. Tuberosity avulsion fractures and Jones fractures seem to be biomechanically stable fractures, as compared with shaft fractures. Our understanding of the literature and experience indicate that current clinical observations and standard therapeutic options are in accordance with the results that we observed in this investigation, with the exception of Jones fractures.
本研究的目的是评估在三种常见骨折类型中，第五跖骨近端骨折愈合过程中维持不同足部姿势的影响。建立了人脚的三维（3D）有限元模型，并评估了三种加载情况，包括：（1）正常负重；（2）患侧脚踝关节背屈站立；（3）患侧脚外翻站立。研究了骨折愈合过程的三个不同阶段，包括：阶段1，骨折边缘之间的物质为初始结缔组织；阶段2，结缔组织被软痂替代；阶段3，软痂被成熟骨替代。因此，分析了30个三维有限元模型，这些模型考虑了骨折类型、足部姿势和愈合阶段。不同的足部姿势对骨折部位的峰值应变没有统计学上的显著影响。当患侧脚外翻或背屈时，骨折部位的应变略高于正常负重位置。在琼斯骨折中，足部外翻会导致进一步的扭转应变，我们认为在第五跖骨基底骨折治疗期间足部固定时应避免这种姿势。与骨干骨折相比，结节撕脱骨折和琼斯骨折似乎是生物力学稳定的骨折。我们对文献的理解和经验表明，除琼斯骨折外，目前的临床观察和标准治疗选择与我们在本研究中观察到的结果一致。
