Abstract

Objective The aim of this study was to determine how increasing stiffness of fracture site tissues distal to the pins in an equine distal limb transfixation cast influences stress at the bone–pin interface, within the bones distal to the transcortical pins, and contact pressure between the foot and the cast.

Study Design A transfixation cast finite element model was used to compare the bone–pin interface stress, pin stress, bone stress distal to the pins and contact pressure between the foot and the cast, using six stiffness values for a composite tissue block representing progressive stages of fracture healing.

Results Increasing stiffness of the composite tissue block resulted in a decrease in the maximum stresses at the bone–pin interface, an increase in stresses distal to the transcortical pins and a decrease in the maximum pin stresses. As the composite tissue block stiffness was increased, contact pressure between the bottom of the composite tissue block and the cast increased and the stress patterns surrounding the pin holes became less focal.

Conclusion The findings of this study illustrate that with good foot to cast contact within a transfixation cast, increases in tissue stiffness due to progressive fracture healing are expected to reduce bone-pin interface stresses, and increase fracture site loading and stress. Increasing the contact pressure between the foot and the cast could reduce transfixation casting complications such as pin loosening, pin hole fracture and poor fracture healing, if these results transfer to ex vivo and in vivo settings.

Authors' Contributions

Timothy Lescun contributed to the conception of study, study design, acquisition of data and data analysis and interpretation. Stephen Adams contributed to data analysis and interpretation. Eric Nauman contributed to study design, data analysis and interpretation. Gert Breur contributed to conception of study, study design and data analysis and interpretation. All authors drafted, revised and approved the submitted manuscript.

中文翻译：

---

骨折部位刚度增加对马远端肢体固定石膏中骨钉界面应力和足部接触压力的影响：有限元分析。

摘要

目的 这项研究的目的是确定在马远端肢体固定式石膏中钉远端的骨折部位组织的刚度增加如何影响在骨皮质钉远端的骨-钉界面处的应力，以及骨皮质之间的接触压力。脚和演员。

研究设计 使用固定铸件有限元模型，使用六个刚度值代表渐进阶段，比较骨钉界面应力，钉应力，钉远端的骨应力以及脚与铸件之间的接触压力。骨折愈合。

结果 复合组织块的刚度增加导致在骨钉界面的最大应力降低，经皮皮质钉远端的应力增加以及最大钉应力的降低。随着复合组织块的刚度增加，复合组织块的底部与铸件之间的接触压力增加，针孔周围的应力模式变得不那么集中。

结论 ：本研究的结果表明，在脚注石膏中良好的脚与脚石膏接触，由于进行性骨折愈合而导致的组织刚度增加有望减少骨钉界面应力，并增加骨折部位负荷和应力。如果将结果转移到离体和体内设置，则增加脚与铸件之间的接触压力可以减少固定式铸件的并发症，例如针松动，针孔骨折和不良的骨折愈合。

作者的贡献

蒂莫西·莱斯昆（Timothy Lescun）为研究，研究设计，数据获取以及数据分析和解释的概念做出了贡献。Stephen Adams为数据分析和解释做出了贡献。埃里克·瑙曼（Eric Nauman）为研究设计，数据分析和解释做出了贡献。Gert Breur为研究概念，研究设计以及数据分析和解释做出了贡献。所有作者都起草，修改和批准了提交的手稿。