有限元分析在橈骨遠端骨折中的應用

屈任伸 梁錦成 黃彬鋮

[摘要]目的 探討有限元分析在橈骨遠端骨折中的應用效果。方法 采集正常橈骨CT薄層掃描圖像，憑借有限元分析軟件Ansys l0.0，三維重建軟件Mimics 10.01構建橈骨遠端有限元模型，并在此基礎上構建橈骨遠端骨折模型，采用傳統小夾板固定實現緊固的目標。設定骨折端不穩(wěn)移位的壓縮，拉伸載荷分別是66.7 N，內外旋載荷是22 N，同時對常規(guī)杉樹皮夾板的應力發(fā)布情況進行分析。結果 壓縮情況下，夾板系統應力的最大值為29.89 Mpa;拉伸情況下，夾板系統應力的最大值為25.48 Mpa;外旋情況下，夾板系統應力的最大值及位移分別為32.69 Mpa;內旋情況下，夾板系統應力的最大值及位移分別為30.33 Mpa。結論 建模方式與實際橈骨力學性能的三維有限元模型非常接近，且可以將患者真實的臨床情況體現出來，并在此基礎上，對橈骨結構及材料力學性能進行深入研究，可確定橈骨在骨折時應力應變與夾板固定后的改變，進而為夾板設計的完善及優(yōu)化提供參考。

[關鍵詞]橈骨遠端骨折：傳統小夾板;外固定術;有限元分析

[中圖分類號] R683? ? ? ? ? [文獻標識碼] A? ? ? ? ? [文章編號] 1674-4721（2019）8（a）-0086-03

[Abstract] Objective To explore the application effect of finite element analysis in distal radius fracture. Methods The normal humeral CT thin-layer scan image was acquired， and the finite element model of the distal radius was constructed by the finite element analysis software Ansys l0.0 and the three-dimensional reconstruction software Mimics 10.01， based on this， a distal radius fracture model was constructed， which was fixed by traditional small splint. The compression of the unstable displacement of the fracture end was set. The tensile load was 66.7 N and the internal and external rotation load was 22 N. At the same time， the stress release of the conventional cedar bark splint was analyzed. Results In the case of compression， the maximum stress of the splint system was 29.89 Mpa. Under tension， the maximum stress of the splint system was 25.48 Mpa. Under the circumstance of external rotation， the maximum stress and displacement of the splint system were 32.69 Mpa， respectively. In the case of internal rotation， the maximum stress and displacement of the splint system were 30.33 Mpa， respectively. Conclusion The modeling method is very close to the three-dimensional finite element model of the actual mechanical properties of the radius， and can reflect the real clinical situation of the patients. On this basis， the mechanical properties of the radius structure and materials are deeply studied. The stress-strain changes of the radius during fracture and the changes after splint fixation can be determined， and then splints can be set up. It provides reference for the improvement and optimization of the design.

[Key words] Distal radius fracture; Traditional small splint; External fixation; Finite element analysis

健康人的橈骨遠端關節(jié)面向掌側的傾斜范圍為10°～15°，向尺側傾斜的范圍為20°～25°（尺傾角）。橈骨遠端具備尺，掌，橈，背4個面，背側凸起，掌側光滑凹陷，共具備4個骨性腿溝，下尺橈關節(jié)是前臂旋轉的樞紐，其由尺側面構成。若橈骨遠端發(fā)生骨折的情況，不僅橈骨下端的關節(jié)面會改變角度，而且腿部肌肉會出現扭曲的情況。倘若復位的情況相對較差，會影響患者的腕與手指功能[1]。因此，橈骨遠端若發(fā)生骨折的情況，務必運用科學的固定方式及器械，固定物的位置、手術后的制動設備會在很大程度上影響骨折患者的臨床治療。在橈骨遠端骨折試驗的實際應用階段，采用有限元的方式針對腕關節(jié)的形變、骨小梁以及應力進行分析及研究?；颊叩墓钦鄄课槐还潭ê?，應結合患者骨骼與鄰近軟組織對關節(jié)部的力學特性，采用合適的固定方法對患者進行治療，同時分析各項體位與功能鍛煉對骨折斷端產生的作用及影響，應用現代化的計算機技術進行數據的輸出，能為患者的骨折治療奠定數據基礎。有限元分析方式的骨折仿真方式具備較強的吸引力，且治療效果較佳。有限元分析方式應用模擬手術，能有效處理內外固定后對關節(jié)所致的不良反應，使動物實驗統計周期長、繁瑣的不足之處得到彌補，現報道如下。