蜂巢式髓芯减压术治疗早中期股骨头缺血性坏死的有限元分析

Finite element analysis on treatment of early stage avascular necrosis of the femoral head by honeycomb core decompression

目的应用有限元分析的方法对蜂巢式髓芯减压术(Honeycomb core decompression surgery,HCD)和单孔髓芯减压术(Core decompression surgery,CD)治疗早中期股骨头缺血坏死(Avascular necrosis of the femoral head,ANFH)进行比较研究。方法选择在我院住院治疗的股骨头坏死患者,FicatⅠ、Ⅱ、Ⅲ期各1例,按照成人股骨头坏死诊疗专家共识(2012版)标准进行纳入和排除。用GE 64排Light spead VCT工作站获取数据,以Dicom格式导入IBM w520个人笔记本电脑,用Mimics16.0软件进行建模。利用Mimics 16.0 CAD功能和3Matic3.0软件,建立Ⅰ、Ⅱ、Ⅲ期共6个单孔和蜂巢式髓芯减压模型。将6个模型在3Matic3.0软件内进行面网格划分和体网格划分,然后导回Mimics16.0软件中,并参照软件中材料公式及灰度值进行材料赋值。导入到ANSYS14.0软件中,进行有限元仿真实验。计算股骨颈和通道应力集中部位的应力,在应力集中部均匀选取10个节点,计算其均值。结果通过有限元数据分析,Ⅰ、Ⅱ、Ⅲ期中,加载一定应力后,CD和5孔HCD分别比较股骨头应力,股骨头应变。股骨头和粗隆处髓芯减压术开口处等数据分析说明:股骨头缺血坏死不论Ⅰ期还是Ⅲ期,减压后,无论应力和变形,HCD均优于单孔髓芯减压术。多通道减压更稳定、安全。结论蜂巢式髓芯减压术治疗早中期股骨头坏死具有手术疗效肯定,创伤小,出血少,术后恢复快特点,易于在临床应用推广。

Objective Use finite element analysis to compare the difference between honeycomb core decompression and foramina singulare core decompression for adults＇ avascular necrosis of femoral head in early-to-mid Stage. Methods Patients of ANFH who were hospitalized in our department, one case in Ficat stage Ⅰ, Ⅱ, and Ⅲ respectively, are chosen to incorporate and exclude according to clinical expert consensus for adults＇ ANFH in the 2012 version. Datas are obtained through GE 64 row Light spead VCT workstation, imported to IBM W520 in Dicom format and build model by Mimics16.0 software. The CAD function of Mimics 16.0 and 3Matic3.0 software are used to build six models in Stage I, Ⅱ,and Ⅲ operated by HCD and foramina singulare CD. These models are measured by surface mesh generation and body mesh generation in 3Matic3.0, then imported back to Mimics16.0 and material assignment is conducted according to material formula and gray value in the software. Afterwards, datas are inputted in ANSYS14.0 for finite element simulation experiment. Calculate stess in collum femoris and channel where stress is concentrated on. Ten nodes in stress concentration are selected on average, and mean value is calculated. Results Through finite element analysis, in stage Ⅰ, Ⅱ,and Ⅲ, after some stress is loaded, femoral head stress and femoral head strain are compared in foramina singulare CD and five-foramina HCD. The analysis of data from openings in femoral head and tuberosity by CD shows： for ANFH,whether in stage Ⅰ or Ⅲ, after decompression, HCD is better than foramina singulare CD in the aspect of stress and strain.Decompression through multi-channel is more stable and safer. Conclusion HCD is easy to operate and popularize in clinic with the characteristic of definite therapeutic effect, minimal trauma, few bleeding in surgery and quick recovery after surgery.