人工颈椎间盘置换术后异位骨化三维有限元模型的建立与意义

目的建立包含完整下颈椎(C_3-C_7)的C_(5/6)节段人工颈椎间盘置换(cervical disc replacement,CDR)术后异位骨化(heterotopic ossification,HO)三维有限元模型,为CDR术后HO生物力学相关研究提供基础模型。方法将健康志愿者颈椎CT的DICOM格式数据依次使用Mimics 16.0、Geomagic 12.0及Pro/Engineer 5.0软件构建包含C_3-C_7颈椎的C_(5/6)节段CDR术后HO三维有限元模型,并观察HO对手术节段活动度和小关节压力的影响。结果本研究建立了CDR术后HO三维有限元模型,共包含394 198个单元和765 411个节点。运动加载结果显示HO发生后手术节段活动度有不同程度的下降,曲伸、侧弯及旋转活动较无HO模型减少分别20.6%、14.3%及11.3%;手术节段后方小关节应力在HO发生后在不同工况下有不同程度的下降,后伸、左侧弯、右侧弯、左旋转及旋转活动较无HO模型减少分别4.1%、3.7%、10.7%、26%及12.1%。结论本研究成功构建了包含C_3-C_7下颈椎的C_(5/6)节段CDR术后HO三维有限元模型,为CDR术后HO的生物力学相关研究提供了基础模型。

Development and significance of three-dimensional finite element model of cervical disc replacement with postoperative heterotopic ossification

Objective To develop a three-dimensional finite element (FE) model of C3-C7 with artificial disc prosthesis (Prestige-LP) integrated at the C5-C6 segment for cervical disc replacement (CDR) with postoperative heterotopic ossification (HO), and to provide a basic model for the study of biomechanics of CDR with HO. Methods One case of male healthy volunteer was selected and scanned with 64-slice spiral CT, and the acquired data were used to import into Mimics 16.0, Geomagic 12.0, and Pro/Engineer 5.0 software for three-dimensional reconstruction of C3-C7 FE model of C5/6 segment CDR with HO. Then, the above mentioned FE models were imported into ANSYS 16.0 software and the operative level kinematics and facet joint force were analyzed. The developed C3-C7 FE model was accurate and validated. Results The CDR with HO FE model had 394 198 elements and 765 411 nodes, so it was highly accurate. The ROM in flexion-extension, lateral bending, and axial torsion of operative segment after CDR with HO was decreased by 20.6%, 14.3%, and 11.3% compared with CDR without HO FE model. Similarly, the facet joint force of operative segment in extension, left lateral bending, right lateral bending, left axial torsion, and right axial torsion after CDR with HO was decreased by 4.1%, 3.7%, 10.7%, 26%, and 12.1%. Conclusion This study successfully developed a three-dimensional C3-C7 FE model of C5/6 segment CDR with HO. This FE model could be used to provide a basic model for the study of biomechanics of CDR with HO.