组配式人工半骨盆假体重建的生物力学分析  

Biomechanical analysis of pelvic reconstruction with modular henri-pelvic prosthesis

作　　者：姬涛[1] 郭卫[1] 董森[1] 郝智秀[2] 高相飞[2] 

机构地区：[1]北京大学人民医院骨与软组织肿瘤治疗中心,100044 [2]清华大学精密仪器与机械学系

出　　处：《中华骨科杂志》2009年第10期954-959,共6页Chinese Journal of Orthopaedics

摘　　要：目的探讨组配式人工半骨盆假体重建后骨盆生物力学改变及假体力学结构特点。方法（1）建立正常骨盆的三维有限元模型和离体试验骨盆模型。于骨盆表面选取8个特征测点，在相同的载荷及边界条件下，利用有限元模型计算测点表面应力（σFEM），通过离体试验测量测点应变值，并计算标本表面应力（σEXP）。对σFEM和σEXP进行线性回归分析验证。（2）利用验证的正常骨盆有限元模型进行左侧骨盆缺损（Ⅱ＋Ⅲ区）及人工假体重建模型的建模。计算重建骨盆健侧特征测点的表面应力（σRS）及患侧髂骨截骨处内、外侧皮质表面应力（σRR），分别与正常骨盆相同位置测点应力值（σNS，σNR）进行比较。（3）分析假体应力传导结构表面应力分布特点及应力集中部位。结果（1）骨盆有限元计算结果与离体试验结果有良好的一致性（R^2=0．87），模型仿真度较高。（2）重建后健侧特征测点σRS与正常骨盆σNS近似（t=1．81，P=0．08）。患侧髂骨截骨处内侧皮质σRR与σNR差异无统计学意义（t=0．47，P=0．65），外侧皮质σRR明显高于σNR（t=2．78，P=0．02）。（3）假体应力传导结构主要由后侧传导。应力集中部位位于下排钉孔周围、髂骨固定座与侧面固定翼片连接处、人工髋臼与髂骨固定连接处，系统应力峰值（183MPa）位于人工髋臼与髂骨固定座连接部位。结论组配式人工半骨盆假体重建符合骨盆生物力学特点，较好地恢复了应力传导。Objective To analysis the biomechanical characteristics of the reconstructed pelvis with modular hemi-pelvic prosthesis by finite element （FE） method. Methods A subject-specific finite element model of pelvis was established. Th experiment was performed on the same cadaveric pelvis. Eight points on the surface of cortical bone was determined. Both the same load and boundary conditions were applied on the FE model and experiment. The stress by experiment （σEXP） was calculated based on the data collected from the strain discs. Linear regression was performed with the stress predicted by FE model （σFEM） and experiment data to validate the FE model. A defect pelvic （with zone Ⅱ ＋ Ⅲ in left hemi-pelvis） FE model was constructed and assembled with the prosthesis. The stress distribution on the contra lateral hemi-pelvis was calculated by the reconstructed pelvic FE model （σRS）, and the results were compared with that of the normal pelvis （σNS）. Also the comparison was done at the resection level of the affected hemi-pelvis between normal pelvic FE model （σNR） and reconstructed model （σRR） both on medial and lateral cortical bone of the pelvis. Structural analysis was performed on the whole set of implant. Results FE predictions were strongly correlated with experimental results （R^2=0.87）. No significant difference was found between the σRS and σNS （t=1.81, P=0.08）. Regarding to the stress distribution at iliac resection level, no difference was found between σNR and σRR on the medial side （t=0.47, P=0.65）. However, on the lateral side, σRR were significantly higher than the σNR （t=2.78, P=0.02）. The peak stress of the prosthesis was about 183 MPa located at the conjunction of the acetabulum and the iliac fixation part. The main load conduction path on the prosthesis was at the posterior side of column portion part of the iliac fixation. Conclusion Reconstruction with modular hemi-pelvic prosthesis could recover the pelvic biomechanics with rational mech

关 键 词：有限元分析 骨盆 假体和植人物 生物力学 

分 类 号：R686[医药卫生—骨科学]