电针治疗膝骨性关节炎患者上下楼梯的三维有限元分析

针对电针治疗膝骨性关节炎患者上下楼梯运动生物力学特性改变进行有限元仿真研究,对比分析膝关节生物力学行为改变与电针治疗疗效的相关性。基于CT和MRI图像数据,结合Mimics和Geomagic医学图像处理软件,建立人体膝关节下楼梯屈曲15°和上楼梯屈曲50°时的三维有限元模型,模型包括股骨、胫骨、腓骨、内外侧半月板、股骨软骨、内外侧胫骨软骨结构等。通过临床力学实验,测取电针治疗前后膝关节所受支反力、力矩,并施加于所建立的有限元模型,对比分析治疗前后半月板及关节软骨的应力分布情况。膝骨性关节炎在电针治疗后,内外侧半月板、股骨软骨、内外侧胫骨软骨的应力均得到不同程度的恢复,与治疗前相比,下楼梯屈曲15°时最大应力值分别减小0.543、0.236、0.194、0.239和0.327 MPa,上楼梯屈曲50°时分别减少0.253、0.31、0.227、0.112和0.122 MPa,软骨的应力峰值趋向于正常值,应力分布范围也更接近于正常膝关节,且关节内侧软骨及半月板比外侧受到的负荷大,软骨应力比更接近于正常值,这与临床上内侧型膝骨性关节炎患者多于外侧型患者的现象相符合,从而证明电针治疗可影响膝关节中力的传递,使病变膝关节的应力吸收能力得到改善和提高。电针治疗膝骨性关节炎能有效改善关节软骨的压应力,使关节内力平衡得到恢复,延缓关节软骨退变,促进关节软骨的修复;电针治疗下膝关节生物力学特性的研究,可为膝关节临床治疗和评价提供理论依据。

Three-Dimensional Finite Element Analysis of Electroacupuncture for Patients with Knee Osteoarthritis During Ascent and Descent Stair

To explore the availability of finite element analysis method to simulate the biomechanical properties of knee osteoarthritis in the treatment of ascent and descent stair movements, the correlation between the changes of knee biomechanical behavior and the efficacy of electro-acupuncture treatment was compared. Based on image data obtained from CT and MRI, in combination with medical image processing software including Mimics and Geomagic, we established the three-dimensional finite element model of knee flexion 15° downstairs and 50° upstairs. The model included bone and soft tissue structures such as femur and tibia, humerus, medial and lateral meniscus, femoral cartilage, medial and lateral iliac cartilage. The stress distribution of the medial and lateral meniscus, femoral cartilage and medial and lateral tibial cartilage under electroacupuncture treatment were compared by applying the corresponding load on the center of the femoral condyle of the knee joint model of ascent and descent stairs. The research of knee osteoarthritis under electroacupuncture showed that the stress of the medial and lateral meniscus, femoral cartilage, and medial and lateral tibial cartilage was restored to varying degrees after electroacupuncture treatment. The maximum stress at the descent stairs was reduced by 0.543, 0.236, 0.194, 0.239 and 0.327 MPa, respectively. The maximum stress at the ascent stairs was reduced by 0.253, 0.31, 0.227, 0.112 and 0.122 MPa. The stress peak of each cartilage further tends to the normal knee joint, and the stress distribution range was closer to the normal state. The medial cartilage and meniscus of the joint were more loaded than the lateral side, which was consistent with the phenomenon that the clinical medial type of knee osteoarthritis is more than the lateral type. Therefore, it was demonstrated that electroacupuncture treatment could affect the transmission of the force in the knee joint, delay the degradation of cartilage in various parts of the knee joint, and make the stress ratio of each cartilage closer to the normal value. Therefore, the stability of the diseased knee joint was improved. In conclusion, the electroacupuncture treatment could effectively alleviate the stress concentration of articular cartilage in patients with knee osteoarthritis. The biomechanical properties of knee osteoarthritis under electroacupuncture could provide a theoretical basis for the treatment options of clinical knee joints.