1.首都医科大学;2.首都医科大学 生物医学工程学院;3.首都医科大学附属北京潞河医院 骨关节外科
1.School of Biomedical Engineering,Capital Medical University;2.Department of Orthopaedic Surgery,Beijing Luhe Hospital,Capital Medical University
目的 比较、分析全膝关节置换患者术前、术后步态周期站立相的下肢肌肉激活规律和膝关节受力。方法 基于Opensim平台建立1名健康受试者和3名单侧全膝关节置换患者术前、术后下肢肌骨模型。使用三维动作捕捉系统和测力台采集受试者步行期间下肢运动学数据和地反力作为输入参数，模拟计算下肢肌肉激活和膝关节受力。结果 肌骨模型计算结果与基于三维动作捕捉系统的逆动力学计算结果基本一致。不同于健康受试者，患者股直肌在承重反应期、支撑相中期激活，三名患者术后股四头肌的激活时间与激活程度较术前明显不同。患者术前关节受力峰值为3.15、2.95、3.43倍体重，支撑相中期维持2倍体重以上的载荷。术后关节受力峰值分别2.09、2.48和3.73倍体重。结论 本研究中的肌骨模型计算结果具有一定的可靠性，该模型今后可为全膝关节置换治疗提供生物力学的辅助手段。
Objective To compare and analyze the lower limb muscle activity and knee joint force during the stance periods of gait cycle in patients with osteoarthritis before and after total knee arthroplasty (TKA). Methods Based on the Opensim platform, lower extremity musculoskeletal models of one healthy subject and three patients with osteoarthritis before and after TKA were established. A three-dimensional motion capture system and a force platform were used to collect the lower limb kinematic data and the ground reaction force during walking that were used as input parameters to simulate the lower limb muscle activation and knee joint forces. Results The results from the musculoskeletal model are consistent with the results by the inverse dynamics based on the three-dimensional motion capture system. The patient's rectus femoris is activated in the loading response and mid stance phases, different from healthy subjects. The activation timing and amplitude of the quadriceps muscle in the three patients was significantly different before and after TKA. The patient's peak joint forces before TKA were 2.95, 3.15 and 3.43 times of body weight with the constant load of more than 2 times of body weight during stand phase. The peak joint force after TKA were 2.09, 2.48 and 3.96 times of body weight respectively. The joint force was not improved and the knee function did not reach the normal level six months after TKA. Conclusion The results of the musculoskeletal model in this study have certain reliability, this model can provide a biomechanical auxiliary method for total knee replacement surgery in the future.