Chen Zhenxian, Gao Yongchang, Chen Shibin, Zhang Qida, Zhang Zhifeng, Zhang Jing, Zhang Xuan, Jin Zhongmin
Key Laboratory of Road Construction Technology and Equipment of MOE, Chang'an University, Xi'an, China.
State Key Laboratory for Manufacturing System Engineering, School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, China.
Proc Inst Mech Eng H. 2018 Dec;232(12):1209-1218. doi: 10.1177/0954411918811855. Epub 2018 Nov 21.
The uses of mechanical and kinematic alignments in total knee arthroplasty are under debate in recent clinical investigations. In this study, the differences in short-term biomechanics and long-term wear volume between mechanical and kinematic alignments in total knee arthroplasty were investigated, based on a subject-specific musculoskeletal multi-body dynamics model during walking gait simulation. An increase of 8.2% in the peak tibiofemoral medial contact force, a posterior contact translation by maximum 4.7 mm and a decrease of 5.5% in the wear volume after a 10-million-cycle simulation were predicted in the kinematic alignment, compared with the mechanical alignment. Nevertheless, the tibiofemoral contact mechanics, the range of motions and the long-term wear were not markedly different between mechanical and kinematic alignments. Furthermore, the mechanical alignment with a posterior tibial slope similar to that under the kinematic alignment was found to produce similar anterior-posterior translation and the range of motion, and an approximate wear volume, compared with the kinematic alignment. The ligament forces under the kinematic alignment were influenced markedly by as much as 25%, 50% and 77% for the medial collateral ligament, lateral collateral ligament and posterior cruciate ligament forces, respectively. And, a maximum increase of 40% for patellofemoral contact force was predicted under the kinematic alignment. These findings suggest that the kinematic alignment is an alternative alignment principle but no marked advantages in biomechanics and wear to the mechanical alignment. The adverse effects of the kinematic alignment on patella loading and soft tissue forces should be noticed.
全膝关节置换术中机械对线和运动学对线的应用在近期的临床研究中存在争议。在本研究中，基于步行步态模拟期间的个体特异性肌肉骨骼多体动力学模型，研究了全膝关节置换术中机械对线和运动学对线在短期生物力学和长期磨损量方面的差异。与机械对线相比，运动学对线在1000万次循环模拟后预测胫股内侧接触力峰值增加8.2%，接触后移最大4.7毫米，磨损量减少5.5%。然而，机械对线和运动学对线之间的胫股接触力学、运动范围和长期磨损没有明显差异。此外，发现与运动学对线具有相似后胫骨坡度的机械对线与运动学对线相比，产生相似的前后平移和运动范围以及近似的磨损量。运动学对线时，内侧副韧带、外侧副韧带和后交叉韧带的韧带力分别受到高达25%、50%和77%的显著影响。并且，预测运动学对线时髌股接触力最大增加40%。这些发现表明，运动学对线是一种替代的对线原则，但在生物力学和磨损方面对机械对线没有明显优势。应注意运动学对线对髌骨负荷和软组织力的不利影响。
