Institute for Biomechanics, ETH Zurich , Leopold-Ruzicka-Weg 4, 8093 Zürich , Switzerland.
J R Soc Interface. 2019 Feb 28;16(151):20180678. doi: 10.1098/rsif.2018.0678.
Although total knee arthroplasty (TKA) has become a standard surgical procedure for relieving pain, knowledge of the in vivo knee joint kinematics throughout common functional activities of daily living is still missing. The goal of this study was to analyse knee joint motion throughout complete cycles of daily activities in TKA subjects to establish whether a significant difference in joint kinematics occurs between different activities. Using dynamic videofluoroscopy, we assessed tibio-femoral kinematics in six subjects throughout complete cycles of walking, stair descent, sit-to-stand and stand-to-sit. The mean range of condylar anterior-posterior translation exhibited clear task dependency across all subjects. A significantly larger anterior-posterior translation was observed during stair descent compared to level walking and stand-to-sit. Local minima were observed at approximately 30° flexion for different tasks, which were more prominent during loaded task phases. This characteristic is likely to correspond to the specific design of the implant. From the data presented in this study, it is clear that the flexion angle alone cannot fully explain tibio-femoral implant kinematics. As a result, it seems that the assessment of complete cycles of the most frequent functional activities is imperative when evaluating the behaviour of a TKA design in vivo.
尽管全膝关节置换术（TKA）已成为缓解疼痛的标准手术程序，但对于 TKA 患者在日常常见功能活动中的体内膝关节运动学仍知之甚少。本研究的目的是分析 TKA 患者在日常活动的完整周期中的膝关节运动，以确定不同活动之间是否存在关节运动学的显著差异。使用动态荧光透视术，我们评估了 6 名受试者在行走、下楼梯、从坐到站和从站到坐等完整周期中的胫股关节运动学。所有受试者的髁间前后平移的平均范围均表现出明显的任务依赖性。与平地行走和从站到坐相比，下楼梯时观察到明显更大的前后平移。在不同任务中，大约 30°屈曲时观察到局部最小值，在负重任务阶段更为明显。这种特征可能与植入物的特定设计相对应。从本研究提供的数据可以清楚地看出，仅屈曲角度不能完全解释胫股植入物的运动学。因此，在体内评估 TKA 设计的行为时，似乎必须评估最常见功能活动的完整周期。
