Wang H, Simpson K J, Chamnongkich S, Kinsey T, Mahoney O M
Department of FNES, Queens College, 203 Fitzgerald Gym., Flushing, NY 11367, USA.
Clin Biomech (Bristol). 2005 May;20(4):428-33. doi: 10.1016/j.clinbiomech.2004.12.003. Epub 2005 Jan 19.
Compared to the design of a traditional multi-axis total knee arthroplasty, the single-axis arthroplasty studied has a fixed flexion/extension center of rotation in the femoral component. The influence of this characteristic on functional daily activity, i.e., stand-to-sit, is not well understood. The purpose of this study was to investigate the effect of different arthroplasty designs on knee kinematic and lower limb muscular activation for the stand-to-sit movement.
Sixteen unilateral, posterior-stabilized knee arthroplasty participants (8 single-axis and 8 multi-axis) with excellent Knee Society scores performed 4 trials of the stand-to-sit test. Three-dimensional video analysis of whole body and joint kinematics and electromyography analysis of quadriceps and hamstrings were conducted. One-way ANOVAs were used for statistical analyses (alpha=0.05).
The multi-axis group showed some functional adaptations while sitting down. The single-axis group exhibited less arthroplasty limb quadriceps electromyography and hamstring co-activation electromyography than the multi-axis group. For the arthroplasty limb, single-axis demonstrated less abduction angular displacement and reached peak abduction earlier than the multi-axis arthroplasty limb. The estimated effect size for this study was 0.196.
The single-axis design requires less eccentric knee extensor muscle activation and exhibits greater medio-lateral stability than the multi-axis designs. Findings from this study could provide useful information to orthopedic knee surgeons and rehabilitative specialists.
与传统多轴全膝关节置换术的设计相比，所研究的单轴置换术在股骨部件中具有固定的屈伸旋转中心。这种特性对日常功能活动（即从站立到坐下）的影响尚不清楚。本研究的目的是调查不同置换术设计对从站立到坐下运动时膝关节运动学和下肢肌肉激活的影响。
16名膝关节协会评分优异的单侧后稳定型膝关节置换术参与者（8名单轴和8名多轴）进行了4次从站立到坐下测试的试验。对全身和关节运动学进行三维视频分析，并对股四头肌和腘绳肌进行肌电图分析。采用单因素方差分析进行统计分析（α = 0.05）。
多轴组在坐下时表现出一些功能适应性。单轴组置换术肢体的股四头肌肌电图和腘绳肌共同激活肌电图比多轴组少。对于置换术肢体，单轴组的外展角位移较小，且比多轴置换术肢体更早达到外展峰值。本研究的估计效应量为0.196。
与多轴设计相比，单轴设计需要较少的偏心膝关节伸肌激活，并且表现出更大的中外侧稳定性。本研究结果可为骨科膝关节外科医生和康复专家提供有用信息。
