Hananouchi Takehito, Yamamoto Kengo, Ando Wataru, Fudo Kazumasa, Ohzono Kenji
Department of Orthopaedic Surgery, Kansai Rosai Hospital, 1-69, Inabasou 3 chome, Amagasaki Hyogo 660-8511, Japan.
Knee. 2012 Oct;19(5):601-5. doi: 10.1016/j.knee.2011.08.001. Epub 2011 Sep 1.
A Tensor/Balancer device has been recently developed in order to assess soft tissue balancing in total knee arthroplasty (TKA) under more physiological conditions. This device allows us to measure the joint gap with a trial femoral component in place with the patella reduced. The purpose of this study was to clarify whether the placement of the component changes the intraoperative gap difference (flexion gap distance minus extension gap distance). We prospectively investigated the extension (0°) and flexion (90°) gaps in 73 posterior-stabilized TKAs under 30 lb of joint distraction force. Then, we compared the gap difference with and without the trial femoral component in place. Our results showed that the intraoperative gap difference with the trial femoral component in place was larger than the intraoperative gap difference without the trial component (p=0.00003; with the trial component: mean 4.7 mm (standard deviation (SD): 3.0mm); without the trial component: mean 2.7 mm (SD: 3.3mm)). We consider that the change in gap difference with or without femoral component was caused by a relative difference in the elasticity and/or tightness of the soft tissue in extension versus flexion. Surgeons should be aware of this effect of the femoral component when considering intraoperative soft tissue balancing which leads to postoperative stability of the knee joint consequently.
最近研发了一种张量/平衡器装置，用于在更接近生理条件下评估全膝关节置换术（TKA）中的软组织平衡。该装置使我们能够在髌骨复位且安装试验股骨组件的情况下测量关节间隙。本研究的目的是阐明组件的放置是否会改变术中间隙差异（屈曲间隙距离减去伸展间隙距离）。我们前瞻性地研究了73例后稳定型TKA在30磅关节牵张力下的伸展（0°）和屈曲（90°）间隙。然后，我们比较了安装和未安装试验股骨组件时的间隙差异。我们的结果表明，安装试验股骨组件时的术中间隙差异大于未安装试验组件时的术中间隙差异（p = 0.00003；安装试验组件时：平均4.7毫米（标准差（SD）：3.0毫米）；未安装试验组件时：平均2.7毫米（SD：3.3毫米））。我们认为，安装或未安装股骨组件时间隙差异的变化是由伸展与屈曲时软组织弹性和/或紧张度的相对差异引起的。在考虑术中软组织平衡时，外科医生应意识到股骨组件的这种影响，而这会进而影响膝关节术后的稳定性。
