Matsumoto Tomoyuki, Muratsu Hirotsugu, Tsumura Nobuhiro, Mizuno Kiyonori, Kuroda Ryosuke, Yoshiya Shinichi, Kurosaka Masahiro
J Biomech Eng. 2006 Dec;128(6):867-71. doi: 10.1115/1.2354201.
The management of soft tissue balance during surgery is essential for the success of total knee arthroplasty (TKA) but remains difficult, leaving it much to the surgeon's feel. Previous assessments for soft tissue balance have been performed under unphysiological joint conditions, with patellar eversion and without the prosthesis only at extension and 90 deg of flexion. We therefore developed a new tensor for TKA procedures, enabling soft tissue balance assessment throughout the range of motion while reproducing postoperative joint alignment with the patellofemoral (PF) joint reduced and the tibiofemoral joint aligned. Our purpose in the present study was to clarify joint gap kinematics using the tensor with the CT-free computer assisted navigation system.
Joint gap kinematics, defined as joint gap change during knee motion, was evaluated during 30 consecutive, primary posterior-stabilized (PS) TKA with the navigation system in 30 osteoarthritic patients. Measurements were performed using a newly developed tensor, which enabled the measurement of the joint gap throughout the range of motion, including the joint conditions relevant after TKA with PF joint reduced and trial femoral component in place. Joint gap was assessed by the tensor at full extension, 5 deg, 10 deg, 15 deg, 30 deg, 45 deg, 60 deg, 90 deg, and 135 deg of flexion with the patella both everted and reduced. The navigation system was used to obtain the accuracy of implantations and to measure an accurate flexion angle of the knee during the intraoperative joint gap measurement.
Results showed that the joint gap varied depending on the knee flexion angle. Joint gap showed an accelerated decrease during full knee extension. With the PF joint everted, the joint gap increased throughout knee flexion. In contrast, the joint gap with the PF joint reduced increased with knee flexion but decreased after 60 deg of flexion.
We clarified the characteristics of joint gap kinematics in PS TKA under physiological and reproducible joint conditions. Our findings can provide useful information for prosthetic design and selection and allow evaluation of surgical technique throughout the range of knee motion that may lead to consistent clinical outcomes after TKA.
手术过程中软组织平衡的管理对于全膝关节置换术（TKA）的成功至关重要，但仍然具有挑战性，很大程度上依赖于外科医生的手感。以往对软组织平衡的评估是在非生理关节条件下进行的，仅在伸直位和90度屈曲位时进行髌骨外翻且不安装假体的情况下评估。因此，我们开发了一种用于TKA手术的新型张量仪，能够在整个运动范围内评估软组织平衡，同时在减少髌股（PF）关节并使胫股关节对线的情况下再现术后关节对线。我们在本研究中的目的是使用该张量仪结合无CT计算机辅助导航系统来阐明关节间隙运动学。
在30例骨关节炎患者中，使用导航系统对30例连续的初次后稳定型（PS）TKA进行关节间隙运动学评估，关节间隙运动学定义为膝关节运动过程中的关节间隙变化。使用新开发的张量仪进行测量，该张量仪能够在整个运动范围内测量关节间隙，包括在减少PF关节并安装试验股骨组件后的TKA相关关节条件下。在髌骨外翻和复位的情况下，通过张量仪在伸直位、5度、10度、15度、30度、45度、60度、90度和135度屈曲位评估关节间隙。导航系统用于获得植入的准确性，并在术中关节间隙测量期间测量膝关节的准确屈曲角度。
结果表明，关节间隙随膝关节屈曲角度而变化。在膝关节完全伸直过程中，关节间隙呈加速减小。当PF关节外翻时，关节间隙在整个膝关节屈曲过程中增大。相比之下，PF关节复位时的关节间隙随膝关节屈曲而增加，但在屈曲60度后减小。
我们阐明了在生理和可重复的关节条件下PS TKA中关节间隙运动学的特征。我们的研究结果可为假体设计和选择提供有用信息，并允许在整个膝关节运动范围内评估手术技术，这可能导致TKA术后获得一致的临床结果。
