Kirking Bryan, Krevolin Janet, Townsend Christopher, Colwell Clifford W, D'Lima Darryl D
Orthopaedic Research Laboratories, Shiley Center for Orthopaedic Research & Education at Scripps Clinic, CA, USA.
J Biomech. 2006;39(9):1744-51. doi: 10.1016/j.jbiomech.2005.05.023.
Accurate in vivo measurement of tibiofemoral forces is important in total knee arthroplasty. These forces determine polyethylene stresses and cold-flow, stress distribution in the implant, and stress transfer to the underlying implant bone interface. Theoretic estimates of tibiofemoral forces have varied widely depending on the mathematical models used. The six degrees of freedom of motion, complex articular surface topography, changing joint-contact position, intra- and extra-articular ligaments, number of muscles crossing the knee joint, and the presence of the patellofemoral joint contribute to the difficulty in developing reliable models of the knee. A prototype instrumented total knee replacement tibial prosthesis was designed, manufactured, and tested. This prosthesis accurately measured all six components of tibial forces (R2>0.997). The prosthesis was also instrumented with an internal microtransmitter for wireless data transmission. Remote powering of the sealed implanted electronics was achieved using magnetic coil induction. This device can be used to validate existing models of the knee that estimate these forces or to develop more accurate models. In conjunction with kinematic data, accurate tibiofemoral force data may be used to design more effective knee-testing rigs and wear simulators. Additional uses are intraoperative measurement of forces to determine soft-tissue balancing and to evaluate the effects of rehabilitation, external bracing, and athletic activities, and activities of daily living.
在全膝关节置换术中，准确进行体内胫股关节力的测量非常重要。这些力决定了聚乙烯的应力和冷流、植入物中的应力分布以及应力向植入物下方骨界面的传递。根据所使用的数学模型，胫股关节力的理论估计值差异很大。膝关节的六个运动自由度、复杂的关节表面形态、不断变化的关节接触位置、关节内和关节外韧带、跨越膝关节的肌肉数量以及髌股关节的存在，都增加了建立可靠膝关节模型的难度。设计、制造并测试了一种原型的带传感器的全膝关节置换胫骨假体。该假体能够准确测量胫骨力的所有六个分量（R2>0.997）。该假体还配备了一个内部微型发射器用于无线数据传输。通过电磁感应实现了对密封植入式电子设备的远程供电。该装置可用于验证现有的估计这些力的膝关节模型，或开发更精确的模型。结合运动学数据，准确的胫股关节力数据可用于设计更有效的膝关节测试装置和磨损模拟器。其他用途包括术中测量力，以确定软组织平衡，并评估康复、外部支具和体育活动以及日常生活活动的效果。
