Shaat Mohamed
Department of Mechanical and Aerospace Engineering, New Mexico State University, Las Cruces, NM 88003 e-mails: .
J Biomech Eng. 2017 Oct 1;139(10). doi: 10.1115/1.4037561.
In this study, the fatigue characteristics of femoral and tibial locking compression plate (LCP) implants are determined accounting for the knee biomechanics during the gait. A biomechanical model for the kinematics and kinetics of the knee joint during the complete gait cycle is proposed. The rotations of the femur, tibia, and patella about the knee joint during the gait are determined. Moreover, the patellar-tendon force (PT), quadriceps-tendon force (QT), the tibiofemoral joint force (TFJ), and the patellofemoral joint force (PFJ) through the standard gait cycle are obtained as functions of the body weight (BW). On the basis of the derived biomechanics of the knee joint, the fatigue factors of safety along with the fatigue life of 316L stainless steel femoral and tibial LCP implants are reported as functions of the BW and bone fracture location, for the first time. The reported results reveal that 316L stainless steel LCP implants for femoral surgeries are preferred for conditions in which the bone fracture is close to the knee joint and the BW is less than 80 kg. For tibial surgeries, 316L stainless steel LCP implants can be used for conditions in which the bone fracture is close to the knee joint and the BW is less than 100 kg. This study presents a critical guide for the determination of the fatigue characteristics of LCP implants. The obtained results reveal that the fatigue analyses should be performed on the basis of the body biomechanics to guarantee accurate designs of LCP implants for femoral and tibial orthopedic surgeries.
在本研究中，考虑到步态期间的膝关节生物力学，确定了股骨和胫骨锁定加压接骨板（LCP）植入物的疲劳特性。提出了一个用于完整步态周期中膝关节运动学和动力学的生物力学模型。确定了步态期间股骨、胫骨和髌骨围绕膝关节的旋转。此外，还获得了整个标准步态周期中髌腱力（PT）、股四头肌肌腱力（QT）、胫股关节力（TFJ）和髌股关节力（PFJ）作为体重（BW）的函数。基于推导得出的膝关节生物力学，首次报告了316L不锈钢股骨和胫骨LCP植入物的疲劳安全系数以及疲劳寿命作为BW和骨折位置的函数。报告结果表明，对于骨折靠近膝关节且BW小于80 kg的情况，股骨手术首选316L不锈钢LCP植入物。对于胫骨手术，316L不锈钢LCP植入物可用于骨折靠近膝关节且BW小于100 kg的情况。本研究为确定LCP植入物的疲劳特性提供了关键指导。所得结果表明，应基于人体生物力学进行疲劳分析，以确保股骨和胫骨骨科手术中LCP植入物的准确设计。
