Boudali A Mounir, Shatrov Jobe, Abe Koki, Zavala Marcus, Parker David, Walter William L, Clarke Elizabeth
Murray Maxwell Biomechanics Laboratory, Kolling Institute, Northern Sydney Local Health District, 10 Westbourne St, St Leonards, NSW 2065, Australia.
Landmark Orthopaedics, Level 2, 500 Pacific Highway, St Leonards, NSW 2065, Australia.
SICOT J. 2025;11:49. doi: 10.1051/sicotj/2025043. Epub 2025 Aug 26.
Complications arising from the patellofemoral joint (PFJ) represent the third most common cause for revision in total knee arthroplasty (TKA). Previous in vitro biomechanical studies have altered the native attachments of muscles controlling the PFJ. The purpose of this study was to design an in vitro biomechanical setup that would allow testing of both native and arthroplasty knee joints, specifically the PFJ, without disturbing the native attachments of the quadriceps and hamstrings muscles.
After finalising a prototype, a pelvis-to-toe human cadaver specimen was tested. The simVITRO platform was used to simulate movement and control force trajectories. A motion capture system was used to capture the motion of the bones and to measure knee flexion angle and patellar movement with respect to the femur. The forces applied in the PFJ were measured using a custom patella sensor.
Displacement of the reflective cluster attached to the femur was measured during compression loading at different flexion angles, passive flexion and stairs descent trajectory. The femur showed less than 1 mm and 3 mm displacement with respect to the femur clamp in passive flexion and stairs descent. The most translation of 8.37 mm (<2% average femur length) was observed at 90° flexion which occurred at 483 N simulated compression force.
This novel design provides a methodology for studying the biomechanics of the PFJ in vitro that preserves the soft tissues influencing the behaviour of the joint. This setup provides a biomechanics model that can be utilised to better understand and study the PFJ in vitro.
髌股关节（PFJ）引发的并发症是全膝关节置换术（TKA）翻修的第三大常见原因。以往的体外生物力学研究改变了控制PFJ的肌肉的天然附着点。本研究的目的是设计一种体外生物力学装置，能够对天然膝关节和人工膝关节，特别是PFJ进行测试，而不干扰股四头肌和腘绳肌的天然附着点。
在确定原型后，对一具从骨盆到脚趾的人体尸体标本进行了测试。使用simVITRO平台模拟运动并控制力轨迹。使用运动捕捉系统捕捉骨骼的运动，并测量膝关节屈曲角度以及髌骨相对于股骨的运动。使用定制的髌骨传感器测量PFJ施加的力。
在不同屈曲角度的压缩加载、被动屈曲和下楼梯轨迹过程中，测量了附着在股骨上的反光标记簇的位移。在被动屈曲和下楼梯时，股骨相对于股骨夹具的位移小于1毫米和3毫米。在90°屈曲时，观察到最大位移为8.37毫米（<平均股骨长度的2%），此时模拟压缩力为483牛。
这种新颖的设计提供了一种在体外研究PFJ生物力学的方法，该方法保留了影响关节行为的软组织。这种装置提供了一个生物力学模型，可用于在体外更好地理解和研究PFJ。
