Steinbrück Arnd, Schröder Christian, Woiczinski Matthias, Müller Tatjana, Müller Peter E, Jansson Volkmar, Fottner Andreas
Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, University Hospital of Munich (LMU), Campus Grosshadern, Marchioninistr. 15, 81377, Munich, Germany.
Knee Surg Sports Traumatol Arthrosc. 2016 Aug;24(8):2395-401. doi: 10.1007/s00167-015-3503-1. Epub 2015 Jan 11.
Although continuous improvements have been made, there is still a considerable amount of unsatisfied patients after total knee arthroplasty (TKA). A main reason for this high percentage is anterior knee pain, which is supposed to be provoked by post-operative increased retropatellar peak pressure. Since rotational malalignment of the implant is believed to contribute to post-operative pain, the aim of this study was to examine the influence of tibial component rotation on knee kinematics and retropatellar pressure.
Eight fresh-frozen knee specimens were tested in a weight-bearing knee rig after fixed-bearing TKA under a loaded squat from 20° to 120° of flexion. To examine tibial components with different rotations, special inlays with 3° internal rotation and 3° external rotation were produced and retropatellar pressure distribution was measured with a pressure-sensitive film. The kinematics of the patella and the femorotibial joint were recorded with an ultrasonic-based motion analysis system.
Retropatellar peak pressure decreased significantly from 3° internal rotation to neutral position and 3° external rotation of the tibial component (8.5 ± 2.3 vs. 8.2 ± 2.4 vs. 7.8 ± 2.5 MPa). Regarding knee kinematics femorotibial rotation and anterior-posterior translation, patella rotation and tilt were altered significantly, but relative changes remained minimal.
Changing tibial rotation revealed a high in vitro influence on retropatellar peak pressure. We recommend the rotational alignment of the tibial component to the medial third of the tibial tuberosity or even more externally beyond that point to avoid anterior knee pain after TKA.
尽管全膝关节置换术（TKA）已持续改进，但术后仍有相当数量的患者不满意。前膝痛是导致这一高比例的主要原因，推测其由术后髌后峰值压力增加所致。由于植入物的旋转不良被认为会导致术后疼痛，本研究旨在探讨胫骨组件旋转对膝关节运动学和髌后压力的影响。
八具新鲜冷冻膝关节标本在固定平台TKA后，于负重膝关节试验台上进行20°至120°屈曲的负重深蹲测试。为检测不同旋转角度的胫骨组件，制作了3°内旋和3°外旋的特殊嵌体，并用压敏膜测量髌后压力分布。采用基于超声的运动分析系统记录髌骨和股胫关节的运动学情况。
从胫骨组件3°内旋到中立位再到3°外旋，髌后峰值压力显著降低（8.5±2.3 vs. 8.2±2.4 vs. 7.8±2.5MPa）。在膝关节运动学方面，股胫旋转和前后平移、髌骨旋转和倾斜均有显著改变，但相对变化仍很小。
改变胫骨旋转角度在体外对髌后峰值压力有很大影响。我们建议将胫骨组件的旋转对线调整至胫骨结节内侧三分之一处，甚至更向外超出该点，以避免TKA术后前膝痛。
