Small S R, Rogge R D, Malinzak R A, Reyes E M, Cook P L, Farley K A, Ritter M A
JRSI Foundation, Inc., 1199 Hadley Road, Mooresville, IN 46158, USA
JRSI Foundation, Inc., 1199 Hadley Road, Mooresville, IN 46158, USA.
Bone Joint Res. 2016 Apr;5(4):122-9. doi: 10.1302/2046-3758.54.2000481.
Initial stability of tibial trays is crucial for long-term success of total knee arthroplasty (TKA) in both primary and revision settings. Rotating platform (RP) designs reduce torque transfer at the tibiofemoral interface. We asked if this reduced torque transfer in RP designs resulted in subsequently reduced micromotion at the cemented fixation interface between the prosthesis component and the adjacent bone.
Composite tibias were implanted with fixed and RP primary and revision tibial trays and biomechanically tested under up to 2.5 kN of axial compression and 10° of external femoral component rotation. Relative micromotion between the implanted tibial tray and the neighbouring bone was quantified using high-precision digital image correlation techniques.
Rotational malalignment between femoral and tibial components generated 40% less overall tibial tray micromotion in RP designs than in standard fixed bearing tibial trays. RP trays reduced micromotion by up to 172 µm in axial compression and 84 µm in rotational malalignment models.
Reduced torque transfer at the tibiofemoral interface in RP tibial trays reduces relative component micromotion and may aid long-term stability in cases of revision TKA or poor bone quality.Cite this article: Mr S. R. Small. Micromotion at the tibial plateau in primary and revision total knee arthroplasty: fixed versus rotating platform designs. Bone Joint Res 2016;5:122-129. DOI: 10.1302/2046-3758.54.2000481.
在初次和翻修全膝关节置换术（TKA）中，胫骨托的初始稳定性对于手术的长期成功至关重要。旋转平台（RP）设计可减少胫股界面的扭矩传递。我们探讨了RP设计中这种扭矩传递的减少是否会导致假体部件与相邻骨之间的骨水泥固定界面处的微动随之减少。
将复合胫骨植入固定和RP初次及翻修胫骨托，并在高达2.5 kN的轴向压缩和10°的股骨部件外旋下进行生物力学测试。使用高精度数字图像相关技术对植入的胫骨托与相邻骨之间的相对微动进行量化。
在RP设计中，股骨和胫骨部件之间的旋转排列不齐导致胫骨托的整体微动比标准固定承重胫骨托少40%。在轴向压缩模型中，RP托可将微动减少多达172 µm，在旋转排列不齐模型中可减少84 µm。
RP胫骨托在胫股界面处扭矩传递的减少降低了部件之间的相对微动，并可能有助于翻修TKA或骨质量较差病例的长期稳定性。引用本文：S. R. Small先生。初次和翻修全膝关节置换术中胫骨平台的微动：固定平台与旋转平台设计。骨关节研究2016；5：122 - 129。DOI：10.1302/2046 - 3758.54.2000481。
