Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Department of Surgery, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Imaging Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
Department of Medical Biophysics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada; Imaging Group, Robarts Research Institute, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
J Arthroplasty. 2023 Jun;38(6):1166-1171. doi: 10.1016/j.arth.2023.03.002. Epub 2023 Mar 7.
There has been a recent increase in the use of cementless fixation for primary total knee arthroplasty. While the early results of contemporary cementless implants are promising, understanding the behavior of cementless tibial baseplates under loading remains an ongoing interest. The objective of this study was to identify the pattern of displacement that occurred under loading for a single cementless tibial baseplate design at one year post operation for stable and continuously migrating implants.
There were 28 subjects from a previous trial of a pegged highly porous cementless tibial baseplate evaluated. Subjects underwent supine radiostereometric exams from two weeks through one year after surgery. At one year, subjects also underwent a standing radiostereometric exam. Fictive points on the tibial baseplate model were used to relate translations to anatomical locations. Migration over time was calculated to determine if subjects displayed stable or continuous migration. The magnitude of inducible displacement between the supine and standing exams was calculated.
Inducible displacement patterns were similar between stable and continuously migrating tibial baseplates. Displacements were greatest in the anterior-posterior axis followed by the lateral-medial axis. Correlation of displacements between adjacent fictive points in these axes indicated an axial rotation of the baseplate occurred under loading (r = 0.689-0.977, P < .001). Less displacement occurred in the superior-inferior axis and correlations indicated an anterior-posterior tilt of the baseplate occurred under loading (r = 0.178-0.226, P = .009-.023).
From supine to standing position the predominant pattern of displacement for this cementless tibial baseplate was axial rotation, with some subjects also displaying an anterior-posterior tilt.
近年来，在初次全膝关节置换术中，非骨水泥固定的应用有所增加。虽然现代非骨水泥植入物的早期结果很有前景，但了解负载下非骨水泥胫骨基板的行为仍然是一个持续的关注点。本研究的目的是确定在稳定和持续迁移植入物的情况下，一种非骨水泥胫骨基板设计在术后一年的加载下发生的位移模式。
对先前使用带钉高多孔非骨水泥胫骨基板进行的试验中的 28 名受试者进行评估。受试者在手术后两周至一年期间接受仰卧位放射立体测量检查。在一年时，受试者还接受了站立位放射立体测量检查。使用胫骨基板模型上的虚构点将平移与解剖位置相关联。计算随时间的迁移量，以确定受试者是否显示稳定或持续迁移。计算仰卧位和站立位检查之间的诱导位移量。
稳定和持续迁移的胫骨基板之间的诱导位移模式相似。在前后轴上的位移最大，其次是外侧-内侧轴。这些轴上相邻虚构点之间的位移相关性表明在加载下发生了基板的轴向旋转（r=0.689-0.977，P<.001）。在上下轴上的位移较小，相关性表明在加载下发生了基板的前后倾斜（r=0.178-0.226，P=.009-.023）。
从仰卧位到站立位，这种非骨水泥胫骨基板的主要位移模式是轴向旋转，一些受试者还显示出前后倾斜。
