Bozkurt Murat, Akkaya Mustafa, Tahta Mesut, Gursoy Safa, Firat Ahmet
Department of Orthopedics and Traumatology, Yildirim Beyazit University Faculty of Medicine, Ankara, Turkey.
Department of Orthopaedics and Traumatology, Yenimahalle Training and Research Hospital, Yildirim Beyazit University, Ankara, Turkey.
Clin Orthop Surg. 2017 Sep;9(3):280-285. doi: 10.4055/cios.2017.9.3.280. Epub 2017 Aug 4.
Ideal positioning and best coverage of the tibial base plate are essential in total knee arthroplasty. There are 2 types of tibial base plates: symmetric and asymmetric. The superiority of one to the other is still controversial. The aim of this study was to compare symmetric and asymmetric tibial base plates for total knee arthroplasty in terms of rotational alignment and coverage.
The study was conducted on a total of 80 cadaveric tibial bones. Two surgeons were asked to place 20 symmetric (group 1) and 20 asymmetric (group 2) tibial base plates taking care to ensure the best coverage that they were able to determine. Afterwards, the rotational errors and coverage were assessed with reference to the posterior tibial margin and posterior condylar axis on the three-dimensional computed tomography (3D CT) scan. In the second part of the study, the surgeons were asked to place 20 symmetric (group 3) and 20 asymmetric (group 4) base plates taking care to ensure the best rotational alignment. The rotational errors and the areas uncovered or overstuffed after the application were measured on the 3D CT scan.
On the comparison of rotational errors, while there was no significant difference between group 1 and group 2 in terms of coverage ( = 0.624), the mean external rotation error was significantly greater in group 2 ( = 0.034). On the comparison of coverage, while there was no significant difference between group 3 and group 4 in terms of rotation ( = 0.36), the mean ratios of the uncovered tibial surface to the total tibial surface ( = 0.041) and also the overstuffed area to the total base plate surface ( = 0.029) were significantly greater in group 4.
The determination of correct size and rotation of the tibial component is essential for favorable outcomes of total knee arthroplasty. In this study, the symmetric tibial base plate design was more effective than the asymmetric design in providing the ideal tibial rotation and coverage.
在全膝关节置换术中，胫骨基板的理想定位和最佳覆盖至关重要。胫骨基板有两种类型：对称型和非对称型。两者孰优孰劣仍存在争议。本研究的目的是比较对称型和非对称型胫骨基板在全膝关节置换术中的旋转对线和覆盖情况。
本研究共对80具尸体胫骨进行。要求两名外科医生分别放置20个对称型（第1组）和20个非对称型（第2组）胫骨基板，注意确保达到他们所能确定的最佳覆盖。之后，在三维计算机断层扫描（3D CT）上，参照胫骨后缘和后髁轴评估旋转误差和覆盖情况。在研究的第二部分，要求外科医生分别放置20个对称型（第3组）和20个非对称型（第4组）基板，注意确保达到最佳旋转对线。在3D CT上测量应用后出现的旋转误差以及未覆盖或填充过多的区域。
在旋转误差比较方面，第1组和第2组在覆盖方面无显著差异（ = 0.624），但第2组的平均外旋误差显著更大（ = 0.034）。在覆盖比较方面，第3组和第4组在旋转方面无显著差异（ = 0.36），但第4组未覆盖胫骨表面与胫骨总表面的平均比率（ = 0.041）以及填充过多区域与基板总表面的平均比率（ = 0.029）显著更大。
确定胫骨部件的正确尺寸和旋转对于全膝关节置换术取得良好效果至关重要。在本研究中，对称型胫骨基板设计在提供理想的胫骨旋转和覆盖方面比非对称型设计更有效。
