Abstract：
BACKGROUND: There is an increasing number of different brands of robotic total knee arthroplasty (TKA) systems. Most robotic TKA systems share the same coronal alignment, while the definitions of sagittal alignment vary. The purpose of this study was to investigate whether these discrepancies impact the sagittal alignment of the lower extremity.
METHODS: A total of 72 lower extremity computed tomography scans were included in our study, and 3-dimensional models were obtained using software. A total of 7 brands of robotic TKA systems were included in the study. The lower extremity axes were defined based on the surgical guide for each implant. We also set the intramedullary axis as a reference to evaluate the discrepancies in sagittal alignment of each brand of robotic system.
RESULTS: On the femoral side, the axis definition was the same for all 7 robotic TKA systems. The robotic TKA axes showed a 2.41° (1.58°, 3.38°) deviation from the intramedullary axis. On the tibial side, the 7 robots had different axis definitions. The tibial mechanical axis of 6 of the TKA systems was more flexed than that of the intramedullary axis, which means the posterior tibial slope was decreased while the tibial mechanical axis of the remaining system was more extended.
CONCLUSIONS: The sagittal alignment of the lower extremity for 7 different brands of robotic TKA systems differed from each other and all deviated from the intramedullary axis. Surgeons should be aware of this discrepancy when using different brands of robotic TKA systems to avoid unexpected sagittal alignment and corresponding adverse clinical outcomes.
METHODS: Level IV, Therapeutic Study.
METHODS: A total of 72 lower extremity computed tomography scans were included in our study, and 3-dimensional models were obtained using software. A total of 7 brands of robotic TKA systems were included in the study. The lower extremity axes were defined based on the surgical guide for each implant. We also set the intramedullary axis as a reference to evaluate the discrepancies in sagittal alignment of each brand of robotic system.
RESULTS: On the femoral side, the axis definition was the same for all 7 robotic TKA systems. The robotic TKA axes showed a 2.41° (1.58°, 3.38°) deviation from the intramedullary axis. On the tibial side, the 7 robots had different axis definitions. The tibial mechanical axis of 6 of the TKA systems was more flexed than that of the intramedullary axis, which means the posterior tibial slope was decreased while the tibial mechanical axis of the remaining system was more extended.
CONCLUSIONS: The sagittal alignment of the lower extremity for 7 different brands of robotic TKA systems differed from each other and all deviated from the intramedullary axis. Surgeons should be aware of this discrepancy when using different brands of robotic TKA systems to avoid unexpected sagittal alignment and corresponding adverse clinical outcomes.
METHODS: Level IV, Therapeutic Study.
摘要：
背景：越来越多的不同品牌的机器人全膝关节置换术（TKA）系统。大多数机器人TKA系统共享相同的冠状排列，而矢状对齐的定义各不相同。这项研究的目的是调查这些差异是否会影响下肢的矢状排列。
方法：本研究共纳入72例下肢计算机断层扫描，并使用软件获得三维模型。共有7个品牌的机器人TKA系统被纳入研究。根据每个植入物的手术导向确定下肢轴。我们还将髓内轴作为参考，以评估每个品牌的机器人系统矢状对齐的差异。
结果：在股骨侧，所有7个机器人TKA系统的轴定义相同.机器人TKA轴显示为2.41°（1.58°，3.38°）偏离髓内轴。在胫骨侧,7个机器人有不同的轴定义。6个TKA系统的胫骨机械轴比髓内轴更弯曲，这意味着胫骨后斜率减小，而其余系统的胫骨机械轴更远。
结论：7种不同品牌的机器人TKA系统的下肢矢状位彼此不同，并且都偏离了髓内轴。当使用不同品牌的机器人TKA系统时，外科医生应该意识到这种差异，以避免意外的矢状对齐和相应的不良临床结果。
方法：四级，治疗研究。
方法：本研究共纳入72例下肢计算机断层扫描，并使用软件获得三维模型。共有7个品牌的机器人TKA系统被纳入研究。根据每个植入物的手术导向确定下肢轴。我们还将髓内轴作为参考，以评估每个品牌的机器人系统矢状对齐的差异。
结果：在股骨侧，所有7个机器人TKA系统的轴定义相同.机器人TKA轴显示为2.41°（1.58°，3.38°）偏离髓内轴。在胫骨侧,7个机器人有不同的轴定义。6个TKA系统的胫骨机械轴比髓内轴更弯曲，这意味着胫骨后斜率减小，而其余系统的胫骨机械轴更远。
结论：7种不同品牌的机器人TKA系统的下肢矢状位彼此不同，并且都偏离了髓内轴。当使用不同品牌的机器人TKA系统时，外科医生应该意识到这种差异，以避免意外的矢状对齐和相应的不良临床结果。
方法：四级，治疗研究。
