Stryker Corporation, Mahwah, New Jersey.
Northwell Health Orthopedics, Lenox Hill Hospital, New York, New York.
Surg Technol Int. 2024 Jul 15;44:285-293. doi: 10.52198/24.STI.44.OS1758. Epub 2024 Mar 7.
Classical neutral mechanical alignment in total knee arthroplasty (TKA) has been a standard paradigm, while more recently, other alignment schemas, such as kinematic, individualized, and functional, have been explored. This study aimed to investigate the effect of three-dimensional (3D) computed tomography (CT)-based surgical robotics inputs on a classically trained surgeon's TKA component positions and alignment targets over time.
Data from 1,394 consecutive robotically-assisted TKAs by a single surgeon from 2016 to 2020 were analyzed. Metrics collected included pre-balance planned implant component positions, final planned implant component positions after soft tissue balancing, and constitutional alignment from CT scans. Joint line obliquity was plotted against the arithmetic hip-knee angle (aHKA) using coronal plane alignment of the knee (CPAK). Three categories of alignment strategy were defined: true mechanical alignment (tMA), adjusted mechanical alignment (aMA), and no mechanical alignment (noMA).
A shift to overall varus component positioning was observed over the years. Joint line obliquity according to CPAK showed a wider spread in later years, and the distribution of tibial and femoral coronal alignment angles expanded over time.
The study revealed a change in alignment targets and final positioning of components away from neutral biomechanical axes in a large volume of TKAs by a single, classically trained surgeon over five years of using a robotic arm-assisted TKA system with CT-based planning. The most dominant factor for this change was the use of 3D CT planning, allowing the surgeon to assess patient-specific anatomy and plan accordingly. Outcome data is needed to determine if this change in behavior and surgical technique was beneficial. In summary, using a CT scan-based robotically assisted technique led to a gradual and complete shift from tMA to predominantly a non-mechanically aligned philosophy in TKA.
在全膝关节置换术（TKA）中，经典的中性机械对线一直是标准范式，而最近，其他对线方案，如运动学、个体化和功能性，也得到了探索。本研究旨在探讨基于三维（3D）计算机断层扫描（CT）的手术机器人输入对一位传统训练的外科医生在 TKA 组件位置和对线目标方面的影响，以及这种影响随时间的变化情况。
分析了一位外科医生在 2016 年至 2020 年期间进行的 1394 例机器人辅助 TKA 的数据。收集的指标包括平衡前计划植入物组件位置、软组织平衡后的最终计划植入物组件位置以及 CT 扫描的固有对线。关节线倾斜度与算术髋膝角（aHKA）作图，使用膝关节冠状面对线（CPAK）。定义了三种对线策略类别：真正的机械对线（tMA）、调整的机械对线（aMA）和非机械对线（noMA）。
观察到多年来组件总体向内侧放置的趋势。根据 CPAK 的关节线倾斜度显示，在较晚的年份有更广泛的分布，胫骨和股骨冠状面对线角度的分布也随时间扩展。
这项研究揭示了在使用基于 CT 规划的机器人辅助 TKA 系统五年后，一位传统训练的外科医生在大量 TKA 中，对线目标和组件最终定位从中立生物力学轴发生了变化。这种变化的最主要因素是使用了 3D CT 规划，使外科医生能够评估患者特定的解剖结构并相应地进行计划。需要进一步的临床结果数据来确定这种行为和手术技术的变化是否有益。总之，使用基于 CT 扫描的机器人辅助技术导致了从 tMA 到 TKA 中主要非机械对线理念的逐渐和完全转变。
