Salvi Andrea Giordano, Valpiana Pieralberto, Innocenti Bernardo, Ghirardelli Stefano, Bernardi Matteo, Petralia Giuseppe, Aloisi Giuseppe, Zepeda Karlos, Schaller Christian, Indelli Pier Francesco
Südtiroler Sanitätsbetrieb, Department Orthopaedic Surgery, Brixen, Italy.
Hôpital Maisonneuve-Rosemont, Department Orthopaedic Surgery, Montréal, Quebec, Canada.
Arthroplast Today. 2024 Dec 7;30:101586. doi: 10.1016/j.artd.2024.101586. eCollection 2024 Dec.
Unrestricted kinematic alignment (uKA) in total knee arthroplasty (TKA) has the theoretical advantage of reproducing patients' constitutional alignment and restoring the pre-arthritic joint line position and obliquity. However, modifications of the original uKA technique have been proposed due to the potential risk of mechanical failure and instability. Given the significant variability in soft tissue behavior within the same bony morphology group, uKA pure knee resurfacing could be occasionally detrimental. This study aimed to kinematically compare the outcomes of uKA TKA with those of a robotic-assisted KA TKA technique based on specific soft-tissue boundaries.
In this retrospective gait analysis study, 24 TKA patients and 12 healthy controls were recruited. Inclusion criteria were a 9-month minimum follow-up from successfully, primary medial-pivot or medially-congruent TKA performed for isolated degenerative joint disease. Preoperatively, patients were randomly assigned to two surgical groups: A) uKA (#12) and B) robot-assisted (#12), KA (hybrid-kinematic) with boundaries (±3° from hip-knee-ankle neutral axis) and a slight intercompartmental gap asymmetry (max 2 mm lateral-opening). The gait analysis was performed using instrumented treadmills equipped with 3D cameras.
Sagittal knee kinematic data: during the early-stance phase of gait, the uKA group showed a less consistent weight-acceptance phase and a less efficient transition between the first knee-flexion peak and mid-stance-extension plateau with respect to the hybrid-kinematic alignment group. Spatiotemporal and overall gait quality data: no significant differences were found between the two TKA groups regarding walking speed ( = .51) and step length ( = .8534). Control group patients walked more efficiently compared to TKA groups, showing inferior trunk flexion and inferior variation in step length ( < .0001).
This study showed that restoring the pre-arthritic joint line, as advocated by surgeons following the uKA philosophy, does not guarantee a closer-to-normal knee kinematics.
全膝关节置换术（TKA）中的无限制运动学对线（uKA）在理论上具有重现患者自然对线、恢复关节炎前关节线位置和倾斜度的优势。然而，由于存在机械故障和不稳定的潜在风险，人们对原始uKA技术提出了改进。鉴于同一骨形态学组内软组织行为存在显著差异，单纯的uKA膝关节表面置换偶尔可能有害。本研究旨在基于特定软组织边界，对uKA TKA与机器人辅助KA TKA技术的运动学结果进行比较。
在这项回顾性步态分析研究中，招募了24例TKA患者和12名健康对照者。纳入标准为因单纯退行性关节病成功进行初次内侧旋转或内侧匹配TKA后至少随访9个月。术前，患者被随机分为两个手术组：A）uKA组（12例）和B）机器人辅助组（12例），KA（混合运动学），其边界为（相对于髋-膝-踝中立轴±3°）且关节间隙存在轻微不对称（外侧开口最大2 mm）。使用配备3D摄像头的仪器化跑步机进行步态分析。
膝关节矢状面运动学数据：在步态的早期支撑阶段，与混合运动学对线组相比，uKA组在负重接受阶段的一致性较差，且在第一个屈膝峰值与支撑中期伸展平台之间的过渡效率较低。时空和整体步态质量数据：两个TKA组在步行速度（P = 0.51）和步长（P = 0.8534）方面未发现显著差异。与TKA组相比，对照组患者行走效率更高，表现为躯干屈曲程度较低且步长变化较小（P < 0.0001）。
本研究表明，遵循uKA理念的外科医生所倡导的恢复关节炎前关节线，并不保证膝关节运动学更接近正常。
