Stroobant Lenka, Vermue Hannes, Jacobs Ewoud, Arnout Nele, Van Onsem Stefaan, Banks Scott A, Victor Jan, Chevalier Amélie
Department Orthopaedic Surgery, University Hospital Ghent, Ghent, Belgium.
Department of Rehabilitation Sciences, Ghent University Faculty of Medicine and Health Sciences, Ghent, Belgium.
J Orthop. 2025 Apr 22;64:153-162. doi: 10.1016/j.jor.2025.04.004. eCollection 2025 Jun.
The rising incidence of primary total knee arthroplasty (pTKA) is expected to lead to more revision TKAs (rTKA), which pose greater challenges and poorer outcomes, burdening both patients and healthcare systems. Knee kinematics play a key role in pTKA outcomes, but less is known about rTKA, where high-constraint implants and joint line elevation (JLE) may affect knee kinematics. The study aimed to: (1) Compare kinematic patterns between posterior-stabilized (PS) and condylar constrained (CCK) implants during open- and closed-chain exercises in rTKA; (2) Assess the impact of JLE on anteroposterior translation and post-cam engagement.
Thirty patients (19 with PS implants and 11 with CCK implants) who underwent rTKA between 2022 and 2024 were tested at a minimum six-month follow-up. Tibiofemoral kinematics during open-chain flexion-extension (FE) and closed-chain exercises (sit-to-stand (STS) and squatting (SQ)) were analyzed using fluoroscopy. (1) Kinematic patterns were compared between PS and CCK implants, focusing on AP translation, internal-external (IE) rotation, varus-valgus (VV) rotation, range of motion (ROM) and post-cam engagement. (2) Joint line elevation was defined as a ≥4 mm increase compared to the native knee on a weight-bearing radiograph, and comparisons were made between patients with and without JLE.
(1) No significant differences were observed in kinematic patterns between PS and CCK implants in rTKA. (2) A JLE ≥4 mm led to instability during squatting, particularly in early- and mid-flexion, with a significantly more anterior position in the medial compartment (0-30°: p = 0.037; 30-60°: p = 0.021). Although post-cam engagement was delayed in patients with JLE, the difference was not statistically significant (p = 0.173).
(1) CCK implants have a kinematic pattern similar to PS implants in revision setting, supporting their use when appropriate, (2) JLE is associated with instability during squatting in early- and mid-flexion.
原发性全膝关节置换术（pTKA）发病率的上升预计将导致更多的翻修全膝关节置换术（rTKA），这带来了更大的挑战且预后更差，给患者和医疗系统都带来了负担。膝关节运动学在pTKA预后中起关键作用，但对于rTKA了解较少，在rTKA中，高限制性植入物和关节线抬高（JLE）可能会影响膝关节运动学。本研究旨在：（1）比较rTKA中后稳定型（PS）和髁限制性（CCK）植入物在开链和闭链运动时的运动学模式；（2）评估JLE对前后平移和后凸轮啮合的影响。
对2022年至2024年间接受rTKA的30例患者（19例使用PS植入物，11例使用CCK植入物）进行至少6个月的随访测试。使用荧光透视分析开链屈伸（FE）和闭链运动（从坐到站（STS）和下蹲（SQ））过程中的胫股运动学。（1）比较PS和CCK植入物之间的运动学模式，重点关注前后平移、内外（IE）旋转、内翻-外翻（VV）旋转、活动范围（ROM）和后凸轮啮合。（2）关节线抬高定义为在负重X线片上与原生膝关节相比增加≥4mm，并对有和没有JLE的患者进行比较。
（1）rTKA中PS和CCK植入物之间的运动学模式未观察到显著差异。（2）JLE≥4mm会导致下蹲时不稳定，尤其是在屈曲早期和中期，内侧间室位置明显更靠前（0-30°：p = 0.037；30-60°：p = 0.021）。尽管JLE患者的后凸轮啮合延迟，但差异无统计学意义（p = 0.173）。
（1）在翻修情况下，CCK植入物的运动学模式与PS植入物相似，支持在适当的时候使用它们；（2）JLE与下蹲时屈曲早期和中期的不稳定有关。
