Bioengineering Laboratory, Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA, 02114, USA.
Knee Surg Sports Traumatol Arthrosc. 2022 Feb;30(2):652-660. doi: 10.1007/s00167-020-06384-9. Epub 2021 Jan 2.
A new CR TKA design with concave medial and convex lateral tibial polyethylene bearing components was introduced recently to improve functional outcomes. This study aimed to investigate in-vivo articular contact kinematics in unilateral asymmetrical tibial polyethylene geometry CR TKA patients during strenuous knee flexion activities.
Fifteen unilateral CR TKA patients (68.4 ± 5.8 years; 6 male/9 female) were evaluated for both knees during sit-to-stand, single-leg deep lunges and step-ups using validated combined computer tomography and dual fluoroscopic imaging system. Medial and lateral condylar contact positions were quantified during weight-bearing flexion activities. The Wilcoxon signed-rank test was performed to determine if there is a significant difference in articular contact kinematics during strenuous flexion activities between CR TKA and the non-operated knees.
Contact excursions of the lateral condyle in CR TKAs were significantly more anteriorly located than the contralateral non-operated knee during sit-to-stand (3.7 ± 4.8 mm vs - 7.8 ± 4.3 mm) and step-ups (- 1.5 ± 3.2 mm vs - 6.3 ± 5.8 mm). Contact excursions of the lateral condyle in CR TKAs were significantly less laterally located than the contralateral non-operated knee during sit-to-stand (21.4 ± 2.8 mm vs 24.5 ± 4.7 mm) and single-leg deep lunges (22.6 ± 4.4 mm vs 26.2 ± 5.7 mm, p < 0.05). Lateral condyle posterior rollback was not fully restored in CR TKA patients during sit-to-stand (9.8 ± 6.7 mm vs 12.9 ± 8.3 mm) and step-ups (8.1 ± 4.8 mm vs 12.2 ± 6.4 mm). Lateral pivoting patterns were observed in 80%, 73% and 69% of patients during sit-to-stand, step-ups and single-leg deep lunges respectively.
Although lateral femoral rollback and lateral pivoting patterns were observed during strenuous functional daily activities, asymmetric contact kinematics still persisted in unilateral CR TKA patients. This suggests the specific investigated contemporary asymmetrical tibial polyethylene geometry CR TKA design evaluated in this study does not fully replicate healthy knee contact kinematics during strenuous functional daily activities.
III.
最近引入了一种新的 CR TKA 设计，其具有凹形内侧和凸形外侧胫骨聚乙烯承载体，旨在改善功能结果。本研究旨在研究在剧烈膝关节弯曲活动期间单侧不对称胫骨聚乙烯几何 CR TKA 患者的关节接触运动学。
评估了 15 例单侧 CR TKA 患者（68.4±5.8 岁；6 名男性/9 名女性）在坐站、单腿深蹲和单腿台阶上升期间的双侧膝关节，使用经过验证的计算机断层扫描和双荧光透视成像系统相结合。在负重弯曲活动期间量化内侧和外侧髁的接触位置。采用 Wilcoxon 符号秩检验确定 CR TKA 与未手术侧膝关节在剧烈弯曲活动期间的关节接触运动学是否存在显著差异。
在坐站和单腿台阶上升时，CR TKA 的外侧髁的接触位移明显更向前位于对侧未手术膝关节（3.7±4.8mm 对-7.8±4.3mm）和单腿台阶上升（-1.5±3.2mm 对-6.3±5.8mm）。在坐站和单腿深蹲时，CR TKA 的外侧髁的接触位移明显位于对侧未手术膝关节的更外侧（21.4±2.8mm 对 24.5±4.7mm）和单腿深蹲（22.6±4.4mm 对 26.2±5.7mm，p<0.05）。在坐站（9.8±6.7mm 对 12.9±8.3mm）和单腿台阶上升（8.1±4.8mm 对 12.2±6.4mm）期间，CR TKA 患者的外侧髁后滚并未完全恢复。在坐站（80%）、单腿台阶上升（73%）和单腿深蹲（69%）期间，分别观察到 80%、73%和 69%的患者存在外侧旋转模式。
尽管在剧烈的日常功能活动中观察到外侧股骨后滚和外侧旋转模式，但单侧 CR TKA 患者仍存在不对称的接触运动学。这表明，在本研究中评估的特定当代不对称胫骨聚乙烯几何 CR TKA 设计并不能完全复制健康膝关节在剧烈日常功能活动中的接触运动学。
III。
