Department of Orthopaedic Surgery, Joint Reconstruction Center, Yonsei Sarang Hospital, 10 Hyoryeong-ro, Seocho-gu, Seoul, 06698, South Korea.
Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, South Korea.
Knee Surg Sports Traumatol Arthrosc. 2020 May;28(5):1465-1472. doi: 10.1007/s00167-019-05540-0. Epub 2019 May 23.
This study aims to evaluate whether different tibial-femoral conformities for patient-specific mobile-bearing unicompartmental knee arthroplasties (UKAs) preserve natural knee kinematics, using computational simulations.
Different designs for patient-specific mobile-bearing UKAs were evaluated using finite element analysis. Three designs for the identical femoral component were considered: flat (non-conforming design), anatomy-mimetic, and conforming for the tibial insert.
The conforming design for the patient-specific mobile-bearing UKAs exhibited a 1.2 mm and 0.7° decrease in the translation and rotation, respectively, in the swing phase compared with those of the natural knee. In addition, the femoral rollback and internal rotation were 2.6 mm and 1.2° lower, respectively, than those of the natural knee, for the conforming design under the deep-knee-bend condition. The flat design for the patient-specific mobile-bearing UKAs exhibited a 2.2 mm and 1.4° increase in the femoral rollback and rotation compared with the natural knee under the deep-knee-bend condition. The anatomy-mimetic patient-specific mobile-bearing UKAs best preserved the natural knee kinematics under the gait and deep-knee-bend loading conditions.
The kinematics of the loading conditions in patient-specific mobile-bearing UKAs was determined to closely resemble those of a native knee. In additional, by replacing the anatomy-mimetic design with a mobile-bearing, natural knee kinematics during gait and deep-knee-bend motions is preserved. These results confirm the importance of tibiofemoral conformity in preserving native knee kinematics in patient-specific mobile-bearing UKA.
本研究旨在通过计算模拟评估患者特异性活动衬垫单髁膝关节置换术（UKA）的不同胫骨-股骨适配度是否能保持自然膝关节运动学。
使用有限元分析评估了患者特异性活动衬垫 UKA 的不同设计。考虑了三种相同股骨组件的设计：平（非适配设计）、解剖模拟和胫骨衬垫适配。
与自然膝关节相比，患者特异性活动衬垫 UKA 的适配设计在摆动期的平移和旋转分别减少了 1.2mm 和 0.7°。此外，在深屈膝条件下，适配设计的股骨后滚和内旋分别比自然膝关节低 2.6mm 和 1.2°。在深屈膝条件下，患者特异性活动衬垫 UKA 的平设计与自然膝关节相比，股骨后滚和旋转分别增加了 2.2mm 和 1.4°。解剖模拟患者特异性活动衬垫 UKA 在步态和深屈膝加载条件下能最好地保持自然膝关节运动学。
患者特异性活动衬垫 UKA 的加载条件运动学被确定为与自然膝关节非常相似。此外，通过用活动衬垫替代解剖模拟设计，在步态和深屈膝运动中保持了自然膝关节运动学。这些结果证实了胫骨-股骨适配度在保持患者特异性活动衬垫 UKA 中自然膝关节运动学的重要性。
