Ngai V, Schwenke T, Wimmer M A
Department of Orthopedic Surgery, Rush University Medical Center, Chicago, Illinois 60612, USA.
Proc Inst Mech Eng H. 2009 Oct;223(7):889-96. doi: 10.1243/09544070JEIM549.
Differences between wear-scar features of simulator-tested and retrieved tibial total knee replacement (TKR) liners have been reported. This disagreement may result from differences between in-vivo kinematic profiles and those defined by the standard. The purpose of this study was to determine the knee kinematics of a TKR subject group during level walking and to compare them with the motion profiles produced by a wear test conducted according to the force-controlled knee wear testing ISO 14243-1 standard. Ten patients with a posterior cruciate ligament-retaining TKR design were gait tested using the point cluster technique to obtain flexion-extension (FE) rotation, anterior-posterior (AP) translation, and internal-external (IE) rotation motions during a complete cycle of level walking. Motion data were directly compared with the output kinematics from the wear test. The subjects exhibited an FE rotation pattern similar to the output from ISO-14243-1; however, they had higher midstance knee flexion angles. For both AP translation and IE rotation, the standard profiles had significantly smaller total ranges of motion than seen in vivo, with noticeably different patterns of motions. For this particular implant design, significant differences were found in both the pattern and the magnitudes of in-vivo motion during level walking compared with the ISO-14243-1 standard.
已有报道指出，模拟器测试的与翻修的胫骨全膝关节置换（TKR）衬垫的磨损痕迹特征存在差异。这种不一致可能源于体内运动学特征与标准所定义的特征之间的差异。本研究的目的是确定TKR受试者组在平地上行走时的膝关节运动学，并将其与根据力控膝关节磨损测试ISO 14243-1标准进行的磨损测试所产生的运动曲线进行比较。使用点簇技术对10名采用后交叉韧带保留型TKR设计的患者进行步态测试，以获取在平地上行走的一个完整周期内的屈伸（FE）旋转、前后（AP）平移和内外（IE）旋转运动。将运动数据直接与磨损测试的输出运动学进行比较。受试者表现出的FE旋转模式与ISO-14243-1的输出相似；然而，他们在站立中期的膝关节屈曲角度更大。对于AP平移和IE旋转，标准曲线的总运动范围明显小于体内观察到的范围，且运动模式明显不同。对于这种特定的植入物设计，与ISO-14243-1标准相比，在平地上行走时体内运动的模式和幅度均存在显著差异。
