Bargren J H, Day W H, Freeman M A, Swanson S A
J Bone Joint Surg Br. 1978 May;60-B(2):256-61. doi: 10.1302/0301-620X.60B2.659476.
Cadaveric knees replaced with the Geomedic, ICLH, Marmor and Total Condylar prostheses were tested in axial compression, in rotation and in hyperextension in order to observe the strength of fixation of the tibial components. In axial compression the strengths at failure varied widely, both with any one prosthesis and between prostheses. This is attributed largely to the strength of the cancellous bone of the tibia, which was measured in each case and also varied widely. Three natural knees failed at loads of 7300, 7600 and 8300 newtons respectively, whereas the strengths of replaced knees ranged from 3000 to 15750 newtons. At least one example of each design failed at less than 7300 newtons, suggesting little or no reserve of strength. The strength of fixation was greater when the tibial prosthesis was large enough to rest on the whole cross-section of the tibia. In rotation the three prostheses embodying rollers in troughs were stiffer than the Marmor which had a nearly flat tibial-bearing surface. The presence or absence of the cruciate ligaments had a negligible effect on torsional stiffness. In hyperextension, knees replaced with the ICLH, Marmor and Total Condylar prostheses failed by rupture of the posterior capsule at moments of about 60 newton-metres, compared with about 100 for natural knees. With the Marmor prosthesis the anterior cruciate ligament was avulsed at about 20 newton-metres compared with about 75 in natural knees, suggesting that in this respect the retention of the cruciate ligaments contributes little. None of the four knees tested after inserting a Geomedic prosthesis showed strengths as high as those replaced with the other three designs.
对使用Geomedic、ICLH、Marmor和全髁假体置换的尸体膝关节进行了轴向压缩、旋转和过伸测试，以观察胫骨部件的固定强度。在轴向压缩时，无论是同一假体还是不同假体，失效时的强度差异都很大。这主要归因于胫骨松质骨的强度，在每种情况下都对其进行了测量，其强度也有很大差异。三个自然膝关节分别在7300、7600和8300牛顿的载荷下失效，而置换膝关节的强度范围为3000至15750牛顿。每种设计至少有一个例子在小于7300牛顿时失效，这表明几乎没有或根本没有强度储备。当胫骨假体大到足以支撑在胫骨的整个横截面上时，固定强度更大。在旋转时，三种带有槽内滚子的假体比Marmor假体更硬，后者的胫骨承重表面几乎是平的。交叉韧带的存在与否对扭转刚度的影响可忽略不计。在过伸时，使用ICLH、Marmor和全髁假体置换的膝关节在约60牛顿·米的力矩下因后关节囊破裂而失效，而自然膝关节约为100牛顿·米。使用Marmor假体时，前交叉韧带在约20牛顿·米时被撕脱，而自然膝关节约为75牛顿·米，这表明在这方面保留交叉韧带贡献不大。插入Geomedic假体后测试的四个膝关节中，没有一个显示出与其他三种设计置换的膝关节一样高的强度。
