UCLA/OIC Department of Orthopaedic Surgery, David Geffen School of Medicine, Los Angeles, California, USA.
Stanford University, Stanford, California, USA.
Bone Joint J. 2019 Jan;101-B(1_Supple_A):53-58. doi: 10.1302/0301-620X.101B1.BJJ-2018-0500.R1.
Loosening of the tibial component after total knee arthroplasty (TKA) is a common indication for revision. Increasing the strength of the initial tibial implant/cement interface is desirable. There is little information about the surgical techniques that lead to the highest strength. We investigated the effects of eight variables on the strength of the initial tibial baseplate/cement interface.
A total of 48 tibial trays were cemented into acrylic holders using cement from two manufacturers, at three different times (early, normal, and late) using two techniques: cementing the tibial plateau or the plateau and the keel; and involving two conditions of contamination with marrow fat (at the metal/cement and cement/cement interfaces). Push-out tests were performed with load continuously recorded.
Compared with normal conditions, early cementing increased the mean strength of the interface when using the two cements, Simplex and Palacos, by 48% and 72%, respectively. Late cementing reduced the strength by 47% and 73%, respectively. Cementing the keel increased the mean strength by 153% and 147%, respectively, for the two cements. Contamination of the metal/cement interface with fat reduced the mean strength by 99% and 94% for the two cements but adding cement to the underside of the tibial tray prior to insertion resulted in the mean strength being lowered by only 65% and 43%, respectively.
In order to maximize the strength of the tibial tray/cement interface, cement should be applied to the component soon after mixing, contamination of the interface should be avoided, and the keel and the plateau should be cemented.
全膝关节置换术后（TKA）胫骨部件松动是翻修的常见指征。增加初始胫骨植入物/水泥界面的强度是理想的。关于导致最高强度的手术技术的信息很少。我们研究了八个变量对初始胫骨基底/水泥界面强度的影响。
总共将 48 个胫骨托板用来自两个制造商的水泥粘接到丙烯酸固定器中，在三个不同的时间（早期、正常和晚期）使用两种技术：粘接到胫骨平台或平台和龙骨；以及涉及骨髓脂肪在（金属/水泥和水泥/水泥界面）污染的两种情况。进行了推挤测试，连续记录负载。
与正常情况相比，早期用两种水泥（Simplex 和 Palacos）分别将界面的平均强度提高了 48%和 72%。晚期分别降低了 47%和 73%。对于两种水泥，龙骨的粘合分别将平均强度提高了 153%和 147%。金属/水泥界面脂肪污染使两种水泥的平均强度分别降低了 99%和 94%，但在插入胫骨托板之前在其底面添加水泥导致平均强度分别降低了 65%和 43%。
为了使胫骨托板/水泥界面的强度最大化，水泥应在混合后尽快施加到部件上，应避免界面污染，并且应粘合龙骨和平台。
