Lionberger David, Wattenbarger Laura, Conlon Christopher, Walker Timothy J
Southwest Orthopedic Group, The Methodist Hospital at Houston, 6560 Fannin Street, Suite 1016, Scurlock Tower, Houston, TX, 77030, USA.
Texas A&M College of Medicine, The Methodist Hospital at Houston, 6565 Fannin, Street, West Pavilion 5, Houston, TX, 77030, USA.
J Exp Orthop. 2020 Jun 5;7(1):41. doi: 10.1186/s40634-020-00243-9.
Implant surface integrity and cement bonding are assumed to be sufficient in primary total knee replacements to stabilize implants for extended wear without concerns over delamination and loosening. Yet there exists a significant rate of aseptic loosening where failure at implant cement interface occurs. The aim of this study is to look at specific aspects leading to aseptic loosening of the total knee replacement, where cement adhesion to the implant results in the lowest pull off strength.
Virgin ceramic coated and uncoated chrome cobalt tibial trays were used in a pull off study using differing viscosities of cement at varied time intervals to compare which combination is strongest compared to which is least resistant to pull off testing.
Low viscosity cement had a 44% (5.9 kg verses 3.3 kg, p < 0.001) higher pull-off strength compared to high viscosity cement. Coated implants had a 30% (3.9 kg verses 5.5 kg, p = 0.037) lower pull-off strength compared to non-coated. Testing measures were limited to cement utilization less than 5 minutes due to the poor adhesion of the dowels beyond this time. Finally, there was a significant difference in adhesion properties between brand names when utilizing low viscosity cement on the non-coated trays (10.34 kg for Simplex verses 4.87 for Palacos, p = 0.021).
There are differences in adhesion properties between cement vendors, prompting significant concerns over the use of coated implants with particular cement types. Use of low viscosity cement on non-coated surfaces in the early liquid phase of cement curing was found to produce the best chance for adequate adhesion. This study demonstrates that there is variation in the adhesive properties of implants utilized in total knee replacements, and that the orthopedic community should consider not only the implant, cement, and curing time individually, but the overall integrity conferred from the combination of all of these variables.
在初次全膝关节置换术中，植入物表面完整性和骨水泥粘结被认为足以使植入物稳定，以延长使用寿命，而无需担心分层和松动问题。然而，仍存在相当比例的无菌性松动，即植入物与骨水泥界面处发生失效。本研究的目的是探讨导致全膝关节置换术无菌性松动的具体因素，其中骨水泥与植入物的粘附导致最低的拔出强度。
在一项拔出研究中，使用了未涂层和陶瓷涂层的铬钴合金胫骨托，在不同时间间隔使用不同粘度的骨水泥，以比较哪种组合的粘结力最强，哪种最不耐拔出测试。
与高粘度骨水泥相比，低粘度骨水泥的拔出强度高44%（5.9千克对3.3千克，p<0.001）。与未涂层植入物相比，涂层植入物的拔出强度低30%（3.9千克对5.5千克，p=0.037）。由于在此时间之后定位销的粘附性较差，测试措施仅限于骨水泥使用时间少于5分钟的情况。最后，在未涂层托盘上使用低粘度骨水泥时，不同品牌之间的粘附性能存在显著差异（辛普lex为10.34千克，帕拉科斯为4.87千克，p=0.021）。
骨水泥供应商之间的粘附性能存在差异，这引发了对特定骨水泥类型与涂层植入物联合使用的重大担忧。发现在骨水泥固化的早期液相阶段，在未涂层表面使用低粘度骨水泥能产生充分粘附的最佳机会。本研究表明，全膝关节置换术中使用的植入物的粘附性能存在差异，骨科界不仅应分别考虑植入物、骨水泥和固化时间，还应考虑所有这些变量组合所赋予的整体完整性。
