Luring C, Perlick L, Trepte C, Linhardt O, Perlick C, Plitz W, Grifka J
Department of Orthopaedic Surgery, University of Regensburg, Kaiser-Karl-V. Allee 3, 93077, Bad Abbach, Germany.
Arch Orthop Trauma Surg. 2006 Jan;126(1):45-8. doi: 10.1007/s00402-005-0082-5. Epub 2005 Dec 7.
Improving the longevity and reliability of cemented total knee arthroplasty (TKA) remains a major step to achieve. It is still unclear, whether a cemented tibial stem reduces micromotion of the tibial tray and produces therefore a better initial stability or not. The higher conformity of rotating platform design and the possible rotary forces to the tibial platform may produce higher micromotion when the tibial stem remains cementless (hybrid fixation).
An in vitro study was performed using the PFC mobile bearing tibial tray (DePuy, Warswa, IN, USA) to test the hypothesis that the addition of cement surrounding the tibial stem reduces micromotion of the tibial tray in cemented TKA with mobile bearing design. Ten tibial trays with mobile design were implanted in sawbones with a 3-mm cement mantle beneath the baseplate of the tibial tray and with or without the cemented stem. Tibial trays were loaded additionally in the ventral, lateral, medial and posterior positions with 2,500 N using the Zwick Z010 instrumentation and HBM pick up Hottinger Baldwin.
In this study, a significant increased mean maximum liftoff was found when only cementing the tibial baseplate (hybrid fixation), compared to the fully cemented tibial tray (P<0.02).
In conclusion, the stem of mobile bearing tibial components should be cemented to provide increased micromotion and earlier loosening.
提高骨水泥型全膝关节置换术（TKA）的使用寿命和可靠性仍是一个重要目标。骨水泥固定的胫骨柄是否能减少胫骨托的微动从而产生更好的初始稳定性仍不明确。当胫骨柄采用非骨水泥固定（混合固定）时，旋转平台设计的更高贴合度以及作用于胫骨平台的可能旋转力可能会产生更高的微动。
使用PFC活动轴承胫骨托（美国印第安纳州华沙市的DePuy公司）进行了一项体外研究，以检验在采用活动轴承设计的骨水泥型TKA中，围绕胫骨柄添加骨水泥可减少胫骨托微动这一假设。将十个活动设计的胫骨托植入人工骨模型中，在胫骨托基板下方有3毫米的骨水泥套，且有或没有骨水泥固定的柄。使用Zwick Z010仪器和HBM拾音器Hottinger Baldwin在腹侧、外侧、内侧和后侧位置额外施加2500 N的载荷于胫骨托上。
在本研究中，与完全骨水泥固定的胫骨托相比，仅对胫骨基板进行骨水泥固定（混合固定）时，平均最大抬升量显著增加（P<0.02）。
总之，活动轴承胫骨部件的柄应进行骨水泥固定，以增加微动并更早出现松动。
