Toms A D, Barker R L, McClelland D, Chua L, Spencer-Jones R, Kuiper J-H
Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry, England.
J Bone Joint Surg Br. 2009 Feb;91(2):271-7. doi: 10.1302/0301-620X.91B2.21415.
The treatment of bony defects of the tibia at the time of revision total knee replacement is controversial. The place of compacted morsellised bone graft is becoming established, particularly in contained defects. It has previously been shown that the initial stability of impaction-grafted trays in the contained defects is equivalent to that of an uncemented primary knee replacement. However, there is little biomechanical evidence on which to base a decision in the treatment of uncontained defects. We undertook a laboratory-based biomechanical study comparing three methods of graft containment in segmental medial tibial defects and compared them with the use of a modular metal augment to bypass the defect. Using resin models of the proximal tibia with medial defects representing either 46% or 65% of the medial cortical rim, repair of the defect was accomplished using mesh, cement or a novel bag technique, after which impaction bone grafting was used to fill the contained defects and a tibial component was cemented in place. As a control, a cemented tibial component with modular metal augments was used in identical defects. All specimens were submitted to cyclical mechanical loading, during which cyclical and permanent tray displacement were determined. The results showed satisfactory stability with all the techniques except the bone bag method. Using metal augments gave the highest initial stability, but obviously lacked any potential for bone restoration.
翻修全膝关节置换时胫骨骨缺损的治疗存在争议。压实的碎骨移植的地位正在确立，尤其是在包容性缺损中。此前已有研究表明，包容性缺损中打压植骨托盘的初始稳定性与非骨水泥型初次膝关节置换相当。然而，在治疗非包容性缺损时，几乎没有生物力学证据可供决策参考。我们进行了一项基于实验室的生物力学研究，比较了三种用于节段性胫骨内侧缺损植骨包容的方法，并将其与使用模块化金属垫块绕过缺损的方法进行比较。使用近端胫骨的树脂模型，内侧缺损分别占内侧皮质边缘的46%或65%，缺损修复采用网片、骨水泥或一种新型袋装技术，之后采用打压植骨填充包容性缺损，并将胫骨假体用骨水泥固定到位。作为对照，在相同缺损中使用带模块化金属垫块的骨水泥型胫骨假体。所有标本均接受循环机械加载，期间测定循环和永久性托盘位移。结果显示，除骨袋法外，所有技术的稳定性均令人满意。使用金属垫块具有最高的初始稳定性，但显然缺乏任何骨修复潜力。
