Xie Shuqiao, Conlisk Noel, Hamilton David, Scott Chloe, Burnett Richard, Pankaj Pankaj
School of Engineering, Institute for Bioengineering, The University of Edinburgh, Alrick Building, The King's Buildings, Edinburgh EH9 3BF, UK.
Department of Orthopaedics and Trauma, The University of Edinburgh, 49 Little France Crescent, Edinburgh, EH16 4SB, UK.
Knee. 2020 Jun;27(3):656-666. doi: 10.1016/j.knee.2020.02.019. Epub 2020 Apr 30.
In the UK around 10% of hip and knee arthroplasties are revision operations. At revision total knee arthroplasty (rTKA), bone loss management is critical to achieving a stable bone-implant construct. Though tritanium cones have been used to manage bone defects in rTKA, their biomechanical performance with varying defects remains unknown.
Uncontained tibial bone defects at four anatomic locations, with varying depths and widths (Type T2A and T2B) were investigated computationally in a composite tibia which was subjected to four loading scenarios. The ability of the tritanium cone to replace the tibial bone defect was examined using the outcome measures of bone strain distribution and interface micromotions.
It was found that anterior and lateral defects do not significantly alter the strain distribution compared with intact bone. For medial defects, strain distribution is sensitive to defect width; while strain distributions for posterior defects are associated with defect width and depth. In general, micromotions at the bone-implant interface are small and are primarily influenced by defect depth.
Our models show that the cone is an acceptable choice for bone defect management in rTKA. Since all observed micromotions were small, successful osteointegration would be expected in all types of uncontained defects considered in this study. Tritanium cones safely accommodate uncontained tibial defects up to 10 mm deep and extending up to 9 mm from the centre of the cone. Medial and posteriorly based defects managed with symmetric cones display the greatest bone strains and asymmetric cones may be useful in this context.
在英国，约10%的髋关节和膝关节置换术是翻修手术。在全膝关节置换翻修术（rTKA）中，骨量丢失的处理对于实现稳定的骨-植入物结构至关重要。尽管三钛锥已被用于处理rTKA中的骨缺损，但其在不同缺损情况下的生物力学性能仍不清楚。
在一个复合胫骨模型中，对四个解剖位置、具有不同深度和宽度（T2A和T2B型）的非包容性胫骨骨缺损进行了计算研究，该复合胫骨承受四种加载情况。使用骨应变分布和界面微动的结果指标来检查三钛锥替代胫骨骨缺损的能力。
发现与完整骨相比，前侧和外侧缺损不会显著改变应变分布。对于内侧缺损，应变分布对缺损宽度敏感；而后侧缺损的应变分布与缺损宽度和深度有关。一般来说，骨-植入物界面的微动较小，主要受缺损深度影响。
我们的模型表明，三钛锥是rTKA中骨缺损处理的一个可接受选择。由于观察到的所有微动都很小，预计在本研究中考虑的所有类型的非包容性缺损中都能成功实现骨整合。三钛锥可安全容纳深度达10毫米、从锥中心向外延伸达9毫米的非包容性胫骨缺损。用对称锥处理的基于内侧和后侧的缺损显示出最大的骨应变，在这种情况下不对称锥可能有用。
