Griffin M F, O'Toole G, Sabbagh W, Szarko M, Butler P E
Division of Surgery and Interventional Science, University College London and Department of Plastic Surgery, Royal Free Hospital, London, UK; Department of Plastic Surgery, Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK.
Department of Plastic Surgery, Royal Free London NHS Foundation Trust, Pond Street, London NW3 2QG, UK.
J Biomech. 2020 Apr 16;103:109688. doi: 10.1016/j.jbiomech.2020.109688. Epub 2020 Feb 25.
Children born with a small or absent ears undergo surgical reconstruction to restore their auricle. Currently, rib (costal) cartilage is used to carve the auricle. However as alternative, tissue engineered and synthetic materials are being developed to restore the auricle shape to overcome donor site morbidity and limited availability of rib cartilage. However, to date there is limited knowledge regarding the mechanical properties of the auricular and costal cartilage to optimise the required compressive properties of the graft. The remnant auricular and costal cartilage from 20 patients undergoing stage-1 microtia surgery was harvested. On the day of surgery, the cartilage was evaluated in compression, with each sample loaded to 300 g at 1 mm/s. RESULTS: The costal cartilage was observed to have a significantly higher Young's Elastic Modulus than auricular cartilage (average costal cartilage 11.43 MPa vs average auricular cartilage 2 MPa, p < 0.0001). The auricular cartilage showed a significantly higher relaxation rate than costal cartilage (average costal cartilage 0.72 MPa10 vs average auricular cartilage 1.93 MPa10, p < 0.05). The final absolute relaxation was significantly lower for elastic cartilage than costal cartilage (average costal cartilage 3.35 MPa vs average auricular cartilage 0.2 MPa, p < 0.0001). Alloplastic cartilage replacements used as alternatives for reconstruction were also evaluated. Silicone, Gore-Tex and Medpor were observed to have significantly higher Young's Elastic Modulus than costal and auricular cartilage. Costal cartilage has a higher Young's Elastic Modulus in compression compared to auricular cartilage. Current synthetic materials used to replace synthetic cartilage do not mimic costal cartilage, which should be addressed in the future.
天生耳朵小或无耳的儿童需接受外科重建手术来修复耳廓。目前，使用肋软骨雕刻耳廓。然而，作为替代方案，正在研发组织工程材料和合成材料来恢复耳廓形状，以克服供体部位并发症以及肋软骨供应有限的问题。然而，迄今为止，关于耳廓软骨和肋软骨的力学性能以优化移植物所需压缩性能的知识有限。收集了20例接受一期小耳畸形手术患者的残余耳廓软骨和肋软骨。在手术当天，对软骨进行压缩评估，每个样本以1毫米/秒的速度加载至300克。结果：观察到肋软骨的杨氏弹性模量显著高于耳廓软骨（肋软骨平均为11.43兆帕，耳廓软骨平均为2兆帕，p<0.0001）。耳廓软骨的松弛率显著高于肋软骨（肋软骨平均为0.72兆帕10，耳廓软骨平均为1.93兆帕10，p<0.05）。弹性软骨的最终绝对松弛度显著低于肋软骨（肋软骨平均为3.35兆帕，耳廓软骨平均为0.2兆帕，p<0.0001）。还评估了用作重建替代物的异体软骨替代品。观察到硅胶、戈尔特斯（Gore-Tex）和Medpor的杨氏弹性模量显著高于肋软骨和耳廓软骨。与耳廓软骨相比，肋软骨在压缩时具有更高的杨氏弹性模量。目前用于替代合成软骨的合成材料无法模拟肋软骨，这是未来需要解决的问题。
