METHODS: A foot model mirroring natural anatomy was made from synthetic bone and a silicone soft tissue substitute with the same hardness as that of the soft tissues of the foot. Two types of 11 mm Ti6Al4V titanium alloy implants were studied, namely, a rectangular subtalar screw and a cylindrical subtalar screw, a type commonly used in flatfoot reconstruction surgery in children. The screws were placed in the sinus tarsi and subjected to cyclic loading (up to 1,000,000 cycles at a frequency of 5 Hz, with a maximum load of 500 N). Comparative pull-out force tests were performed immediately following implantation and after the dynamic loading test. Wyniki. Following the dynamic loading test, all 12 samples were qualified for the pull-out force test. Cylindrical screws demonstrated higher pull-out force values both for the samples tested immediately following implantation and for those that underwent dynamic loading. Implants of the same shape did not show statistically significant differences in the Mann-Whitney U test (p >0.05). Wniosek. The synthetic research model produces reproducible results in the assessment of risk of implant migration. Long-term loading does not significantly affect the risk of implant migration.
方法:由合成骨和硬度与足部软组织相同的硅胶软组织替代物制成反映自然解剖结构的足部模型。研究了两种类型的11mmTi6Al4V钛合金植入物,即,矩形距下螺钉和圆柱形距下螺钉,儿童扁平足重建术中常用的一种类型。将螺钉放置在关节窦中,并承受循环载荷(在5Hz的频率下高达1,000,000次循环,最大载荷为500N)。在植入后和在动态负载测试后立即进行比较拉出力测试。威尼基.动态加载试验后,所有12个样品都合格的拉出力测试。对于植入后立即测试的样品和经受动态载荷的样品,圆柱螺钉均显示出较高的拔出力值。相同形状的植入物在Mann-WhitneyU检验中没有显示出统计学上的显著差异(p>0.05)。Wniosek.合成研究模型在评估植入物迁移风险方面产生了可重复的结果。长期加载不会显著影响植入物迁移的风险。