Freitas Anderson, Lessa Mariana de Medeiros, de Oliveira Saulo Pereira, Oliveira Pedro Félix Pereira de, Giordano Vincenzo, Shimano Antônio Carlos
Instituto de Pesquisa e Ensino, Hospital Ortopédico e Medicina Especializada (IPE-HOME-DF), Brasília, DF, Brasil.
Serviço de Ortopedia e Traumatologia, Hospital Regional do Gama (HRG-DF), Brasília, DF, Brasil.
Rev Bras Ortop (Sao Paulo). 2020 Sep 25;56(5):641-646. doi: 10.1055/s-0040-1714221. eCollection 2021 Oct.
To evaluate, through a biomechanical assay, the maximum load, energy, and displacement necessary for the occurrence of fractures in synthetic models of femurs after the removal of cannulated screws and the performance of a reinforcement technique with polymethylmethacrylate (PMMA) in different combined positions. In total, 25 synthetic bones were used, and they were divided into 4 groups: the control group (CG), with 10 models without perforation, and the test groups (A, B and C), with 5 models each. The test groups were fixed with cannulated screws using the Asnis technique, and they had the synthesis removed, and two of the holes formed by the reinforcement technique with PMMA were filled. The biomechanical analysis was performed simulating a fall on the large trochanter using a servo-hydraulic machine. All specimens of the CG and of groups A, B and C presented basal-cervical fracture of the femoral neck, except for a single model in group B, which presented a longitudinal fracture. An average of 5.4 mL of PMMA were used to reinforce the groups with filling. According to the analysis of variance (ANOVA) and the Tukey multiple comparison test, at the level of 5%, we observed that the CG presented significant differences in relation to groups A and C in the following parameters: maximum load, energy up to the fracture, and displacement. We observed that groups A and C, when compared to the CG, showed significant differences in the observation of displacement, maximum load, and energy until the fracture.
通过生物力学分析，评估空心螺钉取出后股骨合成模型发生骨折所需的最大负荷、能量和位移，以及聚甲基丙烯酸甲酯（PMMA）在不同组合位置的强化技术的性能。总共使用了25根合成骨，分为4组：对照组（CG），10个未穿孔模型；试验组（A、B和C），每组5个模型。试验组采用阿斯尼斯技术用空心螺钉固定，拆除内固定，并用PMMA强化技术填充形成的两个孔。使用伺服液压机模拟大转子着地进行生物力学分析。CG组以及A、B、C组的所有标本均出现股骨颈基底-颈骨折，但B组有1个模型出现纵向骨折。平均使用5.4毫升PMMA对填充组进行强化。根据方差分析（ANOVA）和Tukey多重比较检验，在5%的水平上，我们观察到CG组在以下参数方面与A组和C组存在显著差异：最大负荷、骨折前能量和位移。我们观察到，与CG组相比，A组和C组在位移、最大负荷和骨折前能量的观察方面存在显著差异。
