Giordano Vincenzo, Freitas Anderson, Pires Robinson Esteves, Battaglion Leonardo Rigobello, Lobo Mariana de Oliveira, Belangero William Dias
Orthopedics and Traumatology Service Prof. Nova Monteiro, Hospital Municipal Miguel Couto, Rua Mario Ribeiro, 117, Rio de Janeiro 22430-160, RJ, Brazil.
Home Hospital Ortopédico e Medicina Especializada, SGAS Quadra 613-Conjunto C-Asa Sul, Brasília 70200-730, DF, Brazil.
Bioengineering (Basel). 2022 Sep 12;9(9):464. doi: 10.3390/bioengineering9090464.
Femoral neck fractures in young adults are uncommon, resulting from high-energy trauma. Despite their infrequency in this population, there is higher rate of complications, especially in the more vertical fracture line, classified by Pauwels as a type-3 femoral neck fracture. The implant type is of paramount importance for maintaining anatomical reduction, since it must resist the deforming forces that act on the fracture. We comparatively evaluated two constructions of the novel locking autocompression implant (X-PIN and X-PIN+P) using the finite element method and previously established methods for treating Pauwels type-3 femoral neck fractures. Six fixation models were developed for the study: a dynamic hip screw (DHS), a DHS with an anti-rotation screw (DHS+P), the inverted triangle multiple cannulated screws construction (ASNIS), the multiple cannulated screws in an L-configuration (L), and the two models of the novel locking autocompression screw (X-PIN and X-PIN+P). Under the same conditions with a load of 2100 N, the following parameters were evaluated using SIMLAB software: the main maximum (Max P), main minimum (Min P), localized maximum P1 (Max P1), localized maximum P2 (Max P2), total displacement, localized displacement, rotation displacement, and von Mises stress. Compared to the DHS+P and ASNIS models, the X-PIN+P model presented, respectively, increases of 51.6% and 64.7% for Max P, 85% and 247% for Min P, and 18.9% and 166.7% for von Mises stress. Max P1 did not differ between the models, but Max P2 was 55% and 50% lower for X-PIN+P than ASNIS and L, respectively. All displacement values were lower for X-PIN+P than the other models. In this FEM testing, the X-PIN+P was superior to the other models, which was due to improvement in all parameters of stress distribution, displacement, and von Mises stress compared to models using a lateral plate (DHS and DHS+P) or not (ASNIS and L).
年轻人的股骨颈骨折并不常见，多由高能量创伤导致。尽管在这一人群中此类骨折并不频发，但并发症发生率较高，尤其是骨折线更为垂直的情况，Pauwels将其归类为3型股骨颈骨折。植入物类型对于维持解剖复位至关重要，因为它必须抵抗作用于骨折处的变形力。我们使用有限元方法和先前确立的治疗Pauwels 3型股骨颈骨折的方法，对新型锁定自动加压植入物的两种结构（X-PIN和X-PIN+P）进行了比较评估。为该研究构建了六种固定模型：动力髋螺钉（DHS）、带防旋转螺钉的DHS（DHS+P）、倒三角多空心螺钉结构（ASNIS）、L形多空心螺钉结构（L）以及新型锁定自动加压螺钉的两种模型（X-PIN和X-PIN+P）。在2100 N载荷的相同条件下，使用SIMLAB软件评估以下参数：主最大力（Max P）、主最小力（Min P）、局部最大力P1（Max P1）、局部最大力P2（Max P2）、总位移、局部位移、旋转位移和von Mises应力。与DHS+P和ASNIS模型相比，X-PIN+P模型的Max P分别增加了51.6%和64.7%，Min P分别增加了85%和247%，von Mises应力分别增加了18.9%和166.7%。各模型之间Max P1没有差异，但X-PIN+P的Max P2分别比ASNIS和L低55%和50%。X-PIN+P的所有位移值均低于其他模型。在此次有限元测试中，X-PIN+P优于其他模型，这是因为与使用外侧钢板的模型（DHS和DHS+P）或未使用外侧钢板的模型（ASNIS和L）相比，其在应力分布、位移和von Mises应力的所有参数方面均有改善。
