Osteoporosis effects on the treatment of intertrochanteric fracture of femur with proximal femoral anti-rotation intramedullary nail: A finite element simulation / 中国组织工程研究

ABSTRACT

BACKGROUND: Proximal femoral anti-rotation intramedullary nail for treating intertrochanteric fracture is widely used in clinical practice, but there are still some cases of failure of internal fixation after operation, and osteoporosis of proximal femur is considered as an important reason. Singh index is an important index to evaluate the severity of osteoporosis in the proximal femur. Based on the Singh index, it is of great significance to explore the effect of different degrees of osteoporosis on the treatment of intertrochanteric fracture with anti-rotation intramedullary nail in the proximal femur, so as to reduce the failure rate of internal fixation and increase the success rate of operation. OBJECTIVE: To explore the effect of different osteoporosis on the treatment of intertrochanteric fracture with proximal femoral anti-rotation intramedullary nail, so as to provide new ideas and experimental basis for clinical treatment of intertrochanteric fracture. METHODS: CT data of one patient with intertrochanteric fracture of the left femur were imported into Mimics 19.0 and Geomagic studio 2017 software to extract and optimize the three-dimensional model of the right femur. SolidWorks 2017 software was used to draw the internal fixation model and assemble it with the femur model according to the standard operation technology, and import it into HyperMesh 14.0 software in STEP format to cut the bone according to AO-2.1 type of intertrochanteric fracture. Trabecular bone based on Singh index 1-6 was established to obtain six models of A-F. Material property parameters, boundary conditions and applied loads were set. Finally, the data were stored as K files and imported into LS-DYNA software for solution. RESULTS AND CONCLUSION: (1) When the femoral head was stressed, the spiral blade in the bone block of the femoral head and neck of Singh 6-Singh 1 was cut, the common bone trabecula disappeared, the stress bone trabecula wrapped with the spiral blade did not disappear, but loaded with certain stress, so that the spiral blade still had a large contact area and holding force, maintained the reduction of the fracture, and reduced the varus and rotation of the bone block of the femoral head and neck. (2) From Singh 6-Singh 1, with the disappearance of stress bone trabecula, the more serious osteoporosis is, the more likely failure will be in the treatment of intertrochanteric fracture with proximal femoral anti-rotation intramedullary nail. (3) The spongy bone trabeculae, especially the stress bone trabeculae, play an important role in maintaining the elastic stability of the proximal femur by resisting and buffering the bending strain.