Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China; Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China; Sports Medicine, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China.
Department of Orthopaedics, The Affiliated Hospital of Guizhou Medical University, Guiyang 550004, China; Center for Tissue Engineering and Stem Cells, Guizhou Medical University, Guiyang 550004, China.
Comput Methods Programs Biomed. 2022 Oct;225:107078. doi: 10.1016/j.cmpb.2022.107078. Epub 2022 Aug 21.
Elderly patients treated for femoral shaft fractures have a higher risk of hip fracture. We hypothesized that intramedullary nails protecting the femoral neck can improve mechanical strength and reduce the risk of subsequent hip fracture. This study aims to analyze the biomechanical stability using intramedullary nails with or without femoral neck protection through finite element analysis.
Thirty finite element models (FEMs) were established, including five different conditions of femoral shaft fracture: Fracture healing, Proximal fractures (Transverse and oblique), Distal fractures (Transverse and oblique), and five different fixation methods. Femoral neck protection groups: cephalomedullary nail (CN), reconstruction nail (RN); No femoral neck protection groups: type-1 of antegrade intramedullary nail (AIN-1), type-2 of antegrade intramedullary nail (AIN-2), and retrograde intramedullary nail (RIN). The maximum stress of bone and internal fixation in the femoral neck region for all type of fixation were calculated to evaluate the biomechanical stability.
Maximum equivalent stress values of bone in the femoral neck region for five different conditions of femoral shaft fracture: AIN-2 (77.23 MPa) >RIN (77.15 MPa) > AIN-1 (76.71 MPa) > CN (60.74 MPa) > RN (57.66 MPa) for the fracture healing; RIN (80.05 MPa) > AIN-1 (79.15 MPa) > AIN-2(78.77 MPa) > RN (65.16 MPa) > CN (65.03 MPa) for the proximal transverse fracture; RIN (80.10 MPa) > AIN-2 (79.36 MPa) > AIN-1 (79.18 MPa) > RN (65.09 MPa) > CN (64.96 MPa) for the proximal oblique fracture; RIN (80.24 MPa) > AIN-2 (79.68 MPa) > AIN-1 (79.33 MPa) > CN (65.02 MPa) > RN (64.76 MPa) for the distal transverse fracture; RIN (80.23 MPa) > AIN-2 (79.61 MPa) > AIN-1 (79.35 MPa) > CN (65.06 MPa) > RN (64.76 MPa) for the distal oblique fracture. Maximum equivalent stress of internal fixation in the femoral neck region is greater than the maximum stress of bone and avoids stress concentration of bone for the femoral neck protection groups (CN and RN).
Intramedullary nails with femoral neck protection in the treatment of femoral shaft fractures improve mechanical strength and prevent secondary hip fractures and decrease the overall risk of reoperation postoperatively.
接受股骨干骨折治疗的老年患者有更高的髋关节骨折风险。我们假设保护股骨颈的髓内钉可以提高力学强度并降低随后髋关节骨折的风险。本研究旨在通过有限元分析分析具有或不具有股骨颈保护的髓内钉的生物力学稳定性。
建立了 30 个有限元模型（FEM），包括 5 种不同的股骨干骨折情况：骨折愈合、近端骨折（横断和斜断）、远端骨折（横断和斜断）和 5 种不同的固定方法。股骨颈保护组：股骨近端髓内钉（CN）、重建钉（RN）；无股骨颈保护组：顺行髓内钉 1 型（AIN-1）、顺行髓内钉 2 型（AIN-2）和逆行髓内钉（RIN）。计算股骨颈区域骨和内部固定的最大应力，以评估生物力学稳定性。
五种股骨干骨折情况的股骨颈区域骨的最大等效应力值：骨折愈合时 AIN-2（77.23 MPa）> RIN（77.15 MPa）> AIN-1（76.71 MPa）> CN（60.74 MPa）> RN（57.66 MPa）；横断近端骨折时 RIN（80.05 MPa）> AIN-1（79.15 MPa）> AIN-2（78.77 MPa）> RN（65.16 MPa）> CN（65.03 MPa）；斜断近端骨折时 RIN（80.10 MPa）> AIN-2（79.36 MPa）> AIN-1（79.18 MPa）> RN（65.09 MPa）> CN（64.96 MPa）；横断远端骨折时 RIN（80.24 MPa）> AIN-2（79.68 MPa）> AIN-1（79.33 MPa）> CN（65.02 MPa）> RN（64.76 MPa）；斜断远端骨折时 RIN（80.23 MPa）> AIN-2（79.61 MPa）> AIN-1（79.35 MPa）> CN（65.06 MPa）> RN（64.76 MPa）。股骨颈区域内固定的最大等效应力大于骨的最大应力，并避免了骨的应力集中，这对股骨颈保护组（CN 和 RN）是有利的。
治疗股骨干骨折时使用具有股骨颈保护的髓内钉可以提高力学强度，预防继发性髋关节骨折，并降低术后再次手术的总体风险。
