Comparative analysis for five fixations of Pauwels-I by the biomechanical finite-element method

• Published in: Journal of investigative surgery Vol. 33; no. 5; pp. 428 - 437
• Main Authors: Jian-Qiao Peng, Matthew, Chen, Hai-Yan, Ju, XiangYang, Hu, Yong, Ayoub, Ashraf, Khambay, Balvinder, Liu, ZiQing, Bai, Bo
• Format: Journal Article
• Language: English
• Published: United States Taylor & Francis 27.05.2020; Taylor & Francis Group
• Subjects: Adult; Biomechanical Phenomena; Bone Plates; Bone Screws; displacement; Elastic Modulus; FEA; Femoral Neck Fractures - classification; Femoral Neck Fractures - diagnosis; Femoral Neck Fractures - surgery; Femur - diagnostic imaging; Femur - injuries; Femur - surgery; Finite Element Analysis; fixation; Fracture Fixation, Internal - instrumentation; Fracture Fixation, Internal - methods; Hemiarthroplasty - instrumentation; Hemiarthroplasty - methods; Hip Prosthesis; Humans; Imaging, Three-Dimensional; Materials Testing; Models, Biological; Osteotomy - instrumentation; Osteotomy - methods; Pauwels-I; Prosthesis Design; stress; Tomography, X-Ray Computed; fixation; stress; displacement; FEA; Pauwels-I
• ISSN: 0894-1939; 1521-0553
• DOI: 10.1080/08941939.2018.1533054

Background: Little is known about how biomechanics govern the five fixtures such as DHS, MLS, DHS + LS, LP, and HA are accepted as common therapeutic techniques. Aims and objectives: A series of numerical models for a femoral neck fracture of Pauwels-I will be constructed by innovative approach of finite element in order to determine the most optimized option in comparison with biomechanical performance. Method: Twenty sets of computer tomography scanned femora were imported onto Mimics to extract 3 D models; these specimens were transferred to Geomagic-Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; 5 sorts of fixture were then expressed by Pro-Engineer virtually. After processing with HyperMesh, all compartments (fracture model + internal implant) were assembled onto 5 systems: "Dynamic Hip Screw (DHS), Multiple Lag screw (MLS), DHS + LS, femoral Locking Plate (LP) and HemiArthroplasty (HA)." Eventually, numerical models of the finite-elemental analysis were exported to AnSys to determine the solution. Result: Four models of fixation and a simulation of HA for Pauwels-I were established, validated, and analyzed with the following findings: In term of displacement, these 5 fixtures ranged between 0.3801 and 0.7536 mm have no significant difference; in term of stress, the averages of peaks for integral assemblage are b(MLS) = 43.5766 ≈< d(LP) = 43.6657 ≈< e(Ha) = 43.6657 < c(DHS + LS) = 66.5494 < a(DHS) = 105.617 in MPa indicate that MLS, LP and HA are not significantly different, but less than DHS + LS or DHS in each. Conclusion: A fixture of MLS or LP with optional HA should be recommended to clinically optimize a Pauwels-I facture.