The effect of pedicle screw angle on stress distribution in lumbar spine fixation: an optimization approach based on finite element analysis
Journal of Orthopaedic Surgery and Research, cilt.21, sa.1, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 21 Sayı: 1
- Basım Tarihi: 2026
- Doi Numarası: 10.1186/s13018-026-06942-w
- Dergi Adı: Journal of Orthopaedic Surgery and Research
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, CINAHL, EMBASE, MEDLINE, Directory of Open Access Journals, Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Anahtar Kelimeler: Finite element analysis, Internal fixators, Lumbar vertebrae, Pedicle screws, Mechanical stress
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Background: Pedicle screw fixation is widely used for lumbar spine stabilization, and technical parameters such as screw insertion angle may influence the biomechanical behavior of the implant–bone construct. Objective: This study aimed to evaluate the effect of different transverse pedicle screw insertion angles (25°, 30°, 35°, and 40°) on stress distribution in the L4–L5 segment using three-dimensional finite element analysis (FEA). Methods: A three-dimensional finite element model of the L4–L5 lumbar segment was developed from computed tomography data of a healthy adult subject. Titanium alloy (Ti-6Al-4 V) pedicle screws (6.5 mm diameter) were modeled at four predefined insertion angles. A 400 N axial compressive load was applied to simulate physiological loading conditions. Stress distributions were analyzed using von Mises criteria within the ANSYS Workbench environment. Results: Maximum von Mises stress values varied across insertion angles. The highest stress (399.26 MPa) was observed at 25°, primarily at the screw head–rod junction and screw–bone interface. The lowest stress (297.86 MPa) was recorded at 40°. A decreasing trend in stress values was observed with increasing insertion angle. Conclusion: Pedicle screw insertion angle affects stress distribution in the L4–L5 segment. Higher insertion angles were associated with lower stress values, suggesting a potentially more favorable biomechanical environment. These findings indicate that insertion angle may be an important parameter in pedicle screw fixation planning.