Biomechanical Evaluation of Fractured Femoral Locking Plates Using Finite Element Analysis

Tamrakar, Himanshu; Kar, Uttam Kumar

doi:10.26706/ijaefea.13.2.20260404

Abstract

The femur is the longest and strongest bone in the human body and plays a critical role in load transfer between the hip and knee joints under physiological loading conditions. Femoral fractures are among the most common orthopaedic injuries and often require internal fixation devices to restore structural stability and facilitate bone healing. The mechanical performance of the fixation system plays a crucial role in determining the success of fracture treatment. In the present study, a finite element-based biomechanical assessment of a fractured femur stabilized with a PMMA/Hydroxyapatite (PMMA/HA) composite locking plate was carried out under various physiological and impact loading conditions. A three-dimensional model of the fractured femur and locking plate assembly was developed from computer-aided design data and analyzed using finite element techniques. The PMMA/HA composite was selected as the plate material due to its favourable biocompatibility and enhanced load transfer characteristics. Four loading scenarios were investigated, namely joint loading during single-leg stance, trochanteric loading during single-leg stance, joint loading during fall, and trochanteric loading during fall. In addition, the biomechanical response of the fixation system was evaluated at four representative stages of the gait stance phase to investigate the influence of dynamic physiological loading. The distributions of equivalent (Von-Mises) stress and total deformation were analyzed to assess the structural behaviour of the bone-implant system. The results revealed that loading location and loading intensity significantly affect stress concentration and deformation patterns. Fall loading generated substantially higher stresses and deformations than normal stance loading, identifying it as the most critical condition for implant safety. Among the investigated loading cases, joint loading during fall produced the highest equivalent stress, whereas trochanteric loading during fall resulted in the largest deformation. The gait analysis further demonstrated that stress and deformation vary throughout the stance phase, with the highest values occurring during the terminal stance stage. A progressive shift of stress concentration from the medial to the lateral side of the femur was also observed during the gait cycle. The findings indicate that the PMMA/HA composite locking plate provides effective fracture stabilization and satisfactory load-bearing capability under both physiological and impact loading conditions. The study contributes to the understanding of the biomechanical behaviour of composite orthopaedic implants and offers useful insights for the design and optimization of next-generation femoral fracture fixation systems.

Keywords

Femur Bone Locking Plate PMMA Gait Loading Finite Element Analysis Stress Distribution Orthopaedic Implant Biomechanics

References

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C. Vallier and W. Immler, “Comparison of the 95-degree angled blade plate and the locking condylar plate for the treatment of distal femoral fractures,” Journal of Orthopaedic Trauma, pp. 327–332, 2012.
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[1] Kraus et al., “Social class, conceptualism, and empathic accuracy,” Psychological Science, vol. 21, pp. 1716–1721, 2010.

[2] Fulkerson et al., “Biomechanics of locked plates and screws,” Journal of Orthopaedic Trauma, vol. 18, pp. 488–493, 2004.

[3] Hingins et al., “Biomechanical comparison of dynamic condylar screw and locking compression plate fixation in unstable distal femoral fractures: An in vitro study,” Journal of Orthopaedic Trauma, vol. 47, pp. 615–620, 2013.

[4] C. Vallier and W. Immler, “Comparison of the 95-degree angled blade plate and the locking condylar plate for the treatment of distal femoral fractures,” Journal of Orthopaedic Trauma, pp. 327–332, 2012.

[5] S. Lahari et al., “Finite element analysis of femur in the evaluation of osteoporosis,” Journal of Pharmaceutical, Biological and Chemical Sciences, 2011.

[6] H. Mehboob, J. Kim, A. Mehboob, and S.-H. Chang, “How post-operative rehabilitation exercises influence the healing process of radial bone shaft fractures fixed by a composite bone plate,” Composite Structures, vol. 159, pp. 307–315, 2017.

[7] P. K. Satapathy et al., “Analysis of fractured femur bone with functionally graded bone plate at femur bone fracture site by adopting finite element method,” IOP Conference Series: Materials Science and Engineering, vol. 330, Art. no. 012027, 2018.

[8] A. R. MacLeod, P. Pankaj, and A. S. Simpson, “Experimental and numerical investigation into the influence of loading conditions in biomechanical testing of locking plate fracture fixation devices,” Bone & Joint Research, vol. 7, pp. 111–120, 2018.

[9] F. Tarlochan, H. Mehboob, A. Mehboob, and S.-H. Chang, “Biomechanical design of a composite femoral prosthesis to investigate the effects of stiffness, coating length, and interference press fit,” Composite Structures, vol. 204, pp. 803–813, 2018.

[10] T. Wisanuyotin, W. Sirichativapee, P. Paholpak, W. Kosuwan, and Y. Kasai, “Optimal configuration of a dual locking plate for femoral allograft or recycled autograft bone fixation: A finite element and biomechanical analysis,” Clinical Biomechanics, vol. 80, Art. no. 105156, 2020. doi:10.1016/j.clinbiomech.2020.105156.

[11] J. Wang, J.-X. Ma, B. Lu, H.-H. Bai, Y. Wang, and X.-L. Ma, “Comparative finite element analysis of three implants fixing stable and unstable subtrochanteric femoral fractures: Proximal Femoral Nail Antirotation (PFNA), Proximal Femoral Locking Plate (PFLP), and Reverse Less Invasive Stabilization System (LISS),” Orthopaedics & Traumatology: Surgery & Research, vol. 106, pp. 95–101, 2020. doi:10.1016/j.otsr.2019.04.027.

[12] G. J. Pereira, S. C. Rahal, W. M. Barboza, I. Moroz, A. L. Leão, M. M. Alves, et al., “Study of a near-cortical over-drilling technique on plate constructs with a conical locking system in a rabbit femoral fracture using a finite element model,” Medical Engineering & Physics, vol. 144, Art. no. 104399, 2025. doi:10.1016/j.medengphy.2025.104399.

[13] U. K. Kar and R. K. Bhushan, “Design and analysis of femoral locking plate under different loading conditions using suitable material,” Materials Today: Proceedings, vol. 21, pp. 1128–1134, 2020.

[14] I. Antoniac, M. Miculescu, V. M. Păltânea, A. S. P. H. Q. G. P. A. R., and K. E., “Magnesium-based alloys used in orthopedic surgery,” Materials, vol. 15, Art. no. 1148, 2022.

[15] A. Dhanopia and M. Bhargava, “Finite element analysis of human fractured femur bone implantation with PMMA thermoplastic prosthetic plate,” Procedia Engineering, vol. 173, pp. 1658–1665, 2017. doi:10.1016/j.proeng.2016.12.190.