Abstract
The study specifically aims to investigate a novel method to increase strength of bone plate and screw system fixation in orthopedic surgery via placing screws at an angle rather than in a transverse direction as in the conventional technique. Biomechanical tests were performed in axial compression and torsion for humeral bone fixation construct using a bone plate and screws system. Fifteen humeral surrogate bone models were utilized to have 3 groups (N = 5). Humerus bone with a simulated 6 mm fracture gap at midshaft was fixated with a 4.5 mm dynamic compression plate and six bi-cortical screws. Three fixation configurations, which were different by the number of oblique screws, were employed. In the control group (C), there was none oblique screw. The single oblique (SO) group had one oblique screw at each end of the plate. The double oblique (DO) group has two oblique screws. All oblique screws were inserted at 30° angle with respect to transverse plane. All groups were tested under axial and torsional loads in a non-destructive cyclic test prior to destructive test. One-way ANOVA test was used to detect significant differences between the group means with 95% confidence interval (p ≤ 0.05). None of the sample failed the 10,000-cycle fatigue test. The axial stiffness of group SO and DO were superior to that of group C (556.4 ± 52.4, 655.3 ± 24.6, and 632.1 ± 70.2 N/mm (p = 0.05) for group C, SO, and DO respectively). The values for yield load and ultimate load were also reported, but they were not significantly different. The post-cyclic torsional stiffness of group C, SO and DO were 0.59 ± 0.01, 0.62 ± 0.02, and 0.63 ± 0.03 Nm/° (p < 0.05). In summary, the oblique screw placement increased the axial stability of the bone construct while it did not alter significantly the torsional stability. When compared between SO and DO groups, test values were relatively equivalent. Using two consecutive oblique screws was not proven to be more effective than using one oblique screw at plate end.
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References
Robert KQ, Chandler R, Baratta RV, Thomas KA, Harris MB (2003) The effect of divergent screw placement on the initial strength of plate-to-bone fixation. J Trauma 55:1139–44. doi:10.1097/01.TA.0000031103.15337.CA
Stoffel K, Stachowiak G, Forster T, Gächter A, Kuster M (2004) Oblique screws at the plate ends increase the fixation strength in synthetic bone test medium. J Orthop Trauma 18:611–6
Karadeniz E, Balcik C, Demirors H, Tuncay C (2011) Biomechanical comparison of conventional technique versus oblique screw placement in plate fixation. J Trauma Inj Infect Crit Care 70
Scolaro JA, Hsu JE, Svach DJ, Mehta S (2014) Plate selection for fixation of extra-articular distal humerus fractures: a biomechanical comparison of three different implants. Injury 45:2040–4. doi:10.1016/j.injury.2014.08.036
Olson SA, Marsh JL, Anderson DD, Latta LL (2012) Designing a biomechanics investigation: choosing the right model. J Orthop Trauma 26
Perren T, von Knoch M, Matter P (2001) Fracture behavior of AO 3.5 mm cortical titanium screws Synthes screws combined with LC-DCP plates. Z Für Orthop Ihre Grenzgeb 139:256–260. doi:10.1055/s-2001-16331
Acknowledgements
We would like to Mercer University School of Engineering and Dr. Ha Van Vo for the support of this study.
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Nguyen, B.N., Le, T.T., Vo, H.V., Webb, L.X. (2018). Biomechanical Comparison of Conventional Technique Versus Oblique Screw Placement Under Axial and Torsional Loading—An In Vitro Study of Humerus Bone Surrogate. In: Vo Van, T., Nguyen Le, T., Nguyen Duc, T. (eds) 6th International Conference on the Development of Biomedical Engineering in Vietnam (BME6) . BME 2017. IFMBE Proceedings, vol 63. Springer, Singapore. https://doi.org/10.1007/978-981-10-4361-1_19
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DOI: https://doi.org/10.1007/978-981-10-4361-1_19
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