Towards optimization of volar plate fixations of distal radius fractures: Using finite element analyses to reduce the number of screws. (February 2021)

• Record Type: Journal Article
• Authors: Synek, Alexander; Baumbach, Sebastian F.; Pahr, Dieter H.
• Is Part Of: Clinical biomechanics. Volume 82(2021)
• Publication Date: 2021-02
• Subjects: Radius fractures -- Volar locking plate -- Fracture fixation -- Finite element analysis -- Optimization -- Patient-specific modelling; Biomechanics -- Periodicals; Osteopathic medicine -- Periodicals; Biomechanics -- Periodicals; Osteopathic Medicine -- Periodicals; 612.76
• DOI: 10.1016/j.clinbiomech.2021.105272
• Languages: English
• ISSNs: 0268-0033

Abstract

Abstract: Background: Using fewer distal screws in volar plate fixation of distal radius fractures could reduce treatment costs and complications. However, there is currently no consensus on the ideal screw configuration, likely due to experimental limitations and its subject-specific nature. In this study, finite element analysis was used to investigate (1) if reducing the number of screws is biomechanically feasible and (2) if an optimal screw configuration is subject-specific. Methods: Validated subject-specific finite element models of 16 human radii with extra articular distal radius fractures and volar plate fixation with six distal screws were used as a baseline. 41 additional configurations with three to six distal screws were simulated for each subject. Axial stiffness and peri-implant strains around the distal screws were evaluated. Subject-specific optimum configurations were determined using a lower bound for the axial stiffness and minimizing peri-implant strains. Findings: Even using three distal screws led to only minor deterioration of the biomechanical properties in the best configuration (axial stiffness: −11.2%, peri-implant strains: −35.0%), but a considerable deterioration in the worst configuration (axial stiffness: −46.2%, peri-implant strains: +112.4%). The optimization showed that the ideal screw configuration is subject-specific and on average 1.9 screws could be saved based on the herein used optimization criterion. Interpretation: This study highlights that not only how many, but which screws are used in volar plate fixation of distal radius fractures is critical. Using a patient-specific selection of distal screws bears potential to save costs and reduce complications. Highlights: 42 screw configurations were compared for 16 subjects using finite element analysis. Not only how many, but which distal screws are used was found as a key factor. Subject-specific optimal screw configurations could save ~2 of 6 distal screws. The number of saved screws correlated with bone mineral density and radius width.