A novel stiffness-distribution-controlled hybrid locking compression plate for osteoporotic midshaft clavicle fractures: a finite element study

Abstract

Abstract Background Fixation of osteoporotic midshaft clavicle fractures in elderly patients requires a careful balance between mechanical integrity and anatomical compatibility. Conventional single-diameter locking plate systems present an inherent trade-off, as larger plates provide robust fixation but often cause soft tissue irritation, whereas low-profile plates often lack the mechanical integrity in osteoporotic bone. This study aimed to biomechanically evaluate a stiffness-distribution–controlled hybrid locking compression plate (Hybrid LCP) designed to mitigate this trade-off using a patient-derived finite element analysis. Methods A three-dimensional finite element model of a clavicle was reconstructed from CT data of a 73-year-old female, incorporating severe osteoporotic cortical thinning (1.0 mm). A Hybrid LCP combining a 3.5-mm central segment with 2.7-mm lateral segments was compared with conventional 3.5-mm and 2.7-mm plates under cantilever bending, axial compression, and axial torsion. Plate stress and peak cortical and cancellous bone stress-strain responses were evaluated to assess structural integrity and the risk of localized bone failure. Results Cantilever bending produced the highest stress levels among all loading scenarios. Under this condition, the maximum von Mises stress in the Hybrid LCP (453.4 MPa) was lower than those of the 2.7-mm systems and the conventional 3.5-mm plate (629.5 MPa), indicating a more favorable plate stress distribution. Also, the Hybrid LCP exhibited 50.4% lower peak cancellous bone strain than the conventional curved 2.7-mm plate (6,300 µε vs. 12,700 µε). Conclusion Under the standardized computational conditions evaluated in this study, the stiffness-distribution–controlled Hybrid LCP reduced stress concentrations associated with low-profile plates and decreased peak cancellous bone strain compared with the curved 2.7-mm plate. These findings suggest that targeted stiffness modulation may provide a promising biomechanical design approach for osteoporotic midshaft clavicle fixation. Further experimental and clinical validation is required before its clinical applicability can be established.