Dual miniplate internal fixation for forearm diaphysis fractures: a clinical and biomechanical study

Purpose: Forearm diaphyseal fractures require anatomical reduction and stable internal fixation to restore pronation and supination function. Conventional 3.5-mm plates are effective but can be associated with hardware irritation and refracture after implant removal. Dual miniplate fixation using low-profile plates may offer a technically advantageous alternative. This study investigated the clinical outcomes and biomechanical performance of dual miniplate fixation for forearm shaft fractures.Methods: A retrospective review was conducted of 24 patients (29 fractures) treated with dual low-profile plates. Biomechanical testing was performed using synthetic radius models with three fixation constructs: a single 3.5-mm locking compression plate (LCP), dual 2.4-mm LCPs with non-locking screws, and dual 2.4-mm LCPs with mixed locking and non-locking screws. Outcomes included torsional stiffness, axial distraction, cantilever bending stiffness, and failure load.Results: All fractures achieved union, with a mean union time of 119.2 days. Two cases of delayed union and one metal failure were observed. Torsional stiffness and failure load were significantly greater in patients treated with a single 3.5-mm plate, while no significant differences were noted in axial distraction or anteroposterior bending stiffness.Conclusion: Despite lower biomechanical performance than the conventional 3.5-mm plate, dual miniplate fixation achieved satisfactory clinical outcomes with appropriate postoperative protocols. This technique may be a reliable alternative for selected fracture patterns if appropriate postoperative protocols are followed.