Biomechanical Optimization of Pediatric Supracondylar Humerus Fracture Fixation: Insights from an Experimental Study and Network Meta-analysis.

Abstract

To comprehensively evaluate the biomechanical properties of traditional and emerging fixation configurations for pediatric supracondylar humerus fractures through experimental testing and network meta-analysis (NMA). The study consisted of two parts: (1) A biomechanical comparison of five fixation configurations: two divergent lateral metal pins (L2D), two divergent lateral bioabsorbable pins (L2D-B), two divergent lateral pins with supplementary lock wire (L2D-W), crossed metal pins (L1M1), and crossed bioabsorbable pins (L1M1-B). Specimens underwent cyclic loading in multiple directions followed by load-to-failure testing. (2) A NMA of 12 published biomechanical studies comparing different fixation methods for supracondylar fractures. In biomechanical testing, crossed metal pin configuration (L1M1) demonstrated superior rotational stability (internal: 279.4±24.8 Nmm/deg; external: 336.0±30.6 Nmm/deg) compared to other configurations. The NMA revealed that two divergent lateral pins plus one medial pin (L2DM1) consistently ranked highest across multiple biomechanical parameters: external rotational stiffness (SUCRA=87.8%), torsional failure torque (SUCRA=100%), varus bending stiffness (SUCRA=99.7%), and valgus bending stiffness (SUCRA=92.9%). External fixation demonstrated the highest performance for internal rotational stiffness (SUCRA=85.7%) and extension bending stiffness (SUCRA=96.1%). This biomechanical analysis demonstrates that crossed pin configurations and external fixation provide superior mechanical stability, while wire-augmented lateral pins offer promising alternatives. Bioabsorbable pins exhibit significantly reduced strength. These biomechanical findings should serve as adjunctive evidence to complement clinical outcome data in guiding optimal treatment selection for pediatric supracondylar humeral fractures.