Posterolateral Tibial Plateau Fractures-Does Fixation Choice Matter? A Biomechanical Investigation.

Abstract

Although surgical management of tibial plateau fractures prioritizes anatomic reduction and stable fixation, a key knowledge gap persists regarding the biomechanical comparison of fixation techniques for posterolateral fractures. This study evaluates three common fixation strategies in fresh cadaveric bone to provide clinically relevant biomechanical data for optimizing surgical outcomes. Twelve fresh cadaveric proximal tibiae were prepared, excluding specimens with preexisting pathology, and a standardized posterolateral fracture was created using defined anatomical angles. The specimens were randomly assigned to three fixation groups-posterolateral buttress plating (using dynamic compression plate, DCP), T-shaped plating, or lateral locking compression plating (LCP)-and biomechanically tested under axial compression until failure (>3 mm displacement), with load tolerance and displacement measured through high-precision motion tracking. Statistical analysis (analysis of variance, Fisher LSD) compared failure loads and subsidence among groups, with significance set at P < 0.05. No notable differences were observed in load-to-failure among three fixation methods (DCP: 445.95 ± 134.66 N, T-plate: 695.43 ± 224.09 N, LCP: 793.65 ± 227.86 N; P > 0.05). However, fragment subsidence varied markedly (P < 0.05), with DCP exhibiting greater displacement under load compared with T-plate and LCP, suggesting T-plate and LCP constructs provide superior stability against incremental displacement despite similar ultimate failure thresholds. Although the difference lacked statistical significance, fixation using both anterior lateral rafting plates and posterior T-plates achieved a higher load-to-failure capacity than posterior DCP fixation in posterolateral tibial plateau fractures.