Can posterolateral tibial plateau fractures be treated with an anterolateral approach? A biomechanical study on novel plating concepts in artificial tibia models

The aim of this study was to evaluate biomechanically whether fixation of posterolateral tibial plateau fractures (PLTPFs) through the more accessible modified anterolateral approach and by using a newly designed lateral plate with or without posterior plate extension or supplemental anteroposterior screw fixation, can provide comparable stability to direct posterolateral buttress plating.

PLTPFs were simulated on 40 artificial tibiae and subsequently fixed with 5 different plating techniques (n = 8), namely using Variable Angle Locking Compression Plate (VA-LCP) Lateral Proximal Tibia Plate 3.5 (VA Lateral), Variable Angle Optimized Locking Technology (VOLT) Lateral Proximal Tibia Plate 3.5 (VOLT Lateral), VOLT Lateral Proximal Tibia Plate 3.5 with Posterolateral Extension (Hug), VOLT Posterolateral Proximal Tibia Plate 3.5 (PL), and VOLT Lateral Proximal Tibia Plate 3.5 with two anteroposterior parallel 3.5 mm locking screws placed superiorly to the plate's lateral-to-medial rafting locking screws (Jail) using a dedicated guide block. Biomechanical testing was performed under progressively increasing cyclic loading to failure. Interfragmentary movements were monitored via motion tracking.

Fragment displacement and its posterior tilt over the first 40,000 cycles did not differ significantly between Hug, PL, and Jail (all p > 0.999). Hug, PL, and Jail outperformed VA Lateral significantly in terms of fragment displacement over 40,000 cycles (p ≤ 0.004). In addition, Hug was associated with significantly less fragment displacement versus VOLT Lateral (p = 0.018). Posterior fragment tilting over 40,000 cycles was significantly lower in Hug, PL, and Jail versus VA Lateral and VOLT Lateral (p ≤ 0.014). Hug, PL, and Jail demonstrated significantly higher cycles to clinical failure and corresponding loads at clinical failure than VA Lateral and VOLT Lateral (p < 0.001), with no significant differences among Hug, PL, and Jail (p > 0.999). For catastrophic failure, Hug demonstrated significantly higher values than all other groups (p ≤ 0.045).

From a biomechanical perspective, VOLT Lateral Proximal Tibia Plate 3.5 with Posterolateral Extension and VOLT Lateral Proximal Tibia Plate with supplemental jail screw fixation provide fixation stability comparable to VOLT Posterolateral Proximal Tibia Plate 3.5 with respect to fragment displacement, posterior tilt, and clinical failure. Whether PLTPFs could be addressed via the more accessible anterolateral approach without compromising the biomechanical stability of fracture fixation remains yet to be clinically validated. Standalone Lateral Proximal Tibia Plate 3.5 (VA-LCP or VOLT) performed inferiorly to their augmented alternatives.