Breaking the treatment dilemma of Schatzker IV fractures: finite element analysis validates hybrid single-plate with tension screw fixation for synergistic optimization of stability and minimally invasive outcomes

TL;DR

This study uses finite element analysis to find a better treatment for Schatzker IV tibial fractures by combining a single plate with tension screws, offering stability and reduced invasiveness.

Contribution

The study introduces a hybrid fixation method combining a single plate with tension screws as a novel solution for Schatzker IV fractures.

Findings

Hybrid fixation with a medial plate and tension screws showed the lowest implant stress compared to single-plate and double-plate methods.

Hybrid fixation provided a more uniform stress distribution in the tibial shaft, similar to double-plate fixation but with less invasiveness.

Type IV-B fractures benefited more from posteromedial tension screws, reducing stress in fracture fragments.

Abstract

The core challenge in treating Schatzker type IV tibial plateau fractures lies in balancing mechanical stability with minimally invasive techniques. Traditional double-plate fixation carries a high risk of soft tissue complications, while single-plate fixation provides insufficient mechanical strength. This study aims to systematically evaluate and compare the biomechanical performance of five internal fixation strategies for Schatzker type IV-A and IV-B fractures using finite element analysis (FEA), exploring whether optimized fixation configurations can achieve synergy between minimally invasive treatment and stability.

Three-dimensional models of Schatzker type IV-A and IV-B fractures were constructed based on CT data from a 43-year-old male patient. Soft tissue models including ligaments and menisci were established. Five fixation methods were simulated: isolated medial plate (IMLP), medial plate with two posteromedial tension screws (IMLP + 2PMS), medial plate with two lateral tension screws (IMLP + 2LTS), posteromedial and medial double plating (PMP + MLP), and medial and lateral double plating (MLDP). Axial loads from 300 N to 2400 N were applied to simulate conditions ranging from standing to vigorous activity. Implant stress, tibial shaft stress, and fracture fragment micromotion were quantified.

Under a 1200 N load, hybrid fixation modes (IMLP + 2PMS and IMLP + 2LTS) demonstrated superior biomechanical performance. They exhibited the lowest peak implant stress (Type IV-A: IMLP + 2PMS 124.21 MPa; Type IV-B: IMLP + 2PMS 115.64 MPa), significantly better than the IMLP group (∼248 MPa), and comparable or superior to double-plate fixation groups (MLDP, PMP + MLP). While fracture fragment displacement showed no significant differences across all fixation methods, IMLP + 2PMS effectively reduced stress in type IV-B fragments. Regarding stress distribution in the tibial shaft, hybrid fixation provided a more uniform and physiological pattern compared to double-plate fixation. The results indicate differential responses to fixation strategies between type IV-A and IV-B fractures, with type IV-B deriving more pronounced benefits from posteromedial tension screws.

The hybrid fixation configuration of a “medial plate combined with tension screws” represents a biomechanically optimal solution for treating Schatzker type IV-A and IV-B fractures. It provides stability comparable to double-plate fixation while significantly reducing implant stress concentration and the “stress-shielding” effect through a minimally invasive approach, achieving a synergy between minimal invasiveness and stability.

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