Is three-point fixation needed to mechanically stabilize zygomaticomaxillary complex fractures?

Area of Science:

• Oral and Maxillofacial Surgery
• Biomechanical Engineering
• Orthopedic Surgery

Background:

• Zygomaticomaxillary complex (ZMC) fractures require stable fixation to prevent malunion.
• Current fixation methods may use excessive hardware, as minimal load transmission occurs through the infraorbital rim (IOR).
• Previous studies suggest IOR plating may not significantly alter bone strain patterns in ZMC fractures.

Purpose of the Study:

• To evaluate the impact of reduced hardware fixation on ZMC fracture stability under simulated muscle loading.
• To test the hypothesis that three-point fixation is not critical for ZMC fracture stability.
• To determine if two-point or one-point fixation provides adequate stability for ZMC fractures.

Main Methods:

• Simulated ZMC fractures on two cadaveric samples.
• Applied muscle loading via simulated mouth openings (20mm and 30mm).
• Measured fracture gap displacement and bone strain with three-point, two-point, and one-point fixation configurations.

Main Results:

• Fracture displacement remained clinically stable (<1mm in 95% of cases) across fixation configurations.
• Two-point and one-point fixation demonstrated comparable stability to three-point fixation.
• Strain measurements showed high variability, likely due to complex load patterns and gauge placement sensitivity.

Conclusions:

• Reduced hardware fixation (two-point or one-point) appears sufficient for ZMC fracture stability under muscle loading.
• Supports the concept of hardware reduction in ZMC fracture management.
• Further investigation into optimal fixation strategies for ZMC fractures is warranted.