Comparison of 2-Dimensional and 3-Dimensional Metacarpal Fracture Plating Constructs Under Cyclic Loading

Area of Science:

• Orthopedic surgery
• Biomechanical engineering
• Materials science

Background:

• Metacarpal fractures often require surgical intervention when closed reduction fails.
• Dorsal plating using 2D or 3D plates is a common fixation method.
• Comparing construct stability between different plate designs is crucial for optimizing treatment.

Purpose of the Study:

• To compare the fixation stability of low-profile 3-dimensional (3D) plates versus larger 2-dimensional (2D) plates in a metacarpal fracture model.
• To evaluate differences in construct stability under cyclic loading and load to failure.

Main Methods:

• Thirty synthetic metacarpal bones with simulated fractures were plated with either 2D or 3D locking plates.
• Constructs underwent cyclic loading (70 N and 120 N) followed by monotonic loading to failure.
• Fracture gap displacement, failure modes, strength, and stiffness were measured.

Main Results:

• All 3D constructs withstood cyclic loading; 33% of 2D constructs failed.
• 3D constructs exhibited a significantly higher load to failure (265 N) compared to 2D constructs (190 N).
• 3D plates demonstrated greater construct stiffness and resistance to displacement.

Conclusions:

• Low-profile 3D metacarpal plates provide superior stability and resistance to failure compared to 2D plates.
• 3D plates may reduce soft tissue complications due to their smaller size and lower profile.
• This suggests 3D plates offer enhanced early postoperative stability for metacarpal fractures.