Are there any differences in various polyaxial locking systems? A mechanical study of different locking screws in
Isabella Mehling1, Rebekka Scheifl, Dorothea Mehler
1Center for Musculoskeletal Surgery, Department of Trauma Surgery, University Medical Center of the Johannes Gutenberg-University of Mainz, Germany. isabella.mehling@unimedizin-mainz.de
Biomedizinische Technik. Biomedical Engineering
|March 2, 2013
Summary
This study compared three distal radius volar plates. Results show significant differences in bending strength and failure modes among polyaxial locking interfaces, impacting clinical use.
Area of Science:
- Orthopedic biomechanics
- Implant design and performance
Background:
- Angular stable plates are crucial for distal radius fractures.
- Limited comparative data exists for polyaxial locking interfaces in these plates.
Purpose of the Study:
- To mechanically compare the bending strength of three different angular stable volar plates for distal radius fixation.
- To evaluate the influence of screw locking angles on the performance of polyaxial locking interfaces.
Main Methods:
- Three plates (VA-LCP, IXOS P4, VariAX) were tested using cantilever bending.
- Screw locking angles of 0°, 5°, 10°, and 15° were assessed for strength.
- Cyclic loading to failure was performed at varying angles, with single and multiple screws.
Main Results:
- VA-LCP plates exhibited highest bending moment at 0° and 5°.
- IXOS P4 showed greatest strength at 10° and 15°.
- VariAX performance varied with angle changes; all plates demonstrated different failure mechanisms.
Conclusions:
- Polyaxial locking interfaces differ significantly in strength and failure modes.
- Plate selection should consider specific fracture patterns and desired screw angulation.
- Further biomechanical studies are needed to optimize implant design for distal radius fixation.
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