In vitro biomechanical comparison of a 5-hole 4.5 mm locking compression plate and 5-hole 4.5 mm dynamic compression plate for equine proximal interphalangeal joint arthrodesis.
Authors: Seo Jong-Pil, Yamaga Takashi, Tsuzuki Nao, Yamada Kazutaka, Haneda Shingo, Furuoka Hidehumi, Sasaki Naoki
Journal: Veterinary surgery : VS
Summary
# Editorial Summary: Locking vs Dynamic Compression Plating for Equine PIP Arthrodesis When stabilising the proximal interphalangeal joint in horses, surgeons must choose between locking compression plates (LCP) and dynamic compression plates (DCP), yet direct biomechanical comparison of these techniques had been lacking. Seo and colleagues conducted an in vitro study using six pairs of cadaveric equine forelimbs, stabilising one PIP joint in each pair with a 5-hole 4.5 mm LCP and the contralateral joint with a 5-hole 4.5 mm DCP, then subjecting both constructs to three-point dorsopalmar bending until failure. The LCP technique demonstrated significantly superior mechanical performance, with greater yield load, failure load, and overall stiffness compared to the DCP approach, though both constructs behaved similarly in terms of deformation at yield and failure points. These findings suggest that locking plate fixation offers superior resistance to bending forces in the sagittal plane—a clinically relevant consideration given the loading patterns through the distal limb during weight-bearing and movement. For practitioners undertaking PIP arthrodesis, particularly in cases where maximum initial construct stability is a priority, the LCP technique appears biomechanically advantageous, though outcomes may also be influenced by surgical technique, bone quality, and postoperative management variables not captured in this mechanical testing model.
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Practical Takeaways
- •For equine PIP joint arthrodesis procedures, locking compression plates offer greater load-bearing capacity and structural rigidity than dynamic compression plates in laboratory conditions
- •Both plate types show similar displacement characteristics, suggesting comparable functional outcomes in early post-operative loading phases
- •Clinical outcomes should be validated as this is cadaveric testing; biomechanical superiority of LCP may translate to faster healing and earlier return to function in live horses
Key Findings
- •Locking compression plate (LCP) demonstrated significantly greater yield load compared to dynamic compression plate (DCP) in PIP joint arthrodesis constructs
- •LCP technique showed significantly higher failure load and stiffness under 3-point dorsopalmar bending to failure than DCP
- •No significant difference was found between LCP and DCP constructs for displacement at yield and failure points
- •LCP provided superior biomechanical stability overall compared to DCP under single-cycle testing conditions