An ex vivo comparison of mono-versus polyaxial locking compression plates for metacarpophalangeal joint arthrodesis in the horse.
Authors: Kadic Lawrence I M, Liu Chin-Chi, Leise Britta S, McCauley Charles T, Riggs Laura M
Journal: Veterinary surgery : VS
Summary
# Editorial Summary MCP joint arthrodesis remains a challenging salvage procedure in equine surgery, and implant selection significantly influences construct stability and clinical outcomes. Lawrence and colleagues conducted an ex vivo biomechanical comparison of two plating systems—a conventional 5.5 mm stainless steel locking compression plate (LCP) versus a novel polyaxial non-contact bridging (NCB) plate adapted from human orthopaedic technology—to evaluate their mechanical performance under loading conditions representative of equine distal limb function. The polyaxial NCB system demonstrated superior load-sharing characteristics and improved stress distribution across the arthrodesis site compared to the traditional monoaxial LCP, with quantifiable advantages in resistance to shear forces and construct stiffness under physiologically relevant loading. These findings suggest that polyaxial plating geometry may reduce stress concentration at implant-bone interfaces, potentially decreasing complications such as implant loosening, bone lysis, and construct failure—complications that have historically limited long-term success rates in equine MCP arthrodesis cases. For practitioners considering surgical intervention in horses with severe MCP joint disease, these biomechanical data provide evidence-based justification for adopting polyaxial plate systems where available, though clinical validation through prospective case series remains necessary to confirm whether improved laboratory performance translates to superior functional outcomes and longevity in post-operative patients.
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Practical Takeaways
- •A newer polyaxial plate system adapted from human orthopedics may offer improved biomechanical stability for MCP joint arthrodesis compared to traditional stainless steel plates
- •This technology could potentially reduce complications and improve outcomes for horses requiring MCP joint fusion, though clinical validation in live animals is still needed
- •Consider discussing advanced fixation options with your surgical team when planning MCP joint arthrodesis cases
Key Findings
- •Polyaxial locking compression plate system demonstrated biomechanical advantages over traditional 5.5 mm stainless steel locking compression plate in ex vivo testing
- •Novel non-contact bridging plate technique shows potential clinical benefits for equine MCP joint arthrodesis
- •Comparative biomechanical testing revealed differences in load distribution and stability between mono- versus polyaxial fixation systems