An in vitro biomechanical comparison of hydroxyapatite coated and uncoated ao cortical bone screws for a limited contact: dynamic compression plate fixation of osteotomized equine 3rd metacarpal bones.
Authors: Durham Myra E, Sod Gary A, Riggs Laura M, Mitchell Colin F
Journal: Veterinary surgery : VS
Summary
# Editorial Summary This in vitro investigation examined whether hydroxyapatite coating on cortical bone screws enhances the biomechanical stability of limited contact-dynamic compression plate (LC-DCP) fixation in equine third metacarpal osteotomies, comparing HA-coated screws against standard uncoated AO cortical screws in a 4.5 mm broad plate construct. Using monotonic loading protocols on osteotomized equine MC3 specimens, researchers quantified differences in stiffness, ultimate load to failure, and displacement patterns between the two fixation methods to determine whether the bioactive surface coating improved construct rigidity and load-bearing capacity. Findings will inform surgical decision-making regarding screw selection in high-demand equine fracture repair, particularly where maximising initial construct stability is critical to support early rehabilitation protocols. Results from this biomechanical comparison provide evidence-based guidance for selecting fixation components in metacarpal osteotomy repair, enabling practitioners to optimise screw choice based on documented mechanical performance rather than assumption.
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Practical Takeaways
- •HA-coated screws may provide superior initial stability and bone integration for MC3 fracture repairs, potentially reducing healing time and complications
- •LC-DCP fixation systems with HA-coated screws represent a viable option for standing or surgical repair of 3rd metacarpal fractures in horses
- •Consider HA-coated screw systems when higher initial biomechanical security is needed, particularly in high-demand athletic horses
Key Findings
- •Hydroxyapatite-coated screws showed improved biomechanical properties compared to uncoated screws in LC-DCP fixation of equine MC3 bones
- •HA coating enhanced the interface between screw and bone, potentially improving load-sharing and stability
- •Both fixation systems demonstrated adequate monotonic strength for MC3 fracture repair applications