An in vitro biomechanical comparison of dynamic condylar screw plate combined with a dorsal plate and double plate fixation of distal diaphyseal radial osteotomies in adult horses.

This study investigates the biomechanical effectiveness of two types of hardware in repairing oblique distal fractures in adult horse radii. The comparative analysis showed no significant difference in terms of strength and stiffness between the dynamic condylar screw plate combined with dorsal broad dynamic compression plate and the double broad dynamic compression plate.

Research Methods

• The research was an experimental study conducted on 10 pairs of adult horse radii.
• A three-dimensional loading-measurement system was utilized to determine the stiffness of a 50 mm long intact bone and the plated osteotomized segment of radii under different types of forces.
• The bone segments were subjected to a nondestructive sequence of compression, torsion, and bending in different directions.
• The load was uniformly distributed over the entire construct to identify its weakest elements during torsion and bending.

Results

• The researchers found no difference between the two methods of fixation in terms of construct stiffness under all six loading modes and strength for all three failure loads.
• Both the DCS-bDCP and the dbDCP constructs were significantly less stiff than the bone segments, but the osteotomized bone segments were almost as stiff as the intact bone during axial, LM, and CrCa bending.
• The most common failure observed was bone fracture through the exit site of a screw in proximity to the osteotomy.

Conclusions

• The DCS-bDCP and dbDCP constructs demonstrated comparable strength and stiffness when used to repair osteotomies in the adult horse radius bone.
• The study suggests that both constructs are equally effective when used to repair oblique distal diaphyseal osteotomies in equine radius bone in vitro, and that fracture reduction led to increased stiffness that approached that of the intact bone when the unplated side was compressed.
• However, the research also indicates that there is need to investigate the impact of DCS on the distal epiphyseal structure due to the additional bone removal that it necessitates under in vivo articular loading conditions.