An In Vitro Biomechanical Comparison of a 5.5 mm Limited‐Contact Dynamic Compression Plate Fixation with a 4.5 mm Limited‐Contact Dynamic Compression Plate Fixation of Osteotomized Equine Third Metacarpal Bones

Abstract

The results of this in vitro study may provide information to aid in the selection of a biological plate for long bone fracture repair in horses.

An In Vitro Biomechanical Comparison of a 5.5 mm Locking Compression Plate Fixation with a 4.5 mm Locking Compression Plate Fixation of Osteotomized Equine Third Metacarpal Bones

“…The maximum load of 7.5 kN was chosen to be 50% of the mean yield load of the 4.5 mm broad limited‐contact dynamic compression plate‐MC3 construct in a pilot study, thus within the elastic region of the load deformation curve 9 . This maximum load of 7.5 kN was chosen in this study, as well as others studies, 6,7 to be consistent with an early study 8 . The number of cycles to failure was recorded, with failure defined as screw loosening, plastic deformation of implants, or catastrophic failure of implants, determined by a sudden decrease in load.…”

“…To maintain consistency with previous studies, 6,7 an 8‐hole 5.5 LCP was required; however, the 5.5 LCP is only available in 10 holes and greater. A 10‐hole 5.5 LCP was placed in a positioning jig and the first and the 10th holes were cut off using an abrasive cut‐off saw.…”

“…The biomechanical variables we examined were designed to highlight the forces on plate‐MC3 constructs that are most likely to cause failure with the fixation types used. These biomechanical variables obtained through the chosen modes of load application (palmarodorsal 4‐point bending and torsion) have been reliably used to document important characteristics of orthopedic implants applied to the MC3 bone 6,7,10,11 . During walking, MC3 is almost entirely axially loaded throughout the stride, although the dorsal and, to a lesser extent, medial surfaces endure more tension than the palmar and lateral surfaces of the diaphysis 12–14 .…”

In Vitro Biomechanical Comparison of Locking Compression Plate Fixation and Limited‐Contact Dynamic Compression Plate Fixation of Osteotomized Equine Third Metacarpal Bones

“…The results of a previous study 7 and the companion study 11 demonstrated that an important factor affecting the number of cycles to failure is the relative plate‐bone contact of the different constructs; however, there are other factors that contribute to the difference between the number of cycles to failure under palmarodorsal 4‐point bending, for the 2 fixation methods. Such factors include screw size, screw type, and pattern of screw placement used in securing the plate.…”

Advances in osteosynthesis in the horse

“…Das Akronym "PC-FIX" steht für "Point-Contact Fixateur", was eine Weiterentwicklung der LC-DCP darstellt und als eigentlicher "Fixateur Interne" angesehen werden kann (Tepic und Perren 1995 Zahlreiche In vitro-Studien konnten die Überlegenheit der Verriegelungssysteme über die früheren Frakturfixationstechniken beweisen (Sod et al 2008a, 2008b, Ahern et al 2013 (Bramlage 1999, Fürst 2012 …”