An In Vitro Biomechanical Comparison of an Interlocking Nail System and Dynamic Compression Plate Fixation of Ostectomized Equine Third Metacarpal Bones

Abstract

No significant differences in biomechanical properties were identified between an interlocking nail and double plating techniques for stabilization of ostectomized equine MC3 in caudocranial four-point bending. Double plating fixation was superior to interlocking nail fixation in torsion.

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 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 .…”

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

“…In palmarodorsal 4‐point bending, both in single cycle to failure and cyclic fatigue testing, the 2 inner support points could not be more widely spaced without 1 point contacting the bone before the other because of the irregular shape of the bone. Other investigators have encountered this problem 11–13 . For purposes of 4‐point bending, in our study, the plate‐MC3 construct was considered to include only that portion of MC3 spanned by the outer support points and not the entire MC3 bone.…”

“…For purposes of 4‐point bending, in our study, the plate‐MC3 construct was considered to include only that portion of MC3 spanned by the outer support points and not the entire MC3 bone. This approach to 4‐point bending has been used previously 11–17 . 4‐point bending with a uniform bending load over the entire plated region has been used in in vitro studies involving bone substitutes, such as a Canevasit tube of uniform shape and thickness and a cortical bone density polyurethane foam block 17,18 .…”

An In Vitro Biomechanical Comparison of a Prototype Equine Metacarpal Dynamic Compression Plate Fixation with Double Dynamic Compression Plate Fixation of Osteotomized Equine Third Metacarpal Bones

“…In palmarodorsal 4‐point bending, the 2 inner load points could not be more widely spaced without 1 point contacting the bone before the other because of the irregular shape of the bone. Other investigators have encountered this problem 17–21 . For purposes of 4‐point bending, in this study, the plate‐MC3 construct was considered to include only that portion of MC3 spanned by the inner support points and not the entire MC3 bone.…”