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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
Author(s) -
SOD GARY A.,
HUBERT JEREMY D.,
MARTIN GEORGE S.,
GILL MARJORIE S.
Publication year - 2005
Publication title -
veterinary surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.652
H-Index - 79
eISSN - 1532-950X
pISSN - 0161-3499
DOI - 10.1111/j.1532-950x.2005.00093.x
Subject(s) - cadaveric spasm , metacarpal bones , dynamic compression plate , fixation (population genetics) , medicine , biomechanics , orthodontics , population , anatomy , internal fixation , environmental health
Objectives To compare the monotonic biomechanical properties of a prototype equine third metacarpal dynamic compression plate (EM‐DCP) fixation with a double broad dynamic compression plate (DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Study Design In vitro biomechanical testing of paired cadaveric equine MC3 with a mid‐diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Population Twelve pairs of adult equine cadaveric MC3 bones. Methods Twelve pairs of equine MC3 were divided into 3 test groups (4 pairs each) for (1) 4‐point bending single cycle to failure testing, (2) 4‐point bending cyclic fatigue testing, and (3) torsional testing. The EM‐DCP (10‐hole, 4.5 mm) was applied to the dorsal surface of one randomly selected bone from each pair. Two DCPs, 1 dorsally (10‐hole, 4.5 mm broad) and 1 laterally (9‐hole, 4.5 mm broad) were applied to the contralateral bone from each pair. All plates and screws were applied using standard AO/ASIF techniques to MC3 bones that had mid‐diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t‐test within each group. Significance was set at P <.05. Results Mean 4‐point bending yield load, yield bending moment, bending composite rigidity, failure load and failure bending moment of the EM‐DCP fixation were significantly greater ( P <.0001) than those of the double broad DCP fixation. Mean cycles to failure in 4‐point bending of the EM‐DCP fixation was significantly greater ( P <.0008) than that of the double broad DCP fixation. Mean yield load, composite rigidity, and failure load in torsion of the EM‐DCP fixation were significantly greater ( P <.0035) than that of the double broad DCP fixation. Conclusion The EM‐DCP provides increased stability in both static overload testing and cyclic fatigue testing. Clinical Relevance Results of this in vitro study support the conclusion that the prototype EM‐DCP fixation is biomechanically superior to the double broad DCP fixation for the stabilization of osteotomized equine MC3.