An in vitro evaluation of plate luting using osteotomized equine third metacarpal bones with a limited contact-dynamic compression plate.
OBJECTIVE
To evaluate the effects of plate luting on the biomechanical properties of a broad limited contact-dynamic compression plate (LC-DCP) fixation to repair osteotomized equine 3rd metacarpal (MC3) bones.


METHODS
In vitro biomechanical testing of paired cadaveric equine MC3 with a mid-diaphyseal osteotomy, stabilized by LC-DCP fixation, with 1 of the pair luted with polymethylmethacrylate (PMMA).


METHODS
Ten pairs of adult equine cadaveric MC3 bones.


METHODS
Ten pairs of equine MC3 were divided into 2 test groups (5 pairs each) for (1) palmarodorsal 4-point bending single cycle to failure testing and (2) palmarodorsal 4-point bending cyclic fatigue testing. The LC-DCP (8 hole, 4.5 mm) was applied to the dorsal surface of each pair of MC3 bones. All plates and screws were applied using standard AO/ASIF techniques. All MC3 bones had mid-diaphyseal osteotomies. One of the matched pairs of LC-DCP-MC3 constructs were randomly chosen to be luted with PMMA. 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 palmarodorsal 4-point bending yield bending moment, failure bending moment of the LC-DCP fixation with luting was not significantly different (P>.05) than those of the LC-DCP fixation without luting. Mean cycles to failure for palmarodorsal 4-point bending was significantly (P<.0003) greater, with a 7.2-fold increase, for the LC-DCP fixation with luting compared with the LC-DCP fixation without luting.


CONCLUSIONS
Luting the broad LC-DCP with PMMA in the fixation osteotomized equine MC3 bones increases the fatigue life of cyclic loading for palmarodorsal 4-point bending under the in vitro conditions studied.


CONCLUSIONS
The cyclic fatigue data supports the conclusion that luted broad LC-DCP fixation is biomechanically superior to the non-luted broad LC-DCP fixation in osteotomized equine MC3 bones.
Sod
Gary A
GA
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA. gsod@vetmed.lsu.edu
Hubert
Jeremy D
JD
Martin
George S
GS
Gill
Marjorie S
MS
D000818:Animals; D001696:Biomechanical Phenomena; D001843:Bone Cements / Q000627:therapeutic use*; D001858:Bone Nails / Q000662:veterinary; D001860:Bone Plates / Q000662:veterinary; D002102:Cadaver; D019245:Compressive Strength / Q000502:physiology; D005593:Fracture Fixation, Internal / Q000662:veterinary; D050723:Fractures, Bone / Q000601:surgery / Q000662:veterinary; D006736:Horses / Q000293:injuries* / Q000601:surgery; D050279:Metacarpal Bones / Q000293:injuries* / Q000601:surgery*; D010027:Osteotomy / Q000379:methods / Q000662:veterinary*; D019904:Polymethyl Methacrylate / Q000627:therapeutic use*; D011897:Random Allocation; D014102:Torsion Abnormality / Q000662:veterinary
D001843:Bone Cements; D019904:Polymethyl Methacrylate