Intervertebral biomechanics of locking compression plate monocortical fixation of the canine cervical spine.
OBJECTIVE
To evaluate the use of a locking compression plate (LCP) with monocortical screw purchase for stabilization of the canine cervical spine.


METHODS
Experimental study.


METHODS
Cadaveric canine cervical spine specimens (n = 7).


METHODS
Flexion and extension bending moments were applied to canine cadaveric specimens (C3-C6) in 4-point bending, before and after creation of a ventral slot at C4-C5, and after fixation with a 5 hole, 3.5 mm LCP with monocortical screw placement. Screw placement and penetration into the vertebral canal were determined by radiography. Range of motion, stiffness, and energy for passive physiologic loads were determined for the C3-C4, C4-C5, and C5-C6 vertebral motion units (VMU). Monotonic failure properties were determined for cervical extension. Effects of treatments on biomechanical variables were assessed using repeated measures analysis of variance and least square means (P ≤ .05).


RESULTS
The ventral slot procedure increased range of motion at the treated VMU. Plate fixation decreased range of motion, increased stiffness, and decreased energy at the treated VMU. No changes were observed at adjacent VMUs. None of the screws penetrated the vertebral canal. Mean (± SD) yield bending moment of plate stabilized, slotted spines was 15.6 ± 4.6 N m.


CONCLUSIONS
LCP fixation with monocortical screws stabilized the canine cervical spine.
William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA, USA. kagnello@vet.upenn.edu
Kimberly A
KA
Agnello
Amy S
AS
Kapatkin
Tanya C
TC
Garcia
Kei
K
Hayashi
Anja T
AT
Welihozkiy
Susan M
SM
Stover
D000818:Animals; D001696:Biomechanical Phenomena / Q000502:physiology; D001860:Bone Plates / Q000662:veterinary*; D001863:Bone Screws / Q000662:veterinary; D002574:Cervical Vertebrae / Q000503:physiopathology / Q000601:surgery*; D004283:Dog Diseases / Q000503:physiopathology / Q000601:surgery; D004285:Dogs; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D016268:Internal Fixators / Q000662:veterinary*; D020393:Manipulation, Spinal / Q000662:veterinary; D008422:Materials Testing / Q000662:veterinary; D016059:Range of Motion, Articular / Q000502:physiology; D016103:Spinal Fractures / Q000503:physiopathology / Q000601:surgery / Q000662:veterinary