Evaluation of Three Human Cervical Fusion Implants for Use in the Canine Cervical Vertebral Column
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BORIS DOI
Publisher DOI
PubMed ID
27598029
Description
OBJECTIVE:
To assess technical feasibility and mechanical properties of 3 locking plate designs (Zero-P, Zero-P VA, and Uniplate 2) for use in the canine cervical spine.
STUDY DESIGN:
Prospective ex vivo study.
ANIMALS:
Cadaver cervical spines from skeletally mature large breed dogs (n = 18).
METHODS:
Specimens were screened using radiography and allocated into balanced groups based on bone density. Stiffness of intact C4-C5 vertebral motion units was measured in extension, flexion, and lateral bending using nondestructive 4-point bend testing. Uniplate 2 was then implanted at C4-C5 and mechanical testing was repeated. Mechanical test data were compared against those from 6 spines implanted with monocortical screws, an allograft ring spacer, and PMMA.
RESULTS:
The Zero-P and Zero-P VA systems could not be surgically implanted due to anatomical constraints in the vertebral column sizes of the canine cervical spines used in this study. Fixation with Uniplate 2 or with screws/PMMA significantly increased stiffness of the C4-C5 vertebral motion units compared to unaltered specimens (P < .001) in extension. Stiffness of the titanium screw/PMMA fixation was significantly greater than the Uniplate 2 construct in extension. Flexion and lateral bending could not be evaluated in 3 of 6 specimens in the Uniplate 2 group due to failure at the bone/implant interface during extension testing.
CONCLUSION:
Fixation with Uniplate 2 was biomechanically inferior to screws/PMMA. Particularly concerning was the incidence of vertebral fracture after several testing cycles. Based on our results, Zero-P, Zero-P VA, and Uniplate 2 cannot be recommended for use in dogs requiring cervical fusion.
To assess technical feasibility and mechanical properties of 3 locking plate designs (Zero-P, Zero-P VA, and Uniplate 2) for use in the canine cervical spine.
STUDY DESIGN:
Prospective ex vivo study.
ANIMALS:
Cadaver cervical spines from skeletally mature large breed dogs (n = 18).
METHODS:
Specimens were screened using radiography and allocated into balanced groups based on bone density. Stiffness of intact C4-C5 vertebral motion units was measured in extension, flexion, and lateral bending using nondestructive 4-point bend testing. Uniplate 2 was then implanted at C4-C5 and mechanical testing was repeated. Mechanical test data were compared against those from 6 spines implanted with monocortical screws, an allograft ring spacer, and PMMA.
RESULTS:
The Zero-P and Zero-P VA systems could not be surgically implanted due to anatomical constraints in the vertebral column sizes of the canine cervical spines used in this study. Fixation with Uniplate 2 or with screws/PMMA significantly increased stiffness of the C4-C5 vertebral motion units compared to unaltered specimens (P < .001) in extension. Stiffness of the titanium screw/PMMA fixation was significantly greater than the Uniplate 2 construct in extension. Flexion and lateral bending could not be evaluated in 3 of 6 specimens in the Uniplate 2 group due to failure at the bone/implant interface during extension testing.
CONCLUSION:
Fixation with Uniplate 2 was biomechanically inferior to screws/PMMA. Particularly concerning was the incidence of vertebral fracture after several testing cycles. Based on our results, Zero-P, Zero-P VA, and Uniplate 2 cannot be recommended for use in dogs requiring cervical fusion.
Date of Publication
2016
Publication Type
Article
Subject(s)
Language(s)
en
Contributor(s)
Morrison, Emily J. | |
Litsky, Alan S. | |
Allen, Matthew J. | |
Fosgate, Geoffrey T. |
Additional Credits
Series
Veterinary surgery
Publisher
Wiley-Blackwell
ISSN
0161-3499
Access(Rights)
restricted