Biomechanical analysis of a newly designed bioabsorbable anterior cervical plate. Invited submission from the joint section meeting on disorders of the spine and peripheral nerves, March 2005.
OBJECTIVE
The authors present a biomechanical analysis of a newly designed bioabsorbable anterior cervical plate (ACP) for the treatment of one-level cervical degenerative disc disease. They studied anterior cervical discectomy and fusion (ACDF) in a human cadaveric model, comparing the stability of the cervical spine after placement of the bioabsorbable fusion plate, a bioabsorbable mesh, and a more traditional metallic ACP.


METHODS
Seven human cadaveric specimens underwent a C6-7 fibular graft-assisted ACDF placement. A one-level resorbable ACP was then placed and secured with bioabsorbable screws. Flexibility testing was performed on both intact and instrumented specimens using a servohydraulic system to create flexion-extension, lateral bending, and axial rotation motions. After data analysis, three parameters were calculated: angular range of motion, lax zone, and stiff zone. The results were compared with those obtained in a previous study of a resorbable fusion mesh and with those acquired using metallic fusion ACPs. For all parameters studied, the resorbable plate consistently conferred greater stability than the resorbable mesh. Moreover, it offered comparable stability with that of metallic fusion ACPs.


CONCLUSIONS
Bioabsorbable plates provide better stability than resorbable mesh. Although the results of this study do not necessarily indicate that a resorbable plate confers equivalent stability to a metal plate, the resorbable ACP certainly yielded better results than the resorbable mesh. Bioabsorbable fusion ACPs should therefore be considered as alternatives to metal plates when a graft containment device is required.
Ames
Christopher P
CP
Department of Neurological Surgery, University of California at San Francisco, California 94122, USA. amesc@neurosurg.ucsf.edu
Acosta
Frank L
FL
Chamberlain
Robert H
RH
Larios
Adolfo Espinoza
AE
Crawford
Neil R
NR
D020341:Absorbable Implants; D001696:Biomechanical Phenomena; D001860:Bone Plates; D002102:Cadaver; D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery; D017586:Diskectomy / Q000379:methods*; D004867:Equipment Design; D006801:Humans; D016059:Range of Motion, Articular; D013123:Spinal Fusion / Q000379:methods*; D013526:Surgical Mesh