title: Anterior cervical interbody constructs: effect of a repetitive compressive force on the endplate.
abstract: Graft subsidence following anterior cervical reconstruction can result in the loss of sagittal balance and recurring foraminal stenosis. This study examined the implant-endplate interface using a cyclic fatigue loading protocol in an attempt to model the subsidence seen in vivo. The superior endplate from 30 cervical vertebrae (C3 to T1) were harvested and biomechanically tested in axial compression with one of three implants: Fibular allograft; titanium mesh cage packed with cancellous chips; and trabecular metal. Each construct was cyclically loaded from 50 to 250 N for 10,000 cycles. Nondestructive cyclic loading of the cervical endplate-implant construct resulted in a stiffer construct independent of the type of the interbody implant tested. The trabecular metal construct demonstrated significantly more axial stability and significantly less subsidence in comparison to the titanium mesh construct. Although the allograft construct resulted in more subsidence than the trabecular metal construct, the difference was not significant and no difference was found when comparing axial stability. For all constructs, the majority of the subsidence during the cyclic testing occurred during the first 500 cycles and was followed by a more gradual settling in the remaining 9,500 cycles.
authors: Department of Orthopedic Surgery, SUNY Upstate Medical University, 750 East Adams Streets, Syracuse, 13201 New York, USA. ordwayn@upstate.edu
authors: Nathaniel R
authors: NR
authors: Ordway
authors: Byeong Cheol
authors: BC
authors: Rim
authors: Rong
authors: R
authors: Tan
authors: Rebecca
authors: R
authors: Hickman
authors: Amir H
authors: AH
authors: Fayyazi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology; D016025:Bone Transplantation / Q000295:instrumentation / Q000379:methods / Q000502:physiology; D002102:Cadaver; D002574:Cervical Vertebrae / Q000502:physiology* / Q000601:surgery*; D019245:Compressive Strength / Q000502:physiology*; D019544:Equipment Failure Analysis; D005260:Female; D005360:Fibula / Q000637:transplantation; D015775:Fractures, Stress / Q000503:physiopathology; D006801:Humans; D007403:Intervertebral Disc / Q000502:physiology* / Q000601:surgery*; D008297:Male; D013123:Spinal Fusion / Q000295:instrumentation / Q000379:methods; D059145:Total Disc Replacement / Q000295:instrumentation / Q000379:methods*; D016474:Weight-Bearing / Q000502:physiology