Biological Systems Engineering


Date of this Version



Published in NASS 31st Annual Meeting Proceedings / The Spine Journal 16 (2016) S113–S250.


Copyright © 2016 Elsevier BV. Used by permission.


BACKGROUND CONTEXT: Biomechanics play an important role in spine fusion, but the in vivo biomechanics of the cervical spine are not well characterized and the in vivo biomechanics after spinal arthrodesis have never been studied. Load sharing facilitates fusion, but overloading of interbody implants can lead to subsidence and failure. In vitro studies have demonstrated that anterior plating significantly alters mechanical loading in the cervical spine. The instantaneous axis of rotation is shifted anteriorly and loading is reversed relative to an uninstrumented spine; the interbody space is compressed during extension and unloaded during flexion. However, this has never been tested in vivo and the magnitude of loads in the instrumented and uninstrumented cervical spine are unknown.

PURPOSE:The purpose of this studywas to use a novel force-sensing implant to directly measure interbody loading in the cervical spine in real time in vivo in a large animal model following instrumented or uninstrumented arthrodesis.

STUDY DESIGN/SETTING: In vivo biomechanical loading following anterior cervical discectomy and fusion (ACDF) in goats.