Abstract
Author(s): Giancarlo Guizzardi,Sylvain Persohn,Sophie Campana ,Caspar Aylott, Piero Petrini ,and Wafa Skalli
Introduction.The Intra SPINE is an e winter laminar device that has been proposed with the aim to decompress the spinal canal with out reducing the extension motion.The purpose of this study was therefore to evaluate the biomechanical behavior of L4-L5 spinal units implanted with this interlaminar device, in terms of ranges of motion, intradiscal pressure, and centers of rotation. Material and Methods. Six human lumbar spines were harvested within 10 days after death. A speciï¬c spine testing device was used to apply moments upto10Nminï¬exion-extension,lateral bending(left-rightï¬exion)and left-right axial rotation (torsion),with measurement of vertebral 3D motion and of intervertebrald is c pressure. Protocol was repeated for each specimen in 5 conï¬gurations: intact specimen; after L4-L5 bilateral medial hemifacetectomy and both yellow ligament resection; after implantation of the interlaminar device at the L4-L5 level; after removal of the L4-L5 supraspinous ligament, resection of the posterior third of the discand addition of an artiï¬cial ligament;after device and artiï¬cial ligament removal. Results.Theimplant reduced increases in segmental ï¬exion seen following injury particularly when applied with the artiï¬cial ligament. Intradiscal pressure reduced following application of the implant with out reducing extension range.A small posterior shift of the Mean Centers of Rotation(MCR) was noticed after instrumentation.To rsion and lateral bending range was unaï¬ected by the interlaminar device. Conclusion.This biomechanical study yields a better understanding of this interlaminar implant eï¬ect.A large clinical trial with follow-up would be required to evaluate and conï¬rm in vivo the observed invitro biomechanical behavior of the device
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